Welcome

AF5NP Amateur Radio

Welcome to the NewHams.info site.  Its purpose is to provide training, information and general encouragement to new or prospective amateur radio operators (hams).  Sort of a virtual “Elmer”, as we say.  Experienced hams should find it interesting and useful as well.

Organized in sort of a blog format, post topics are usually small and simple. You can scroll through the posts sequentially or search for key words or click on a category of interest.

The reader can sign up for email notification of new posts by clicking on the Follow button below Categories on the sidebar.

Topics generally cater to USA hams getting started in amateur radio with local VHF/UHF communications.  However, HF band operators and hams in other countries should find something interesting here as well.

You will see US license exam questions and answers in green boxes in various posts to to clarify the topic and refresh your knowledge.

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Other Resources for New Hams

AF5NP Amateur Radio, ARRL, New Ham, Podcast, Website

Here at NewHams.info we don’t pretend to be the ultimate authority or only game in town.  While we may have a lock on this website domain name, there are other truly useful and interesting sources with good information for new or prospective ham radio operators and we want to share some of these with you here.

The ARRL produces an audio podcast entitled So Now What?  It is a “bi-weekly podcast geared to those who are just getting started on their Amateur Radio adventure. Whether you’re new to the hobby or looking to get back on the air after an absence, we know that you’ve got lots of questions.”

You can access and/or subscribe on Apple and Android to listen in with mobile phones or you can link to a web stream via Blubrry here.

A page on N0JI’s website is entitled, For New Hams.  It has quite a bit of detail; topics include:

  • First steps
  • Equipment
  • Making contact
  • Service and groups
  • Preparedness
  • Activities
  • Just curious
  • Above and beyond
  • Assistance

eHam.net has an informational page:  Guide to Amateur Radio for New Hams.

St Louis radio club web page:  New Ham Radio User Portal.

State of Play site topic: All About Ham Radio for Beginners  has some good links and info.  Thanks to Connor for the suggestion.

Great website with tons of educational material, Ham Radio School: Basics         HRS also has a topic, I Got My License, Now What?

As other related new ham resources come to our attention we will update this post to add links.

Call Districts (number in a call sign)

AF5NP Call (Call Sign), District, Geographic, Number

Specifically relevant to USA hams, with some general application in other countries, this topic involves the number in an amateur radio call sign.  None of this info is included in the license exam questions, so no green test boxes here; it’s really just good basic info for all hams to know.

As related in our post What Will My New Call Sign Be?, amateur radio call signs are systematically generated by the FCC in the USA with the numeric portion (KJ5QST) assigned by geographic location of a new ham’s registered address following successful completion of their exam.

The USA is divided up into call districts 0-9 (or 1-0, as historically deployed) per the map below:

Call districts

Actually, it’s 13 districts when you include AK, the Pacific (including HI), and the Caribbean (including PR), but still only 10 numbers.

This is for administrative purposes so that the issuing agency (FCC in USA) doesn’t run out of  2 and 3 letter suffixes, and also give a general idea where the ham is located.

Generally speaking, a station with a 4 in its call (sometimes we say 4-land) is likely to be in a southeastern state, and so with other numbers 1 thru 0 per the map.  Before ~1978, you could count on a call with 2 in it to be located in NY or NJ, but times have changed. Back then if you moved out of your call district, you were required to get a new call assigned with the appropriate district number.

With FCC rules relaxing about portability, plus a generous vanity call system, a 2 call could very well be in California today.  So geographic link to the call district is now a general probability, no longer a certainty.  By one estimate, approximately 88% of all amateur radio operators have call signs that reflect the district in which those operators live (2011 data, likely changed since). Even today it’s good practice to avoid confusion by modifying your call when operating out of district by appending /X where X is the mobile/portable zone of operation different from your call sign.

All this means is that new hams testing for their initial license in Ohio, for example, will receive a sequentially assigned 8-land call  like KE8ABC.  If they don’t like it, or prefer a different number of special significance, or to help create a memorable call sign, they can apply for an available vanity call sign with a different number 0-9, and whatever letters they apply for, as available, and as eligible.

We hinted that things have changed over time. For reference, here are the USA call districts from the early days of ham radio:

USA districts 1937

Note no district 0; district 6 was rather large; this was long before AK and HI were states.

Also as suggested, some of this applies to other countries besides the US of A. Call districts for Canada, Mexico, Brazil, Japan, Continue reading →

Morse Code for CW Mode

AF5NP CW, Mode, Morse Code, SKCC, Technician Class

JJ38

Most people recognize Morse code even if they cannot decipher the sounds. It’s one of those things that we hear in old movies and TV shows and occasionally in radio or TV ads. As a ham you may hear it on local repeaters and HF voice for identification.

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Continuous Wave (CW), where the signal is modulated by Morse code, is the original amateur radio mode, and has a long history with hams. Old telegraph codes exist but in ham radio when we say Morse code we mean International Morse code.

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For decades Morse code proficiency was a requirement for amateur radio licensing in most countries with speed increasing proportional to license class/privilege. Morse code requirements for all license classes ended in the USA in 2007 (Technician dropped in 1991), opening doors to many hams who were otherwise interested in getting licensed but found Morse to be a real obstacle. This followed an ITU agreement in 2003 that Morse Code testing of radio amateurs would no longer be an international requirement.

Does this mean Morse code is dead? Hardly! While the number of CW (Morse) operators is fewer in number now than 50 years ago, there are still thousands of active hams whose primary (or even only) mode is CW. Why? Besides being fun and challenging, CW has some real advantages:

  • Because nearly all the transmitter power goes into a narrow (~100Hz) signal, practically all signal power is useful, as opposed to phone (voice) modes. 

T8A05-2018Sometimes when SSB voice signals are inaudible due to poor skywave propagation, CW signals punch right through. In fact, many rare stations (DX) primarily use CW mode to reach more hams eager to work an odd location. A CW signal can have more than a 10-20 dB advantage over a SSB signal.T8A11-2018

  • The signal to noise ratio (SNR) is much better, making communication much more effective.
  • Adjacent noise or signals (QRM) can be filtered much easier in the receiver with a narrow CW signal.
  • Due to CW’s efficiency, lower power radios work well, and can run longer off-grid.
  • CW-only radios are small, simple, and cheap, with more bang for the buck.
  • Finally, a few hams prefer not to use their voice, and CW (along with digital modes) frees them up from being disabled or mic shy.

In addition to these general advantages, CW mode is the only high frequency (HF) mode that USA Technician class licensees can operate below 28MHz. So Techs can actually make contacts using Morse on 80, 40, and 15m, outside their typical local repeater range.

Perhaps Morse is intimidating to you as a prospective ham or Technician class licensee who wants to communicate beyond the local area. Even though we no longer need to know Morse to get a license, the reasons above should give you some incentive to learn it. Besides, it’s really not as tough as it might seem. And even though some hams blaze away above 25 words per minute (wpm), you can almost always send/receive slower at a more comfortable beginner’s pace and work through your mistakes.

While Morse may seem like a second language to most people, it is actually much simpler and easier to master than a new tongue with all its complexities. You need know only 26 alphabet symbols, 10 numbers, and several punctuation marks and common shortcuts to be proficient.

So how does one go about learning Morse code and using it? The Boy Scouts had a merit badge for Morse and the military may still teach you but these are less common nowadays. Don’t despair; there are many resources for learning Morse, some linked below. Here are four suggested steps:

  1. Learn to receive Morse code- the important beginning stage to become familiar with letters, numbers, and punctuation. Just learn it; you don’t have to be fast.
  2. Learn to send Morse code- it is important to have a good “fist” for others to copy at any speed; this involves timing, practice and good habits.
  3. Learn CW/Morse ham radio procedures- know what certain prosigns mean and how hams perform an exchange or QSO.
  4. Practice off-air with a CW Elmer or experienced friend

Then you’re ready to try for real over the radio!

You have many resources available to learn Morse and CW protocol: stand-alone PC apps, online apps, and some clubs or organizations geared towards not only learning Morse but also training for real contacts. Links to some below and more links within links.

One thing many of these training tools have in common is the Koch method and Farnsworth timing, which is considered an improvement over rote learning with gradual speed increases. Most people have a natural limit to their ability to copy or send above a certain rate (wpm). No matter; you can still enjoy CW at almost any speed.

Of the links below to various Morse resources, the last one is truly useful and interesting and worth checking out: All About the Telegraph and Deciphering Morse Code. Thanks to Noah Bass for suggesting this excellent resource. He found it while working on his Boy Scouts radio merit badge.

Perhaps you’re interested in learning Morse in CW mode but find the protocols intimidating? There are groups of hams to train and encourage good CW practice, such as CWops and LI CW club. One that the author likes is the Straight Key Century Club (SKCC), which promotes non-electronic Morse sending using purely mechanical keys (not computerized or electronically aided). By definition it’s mostly slow-paced, as not many folks can send more than 20wpm using a straight telegraph key. It’s free and members mainly do simple exchanges to gain low-stress experience. They are a generally supportive and helpful bunch who tolerate newbies and coach them along.

By the way, when describing Morse code, hams don’t use the terms dots and dashes, even though it may look like that on paper. We say dits and dahs, which aligns more with how it sounds, as opposed to how it looks.

Useful web links

The Endurance of CW in Amateur Radio

Morse code is still worth learning – but why?

Become a Morse Code Expert– The Art of Manliness

Morse Code World

Just Learn Morse Code -PC app which author likes

CWops CW Academy– highly regarded way to learn both Morse and procedures

Learn Morse Code-CW with the Long Island CW Club, another highly-regarded resource

Learn Morse Code (CW) Online

Learning Morse Code – ARRL

American Morse Code -Somewhat different from international (modern), because of telegraph sound

All About the Telegraph and Deciphering Morse Code. Thanks to Noah Bass for suggesting this excellent resource. He found it while working on his Boy Scouts radio merit badge.

Famous Hams

AF5NP Celebrity, Ham

Thinking about becoming a ham, or already a ham and are worried that you will be perceived as a weirdo or geek? Well, maybe that’s true for you (depending on your personality 🙂 ) but being a radio amateur in itself does not make you a pariah. There are many famous, accomplished, and reputable people who hold (or have held) amateur radio licenses. There are lists on amateur radio sites (links below) to some of them.

We will share one of the more interesting lists here of celebrity or famous hams, along with their notability. Some have passed away but others are still alive and kicking and active on the air. We’re talking about royalty, politicians, business pioneers, musicians, scientists, inventors, newscasters, journalists, and many astronauts (so they can communicate with earth stations while not doing official duties). While there is a [occasionally valid] stereotype of hams being grumpy brainy suspender-wearing heavyset bearded anti-social elderly men, that isn’t always the case. So after reading this list, the dork factor shouldn’t scare you off.

Here are some notable amateur radio operators known for prominent positions and/or achievements:

  • W1AW Hiram Percy Maxim, ARRL founder, silencer inventor
  • K1JT Dr. Joseph Taylor, 1993 Nobel Prize Winner in Physics
  • KB1NXP John Baldacci, former Governor of Maine
  • W1ZE Irving Vermilya, first licensed radio amateur in the US
  • K2AMH Robert Moog, inventor of Moog synthesizer
  • W2BML Dr. Harold Beverage, inventor of Beverage antenna
  • K2GL Hazard Reeves, inventor of stereo sound system
  • KB2GSD Walter Cronkite, newscaster
  • K2ORS Jean Shepherd, writer, humorist
  • NE2Q Jay Kolinsky, electronic siren inventor
  • W2SGG Robert Cusumano, co-inventor of printed circuits
  • K2ZCZ George Pataki, former Governor of NY
  • NS3T Jamie Dupree, radio news correspondent
  • W4CGP Chet Atkins, singer, composer
  • WB4KCG Ronnie Milsap, singer, songwriter
  • K4EB Larry Junstrom, 38 Special band member(bass) and founding Lynyrd Skynrd member
  • N4KET David French, CNN news anchor
  • W4LAA Paul Kangas, co-anchor of Nightly Business Report
  • K4LIB Arthur Godfrey, TV personality
  • WD4LZC Larnell Harris, country & Christian music singer
  • WB4MCJ Carl Rochelle, news columnist
  • WA4SIR Ron Parise, astronaut
  • KD4WUJ Patti Loveless, singer
  • W4XAA/K2AES Tom Kneitel, magazine editor, columnist
  • K4ZVZ Gen. Paul Tibbets, WWII Enola Gay pilot (first atom bomb drop)
  • WA5AVA Dale Seidenschwarz (Clyde Clifford), Beaker St. radio host
  • KF5BOX Doug Wheelock, ISS astronaut
  • K5CSG Peggy Sue Gerron, subject of Buddy Holly hit song
  • W5GLJ George Marti, remote broadcast technology pioneer
  • W5LFL Dr. Owen Garriot, astronaut
  • N5QWL Jay Apt, astronaut
  • N5RAX Linda Godwin, astronaut
  • WB6ACU Joe Walsh, (Eagles) singer, guitarist, composer, record producer
  • W6BNB Robert Shrader, Electronic Communications text author
  • K6DUE Roy Neal, TV personality, news correspondent
  • W6EZV/K0GRL General Curtis Lemay, WWII leader and 1968 VP candidate
  • N6FFT Ray Briem, radio talk show host
  • N6FUP Stu Cook, bass player Creedence Clearwater Revival
  • W6FZZ Samuel F.B. Morse III, great grandson of code inventor
  • KA6HVK Burl Ives, singer and entertainer
  • NN6JA John Amodeo, TV Producer
  • N6KGB Stewart Granger, actor
  • KB6LQS Dick Rutan, pilot of Voyager airplane
  • KI6M Stu Gilliam, comedian
  • W6OBB Art Bell, syndicated radio personality
  • KD6OY Garry Shandling, actor, comedian
  • KE6PZH/FO5GJ Marlon Brando, actor
  • WB6RER Andy Devine, actor
  • W6UK Alvino Rey, musician, band leader
  • KA6UXR Dr. Alexander Comfort, author
  • N6YOS Priscilla Presley, actress
  • W6ZH Herbert Hoover, Jr. IARU & ARRL President
  • W6ZH/W6APW Herbert “Pete” Hoover III, AMSAT fundraiser
  • W7EQI Greg Walden, U.S. Congressman (1999-2020)
  • KA7EVD Donnie Osmond, singer
  • NK7U Joe Rudi, major league baseball player
  • K7UGA/6BPI/K3UIG Barry Goldwater, US Senator, 1964 Pres. candidate
  • 8CR Powell Crosley, broadcast pioneer, founded WLW
  • W8OK Frank Schwab, Mr. Hamvention
  • 9ALD Edgar Johnson, founder of E F Johnson Company
  • 9DRV David Packard, co-founder of Hewlett Packard
  • W9EGV John Frye, columnist Carl & Jerry, Mac’s Service Shop
  • K9EID Bob Heil, concert sound engineer, inventor
  • W0CXX Art Collins, founder of Collins Radio
  • W0FQY Carl Mosley, founder of Mosley Electronics
  • DG1KIM Ulrich Walter, astronaut
  • EA0JC Juan Carlos, King of Spain
  • HS1A Bhumiphol Adulayadej, King of Thailand
  • I0FCG Francesco Cossiga, President of Italy
  • JY1 King Hussein of Jordan
  • RV3DW Sergei Avdeyev, astronaut
  • TI2DR David Ruben M. D., author
  • VU2RJ Rajiv Gandhi, Prime Minister of India
  • YN1AS General Anastasio Somoza, President of Nicaragua
  • 9N1MM Rev. Marshall Moran, Jesuit Priest, Educator (Nepal)
  • WB4APR Bob Bruninga (SK), inventor of APRS in 1992

A couple of bass players there, interestingly enough, and the author worked K4EB before he died; also worked K1JT, for total of two notables on this list.

This is not a comprehensive list, and it may be dated, as are some others you can look at:

WB4HFN list (dated)

Famous Hams QRZ discussion

Famous Hams on HF Underground wiki

Oxley Region ARC list

Ham Radio Insider list

QSL Net list

Famous Hams and their Callsigns

YouTube video Top20 hams

There. Now now after seeing this list, don’t you feel better about our great pastime?

Radio Contact (QSO) Basics

AF5NP Contact, Log, Q-Codes, QSO

As mentioned way back in our Q-code topic, ham radio still uses many old telegraphy codes as shortcuts for longer terms. We have already discussed some of them: QRZ, QSL, QTH.

Sorry that we haven’t yet covered one of the most basic terms that a ham is likely to encounter: QSO. Officially the Q-code QSO means, “I can communicate with _ direct “. However, in common usage, it has become a noun meaning direct communication, or contact.

This use of QSO is so pervasive that it actually signifies a radio contact. Logbooks and reports will include a list of QSOs (contacts). So your logbook on QRZ will look like this:

QRZ QSO list

And Logbook of The World (LoTW) will show QSOs like this:

LoTW QSO List

Both examples above mention QSO three times, and the term abounds throughout ham radio, both verbally and in print. Other print and electronic logging tools will have similar features and reference QSOs. The author has also been thanked for the QSO after a long phone chat with another ham.

When pronouncing it you can say “cue-ess-oh”, or, more commonly, “cue-soh”. While it mainly applies to radio contact, a face to face meeting between hams is often called an “eyeball QSO” in yet another variant of ham-speak.

So what constitutes a QSO, anyway? Since it means contact, at minimum it would be an exchange of call signs over the air. You can log and confirm (QSL) that with appropriate mode, date and time to be a legal QSO. From the examples above you can see that minimum basic data in QRZ and LoTW , along with confirmations if the other station uses the same tools. In ham-speak you would say that you “worked” the other station/state/county/country.

More commonly, and many would say a requirement, you would exchange signal reports and log that as well. You may hear hams mention this as minimum QSO data– call sign and signal report, which is often all you get when working a rare DX station or during a contest.

Beyond this, many–if not most–hams will try to exchange names and location in their QSO, depending on mode. The popular digital mode FT8 permits only call sign, signal report and grid square; it does not have operator name included in the standard script.

Going beyond call sign, signal report, op name and location (QTH), the usual things included in a voice (phone) or Morse (CW) QSO are local weather, equipment (radio/antenna/power/mic/key), and then whatever the ops feel like exchanging (hobbies, how long a ham, pets). If confirmation is unclear, an exchange of QSL method may be included.

For more info and details, check out some interesting and useful web links below.

How to Talk to Someone Using Ham Radio

Example of the Art of the QSO – YouTube

Typical HF ham radio contact or QSO format

What is a QSO? How many types are there? Am I doing my QSO correctly?

Contact (amateur radio) – Wikipedia

Making your first QSO – Radio society of Great Britain

Ham Radio Q Codes

Using a Multimeter

AF5NP Amps (Amperes), Current, Multimeter, Ohms, Resistance, Safety, Test/Testing, Volts/Voltage

 

DMMEvery ham should have a multimeter and know how to use it.  Multimeter use is a practical skill not only for ham radio but also around the house for general power and wiring work.  As with many topics on this site, details of the subject are too extensive to cover in a simple post so we will give you just basic info along with some resources for further study on your own.  Even with minimal detail this is still a long, involved post.

By definition multimeters measure more than one thing.  In electrical work a multimeter typically measures voltage, current, and resistance.  Sometimes it is called a volt-ohm-milliammeter or simply a volt ohm meter (VOM).  Note that these are the three fundamental electrical parameters as described by Ohm’s law.

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In addition to measuring the three core electrical parameters, multimeters may also read other things such as temperature, frequency, capacitance, plus provide quick checks of diodes and continuity.   At minimum they will measure voltage and resistance, since these are the two most commonly read values.

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To measure voltage  you connect the meter leads between (across) two points. This parallel connection allows real-time undisturbed readings in live circuits or power sources.

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Note that resistance measurements are also made with test lead parallel connections but never on live circuits; more on that below.

Measuring current with a common multimeter is more disruptive because it requires the circuit to be broken somewhere and have the meter leads inserted in-line to read amperage, and that is not often very convenient. 

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This series connection requirement for measuring current is the main reason it is less commonly used, and why clamp-on (non-contact) current meters are sometimes favored at the expense of accuracy and greater cost.

So what would the ham or handy homeowner need a multimeter for?  The possibilities are endless but common scenarios are testing batteries, locating blown fuses, verifying DC and AC power supply voltages, and checking cables for undesired opens or shorts.  For kit or DIY circuit builds it is also useful to verify resistor values and test active circuit voltages.  Here is a link to a list of Ten uses for a multimeter from Ham Radio School.

There are a few safety considerations to note when using a multimeter.  Two involve the test leads which connect the meter terminals to the circuit being measured.  First, the leads (probes, wires, and connectors) should be rated for at least the voltage being measured. The meter itself must also be rated to exceed this voltage.

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Good meter leads will have shrouded plugs, high quality flexible insulation, and finger guards (flanges) at the probe tips:

DMM LeadsThey will also be rated at least 600V as marked on the probe for general measurement below that voltage.  Special Continue reading →

Cells and Batteries

AF5NP Battery, Cell, Emergency Communications (EmComm), Power, Primary, Rechargeable

Batteries are quite important to radio amateurs, especially when working portable or when using handheld transceivers.  There are a number of US license exam questions on the subject and hams should have a fair understanding of batteries and how they are used in amateur radio.

Figure T-1
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Let’s start with some terminology.  A battery is a collection of electrochemical (galvanic) cells connected in series (greater voltage) or parallel (more current) for a given application. The schematic symbol above hints that there is more than one cell in series to represent a generic battery. More on cells vs batteries at the end of this post.

There are various battery types and many battery sizes but for all applications–not just ham radio–there are two basic kinds of battery: Primary and Secondary.

Primary batteries are used once, then disposed of (non-rechargeable). Years ago these were mainly carbon-zinc composition but today we find alkaline and lithium give better performance and are more commonly used, along with smaller coin cell silver oxide and mercury compositions. The advantages of primary batteries or cells over secondary ones are higher energy per unit, longer storage times, and instant readiness.

Secondary batteries are rechargeable, which is their only real advantage over primary batteries. The most common rechargeable battery technologies today are lead-acid, Nickel-Cadmium, Nickel-Metal Hydride and Lithium-ion, and all are used in ham radio.

What does this really mean for hams?

Many years ago, radios used vacuum tubes (electron valves) and required multiple high voltages. Two or three different dry cell batteries were used, often wired in series, and they had to be replaced frequently. Be glad those days are long gone.

Nowadays modern ham radio gear runs off 12V DC power or lower, and there are occasions to use either primary or secondary batteries. Generally, secondary (rechargeable) batteries are preferred most of the time. The typical handheld transceiver (HT) comes with a rechargeable battery pack. Working portable HF or VHF/UHF with no AC power requires a battery, and this is almost always a secondary unit (lead-acid or Lithium-ion brick).

One instance where non-rechargeable (primary) batteries is smart is when using a HT in an emergency situation where there is no power or facility to recharge the unit. You can buy accessory primary battery packs for many HTs. It’s a good idea to keep one of these available along with spare alkaline or lithium cells in your go-kit for a real-life EmComm scenario. AA cells can almost always be purchased or scrounged in an emergency.

HT with stock rechargeable battery (7.2V) on right, AA pack (6×1.5=9V) on left

The lead-acid battery is still a primary reference in ham radio, largely because it is a vehicle’s power source for starting engines and powering on-board electronics (including mobile ham radio equipment). In fact, the 12V power standard for most modern ham gear derives from the car battery and is really 12.6V nominal with 13.6V standard level as when a car’s alternator is running to charge the lead-acid battery. That’s why ham radio 12V DC power supplies typically run around 13.5 to 13.8V; our equipment is designed for in-vehicle operation with a running engine.

12V lead-acid batteries for non-vehicle use often are sealed (SLA) with a gel electrolyte instead of liquid, making them less hazardous to handle and store. Absorbent glass mat (AGM) batteries are a similar variant of the lead-acid battery. All of these tend to deplete at around 10.5V. Draining the battery below this level may compromise its ability to fully re-charge, and possibly damage the battery.

The main advantages of lead-acid batteries are that they are relatively simple, inexpensive, durable, dependable, with low self-discharge rates yet capable of high discharge rates. Disadvantages of SLA or AGM batteries include bulk and weight (very heavy), limited number of full discharge cycles, limited discharge (not deep-cycle), and environmental concerns (hazardous waste).

Lithium-ion polymer (LiPo) technology is relatively new but is perhaps the best performing rechargeable battery as of this writing, and is relatively light weight, making it ideal for radio amateur portable use; very popular today. One manufacturer has ham-specific lithium ion phosphate (LiFePO4) products and even has equipment operating charts to help select an appropriate battery. A bit expensive but worth it to portable operators or those looking for emergency backup power.

One advantage of Nickel-Cadmium (NiCd or NiCad) batteries over other rechargeable types is low internal resistance, meaning you can suck a lot of energy out of them quickly (high-drain), so are popular with the radio control (RC) model crowd, despite their inferiority in other ways (including the “memory effect“).

As mentioned earlier, cells and batteries are not exactly the same thing, even though the term battery is quite often used for individual cells. A battery consists of one or more cells, most always connected in series to reach a desired voltage.

Continue reading →

Series and Parallel Circuits

AF5NP Battery, Capacitor, Circuit, Component, Electronic, Impedance, Inductor, Parallel, Resistor, Series

jumblecircuit

All hams should have at least a limited understanding of basic circuits, and this means being able to differentiate between series and parallel components.

Besides numerous license exam questions (dozens below in green boxes; knowing helps you pass the exams), some technical discussions in ham radio will throw the terms around so let’s explore the matter here.  In addition to our own presentation, some excellent web references are given at the end for further (and often more interesting) information.

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Before jumping into circuits, let’s discuss series and parallel connections.  Visualizing this will help us understand series and parallel circuits.

As the name suggests, series connections are lined up end-to-end.

series res

We’re demonstrating with resistors but the principle applies to any two-terminal component: capacitors,  inductors, diodes, cells/batteries, and light bulbs can all be wired in series with two or more of each (or a mix of different parts).  Lining them up terminal to terminal makes a series connection.

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Schematically, 3 parts in series looks like this:

Series schem

From this simple schematic we intuitively see that the current flowing through a series string has to be the same though the chain; there is nowhere else for electrons to flow (current).

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Equal current is one way of defining a series circuit.

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Also as the term suggests, parallel connections are side-by-side.

parallel res

Again, demonstrating with resistors and again, the principle applies to any two terminal component.  Arranging components across each other makes a parallel connection.

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Schematically, 3 parts in parallel looks like this:

Parallel schem

From this simple schematic we intuitively see that the voltage across parallel components must be the same.

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Equal voltage is one way of defining a parallel circuit.

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We just learned that current is the same through components in series, and voltage is the same across components in parallel.  What about  the voltage across series components, and current through parallel components? Continue reading →

Hams Are Monitored (FCC/OO/VM)

AF5NP ARRL, FCC, Monitor, Observer, Volunteer

In an older post we mentioned that hams have no expectation of privacy; assume that anything you say over the air is heard (someone is listening). In another post we discussed what can you say as a ham, focusing on what is illegal. Words are not the only problem; there are a number of activities against regulations.

As licensed radio amateurs we are obliged to abide by our governing authority’s rules for ham radio. In the USA that is found in the Code of Federal Regulations, Title 47, Part 97 (47 CFR 97) , managed by the Federal Communications Commission (FCC).

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FCC Seal1 As with broadcast transmissions (radio, television) the FCC enforces the rules.  Other countries have similar rules and structure so if you are outside of the USA, study up your applicable regulations.

Years ago the FCC was actively involved in monitoring not only commercial broadcast frequencies, but ham radio bands as well.  There were monitoring stations set up around the country for this purpose.

GI Monitor1

They also had mobile vans for locating offenders.  Violators might get a very stern letter or possibly a personal visit.

FCC Warning

It’s one of the reasons we are supposed to keep a copy of our license posted at our station.  A FCC Inspection Fact Sheet gives good information related to home inspection.

Those days are long gone.  The FCC has closed many regional offices and pared back their enforcement staff to a minimum.  However, they are still the ultimate authority for radio in the US and still have teeth.

When the FCC reduced their enforcement resources they partnered with the ARRL to have hams help do much of the monitoring and reporting.  Originally called Official Observers (OOs), they were hams who were qualified and trained by the ARRL as part of the Amateur Auxiliary program.  While there are fewer FCC agents, we are still being monitored for Part 97 violations, primarily by fellow hams.

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The OO scheme was replaced by the Volunteer Monitor (VM) program in January 2020 with a new agreement between the FCC and the ARRL.

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The intent of the VM program is to re-energize enforcement efforts in the Amateur Radio bands.  Its role is to monitor the airwaves and collect evidence that can be used both to correct misconduct or recognize exemplary on-air operation. Cases of flagrant violations will be referred to the FCC by the ARRL for action in accordance with FCC guidelines.

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Note that good behavior is also recognized. Be the ham that gets a favorable postcard from a VM, not for an infraction. 🙂

Bad behavior is what monitors are really trying to weed out.  A cautionary notice may be sent to hams who violate rules.  If the violation continues, the VM system has a streamlined enforcement process with the FCC who can take legal action.

So what are some of the bad practices and violations that VMs are looking for?

While not exhaustive, violations include:

  • Transmitting without a license
  • Operating outside frequencies permitted by license class
  • Operating modes or power outside privileges
  • Willful interference
  • Obscene language
  • Conducting business or making money over the air (for yourself or someone else)
  • Transmitting music
  • Failure to identify properly

An interesting (somewhat dated) list of current FCC enforcement actions is found here.

Finally, the stereotypical monitoring van may still be used.  VMs and federal agents may occasionally have to track down an offending signal using direction finding techniques.

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RFI Filters and Ferrite Chokes

AF5NP Bead, Choke, EMI, Ferrite, Filter, Interference, RF, RFI

In our previous post we introduced the reality of radio frequency interference (RFI) which can affect hams on occasion.

A potential remedy for RFI (in addition to shielding, as mentioned there) is some form of RF filtering.  Filters are used to either reject (attenuate) or accept (pass) signals over a range of frequencies. A couple of license exam questions down below exemplify this topic.

Filters are a fundamental concept in electronics but details can get complicated so we will share only basic info and give several references for your own research.

Before reading further the reader is strongly advised to review an excellent article, Introduction to Filters, from All About Circuits.  Credit to that site for the filter diagram below.

Filters can be categorized into four essential types:

  • Low-Pass: Passes frequencies below cutoff and attenuates higher frequencies
  • High-Pass: Passes frequencies above cutoff and attenuates lower frequencies
  • Band-Pass: Passes frequencies only within a specific range, attenuates others
  • Band-Stop/Band-Reject (Notch): Attenuates frequencies within a specific range, passes others

This diagram compares and clearly illustrates how these four operate:

Four filter types

Regardless of design and type, all filters will introduce some loss of the passed signal (insertion loss).  Good filter designs will minimize loss and allow the protected device to function properly.

In audio equipment the tone controls are typically high-pass and low-pass filters with adjustable cutoff for treble and bass .  More sophisticated tone controls may add a mid-range adjustment while a graphic equalizer adds filters for multiple narrow frequency ranges.

Many RFI filters are low-pass because hams may need to remove transmitted HF or VHF/UHF signals from low frequency (50/60Hz) AC power lines, audio (25Hz-25kHz) signals, VGA video (31kHz) signals, or lower-frequency (AM) radio.

Filters can be made using active circuits and/or software but more commonly, RF filtering is accomplished with simple passive electronic components: capacitors (C), inductors (L), and resistors (R).  Simple LC, RC, RL, or RLC filters can be made from combinations of these parts. The simplest low-pass filter is a capacitor across (shunt) a signal, an inductor in line (block), or both.

Besides electronic components, something completely different and maybe unexpected can also form of passive low-pass filter.  Ever wonder what that bulge is near the end of many audio, video, and computer cables?

Ferrite1

Specifically, it’s a ferrite bead or choke.  If you cut one open, under that plastic cover you would find that the cable passes through a gray tube.

220px-Ferrite_bead_no_shell

That tube is made of  ferrite material, a ceramic with high iron content and high permeability.  While more complex than this, an easy way to visualize how ferrite beads work is to say that the higher frequency signals passing through them are coupled into the material which becomes resistive over the intended frequency range and dissipates the unwanted energy as heat, while passing through the lower frequencies with minimal attenuation.

FerriteBeadAnimation

Seems a bit mysterious and magical, but it’s science.  Different ferrite compositions have varying frequency, power handling, and temperature characteristics so selection is critical.

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Ferrite beads (chokes) are typically simple and inexpensive interference filters to install Continue reading →

Radio Frequency Interference (RFI)

AF5NP EMI, Filter, Interference, RF, RFI

Radio frequency interference (RFI) can be a problem for hams.  We transmit radio waves which can sometimes cause problems for other electronics (radio, TV, telephones, etc.)  Sometimes other devices generate RF noise that interferes with our radio reception.

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Also known as electromagnetic interference (EMI), there are several US license exam questions involving this subject.  Effects of RFI vary from nuisance audio noise or video snow to disabling electronics.

rfi1

Sometimes even normal, legal RF signals cause RFI to sensitive devices in our homes or our neighbor’s.  Even with the switch from the old analog TV broadcasts to digital format, certain ham radio transmissions can scramble over-the-air (OTA) and cable TV video and audio reception.

One common problem with cable TV interference is poor quality or improperly terminated coaxial cables.

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Right or wrong, hams get blamed for any form of interference and it’s been that way for the whole century of amateur radio’s existence.  You may run across jokes and cartoons about amateur RFI like this:

interference cartoon bw

And this mock award:

WAN Award

Just be aware that hams get a lot of blame and extra scrutiny for interference, often baseless.  Still we need to be good neighbors and work with others if there is a problem.

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This goes both ways.  Sometimes neighbors can cause interference with ham radio reception. Continue reading →

APRS

AF5NP APRS, Emergency Communications (EmComm), FM (Frequency Modulation), GPS (Global Positioning System), Packet, Position, VHF/UHF

You may have read or heard the term APRS.  This four letter acronym isn’t self-explanatory but is popular and important enough that we should cover the basics.

Do you need APRS? Unlikely.  Do you want it? Maybe.   Planning to buy a new VHF/UHF radio and wonder if this is a feature worth paying for?  Read on.  APRS is a big topic with way more detail than we can present here so we’ll give you a general idea of what it involves along with some research links to answer these questions yourself.

For starters, APRS stands for Automatic Packet Reporting System.

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Some publications mistakenly call it Automatic Position Reporting System

Refer to our packet topic for a background on what packet radio is all about.  What makes APRS a specialized form of packet is what info is transmitted.

APRS supports four data types, including Position/objects, Status, Messages and Queries.  The position packets contain latitude and longitude, a symbol to be displayed on a map, plus optional fields for altitude, course, speed, radiated power, antenna height above average terrain, antenna gain, and voice operating frequency.

While APRS can send packets over greater distances on HF bands, it is more commonly used with VHF FM (2m) radios to share data of interest in the local area such as GPS coordinates, weather, alerts, announcements, and such.

APRS info and messages can be directly between hams but more commonly, packet data is collected by local repeaters (gateways) and sent to the APRS Internet System (APRS-IS) for retrieval anywhere by anybody with a web browser.  Meaning your unlicensed spouse can see where you are located (technically, your transceiver) at any given time.  It is not a one-way system; APRS both transmits and receives packet data.

Also unlike normal packet radio, APRS blindly sends out data addressed to no one in particular (unconnected). Two things to know about this system: 1) no error correction (clean, strong signals required), 2) someone or something must be monitoring to be useful (another APRS ham or internet gateway).

In addition to several good references below, an excellent resource worth reading right now: Intro to APRS (PDF file link), a presentation prepared by John Gorkos AB0OO of the Joplin (MO) ARC.   It discusses what the system is not, significant info you can get through it, what you can do with it (note two separate sections for this), and suggests next steps for getting involved with APRS.

Given all the possibilities above, the primary use of APRS in ham radio is to have a transmitter location reported to a central database periodically so that others can see where a mobile/portable ham is located.

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This makes APRS particularly useful for public service events and emergency communication (EmComm) situations where managers can easily track mobile resources who have messaging capabilities.

There are numerous web services for viewing APRS maps and data but the main one (and simplest) is  aprs.fi .  Click there and you will be taken to a local map showing locations of ham APRS transmitters in your own area.  Looks like this example:

APRS Map

In North America all APRS data is transmitted on 144.390 MHz.

APRSVHFworldmapXx

Just tune your VHF radio to your global frequency to hear the packet squeal, if you are wondering what it sounds like.

APRS requires not only a 2m FM transceiver but also a computer with display and TNC radio-computer interface, plus (normally) a GPS receiver.  Radios with APRS features built in cost more than ordinary mobile or handheld transceivers, mainly because Continue reading →

LEDs

AF5NP Component, Electronic, LED

LED Animated GIFThe light emitting diode (LED) comes in a wide variety of sizes, shapes, and colors, and is something every ham should be familiar with.  There are a number of exam questions related to LEDs.

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LEDs are more common than you may realize.  Not only used on ham radio equipment, they are typically found on most electronic gadgets, primarily as indicator lights, most often as power or status indicators.

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Developed in the early 1960s, visible LEDs became practical replacements for miniature incandescent lamps in the 1980s.  Their main advantage is in efficiency (wasting little power), but they also last many years and illuminate instantly, all compared to incandescent light bulbs.

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The above question phased out of the General class exam pool in 2019 but it speaks to the benefits of LEDs over other technology.  This example from the Tech license exam pool shows an LED being used in a traditional power supply circuit as a power indicator:

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Useful as more than just on/off indicators, LEDs, when grouped, really open up interesting applications.  When formed as bars in a figure 8 arrangement, the classic seven segment display is created:

seven seg display

This revolutionized electronics to display numbers quickly and inexpensively and were an early use of the technology starting in the 1970s.

Also, when different color LEDs are bunched together their combined light can form a different color, often to achieve white.  RGBThis is the principle of LED back lighting for flat panel displays and for the recent adoption for home and general lighting (replacing light bulbs).

LED Bulb White LEDs (or a blend of other colors to make white) weren’t practical until the mid-1990s, and it took years to become economical.  The widespread use of LEDs for display back lighting and general lighting is now less than 15 years old.

For those interested in the technology, we’ll dive into some of the details of LEDs now.  As the name implies, an LED is a form of diode, the simplest possible semiconductor device formed by Continue reading →

Selective Calling & Tone Squelch

AF5NP CTCSS, DCS, Emergency Communications (EmComm), FM (Frequency Modulation), PL, Selective Calling, Squelch, Tone

In a previous post we introduced the term squelch and how it was used in basic operation.  As mentioned there modern ham radio work (especially with repeaters) often involves other technologies that fall under a different category named selective calling, tone squelch being the most common form.

Selective calling is different from ordinary carrier or noise squelch.  In practice it is more of a security or channel sharing function.  Selective calling encompasses several similar technologies which largely do the same thing: prevent a transmitted signal from being received by other radios unless a particular code is entered by the sender.

From the Wikipedia article, “Selective calling is akin to the use of a lock on a door. A radio with carrier squelch is unlocked and will let any signal in. Selective calling locks out all signals except ones with the correct “key”, in this case a specific code.”

The most common form of selective calling in use by hams is a tone squelch system with the awkward name of continuous tone-coded squelch system (CTCSS).  Squelch in general is used to keep commercial and amateur radio repeaters from continually transmitting. Since a carrier squelch receiver cannot tell a valid carrier from a spurious signal (noise, etc.), CTCSS is often used as well, as it avoids false key-ups. Use of CTCSS is especially helpful where nearby repeaters may share the same frequency or in a high electrical noise or RF environment.

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As the name implies, CTCSS sends out a continuous tone along with the transmit audio.  The tone is termed, “sub-audible”, although it is often a low audible frequency.  Most radio systems filter out these low frequencies so it is unlikely that you will hear the tone when listening to another ham unless you have an unusual radio and/or are wearing high fidelity headphones.

The CTCSS tone is selected by a repeater operator to avoid duplication with nearby repeaters on the same frequency.  In most cases, the objective is to reduce interference and not restrict legitimate access.  There are 100 established CTCSS frequencies but some are more commonly used than others.

CTCSS is often referred to as PL because it’s easier to say.  They mean the same thing but PL® (stands for Private Line) is a registered trademark of Motorola’s implementation and was the original employment of CTCSS.

 

Besides CTCSS, other forms of selective calling in use by hams include:

  • Selcall (mostly European)
  • Digital-Coded Squelch (DCS)
  • XTCSS

Why it matters to us

T2B04-2018Because various forms of selective calling prevent a signal from being re-transmitted (repeater) or received (simplex) without the proper code or tone, use of CTCSS or DCS is a possible reason other stations cannot receive you.  Especially on a repeater, if others cannot hear you it’s quite likely that you have the wrong code or your tone squelch is turned off.  How to know what the proper setting is?  Consult the repeater directory.

Some Useful Links

CTCSS – RadioReference

How radio “privacy tones” or CTCSS tones work – YouTube video

CTCSS – MDARC

Get the Right Signal Tone – Ham Radio School

Hey, Why Can’t I Access the Repeater? – Ham Radio School

Differences between CTCSS and DCS – Retevis

CTCSS & Tone Burst Ham Radio Repeater Access – electronicsnotes

A Historical and Technical Overview of Tone Squelch Systems – WA6ILQ

Repeater Related Terminology – Repeater Builder group

Squelch

AF5NP Emergency Communications (EmComm), FM (Frequency Modulation), Squelch

Squelch is a funny word that is familiar to many of us without understanding what it really means.  Hard to improve on the definition beyond that in the Technician license exam question:

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Most useful when using voice modes (phone), squelch makes radio operation more bearable by turning off the audio when there is no valid signal.  Without squelch our radios would be cranking out a lot of unwanted background noise.

The reality of both AM and FM radio (which we covered recently) is that there is electrical noise in the bands from many sources, natural and man-made.  This noise is often randomized so that it appears as hiss or fuzz (white noise) from radio receivers.  A squelch circuit mutes receiver audio to block the noise when there is no real signal.  Squelch acts as a noise gate which closes for random noise and opens when a real signal (such as modulated voice) appears on frequency.  How the squelch circuit determines what is a valid signal and what is noise varies; there are a few common techniques (refer to algorithm link in references below).

Squelch is built into more expensive broadcast receivers.  It may also be found on AM transceivers (particularly CB radios) and is a feature of nearly every FM amateur rig.

While less prone to electrical noise, FM technology is susceptible to a lack of true signal.  Traditional FM receivers use an LC tuning circuit that generates ‘hiss’ with no signal present.  You may have noticed this while tuning between stations  on your broadcast FM radio.  Since hams commonly use VHF/UHF FM transceivers for local chat and EmComm work, the squelch feature of our rigs is of particular interest.

Squelch setting is important because if you make it too tight you may not hear a weak signal; too loose and you get constant noise.  General good practice (at least a starting point) is to turn down the squelch until you hear background noise (hiss), then increase the threshold until the noise goes away, then just a little more.

Squelch threshold is always settable on your FM transceiver.  There may be a knob to turn as in the example below, or it may be through keypad menu.

Squelch Adj FT7900

Squelch tail is a common term that is related to all this.  The tail is the brief “pfffft” sound heard when another station stops transmitting.  Audio example on YouTube here.  It is the natural presence of noise during the delay between the time a signal drops and the squelch kicks in.  On a repeater it will often followed by an audible beep or similar courtesy tone.

So far we have discussed the basic squelch feature of common ham radio transceivers. There are other squelch techniques in common use with repeaters such as CTCSS, DCS, and PL.  These fall into a separate category called selective calling or one specific variant known as tone squelch, mainly because they have a different purpose and functionality.  We may discuss this in a future post.

Some Useful Links

Squelch setting – W3ATB blog

Squelch algorithms – PA3FWM site

Squelch Tail – DAP-COM reference

 

Voice Modulation- SSB

AF5NP AM (Amplitude Modulation), Bandwidth, FM (Frequency Modulation), HF (High Frequency), Modulation, SSB (Single Sideband), VHF/UHF

In the last post we explored voice modulation and learned that AM and FM are the two primary modes.  We also noted that single sideband (SSB), a variant of AM, is the dominant form of voice communication on the ham bands below 50 MHz.   This post will delve into the details of SSB.

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SSB is important because it significantly improves the plain AM signal in both efficiency and bandwidth.

G2A06-2019In context of voice modulation, bandwidth means the range of frequencies the signal occupies.  In general, wider bandwidth means higher audio quality but less efficiency, and vice versa.

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The SSB signal is generated using AM but before it is transmitted the carrier and one sideband are removed.  A diagram of an AM signal helps visualize how it starts:

sidebands1

SSB transmission reduces the power required (more efficient) and occupies a smaller slice of the RF spectrum (narrower bandwidth, ~3kHz), when compared to AM.

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The transmitter circuitry is essentially AM but adds carrier and sideband filters at nominal cost.  The SSB receiver is more complex and expensive than AM because it must reconstruct the missing (mirror image) sideband to create a full voice signal, as well as replace the carrier with a local signal.

Because it has to recover the opposite sideband the SSB receiver is somewhat sensitive to tuning to make the voice sound normal or natural.  You will find that voices sound quite different in clarity and pitch when tuning around the transmit frequency.   A common reaction to hearing off-tune SSB is that it sounds like a quacking duck.  A great video demonstrating some of the nuances of SSB sound and tuning can be found in the links at the bottom.

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So SSB transmits only one sideband, but which one, you ask?  The answer is either.  When the upper sideband is transmitted and received, the operation is called upper sideband (USB).

USB waveform

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Conversely, when the lower sideband is used, the operation is called lower sideband (LSB).

LSB waveform

G2A02-2019In ham radio either one is legal to use in the phone portion of the band plan but by convention LSB is used below 10MHz, and USB is used above 10MHz (note that Continue reading →

Voice Modulation- AM & FM

AF5NP AM (Amplitude Modulation), FM (Frequency Modulation), Modulation, PM (Phase Modulation), SSB (Single Sideband)

In the last post we introduced the concept of modulation as one of the five meanings of the term mode.  Voice is the most common and obvious mode of modulation so let’s dive into that a bit as it is one of the basic concepts of amateur radio.  

Modulation is the means to impress information on a radio signal.  It’s how a circuit puts our voice onto the radio signal through a microphone.

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If you are (or were) fortunate enough to receive US Technician license training using the ARRL course book and companion slides you would find some good info as follows:

When information is added to the radio wave, (the carrier) we modulate the wave.
     •Turn the wave on and off (Morse code)
     •Speech or music
     •Data

In the physics of waves there are three characteristics we might control to impart information (three possible modulation methods or modes).

Different modulation techniques vary different properties of the wave to add the information:   amplitude, frequency, or phase.

These three are commonly known as Amplitude Modulation (AM), Frequency Modulation (FM), and Phase Modulation (PM).

AM is relatively easy to understand and visualize.  The RF carrier wave is varied in amplitude according to the audio waveform (as from a microphone) to create a modulated signal.

AM Graphic

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Amplitude modulation is commonly used on the familiar AM broadcast band.  It may occasionally be found on lower frequencies in the HF ham bands.  While it used to be the primary mode of voice communication in the early years, very little pure AM is used nowadays in favor of single sideband (SSB), which is a type of AM. 

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SSB is a big and important topic which merits its own write-up so we will post that soon.

FM is less intuitive and harder to visualize than AM.  The RF carrier is varied in frequency according to the audio waveform (as from a microphone) to create a modulated signal.

FM Graphic

Frequency modulation is commonly used on the familiar FM broadcast band and in ham radio above 28MHz for high quality simplex and repeater operation.

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PM is very similar to FM in the way it operates with only a technical difference between the two (integration of the baseband signal).  Here the RF carrier is varied in phase according to the audio waveform, instead of the frequency.

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Despite the terminology, many (most?) FM radios we routinely use for local communications over repeaters use PM circuitry.   The two are effectively equivalent for ham radio use; interesting discussion here and even more detailed one here.

For the ham radio operator, AM and FM are the two main voice modulation modes to understand.  SSB and PM are simply sub-sets or derivations.  This animated graphic is particularly helpful in visualizing AM vs FM:

AM vs FM animation

Useful comparisons between the two (applies equally to broadcast and ham radio):

  • AM has poorer sound quality (narrow bandwidth); FM better quality (wider).
  • AM is prone to noise interference; FM is relatively immune to electrical noise.
  • AM has narrower bandwidth (more efficient) than FM (trade-off with sound quality)
  • AM circuitry is simpler and cheaper than FM
  • With AM, transmitted power level varies with the amplitude of the signal; with FM transmitted power level is constant, regardless how much modulation (deviation) is applied.

In context of voice modulation, bandwidth means the range of frequencies the signal occupies.

Because of these differences in bandwidth and efficiency, AM and FM are generally used on different Continue reading →

Mode Madness

AF5NP CW, Digital, Mode, Modulation, Operation, Phone, Propagation, Satellite, Split

In ham radio the term mode has at least five distinct meanings.  It’s confusing for even experienced hams so we’ll try to tame some of this madness.

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If you’re a new ham with a handheld or mobile transceiver to talk on the local repeater, mode doesn’t mean much to you.  Your basic radio has no mode controls because it can only do one thing.  In this case you are operating in voice mode using frequency modulation (FM).  Guess what?  These are the first two—and most important—of the definitions of mode.  These are operating and modulation modes.

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Below we will explore the five different contexts for mode found in US license exam questions:

  • Operating
  • Modulation
  • Propagation
  • Satellite
  • Split

Operating Mode-  The most basic definition of mode; a general category of radio transmission and reception.  There are three or four operating modes, depending on how they are categorized.  The common three are:

  • CW (continuous wave), typically for Morse code (radiotelegraphy)
  • Radiotelephony (phone), a fancy term for voice communications
  • Digital, where data is exchanged over the air, requiring computers or machines to interpret signals

For logging and awards these three categories are CW, Phone, and Digital modes.  The ARRL Logbook of The World (LoTW) adds a fourth category:  Image.  Collectively these 3 or 4 are known as mode Groups.

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Modulation Mode-  Modulation is the means to impress information on a radio signal.  It’s how a circuit puts our voice onto the radio signal through a microphone.  There are different forms (modes) of modulation which can be employed within each basic operating mode.

For example, typical modern HF transceivers support voice modes using AM, FM, and SSB modulation modes.  There are a few flavors of CW and dozens of digital modes (and the list keeps growing).  Just look at that mode group list link above.

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To further complicate matters we now have both traditional analog modulation for phone (voice) signals, and digital voice modulation as well.  Many digital modes simply modulate a SSB waveform using specific tones to represent data characters.  We live in an era where computers and radios are really working together to do amazing things.

Operating and modulation modes are hard to separate.  In fact, they sort of overlap and mash together.  Context of the discussion is key here; often it doesn’t really matter.

These two also play a role in the ITU classification of RF signals.  Refer to Types of Radio Emissions link.  Hams may occasionally log their mode according to this or a similar scheme.

Why do so many operational and modulation modes exist?  It’s largely for historic reasons as technology and electronics have advanced over the years.  In the earliest days of radio, only radiotelegraphy existed. Mode had no meaning as CW was the only possibility.   Then came voice technology and a second operating mode was born.  Going from original AM to SSB,  we then had modulation modes, adding FM as an improvement later.  Digital mode entered the scene after voice once people discovered they could encode audio signals to represent data; computer technology has made the digital mode wildly successful, if less personal, in recent years.  Image modes have been around since the early days of television but here again, computers have made them better and easier.

One other reason for different modes is Continue reading →

Generator Use & Safety

AF5NP CO Carbon Monoxide, Emergency Communications (EmComm), Fire, Generator, Ground, Protection, Safety

Spring is [hopefully] coming soon with expected turbulent weather.  A new hurricane season is also upon us.  Both are liable to cause disruptions to utility electrical power.  Annual ARRL Field Day is also approaching.  Time to think about auxiliary power generators.

Small gasoline-powered generators are relatively common and widely available for emergency or portable electrical power.  It’s a good idea for the prepared homeowner to have one, mainly to keep the fridge/freezer cold during times of sustained power outage.  The savvy radio amateur also recognizes the importance of communications capability in a blackout scenario as well.  Power is needed to make our radios work beyond what limited battery capacity we have, particularly in emergency situations.  Most EmComm groups include generators in their plan and have them on hand.  Not every ham does.

Honda Generator

Consider having a small generator for essential power when the lights are out for hours.  Having a generator is good; knowing how to use it safely is the focus of this topic.  We will look at four related safety considerations:

  1. Carbon Monoxide hazards— CO
  2. Fuel handling and storage (fire)
  3. Generator grounding
  4. Shock hazard

Carbon Monoxide (CO) is the primary hazard with generators, since  CO is produced in the exhaust of all gasoline and natural gas combustion engines. 

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NEVER, ever run a generator inside a dwelling or garage where exhaust can seep into the occupied space.  CO is a colorless and odorless gas which can kill or injure humans and animals.   It can be detected only with chemical or electronic CO detectors; it’s wise to have detectors in every home.

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Always operate a power generator outdoors in a well-ventilated area. Continue reading →

Coaxial Cable (Coax)

AF5NP Antenna, Attenuation, Cable, Coax (ial Cable), Impedance, Loss

Because it’s commonly used in radio work, every ham should be familiar with coaxial cable, often simply called coax.

Coaxial cable is most often used between the transceiver (or T/R switch) and antenna.  In this application coax acts as the feed line (AKA transmission line) to carry transmitted and received RF signals between the antenna and radio.  Other types of feed line can be employed but coax is used by many hams because it is easy to work with and readily available.

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Coax  is a type of electrical cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Most coaxial cables also have an insulating outer sheath or jacket.  The term coaxial comes from the inner conductor and the outer shield sharing a geometric axis.

300px-Coaxial_cable_cutaway.svg

To be useful coaxial cable must be terminated with mating RF connectors.  An experienced ham may terminate their own coax; at greater cost they may purchase ready-made and tested assemblies.

coax ca assy  coax ca assy2

A wide variety of coaxial cable and assemblies are available with different characteristics. A quick summary of the important features:

  • Characteristic impedance
  • Signal loss
  • Power capacity
  • Diameter/weight
  • Flexibility
  • Environmental resistance

A seventh important characteristic of coax is velocity factor but that is a more advanced topic of lesser importance so we’ll simply mention it here.

Coaxial cable selection for each installation may be a compromise between features, requirements, and cost. The ham has to factor in what he needs or wants, what is available, and what it costs.

A quick look at these features of coaxial cable: Continue reading →

Family Comms Plan

AF5NP Emergency Communications (EmComm), Family, Plan

One of the more useful applications of ham radio (beyond the obvious enjoyment of the hobby) is for emergency communications (EmComm).  In times of man-made or natural disaster, mobile phones and internet may be inoperative or unreliable.  In such times ham radio may be the only way to communicate.

WhenAllElseFails

Extend this idea to your loved ones with a family communications plan.  This would involve you, a spouse and/or children. For it to be practical all would need to be hams with at least a Technician class license.

familyofhams

A family communications plan would be established and written down for all family members to have near their radios.  This would include primary, secondary, and tertiary repeaters in your area.  Also include a simplex frequency and the national call (simplex) frequency in case the repeaters aren’t working or are tied up.

Make sure to test all frequencies between expected locations (home, work, school) with a dry run to discover any interference or lack of coverage.

To help visualize how this might work, let’s say there is a major tornado outbreak that wipes out a large chunk of a mid-sized city one weekday afternoon.  Dad is at work, Mom is at home, and daughter is at school.  Cell phones (voice & text) and internet are not working so none of these people can let each other know where and how they are.  All three members know that the situation is bad so all get on their radios.  Primary and secondary repeaters are busy with dozens of other local hams reporting in damage and trying to reach their families.  Tertiary repeater is open so all three move there.  From his mobile rig Dad reports that he is fine and will make his way home ASAP.  With the base radio Mom reports minor damage with a fence section down.  With her HT Daughter reports that the college is unaffected but has to wait for clearance to leave campus.  All can share updates as needed, and may have to wait their turn on the repeater.

Great idea, but you may have objections.  Let’s address a couple of these:

  1. Getting everybody licensed.  The necessary Tech license is actually pretty easy to obtain.  Five year olds can do it with a little study and coaching.  Not a good excuse.
  2. Cost.  License exam fee is $15 or less.  Many hams already have at least one VHF/UHF FM radio.  Cheap HTs (minimal requirement) can be had for less than $50 each.  Money should not be an excuse.

The licensed family member can train/coach the others to get a license and work on getting more radios.  It may be that they already have multiple radios (base at home, mobile in car, one or two HTs) so all that is needed is establishing the plan and testing it.

Local comms using VHF/UHF is most important in disaster situations but you could extend this beyond line of sight to more regional or national distances using HF equipment.  It gets more complex in this case and practically speaking a General class license would be needed.  Here also non-voice messaging using WinLink may be useful.

An interesting article on a surge in US licensees for EmComm purposes including family members is found here.

SWR

AF5NP Analyzer, Antenna, Impedance, Standing Waves, SWR (Standing Wave Ratio)

The standing wave ratio (SWR) is an important topic to hams regardless if they are working HF, VHF, UHF or any other frequency range allocated to radio amateurs.  Unfortunately it is technically involved and somewhat complex so is not intuitive or easy for non-technical folks to understand.  We’ll give a simplified explanation of SWR here and give you a basic idea of its significance and how hams relate to it.

The simplest way to think of SWR is as a measure of impedance matching.  Most commonly it is looking at the impedance differences between transceiver, transmission line (more often coaxial cable), and antenna.

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Assuming that all modern radios and cable have 50Ω impedance, the real SWR of interest boils down to the match between the transmission line and antenna.

As we mentioned in a previous post, when impedance of a source equals load impedance the best possible signal coupling occurs. Conversely, when impedances are not the same, signals couple poorly.  This is true of all electronics circuitry involving AC waveforms.

In amateur radio SWR focus is on transceiver to antenna coupling where we want to maximize RF power transfer in both transmit and receive modes.  When impedances do not match, received signals will be weak or non-existent; when transmitting, power will not radiate well from the antenna.  The ideal or “perfect” SWR for best possible transmit/receive coupling is 1:1, meaning a 50Ω radio/transmission line to a 50Ω antenna.

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SWR is simply the ratio of two impedances being measured.  It is commonly expressed in the X:X format and the larger value is always given first, regardless of which side is higher.

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With a 50Ω radio and 50Ω coax cable, a 4:1 SWR could indicate either a 12.5Ω or a 200Ω load (antenna).  Similar examples for 50Ω cable are contained in the General class exam pool:

G9A09-2015G9A10-2015A ham’s main concern with high SWR is significant power reflected back from the load, which stresses the transmitter power amplifier.  While a 1:1 SWR is ideal, practically speaking, 1.5:1 or less is good.  Many modern transceivers automatically reduce transmit power with a SWR greater than 2:1.

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SWR can be measured Continue reading →

Call Sign Order (Calling Protocol)

AF5NP Identify/Identification, Protocol

Ground Control to Major Tom
Ground Control to Major Tom
Take your protein pills
And put your helmet on

With all due respect to David Bowie and his classic song Space Oddity (which most of us probably know well), the lyrics are arranged for rhyming, not for good radio practice.

“This is AF5NP calling K5ZFA”.  If you heard this on a repeater, would it be OK?  The answer is that it is legal but the call sign order is backwards and contrary to protocol.

You may hear a new ham (or a very distracted old timer) on the air identifying first, followed by their target station.  That’s not right.

Well-established radio procedure is calling or identifying in a To-From sequence (call sign order).  Whether answering a CQ, calling a station on a repeater, or simply identifying the two parties in a contact, the other station call sign is given first, followed by your own.

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Using our example above, the proper protocol would be, “Calling K5ZFA, this is AF5NP”, or in its most minimal form, “K5ZFA, AF5NP”.

Note that the basic To-From protocol using just the two call signs satisfies requirements and is well understood on the air.  K5ZFA would hear AF5NP calling and may return the call in the same manner (“AF5NP, K5ZFA”).

This to-from sequence is so ingrained that when the order is reversed other stations are likely to get confused; there is a risk of mistaking one station for the other.

Another reason for using this sequence is that it is normal and natural for a ham to alert on their own call sign.  When it is given in the to-from way, they will tend to pay attention to what comes next, which should be the calling station’s call sign.  Reversing this order means the called station is likely to miss the calling station’s ID because it was given first and they weren’t paying attention until they heard their own ID.

New hams should make this their practice and before long it will become second nature.

So don’t model your call sign order after Space Oddity, no matter how cool the song.  It should have been, “Major Tom from ground control” but that would have changed the flow of things.

Why Hams Care About Solar Activity

AF5NP DX, HF (High Frequency), Ionosphere, Propagation, Solar, Sun

As we learned in an earlier post on the ionosphere, the real magic in ham radio is skywave propagation where HF  band (and sometimes VHF) signals can travel well beyond line of sight (over the horizon), even to the other side of the planet if conditions are right and radio waves may bend back to earth in the ionosphere.

The sun is largely responsible for energizing the ionosphere and affecting its quality (height, density, thickness, disturbance).  Unfortunately for hams, solar activity is highly variable, not constant.  There are periods of excellent skywave propagation when the sun is busy and then times of poor propagation when the sun is quiet.

Solar_Cycle_Montage
Montage of Sun’s activity over 10 years (solar cycle 23)

This topic is very complex and not completely understood.  Study is ongoing and radio amateurs have contributed greatly to the science; much has been learned in the last 100 years or so since radio became a real thing.   Great detail is found below in some excellent web links.  A brief summary of how solar activity influences the ionosphere is presented here:

Sunspot Numbers

  • Sunspot counts are a general indicator of solar activity
  • Propagation on higher frequencies is more influenced by solar activity than the lower frequency bands.
  • Ionospheric condition is influenced by the Earth’s magnetic flux lines.
  • Earth’s magnetic field is strongly influenced by solar wind (largely a day/night phenomenon but solar wind can spike with disturbances).
  • Solar flares, coronal mass ejections (CME), and coronal holes cause geomagnetic storms which affect or disrupt radio communication and create noise.

Solar/Space weather is a study of how solar events affect the earth’s magnetosphere.  A/K (long/short-term) indexes measure the stability of Earth’s magnetic field.

Hams worldwide who are active on HF and VHF bands pay a lot of attention to solar activity because of how it affects propagation and noise levels.  QRZ features N0NBH’s graphic summary of important solar and geomagnetic conditions on their main page as shown below.  Some hams and ham websites include this data on their own pages as well, so you may see this sort of info a lot.

S-T Data QRZ

Presently (2018-2019) we have days on end with no sunspot numbers, resulting in awful HF propagation (note sunspot number SN=0 above).

Solar Activity Level

Despite these poor conditions that limit decent phone (voice) and even CW (Morse) QSOs, hams can still make contact with domestic and international stations using some of the newer digital modes which can decode extremely weak (inaudible) signals.

We are hopefully approaching the end of the current solar minimum with dreams of increasing solar activity in the coming several years.

Solar activity is so important to hams that there are 16 related questions in the General class license exam question pool (only two with the limited privilege Tech pool).  Some Continue reading →

Transmit Power

AF5NP Amplifier, Linear, Power, QRO, QRP, RF, Transmitter

Q. How much RF power can a ham legally transmit with?

A. It varies with frequency/band, license class and licensing authority.  Maximum transmitter power levels are regulated by country; we will discuss the rules in the USA here.  It is one of the important regulatory subjects covered by the question pool for amateur radio license exams.

The average VHF/UHF handheld transceiver (HT) puts out 5 to 10W maximum.  A typical VHF mobile rig is capable of 50 to 75W.  Most modern HF transceivers peak at 100W.

Before we get to maximum levels, in the USA the general guidance is to use the least amount of power needed.

G1C04-2015

Of course, that’s easier said than done so many hams just go with the radio’s max power setting unless they know that a lower power setting works well or are operating a weak-signal mode.

In general, US hams are limited to 1500W (1.5kW) peak envelope power (PEP).  That doesn’t mean you should, just that you legally can.  This applies to General and Extra Class licensees for most bands and Technicians at VHF and higher.

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There are specific power limitations on 2200m, 630m, 60m, and 30m bands:

band_chart_image_for_arrl_web

As you can see from the band plan (based on FCC regulations), Technician class licensees have 200W power limits on the HF bands, with HF privileges rather limited already.

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So why a would a ham want to use more power than their stock radios can transmit, and how would they increase their default power level?

To answer the why question, it is simply that more transmit power gives more signal energy at the receiving end.  Increased wattage improves the chance of making contacts under poor conditions by overpowering signal attenuation and background noise.

To answer the how question, hams use RF amplifiers (linear power amps) to increase the power of their basic transmitter.

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This RF power amplifier must operate linearly so that it does not distort the waveform.

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RF amps can be for single or multiple bands.  More commonly you will find multi-band HF (or HF+6m) amplifiers which tend to be large boxes:

HF Amp

You will also find broadband or single-band VHF and/or UHF amplifiers:

Mirage 2m Amp

Besides all these commercially available amplifiers some hams build their own.  This is partly a nod to tradition—hams being DIY types—and partly because commercial amps may not be readily available for very low or high frequencies.

Ham-speak note:  When a ham says that s/he is running barefoot it means raw transmitter output power, unamplified beyond the stock radio capabilities.  Typically 100W or less.

Power amps are not just for handheld VHF/UHF FM transceivers; they can amplify most any amateur radio RF signal.  They are mainly useful for voice (AM, SSB, FM) and video Continue reading →

Why Hams Care About the Ionosphere

AF5NP Distance, DX, HF (High Frequency), Ionosphere, LUF, MUF, NVIS, Propagation, Skip, Solar, Sun, VHF/UHF

There are many questions concerning the ionosphere and its layers in US license exams.

T3C02-2018

Experienced hams talk about the ionosphere a lot these days and we see plenty written on the topic in amateur radio websites and magazines.  So what’s the importance of the ionosphere?

The real magic in ham radio is skywave propagation where signals can travel well beyond line of sight, even to the other side of the planet if conditions are right.  We can have two-way radio communication between Iceland and Australia and places in between because voice, video and data signals may be bent back to earth by the ionosphere.

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The ionosphere is shell of electrons and electrically charged atoms and molecules (ions) that surrounds the Earth, stretching from a height of about 50 km (31 mi) to more than 1,000 km (620 mi).  Because this band is electrically active the ionosphere is able to reflect or refract electromagnetic radiation at certain frequencies, the HF bands in particular.  For most hams communicating beyond line of sight is a big deal and the ionosphere is what makes long distance (DX) contacts commonplace.

Ionosphere bending

There are two defined ionospheric layers at night and four in daytime, the difference being exposure to the sun which provides most of the energy to the ionosphere.

Ionosphere_Layers

In daylight the F layer separates into F1 and F2 regions.  Because F2 is farthest from the earth’s surface it can bend radio waves the greatest distance.

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Long-distance propagation changes with day/night cycles and seasonal variance away from the equator.  There are numerous anomalies and disturbances that can affect the ionosphere.  Between all these factors the ionosphere is not a uniform shell; it has varying height, thickness, and density.  This continually changing area makes HF propagation highly variable.

Also known as skip, ionospheric propagation of shortwave (HF) radio signals travel a specific radius or skip distance from the transmitting antenna.  This makes received signals particularly strong at the skip distance.

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In addition to single skip distance, the earth itself can reflect/refract signals from the ionosphere back up, resulting in a secondary skip or hop and perhaps Continue reading →

Ham Radio Bands

AF5NP Band(s), HF (High Frequency), RF, VHF/UHF, Wavelength

The term band is thrown around constantly in ham radio discussion and it is included in  many questions in US license exam pools.  So what exactly is a radio band?

Parts of the radio frequency spectrum allocated for a common purpose are called a band.  Besides amateur radio, the reader may be familiar with USA commercial broadcast ranges known as AM band and the FM band, or another personal communication chunk of frequencies called the citizens band (CB).

With amateur radio, bands are generally associated with a number (2m or 40m, for example).  This number is approximately equal to the wavelength of that span of frequencies

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We say approximately because a specific wavelength is only valid at one exact frequency and that may be outside the actual range of the band.

Shown below is a chart of the current US amateur bands (dated 2017):

band_chart_image_for_arrl_web

These 18 bands are are named by their approximate wavelength.  For those who care about such details, the named wavelength (λ) may not actually be inside the designated frequency range.  A table of these is given below:

band wavelengths

Some do, but why don’t all the meter bands line up with wavelengths inside the band?

Lots of discussion on this issue can be found on the internet and two particularly good links are given in the first two references below.  It’s a real combination of history, simplicity, misuse, and existing broadcast band names.

0.7m is the same as 700mm or 70cm; the 70cm name is more commonly used Continue reading →

Software Defined Radio (SDR)

AF5NP SDR (Software Defined Radio)

While not really a topic important to new hams, Software Defined Radio (SDR) crops up often in amateur radio publications and advertising so we should at least introduce the idea here.

As its name suggests, SDR involves software working in radio equipment.  More than just being used for operator interface and general control, SDR software specifically replaces the functions of signal processing hardware employed by traditional radio circuits.

g7c11-2015

SDR greatly simplifies radio circuitry by replacing the functions of hardware oscillators, mixers, filters, modulators/demodulators, and detectors with software.  Since software is easily changed this also means that radio functionality may easily be improved or enhanced, or allow for new modes, protocols, and interfaces to other devices by reconfiguration or reprogramming.

SDR may be used on radio transmitters but the most common implementation is with receivers.  Most of the popular and available SDR products are receivers and most employ direct digital conversion techniques.

e7f01-2016

One of the more defining characteristics of SDR is the user interface (integrated or PC display) waterfall display and menu-driven controls interface.

hdsdr

g2e12-2015

There are various SDR interfaces out there, many (most?) are free applications.  These will typically have a waterfall display showing the entire receiver passband, band/frequency controls, filtering and other features (volume, AGC, noise, mode), and display controls/customization, along with recording and playback capability.

Current SDR use in amateur radio is typically for the HF bands; stand-alone modules or dongles running on PCs are commonly found and complete transceivers are quite popular although more expensive than traditional HF rigs (see references below).  As of this writing, the author is unaware of any widely-available VHF/UHF FM mobile or handheld Continue reading →

Radio Brands

AF5NP Brand/Manufacturer, Quality, Radio, Reliability, Repair

A ham new or old has many choices for radios and radio gear available.  We don’t want to tell radio amateurs what to buy or not to buy but will give some guidance here.

The modern natural progression is to start with a handheld VHF /UHF transceiver, then a mobile VHF /UHF unit, then a base HF rig.  These have different characteristics which must be considered so the first question is what type of radio are we buying?

Beyond the basic type there are several factors in selecting a radio brand.  It usually comes down to the buyer’s top three or four priorities from this list of characteristics:

  • Functionality
  • Features
  • Performance
  • Quality
  • Reliability
  • Durability
  • Ease of use/programmability
  • Memory capacity
  • Familiarity
  • Style/Appearance
  • Portability
  • Price

Unless you are looking for a specialty radio (i.e., low-power portable CW operation), size isn’t much of a factor these days as within a general family all radios have similar weights and dimensions.

From this list the top consideration should be functionality (what it does, exactly) as that is most relevant.  Say you want a dual-band FM HT to work the local repeaters or for EmComm deployment.  You have more than a dozen choices available.

Refining further by features for things like APRS, power levels, battery type, weather resistance, and whatnot will narrow your selection but you still have many to choose from.  At this point you’re likely to think about price and here is where things get fuzzy.  You could choose the nice name brand $350 radio but there’s one that does mostly the same thing for $50.

Sounds like a slam dunk decision to go with the cheaper one, but you should carefully consider this.  Beyond functionality and features, important characteristics suffer.  With that low price you get questionable performance, low quality, poor reliability, and lack of durability, not to mention fewer features.  As the saying goes, you get what you pay for.

Now that doesn’t mean you should never buy a cheap radio, but you should really think about doing so.  Some HTs are so inexpensive they can be considered disposable.  If you lose or break one, you’re out only $30-50.  This may be a good candidate for backup or one you might take boating or on a camping trip or loan to a prospective ham to listen on.  You can find favorable reviews on some of these cheap radios (mainly HTs and mobile rigs).  But you will also find many negative reviews on the same radios, mainly for reliability and durability.  Some of the cheap Chinese radios also have poor RF characteristics, lack FCC certification, and are not strictly legal for use in the USA.  So it’s a crap shoot if you do want to buy a cheap radio.

icomlogo                kenwoodlogo                 yaesulogo

There are three well-known name brands that have reputations for high quality and reliability: Icom, Kenwood, and Yaesu for hand-held, mobile and base station radio equipment.  These will cost more but will give many years of service and are worth repairing should one fail or be broken.  All originate in Japan but have strong presence in the USA and other countries.  American companies Elecraft and FlexRadio make awesome premium HF rigs but they are not competing for hand-helds or mobile units.

Alinco was another Japanese manufacturer with a good reputation, arguably up there with the Big 3 but is now developed and built in China.

Pre-owned equipment will be less expensive than new, of course, but the price between used reputable brands vs unreputable will be proportional.  With used radios you also can find older HF brands with excellent reputations.

The author’s own sad experience with an off-brand mobile radio has led him to this topic and a determination to never again buy a cheap non-disposable radio.  He purchased a Continue reading →

HT Antenna Improvement

AF5NP Antenna, Counterpoise, HT (Handheld Transceiver), J-Pole, Rat Tail, Slim Jim, VHF/UHF

The handheld transceiver (HT) is likely a new ham’s first radio.  This VHF/UHF rig is relatively inexpensive, compact and fairly useful for local communication via repeater or simplex operation.

Unfortunately, HT  performance is typically limited by its low power and cheap factory antenna.

T9A04-2018

There are three easy ways to improve the HT antenna.  These ideas are from our post on Understanding Antennas but we wanted to elaborate a bit on them here.

The first improvement is to get a 2m ¼-wave or 5/8-wave whip antenna.

This 2m ¼-wave whip is much longer (~19″) compared to the factory antenna but gives dramatically better performance (roughly equivalent of 5x power):

QW whip

This telescoping 5/8-wave whip should (in theory) perform better than the ¼-wave monopole (shown with 5/8-wave mobile whip):

5_8 Whip

These two antennas can be purchased new in the $20-30 range; well worth the money.

While the antenna can be improved with a longer whip, vertical monopole performance is also limited by the HT’s indirect ground plane.

The counterpoise that makes the vertical monopole behave like a λ/2 dipole on a HT is the operator’s body.  It is capacitively coupled to the ham’s body through the plastic case and metal shell around the RF circuitry.

This indirect counterpoise coupling is not only weak but also highly variable and unpredictable.

The good news is that we can improve the counterpoise simply by adding a wire to the HT antenna connection.

By connecting a ¼-wave  wire (~19” for 146MHz) to the antenna connector outer terminal, we create a physical counterpoise in place of the indirect ground plane through the operator’s body.

This gives superior performance under difficult conditions and is easy to do.

These physical counterpoise wires are known as rat tails or tiger tails due to their appearance.

Rat tail counterpoise installation is quick and easy.  Simply unscrew the antenna, slip the rat tail over the connector and re-attach the antenna

tiger tail1

tiger tail2

tiger tail3

tiger tail4

The rat tail can simply hang down in a gentle arc where it won’t be much in the way of anything. Even better, you can hold the wire out  in the direction of communication.  Gain/directivity is achieved Continue reading →

What You Need to Know About Electrolytic Capacitors

AF5NP Capacitor, Component, Electrolytic, Repair, Troubleshoot

Capacitors are a fundamental electronic component and their property of capacitance in Farads (F) are a core part of radio circuitry.

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The basic capacitor is a pair of metal plates separated by some form of dielectric insulation.

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Electrolytic capacitors are special because they have a lot of capacitance—hundreds or thousands of microfarads (µF)—in a relatively small package.

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Electrolytic Cap
Electrolytic capacitor assortment

Most big electrolytic caps are in the radial package where both leads are on one side. The axial package with one lead on each end of the cylinder are sometimes used.  See axial vs radial.

Aluminum electrolytic capacitors provide the highest values while remaining relatively inexpensive so are commonly encountered in radio and electronics.   This is possible because of wet chemistry; specifically, an electrolyte solution as part of the dielectric layer between metal plates.  Aluminum foil is the primary conductive surface and the electrolyte is part of the separating insulator.

Al-e-cap-construction.jpg

Aluminum electrolytic capacitors are frequently used in power supply circuits such as shown below, and are found in most every type of electronics:

Figure T-2

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OK, so this is wet chemistry but a dry topic. Why are we boring you with all this?

There is a practical point here for those of you who are handy or brave enough to tackle your own electronics repair; hams tend to be a DIY group.  Be advised that many functional problems in all sorts of electronics—not just radios—can be attributed to failed aluminum electrolytic capacitors.  We hope to encourage you to fix an expensive piece of equipment, not just toss it or pay someone to repair it for you.

Usually an easy fix with just two component leads to un-solder and then re-soldering the replacement. Diagnosis Continue reading →

Indirect RF Hazards

AF5NP Antenna, Controlled, Duty Cycle, Environment, Evaluation, Exposure, Hazard, HF (High Frequency), Ionizing, Limits, MPE, Protection, Radiation, RF, Safety, SAR, Uncontrolled, VHF/UHF

Part 3 on Safety

Safety is an important topic in ham radio.  There are 11 questions on electrical hazards in the USA Technician class license exam pool, 13 questions on tower safety and associated grounding, and 13 questions on radio frequency (RF) hazards.

Part 1 on general electrical hazards and Part 2 on contact RF hazards were posted previously.  This post will address indirect RF hazards.  In case you are not familiar with the specifics of RF energy, refer to our post on the subject.

Here we are concerned about non-contact RF energy.  A long and involved topic (sorry about that) but full of useful detail.

While it involves radiation, RF energy radiates at lower wavelengths where it is least hazardous.

radiation spectrum.JPG

From the electromagnetic spectrum diagram above we see that radio waves are on the low end of energy levels.  As the frequency increases (wavelengths decrease) the energy in electron volts increases exponentially.  Energy above 250eV (or so) is ionizing, which in addition to radiation burns can cause cell damage and mutations, leading to cancer and other maladies, as would radioactive material.

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Fortunately for hams, all radio frequencies are well below the ionizing radiation energy levels.

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Ham radio operators are radio  active, not radioactive. 🙂Amateur radio activeNow just because RF radiation is non-ionizing doesn’t mean it is completely safe.  Besides the direct contact hazard, exposure to radio frequency energy may cause localized tissue heating, particularly in the eyes and male reproductive area (here’s where a lady ham has an advantage, hihi).  Non-thermal effects of RF radiation are being studied constantly because, while compelling, they are somewhat ambiguous and unproven.

Because RF energy has this radiated exposure risk, rules and regulations have arisen to protect people from such hazards.  In the USA this is done at the federal level by both the FCC (radio communications) and OSHA (occupational).  There are also guidelines for RF radiation published by the ARRL and the IEEE.  Internationally, most countries apart from the US have similar guidelines, as does the World Health Organization (WHO).  References to some of these are given at the end of this presentation.

Specific to US radio amateurs, the FCC instituted RF field exposure limits called Maximum Permissible Exposure (MPE). Continue reading →

Silent Key (SK)

AF5NP Ham-Speak, SK (Silent Key)

The term SK is another bit of ham-speak that is not obvious to new or prospective radio amateurs and you should know what it means.

While widely used in ham circles, SK has two differing meanings.  Specific to CW work, SK is a Morse code procedural signal (prosign) for indicating a final transmission in a message or QSO.

More generally, SK means silent key, a term of respect for a deceased ham.  It’s a classy way to denote the loss of a member from the radio amateur community.  Hams will sometimes give tribute to SKs in their biographies as influencers or Elmers.

Silent Key is a dignified term going back to wired telegraphy, adopted in the early days of ham radio when only Morse code was used to honor a CW operator whose key will not be heard again.  This tradition has carried over into modern times when voice, video and data have been added to the amateur radio repertoire.  Considering the prosign SK as “end of transmission,” the double meaning of SK is very fitting.

The ARRL monthly magazine QST prints a list of Silent Keys reported to them.

QST SK

QRZ also has a page dedicated to listing Silent Keys….

QRZ SK

….and they will also note such on Continue reading →

Contact RF Hazards

AF5NP Hazard, Protection, RF, Safety, Skin Effect

Part 2 on Safety

Safety is an important topic in ham radio.  There are 11 questions on electrical hazards in the USA Technician class license exam pool, 13 questions on tower safety and associated grounding, and 13 questions on radio frequency (RF) hazards.

Part 1 on general electrical hazards was posted previously.  This post will address contact RF hazards.  In case you are not familiar with the specifics of RF energy, refer to our post on the subject.  A future post will cover the broad context of non-contact or indirect RF (radiation) safety.  Both direct and indirect RF exposure will heat living tissue.

RF burn2

Here we are concerned about direct contact with a RF signal of significant energy.  This might happen if a person or animal touches a conductor carrying RF energy.  This most likely happens when someone touches an antenna element while the radio is transmitting.  It’s painful…..as in, full of pain.

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Another risk of RF contact is while working on live transmitter equipment or an antenna connector.  It’s not hard to accidentally key the mic with your hands inside a transmitter enclosure or while touching an un-mated RF connector.

Human skin contact with live RF conductors is a painful experience above very low power levels. What makes it painful is that RF energy heats and damages tissue beneath the outer layer of skin, resulting in 2nd and 3rd degree burns.  Not normally superficial, RF burns heal slowly.

RF BURN

Without going into physiological details, we will simply quote one person’s testimony: “For the first half-hour or so, all I could see was a tiny dot on my fingertip, and I didn’t think much of it. As the day went on, it hurt more and more, and by the end of the day there was a big, deep, dark blister that covered my entire fingertip and hurt like hell. It took weeks to heal.”  There are some good references to RF burns at the end of this post, including a number of personal experiences.

There are a several factors involved in RF burns:  Power level (available energy), contact surface area (more is better) , grounding/return contact (less is better) and radio frequency (the body absorbs more energy at certain frequencies).

How much power is needed to create a RF burn?  Again, it varies.  There are reports of people getting fingertip burns by touching the top of the antenna connector on a relatively low-power handheld VHF transceiver (5W) and keying the PTT button with no antenna screwed in.  Obviously, a 100W HF transmitter can do much more damage than this.  You don’t need to touch a 50kW AM broadcast antenna to get a nasty RF burn.

Treatment of RF burns are just like any other type– run cold water over it and/or ice it and seek medical attention.  Avoidance is the best defense.  Of course, most RF burns are unintentional so the best we can do is make you aware.  Stay safe!

Direct RF burns cause more immediate tissue damage than indirect radiation but there is a hazard with both;  be looking for a future posting in indirect RF hazards.

RF burn references

Ham radio school

Forum with several detailed experiences reported

eHam My Very First RF Burn! interesting with experiences of many hams

EEVblog forum how does RF feel/taste? how about rf injury?

Compilation of various research studies

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RF burn3.jpg

No Privacy

AF5NP Encode/Encrypt, ID, Privacy

New or prospective hams should know that there is no expectation of privacy in amateur radio.  Anything that you communicate legally can be received by other people.

Ham radio involves transmitting intelligence (voice, Morse code, text data, pictures) to be received and understood somewhere else.  By its nature when you transmit a RF signal it goes out into the world (maybe beyond) where anybody with the proper equipment can receive it.

If you are transmitting on a repeater or other well-used frequency someone else is likely to copy you.    However, the chances of someone monitoring a random frequency and mode is rather slim.  People scanning repeaters or tuning around the HF bands may listen but if what they hear isn’t interesting they may move on.  So the likelihood of your QSO being listened to depends on frequency, mode, and content.  Basically, others can listen but this doesn’t necessarily mean that they are doing so.

Hams cannot legally encrypt or disguise their messages for privacy as this violates rules against secretive transmissions.

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The two reasonable exceptions are when sending control commands to orbiting amateur satellite repeaters and when operating a hobby model such as a RC airplane.

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Digital (RTTY, PSK, JT, FT, Olivia and the like) and video (ATV, SSTV) signals cannot be interpreted by ear so there is some privacy from the general public listening in.  But anyone with the right equipment can decode these and follow along.  While these modes are technically encoded, they are not secretive because they are commonly used.

You also cannot secure privacy via anonymity.  Stations at both ends of a message must legally identify themselves

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Of course, if someone really wants to be secretive and violate US amateur radio Part 97 rules by encrypting their transmissions or not identifying, that is a possibility.  We hope that all hams choose to play it straight and follow the rules, in which case anything that you say over the air can be picked up.

Our best advice is to not worry about privacy.  Don’t say anything over the air that you don’t want others to hear.  If you must do so, use a different means of communication.

Wavelength

AF5NP RF, Wavelength

We recently discussed radio frequency (RF) signals and radio waves.  Now let’s review the related concept of wavelength because it is often used in ham radio.

At any frequency it takes a certain amount of time for a wave to complete one cycle.  A cycle is any repeating feature of the waveform.  Radio waves have sinusoidal form.

Wavelength cycles

Because the wave moves over time, it travels a certain distance in any given period.

Wavelength distance

Wavelength is the distance a wave travels in one complete cycle.  We measure this in meters.

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Viewed in 3D animation, it’s not only cool to look at, but may help us understand it a little better.Wave animationThe red and blue sine waves are the electric and magnetic fields oscillating at right angles to each other at the radio frequency.  The constant wavelength (λ) follows E field peaks between the X and Z axes. The radio wave is moving along the Y axis (lower right).

Radio waves are typically oscillating millions of times per second (MHz).  They are traveling near the speed of light (300 million meters per second).

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The time it takes for a radio wave to complete one cycle equals the speed of light (approximately) divided by the radio frequency:

300m.JPG

Simplifying the math shows us that to calculate wavelength, we simply divide 300 by the frequency in MHz.  The millions (Megas) cancel each other out.  The resultant wavelength is in meters.

T3B06-2018For the center of one popular HF band the wavelength would be:  300/14.2=21m  See how it works?

The wavelength at the center of our most common VHF radio band would be:  300/146=2.05m   

Logically, higher frequencies complete one cycle in less time than lower frequencies.

Wavelength long short.png

This means that the wavelength of higher frequencies is shorter than that of lower frequencies.  Frequency and wavelength are inversely proportional.

T3B05-2018

Wavelength is simply an inverted way of thinking about radio frequency; they are mathematically related.

It helps to visualize the two overlaid on a RF spectrum chart:

RF-spectrum-RF-Page.jpgYou can see how the yellow wavelength values above the blue frequencies increase in opposite directions.  Note also how the values line up in 1/10/100s and 3/30/300s per the speed of light relationship.

Wavelength becomes practical when dealing with antennas where element lengths need to be some fraction of a particular RF wavelength.

Wavelength is also the most common descriptor of radio frequency bands.  We will follow up with this in a future topic.

Wavelength is not terribly mystifying but it isn’t very obvious either.  Hopefully this gives you a better grasp of this important subject.

A fairly technical yet easily understood video relating frequency, wavelength and the speed of light is worth watching here.

Control Operator

AF5NP Control, License, Operator, Station

The control operator is an important concept in ham radio.  There are many license exam questions involving the control operator so we want to spend a bit of time on the subject.  While legally specific to USA radio amateurs, some of these rules may apply in other countries as well.

A ham radio station control operator is the licensed amateur who is operating a station’s transmit function.   Any unlicensed person or even your cat can manipulate station controls with respect to receiving but when it comes to transmission of any signals, there must be a licensed operator in control of the transmitter.  This is a fundamental rule of the FCC to regulate ham radio transmissions in the US.

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Savvy readers might wonder how this applies to repeaters and more sophisticated stations operated remotely.  Control operators are still required for all amateur transmissions.  Always a control operator.

With repeaters it is done automatically through a sophisticated repeater controller that follows the rules.  However, the repeater station licensee is still responsible and is considered the control operator while using automatic control.

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With remote control the control operator is simply using some method to indirectly control radio settings, including the transmit function.  They are still responsible for transmitter operation even if they are not physically near the radio.

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Even if the radio control point is remote from the transmitter, a licensed control operator must be present.

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The control operator need not be the one speaking into the mic, using a Morse key or typing a digital message; as long as they are in direct control of the transmitter, someone else can be doing the communicating. That means your friend or relative can do the talking as long as you, the control operator, can intervene if something goes wrong.

Guest under supervision.jpg

When you get an amateur radio grant in the US, you actually receive two licenses:  One is your operator license and the other is the station license.  Both are associated with your unique call sign.

License example

More commonly, when a ham is transmitting, the operator and station are one and the same, as when KF5ZFD makes a 20m SSB contact in another state from their home location using their own transceiver and antenna.

So why do American hams have two separate licenses?  We’ll try to explain here.

Firstly, there are three basic types of FCC-issued Amateur station licenses.  Only  the familiar operator/primary station license is for individuals.  The other two—club and military recreation licenses—are stations intended to be used by licensed individuals.

This means that a ham would use their operator privileges to be a legitimate control operator of a club or military recreation station.  In this case the applicable call sign would normally be the station’s, not the operator’s.

Secondly, hams are not restricted to their own station equipment (radio, antenna, accessories).  You might visit another ham’s shack and operate their transceiver.  In this case, the applicable call sign could be Continue reading →

Radio Frequency (RF)

AF5NP HF (High Frequency), RF, VHF/UHF

Radio signals are sent via radio waves, which are a form of electromagnetic energy or radiation. T3A07-2018

Recall that a radio wave consists of both electric and magnetic fields oscillating at right angles to each other.EM Fields.png

 

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Combining electrical and magnetic gives us the term electromagnetic.

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Like all waves, radio waves vibrate or oscillate at a specific rate or frequency.

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ewaves.gifThis vibration frequency is normally measured in cycles per second and its units are Hertz.  T5C05-2018.pngRates of oscillation in radio work are thousands and millions of Hertz (Hz).  With standardized metric prefixes for SI units , this means practical radio frequencies are in kHz, MHz, and GHz.

The common and familiar term RF is short for radio frequency.  It’s really an adjective, not a noun.  While we may say just RF (“You have a big RF leak, there, Fred”), we really mean radio frequency energy or signals.  RF is not a thing in and of itself.

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So what is a radio frequency , then?  They are a large chunk of frequencies in the middle of the electromagnetic spectrum (the range of possible frequencies from 0 to measurably high).  Technically radio frequencies start at low audio frequencies and run up to just below infrared light, basically 30Hz-300GHz.  Different sources specify other upper/lower boundaries because a more practical range is the low frequency band up through microwaves.  However you define it, this range of frequencies is  known as the radio spectrum.

RF Spectrum.gif

While hams can use very low frequencies on one end and go up to microwave frequencies at the high end, the more common radio amateur frequencies are in the shortwave, VHF, and UHF range.

We will follow up with detailed posts on the important topics of RF wavelength and amateur radio bands, along with RF safety.  Coming soon to Newhams.info; stay tuned.

 

License Expiration and Renewal

AF5NP Call (Call Sign), Expire, License, Renew(al), Vanity Call

Relevant to American hams only:  US amateur radio licenses are valid for ten years (10 year grant term).  License term or renewal rules are likely different in other countries.

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So a newly-licensed ham doesn’t have to worry about renewal for a long time to come. Various organizations will nag you via email, postal mail, and on QRZ when your license expiration is on the horizon (“This license expires soon.  Renew Now!”).  So if you intend to keep your license you should have plenty of warning and opportunity to renew.   You can renew within 90 days of expiration but no sooner.

If, for any reason, you let your license expire, you have a two year grace period during which you may file for reinstatement.

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However, you may not operate (transmit) whatsoever once your license has expired.

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Renewal or re-instatement (within the grace period) is simple and straight-forward.  No cost and no re-testing required.  Unlike the old days, you do not need to prove activity for renewal (showing log entries).  Make renewal application on the FCC ULS website.  If you have trouble navigating the process, there are renewal services eager to do the work for you (for a reasonable fee).

Direct renewal via ULS should be very fast.  Your status with new expiration date should show up on the ULS database shortly after processing.  If previously expired, do not transmit until you see a new expiration date a decade away (much like your original license experience).

After the 2 year grace period has passed, the FCC will cancel your license and make it available for reissue. If your license gets canceled, your call sign is lost and you must pass an exam again to get re-licensed. After you have obtained a new license and call sign, you may apply for your old call sign as a vanity call, if it is still available.

Not all new hams are brand new to the game.  Sometimes hams let their license expire due to neglect or lack of interest.  More commonly a ham will find that a career and family interrupt their interest in amateur radio and they just let it slide.  Then years— perhaps decades—later they catch the bug again and want to get back into ham radio.  In some ways they are a new ham because many things have changed (rules&regs, technology).  On the other hand, the basics are familiar so they aren’t totally green.

There is good news for previous holders of General, Advanced or Extra Class licenses.  If you can show Continue reading →

Electrical Hazards

AF5NP Battery, Capacitor, Circuit, Circuit Breaker, Electrical, Fuse, GFCI, Hazard, Protection, Safety

Safety is an important topic in ham radio.  There are 11 questions on electrical hazards in the USA Technician class license exam pool, 13 questions on tower safety and associated grounding, and 13 questions on radio frequency (RF) hazards.

Several of these have been used by us previously but in retrospect we should have given the safety topic more airtime, pun intended.  New hams are unlikely to have antenna towers so we don’t plan to discuss tower safety much.  That leaves electrical and RF hazards to cover.

This post will address general electrical hazards and related safety; a future post will focus on RF hazards.

Radios and accessories are electrical devices so let’s start with the most obvious hazard: electric shock, which is caused by current flowing through a human body.  Current is useful in electronics but harmful when flowing through a person.  Current can disrupt heart and lung function at even low levels.  It can also cause unwanted muscle movement, or prevent it (can’t let go).  At higher levels, electric current will damage skin and internal organs.

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There are many factors in electric shock and there are other electrical hazards.  But this is a big one and you should avoid touching live circuits.

Fire is another electrical hazard.  When too much current flows in conductors, the wires can get very hot and ignite combustible material.  In fact, the US National Electrical Code is actually a document of the National Fire Protection Association (NFPA), not a government agency.

To limit the risk of fire and other damage, every power circuit needs some form of  protection.  Fuses are quite common; their internal metal melts at a pre-determined current to disconnect power.

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Also, a smaller (amp rating) fuse can safely be inserted in a protective circuit but one should never put in a larger one.  A fuse is sized to the circuit requirements and wiring  is sized to the fuse.  So a higher-ampacity fuse will not properly protect the wires or the circuit and serious overheating may occur in both AC and DC power circuits.

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In addition to one-time use fuses, circuit breakers are another popular form of circuit protection; these may be reset and are often used as an on/off switch.

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While fuses and circuit breakers do not directly provide shock protection, they may do so Continue reading →

Repeater Reverse

AF5NP Emergency Communications (EmComm), Offset, Operation, Repeater, Reverse, Split, Transceiver, VFO

If you aren’t familiar with VHF/UHF repeater operation, now is a good time to review it here.  Repeaters are frequently used for chatting with local hams, regular nets, and EmComm use.

An occasional problem with repeater operation is when a weak transmitter doesn’t have enough power to keep the repeater’s squelch open.  That is, you can tell someone is there but hear little or no signal.  Could be that the transmitter is in a sheltered location, doesn’t have a good antenna, or using too little power.

For whatever reason, they can’t break through with a strong enough signal to be heard.  If you suspect this is happening, you can try listening to them directly instead of through the repeater.  It’s possible that you are closer to the weak transmitter than the repeater is.

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Many hand-held radios (HTs) and mobile VHF/UHF transceivers support this with a repeater reverse function, typically by pushing a button on the radio.

Kenwood Reverse

Recall that a repeater re-transmits what it hears on a different frequency.  The difference in transmit and receive frequencies is called repeater offset and this minimal difference is needed to allow for sharp filtering between them so that the strong transmit signal doesn’t damage sensitive receiver circuitry.

By selecting reverse on a transceiver you then listen to the repeater input frequency instead of its output.  In this manner you can get the weak transmitter’s true signal strength and quality, not what the repeater re-transmits.  This assumes that you are receiving better than the repeater, which is a possibility but not a certainty.

Useful when you want to see if a weak signal Continue reading →

Dummy Load

AF5NP Dummy, Heat Sink, Impedance, Load, Resistor, Test/Testing

Radio amateurs should be familiar with the term dummy load, which is a RF-friendly substitute for an antenna when testing a transmitter or piece of equipment such as a Watt meter.

Dummy1   Dummy2   Dummy3

A dummy load is somewhat generic, also having industrial and commercial uses.  As applied in ham radio, it electrically simulates an antenna to allow a transmitter to be tested without radiating radio waves, typically at 50Ω to match transmitter output impedance.

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Dummy loads are rather simple—  just a big resistor and some way to dissipate heat, all in a package that must be non-reactive, meaning it provides insignificant capacitance and inductance.

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Why must a dummy load be non-inductive?  Because of impedance (practically speaking, AC resistance), which increases with frequency based on the formula of inductive reactance XL=2πfL.

XL

Most common power resistors are wire-wound, which have significant inductance.  So RF dummy loads must use resistors with little or no inductance.

As an example, this four-resistor series combination using common Dale metal-clad resistors measures 49.4Ω at 0Hz (DC).  Sounds like a perfect dummy load, right?

DSCN4385

Unfortunately  it also has Continue reading →

Flat Ground Strap

AF5NP Conductor, Ground, Impedance, Reactance, RF, Safety, Strap, Wire

Ever wonder why RF grounds should be flat straps and not regular wires?

This is because ordinary wires are not good conductors at frequencies higher than 50-60Hz. This complicates wiring and bonding requirements.

Impedance (effectively, AC resistance) of a conductor increases with frequency and length due to inductive reactance.  The higher the frequency, the greater the impedance.

XL

All conductors have some measurable inductance, and it doesn’t take much to yield significant impedance.  At KHz or MHz frequencies, long round wires might present hundreds or even thousands of Ohms impedance; not suitable for grounding.

A good ground has less than one ohm impedance.  This is a genuine safety issue.

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Since inductive reactance increases with frequency and length, safety grounds and module bonds need to be something other than long round wires when radio frequencies are involved.

When high frequency grounding is required, use short, wide, and flat conductive straps.  The high aspect ratio minimizes electrical inductance vs. a round wire, as does a short conductor.  This lowers the ground wire’s impedance at higher frequencies.

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So now you know.  Keep it flat and short (KIFS is a lousy acronym).

It’s not just a suggestion; this one might just bite you if you don’t heed the guideline!

Impedance

AF5NP Impedance, Reactance, Resistance

Impedance is an important subject in amateur radio so we want to spend a little time discussing it here.  Several topics on this site will involve impedance so it’s good to have this basic concept well understood.

In ham radio work we deal with impedance in transmission lines, antennas, transmitter outputs, receiver inputs, microphones, speakers, headphones, and other devices.  Impedance matters everywhere a signal couples to something different.

Basic resistance (R) is what opposes current in a DC circuit, and all components have measurable resistance.

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But things get more complicated in AC circuits.  Capacitors and inductors (coils) oppose change.  This includes alternating current, a characteristic of audio, video and radio frequencies.   The properties of capacitance and inductance have well-defined opposition to AC which varies by signal frequency.

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All components have measurable capacitance and inductance so there is always some reactance (X) in a circuit.  There are two flavors of reactance: capacitive and inductive.  Interestingly, they respond oppositely to signal frequency.  Inductive reactance (XL) goes up with frequency while capacitive reactance (XC) goes down.

When you add the constant resistance in a circuit to the capacitive and inductive reactance, the result is impedance (Z=R+jX).  In broad terms, it can be considered “AC resistance”, which is legitimate when we don’t care about the complex phase angle part of the equation.  Resistance plus reactance equals impedance (Z).

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Like DC resistance, impedance (AC resistance) is measured in ohms.

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OK so far?  Click on the many hyperlinks in this article for more detail, along with helpful links below.  Don’t worry, you only need to grasp the basics here; high-level math is not necessary for a working knowledge of impedance.

Now that you know what impedance is, the next important thing to understand is that when an AC signal interfaces with a new circuit, the impedances should match.

When impedance of a source (ZS) equals the load impedance (ZL), the best possible signal coupling occurs. Conversely, when impedances are not the same, signals couple poorly.

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The maximum power-transfer theorem says that to transfer the maximum amount of power from a source to a load, the load impedance should match the source impedance (ZS=ZL).

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Good examples of impedance matching are: audio amplifier output to speaker (8Ω); transceiver RF circuits to antenna feed line (50Ω); microphone to audio input (2000Ω).

Impedance matching can be accomplished by Continue reading →

QSL

AF5NP ARRL, Card, Contact, eQSL, Etiquette, Green Stamps, IRC, Log, LoTW, QSL, QSO

The final courtesy of a radio contact is acknowledgement of the QSO (radio contact).

g2c09

QSL is an old brevity code meaning, “I acknowledge receipt”.  Back in the early 1900s when passing messages was a main function of amateur radio (whence the Amateur Radio Relay League or ARRL), the term QSL made a lot of sense.  Today you may hear a ham speak or write QSL to let you know they received something.

The term QSL now more commonly means to confirm a radio contact.  Early on this was done mainly with postcards.

5nk

Some hams still do send out QSL cards, or send them in reply or if requested.  Collecting cards is a fun aspect of ham radio.  Many cards are interesting or unique.

Besides tradition,  a sense of satisfaction, and general fun, QSO confirmation in the form of valid QSL is a basic requirement for most operating awards.  This may not matter to you but many other hams are eager for your QSL, particularly if they are requesting one.

All hams should provide some form of QSL for all contacts except for routine local ones.  Information in the QSL should include the station call signs, date and time (UTC), band/frequency, mode, signal report, and sender’s location details. Good logging is essential for this and a QSL function is often supported by computer logging utilities.

You can determine how to exchange QSLs with a particular station from their QRZ profile if they have one set up (most active hams do).

Details about QSL cards are given further below.  Mailing cards can get expensive.  While the cost of printing the cards is not so bad, postage adds up, particularly when sending internationally.  Bureau (BURO) services to send/receive cards internationally reduces cost somewhat but is still pricey and response time is generally slow (months to years).  Alternate methods of  providing a QSL have arisen out of the need for keeping costs down.

Non-card QSLs are all electronic in nature, exchanged via internet connection in some manner.  We will briefly mention three here.  You can search for others Continue reading →

Don’t Be a Lid

AF5NP Amateur Radio, CB (Citizens Band), Lid, Operator, Police/Law Enforcement, Prohibited, Voice

“Lid” is ham-speak to denote a poor operator; one who is inept at the practice of the radio amateur art.  It is someone with very poor operating technique, a newbie or an experienced ham that acts like a neophyte. This old term likely originated from the days of wired telegraphy.

A previous post entitled, What Can I Say?,  presented more don’ts than dos, which was appropriate considering the topic.  This is a good time to review it.

In addition to those prohibitions, we’ll expand on the topic and add a few more things a good ham doesn’t do, assuming you don’t want to be known as a lid.  Most are things a good ham should avoid saying.  In fact, this article was originally entitled, What Should I Not Say?

There are some bad habits certain hams need to break, mainly because it demonstrates ignorance and carelessness.  Other amateurs may not take you seriously if you practice these things.  Numerous ham websites list pet peeves containing these bad practices (a few are linked below).

Some liddish behavior is understandable or excusable in a brand new ham but habits form quickly.  These are generally frowned upon and the perpetrator may find themselves publicly shamed (in a hammy context).  Don’t let it happen to you!

Here is a short list of things a ham should not do:

  • Use of CB lingo and police/public safety codes.  “10-4″,”what’s your 20?”, and “breaker” are particularly egregious.
  • Calling CQ or another station on an occupied frequency.  This is the worst form of QRM.  Hams should always ask if a frequency is in use (QRL?) first.
  • Checking into a net or answering a CQ without identifying phonetically.  But once you are acknowledged you should ID without phonetics.
  • Partial phonetics is also bad form (e.g., KG5-alpha-bravo-charlie).
  • Talking too far from or directly into the mic.  See our microphone technique topic.
  • Using the term “broadcasting”.  Hams never, ever broadcast; they transmit.  The word broadcast has a very particular meaning to the FCC.

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  • Using too much power or audio level (splatter) on digital modes
  • Adding an S to 73.  73 by itself is fine, but pluralizing it (73s or 73’s) is the equivalent of saying “best regardses”, which doesn’t make sense.

73

  • Calling your small VHF/UHF radio a Handie-Talkie.  HT means handheld transceiver, not Handy Talkie.

This is a handheld transceiver ⇒       zys-ft-60r

This is a Handie-Talkie ⇒  170px-Portable_radio_SCR536     See the difference?

  • Briefly keying your mic on a repeater without ID.  See our topic on Kerchunking.
  • Calling CQ on a VHF/UHF repeater.

Funny CQ 2m

If you want to talk to somebody/anybody, simply ID and ask for a QSO.

  • Over-use of Q-codes and other unique ham lingo.  Makes sense in CW work but not on a local VHF net.
  • Saying “over” on a repeater.  The closing squelch and courtesy tone let everybody know that you are done transmitting.

All of these are bad practice; lid-like behavior, although only a few are likely to earn Continue reading →

CQ

AF5NP Contact, CQ, Frequency, QRL, QSY

CQ is ham-speak for “calling any station”.  For all modes— voice, Morse, visual, or digital, it signifies a radio amateur looking to make a contact.

The basic, general CQ means looking for any station to respond.

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It can be refined (a directed CQ) to be more specific, often a location.  Common examples are out-of-country long distance (CQ DX), a particular prefix, country or state (CQ VT), a contest or event (CQ SOTA), or perhaps a CW specialty such as using a straight key (CQ SKCC).

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When you hear a station calling CQ, it’s your chance to work them.  Respond by sending their call sign and then your own, much like on a VHF/UHF repeater.

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If a ham doesn’t hear any activity or anyone calling CQ it could mean the band is dead… or it could be a good opportunity to go fishing for a contact by calling CQ.  New hams should get some experience with every new mode before calling CQ themselves.

When calling CQ , make sure that you are permitted to operate on the frequency you have chosen (and keep away from band edges).  Also make sure that the frequency is not in use.  Do not assume that if you hear quiet at a valid frequency that it is free; it could be that another ham is listening to a station you can’t hear.

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Always check if a frequency is in use before calling CQ.  The proper way to do this is to simply ask by voice with your ID (phone), or send the Morse prosign QRL? with your call (CW mode).

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If someone else is working that frequency, they will let you know.  Move to another frequency (QSY) should you receive a response to QRL.

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If nobody replies to your QRL, go ahead with your CQ.  There is no official CQ protocol but there are many suggestions out there.  Continue reading →

Your Grid Square

AF5NP Grid Square, Location, QTH

If you are active on HF or non-repeater VHF/UHF frequencies, you should know your operational grid square when making contacts.  Many hams need to know your exact location for logging and awards purposes.  The grid square system was adopted by the IARU for specifying amateur radio station location in a relatively small area.

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The planet is divided up into 32,400 grid squares roughly 100mi wide by 70mi high (in continental USA) per the Maidenhead Locator System.  More detail here.

Basically, our planet is divided into 18×18=324 fields identified by two letters (AA-RR)
Each field is 20° longitude (east-west) and and 10° latitude (north-south). The first letter represents longitude and the second latitude as shown below.

Maidenhead fields

Each field is sub-divided into 10×10=100 squares starting again in the southwest counting north in columns of tens and shifting east for the next ten.

If you look carefully at field IO above (encompassing most of the UK and Ireland), you can see this refined grid.  It looks like this in a more geodetic (less flat) view:

 

maidenhead field IO

Here you can clearly see square 00, lower left and 99, upper right with the other 98 squares everywhere in between.

This combination of field plus square gives us the basic grid square system.  It follows the specific format as shown below.

Maidenhead detail

Of interest to most readers of this site, the continental United States (CONUS) is Continue reading →

Electronic Connector Types

AF5NP Connector, Electronic

Earlier we reviewed RF connector types commonly used in ham radio applications.

There are also a number of common electronic connectors used in amateur radio that you should be familiar with to have a working knowledge of equipment interconnect and interfacing.

Presented below are eight common non-RF connector types.  Some are for power but most carry audio or control signals between devices and equipment.

D-sub

D-subminiature connector commonly called D-sub.  Name derived from its general “D” shape with one side longer than the other.

Five shell sizes 1-5 (A thru E).  Standard and high density for all five shell sizes.   9-50pins standard, 15-78pins HD.

Ham radio general purpose use such as control interface; also for serial (RS-232) communication plus video between PC and monitor.

dsubs     D-sub conv

d-sub ortho   d-sub sizes

Reference here.

g6b12

RCA

An old, simple, and cheap design still widely used for audio and video signals.  Sometimes called phono plug and jack.

Typically used for L and R stereo audio channels with white and red color coding.

Reference here.

g6b14

Phone, 1/8″ (3.5mm) and 1/4″ (6.35mm)

Another old and reliable design still widely used for audio signals.

1/4 standard and 1/8 mini plug/jack sizes are the most common.

phone compare     phone function

phone jack2     phone jack1

Two wires for mono signals, three for stereo.  A four pole version is occasionally used with two ring contacts.  In ham radio use this might be a HT with speaker, mic and PTT switch; three functions sharing a common fourth terminal.

Reference here.

Mini-DIN type

DIN is an acronym for Deutsches Institut für Normung, the organization for German national standards.  The DIN standard encompasses a wide variety of electrical and electronic connectors. As used in ham radio the specific subset of Mini-DIN is what we normally encounter.

The Mini-DIN is 9.5mm diameter (3/8″) and can range from 3 to 8 pins with unique arrangements:

DIN rangeDIN4DIN5DIN6DIN7DIN8

din m     DIN6F

Used on many modern transceivers for audio, data and control interface. Example below:

DIN ham

Reference here.

g6b17

Modular (RJ45, RJ11) Continue reading →

Distress Call

AF5NP Break-Break, Distress, Emergency, Emergency Communications (EmComm), Mayday, SOS

It’s unlikely that you will hear a radio distress call but hams should know how to respond to one.  Hopefully you will never need to send a distress call yourself but it’s best to know how to call for help in an emergency.

G2B02-2015

While some situations may be questionable, if life/health/property are genuinely threatened, it merits a distress call.  Basically, if you would want police, fire, or ambulance response, it’s a distress scenario.

Obviously if one is in town with a telephone nearby, the proper response is to call local emergency services (in USA, dial 911).  But if the phones are down or someone is very remote, radio may be the only way to communicate.

Distress calls are formally done by voice mode using the term Mayday-Mayday!  SOS is the CW mode or Morse visual equivalent of Mayday; you are even less likely to encounter it.

If you hear a distress call:

First of all, stop whatever you are doing (QSO, or whatever) and cease all transmissions to avoid interfering with the distress call or a response.

Second (very important!), write down everything you hear related to the distress call.  Under duress, people tend to forget things and stress will be high at both ends of the radio.  Details about the incident are crucial for sending help.  Include the date, time, frequency and mode.

Third, see if anybody else responds. Perhaps there is another station in a better position to react (location, facilities, etc.)  If nobody else does, briefly ID and ask what is the nature of the incident.  The distress station may not have a call sign or know proper radio procedure; be prepared to work with a non-ham at the other end.  If time permits, confirm the details you wrote down with the distress caller.

Fourth, determine how to help the distress station.  You need to get them help, but that depends on the location and nature of the trouble.  If unclear or uncertain, contact local emergency services and let them help you sort it out, even if the distress is far away.  In any case you must relay important detail such as the type of emergency, how many people are involved, and the distressed party’s location.  The Mayday caller may also provide specific guidance if they are trained and knowledgeable.

Lastly, maintain contact with the distress station and emergency responders until help has arrived and the danger is passed.

Know also that in a genuine emergency/distress situation, you can violate normal protocol and rules to assist another station, at least in the USA (probably most other countries as well).  If it requires using a mode, frequency, or power level for which you are not authorized, do it!

G2B12-2015

To send a distress call should you ever need to:

If the phones are down, use your VHF/UHF radio on a local repeater or national simplex frequency where other hams are likely  to copy you (choose the most active local repeater).

If you are very remote and there is no chance any line-of-sight radios can pick you up, Continue reading →

Change Your Call Sign

AF5NP Call (Call Sign), Change, Extra Class, FCC, General Class, Technician, Vanity Call

So you just passed the Tech license exam and your new call sign just appeared on the FCC ULS database.  Congratulations!

Let’s say you were assigned KG5ZXY, but that’s both hard to remember and hard to pronounce phonetically.  Or maybe you’ve been licensed for years but just don’t like the call sign you have.

Either way you would really like something different; maybe a catchy one or a call that has your initials or something shorter or easier to remember.  Don’t despair!  You can request a specific call sign if it is available, termed a vanity call.

T1C02-2018

Vanity call signs typically include alphabetical characters of personal significance (e.g., licensees initials, parts of names, hobbies, etc), or sometimes are simply chosen because they are shorter calls, or sometimes they have double or triple duplicate characters (e.g., W1WWW).

Note: this information is valid for USA hams.  Many other countries have vanity call programs but the details and rules will be different.

Now there are limitations to call signs, of course.  This is a good time to review our call sign variations topic where you can learn about valid prefixes, suffixes, formats, and quantity of characters.

It goes without saying that you cannot request a call that is already issued (for two years Continue reading →

Traffic

AF5NP ARRL, Emergency Communications (EmComm), Message, Net (work), Traffic

New hams listening in on a local net are likely to hear the net control station begin the session by asking for stations with traffic.  Seems like there never is traffic, so what’s that all about?

Traffic is ham-speak for passing messages, usually via regular radio nets.

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Messages are almost always formal, written on a form with bureaucratic detail.

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Even friendly, casual messages (“happy birthday, Aunt Edna”) are typically passed this way.

ARRL Radiogram

Such messages (traffic) resemble the old telegram format.  They go back to the very early days of amateur radio when passing messages was a primary function.  In fact, this is from where the US Amateur Radio Relay League (ARRL) derives its name.

Nowadays traffic is mainly an emergency communications (EmComm) function, although the occasional casual message is passed on.  Purpose-specific traffic nets meet regularly to pass messages to stay in practice for when they are really needed, like when there is a local or regional communication outage.  Likewise, local nets support traffic to maintain readiness.

The general traffic flow is from an originating station to a local net where the message is Continue reading →

Keep Up With Rules and Knowledge

AF5NP FCC, Technician, Training

I have enjoyed helping teach technician license classes in the past and may help with more in the future.  When you step into the instructor role you realize how much you don’t know about a subject, or have forgotten.  It’s humbling to discover that you forgot something or really didn’t understand a particular topic.  I’m an extra class operator and was surprised at how many things I forgot or couldn’t answer with certainty on the Technician exam.

So now we will discuss keeping up with rules and knowledge regarding amateur radio, and not just resting on our laurels, having passed a license exam one day in the past.  The reason the FCC requires some basic knowledge about ham radio is because we have the most privileges in the radio spectrum around the world, and we can cause a lot of trouble with that freedom.  In ham radio there is an expectation of continuous learning and that also implies that we should not forget what we already know.

There are seven broad categories of questions in exams of all three license levels.  These are:

  • Regulations
  • Operating practices
  • Electronics
  • Propagation
  • Antennas
  • Safety

Of these seven we might say that three are the most important:  Safety (first!), Regulations and Operating Practices.  That doesn’t mean the other categories are unimportant but we should probably place a priority on these three.

To reinforce the premise that we easily forget important details, let me quiz you on some Continue reading →

What’s So Funny?

AF5NP Ham-Speak, Hi, Jargon, Lingo

Something new hams need to be aware of is a less-than-obvious bit of old-timey ham-speak still in use.

You may hear a ham say, “hi or “hihi” over the air or in person or in writing, and, curiously,  their particular use of the term, “hi” is not in context of a greeting.

In ham-speak the term “hi” means laughter.  Often doubled (hihi), it’s a ham’s way of expressing a humorous response.  So when a ham says, “hi” (s)he is laughing at something.  Kind of like saying LOL in a text message or web post.

Where did this come from?  In the early days of amateur radio, CW was the only mode so all communications were in Morse code. The word HI in Morse is dit-dit-dit-dit  dit-dit, (•••• ••)which sounds like an electronic chuckle.  Quickly adopted, hams have been using “hi” for laughter decades after voice and other modes were added to our radio amateur repertoire.

We’ll wrap up with a ham joke:  Two antennas met on a roof, fell in love and got married. The ceremony wasn’t much, but the reception was excellent.  Hihi

What Can I Say?

AF5NP Amateur Radio, Prohibited, Voice

The new ham may be unsure what they can or cannot talk about over the radio.

Surprisingly, there are few limitations in the Part 97 rules governing prohibited transmission, and we will review these below.

While there aren’t any rules against discussing sex, politics, and religion, these and other controversial topics are best avoided in general radio work.  Now there might be nets or affinity groups that meet on the radio to discuss controversial things.  Participation is fine but be prepared for hecklers who don’t agree with or appreciate the topic.

Foul language is a big no-no, as you might expect:

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Best to avoid any crude words or topics along those lines.

Another prohibition is using amateur radio to do business for yourself or a third party:

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You must never be paid to use your radio, except as narrowly outlined above.

Even selling your own goods is prohibited, although there is an exception for ham gear (occasionally):

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Monthly or weekly swap nets are OK.

You should never play music or sing or whistle over the air:

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Play it safe by keeping background music or audio (including your phone ringtone) muted when keying your mic.

Unlikely that you would want to do so, but you should never use secret words or codes to speak over the air:

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Finally, never make general announcements that do not involve other hams:

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Avoid transmitting anything that might be considered of interest to a wide audience, especially a one-way message with no reply.

Common sense should prevail; avoid controversial topics, don’t cuss and don’t do business over the air.  That leaves plenty of room for things to talk about.

What Flavor of Ham Are You?

AF5NP Amateur Radio

What flavor of ham are you?  Honey-baked, smoked, prosciutto, chipped…  Just as there are many varieties of the pork meat, so there are different kinds of amateur radio ham.

Ham radio isn’t just about talking on the radio.  Radio amateurs use different modes and frequencies.  There are also many unique activities and special interest sub-sets in amateur radio.  One or more should appeal to the new or prospective ham.

We present some of these here to whet your appetite or encourage further interest in our hobby.   Maybe one of these becomes your ham radio passion or niche.  For many hams their focus changes from making voice contacts to something more specific.  Amateurs tend to be an adventurous lot and many are eager to try something new.  Radio work has a myriad of possibilities.  And for many of these, you don’t need fancy or expensive equipment:

  • Chasing DX, DXing-Working distant stations, generally outside your own country.  One of the most basic ham interests.
  • Awards- Recognition from various groups can be achieved for different accomplishments.  Two of the big ones are the ARRL worked all states [WAS] award (confirmed contacts in all 50 states) and their DXCC award (confirmed contacts in 100 countries).
  • Fox hunting- Radio direction finding to locate a hidden transmitter.  Can be competitive or just for fun.
  • Satellite operation- Using repeaters on orbiting amateur radio satellites for quick long-distance contacts.
  • ARISS- Communicating with the International Space Station via VHF radio.
  • ATV/SSTV- Amateur Television or Slow-Scan Television to communicate using video exchanges.
  • Contesting- There is no shortage of opportunities for the competitive ham. Most weekends have some sort of contest scheduled for hams to make as many contacts as possible under various modes and guidelines.
  • Digital modes- Don’t like to talk over the radio and don’t want to learn Morse code?  Digital modes can give you the thrill of long-distance contacts without a mic or key; you need only a computer and simple interface to a HF transceiver to work digital modes.
  • OTA-  Organized events to contact as many stations as possible of a particular type; Mountaintops/Summits (SOTA), Islands (IOTA), National Parks (NPOTA). Continue reading →

Technician Class Distant Contacts

AF5NP Distance, DX, Echolink, EME, General Class, IRLP, Moonbounce, QSO, Technician Class

Making radio contact over great distance is one of the more interesting aspects of ham radio.  For many radio amateurs, it’s their main pursuit.

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Working DX (ham-speak for distance) commonly means contacting a station outside your own country but Alaska and Hawaii are certainly DX stations by distance, and in reality good DX is cross-country in a large entity such as the USA.

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Unfortunately for US hams, the entry-level Technician class license permits rather limited opportunities for making radio contact beyond line of sight.  Don’t despair if you have only a Tech license and want to do more than chat with locals on a repeater.  There are six ways for a Technician licensee to communicate outside of town, outside your state, or even outside the country.  We will briefly mention these here and perhaps cover them in greater detail in future posts.

DX is commonly accomplished on the high frequency (HF) bands due to ionospheric refraction or bending of radio waves.  HF signals routinely reach the other side of the planet and places in between.  So for most hams chasing DX or just working beyond the local area means having a HF transceiver and antenna for the band(s) of interest.

The first two opportunities for Technician licensees to communicate over distance involve traditional HF equipment:

1) USA Technician class operators have privileges to operate CW mode (Morse code) on 80m, 40, 15m and 10m HF bands with a 200W power limit.  This is how hams used to get started in amateur radio and while CW is still quite popular, it is intimidating to many new folks.  So opportunity #1 may not be appealing to many Techs unless they want to learn Morse code (a fun skill, by the way).

2) USA Technicians also have SSB voice and  digital (data) privileges on 10m, again with a 200W limit.

T1B06-2018

This is the only HF voice privilege for this class and the frequency range is very narrow.  The data mode privilege is really helpful here because it allows Techs to work popular digital modes such as JT, FT, PSK,  Olivia and MSK.  However, 10m propagation is highly dependent on solar activity.  The band can be inactive or slow for weeks or months at a time.  So Technicians may be frustrated over a lack of activity for opportunity #2.

Tech license DX opportunities #1 and #2 above on HF bands are admittedly limited by mode and/or active band.  This alone is excellent motivation to upgrade to a General class license.  Consider this possibility.  It’s not a huge leap in learning and study to move up, very achievable for most people.

We know that the VHF and UHF bands for which Technician licensees have full privileges are generally limited to local communication because of line of sight propagation.  Repeaters and/or tall antennas can extend this range but DX is not readily achieved using normal methods.  However, there are four clever technologies that enable DX on VHF/UHF bands: Continue reading →

Clutter

AF5NP Brevity, Clutter, Directed Net, Emergency Communications (EmComm), Etiquette, Facts, factual

New hams, don’t hesitate to make that first radio contact.

Experienced hams, don’t hesitate to try a new band or operating mode.

Technician and General Class hams, don’t hesitate to upgrade your license class.

All hams, don’t hesitate… on the air.  With your mic keyed to transmit, don’t fill up time and space with “um…”, “well…”, “er…”, “aah…” and other such sounds of hesitation.

It’s not only annoying to hear but hesitation really clutters up the airwaves.  In certain cases it impedes more important communication.  For example, during a special event operation or true emergency communication (Emcomm) situation or drill, the Net Control Station (NCS) is constantly talking to various stations.  If you’re using up valuable time on the air, other stations cannot be relaying their info.

A good rule of thumb or general practice is to know exactly what you will say before you key the mic.  Think first, then talk.

If Net Control asks you a question that you cannot immediately answer, don’t take 20 seconds to stall or explain away your delay, just reply that you will get back to them.  This frees up the net for others and lets the NCS know to expect a reply shortly.

The opposite of hesitation in radio work is brevity .  Keep your transmissions short, few, and far between in a special event or Emcomm scenario.

Don’t call in periodically just to let the net know you’re still there.  Net Control and the rest of the net assume you are there unless you have to drop off for a valid reason but you must inform them in such case.

Don’t use 50 words where ten would do. Unfortunately, some hams are long-winded on a special event net.  It takes forethought and practice to keep a report short and simple.   Use the minimum number of words to communicate effectively.

Don’t talk to sound important or just to hear your own voice.  This is heard occasionally on a special event net; others can usually tell when this happens and it’s aggravating.

Study up on Emcomm radio practices, guidelines, procedures and etiquette and then practice these.  Drills and special events are perfect exercise.  Refer to our “EmComm Toolbox” topic for such info.

Another form of clutter to avoid during a special event or Emcomm operation is speculation.  Rumor, guessing, second-hand info, and supposition often lead to confusion and unnecessary concern.  Just the facts, ma’am.  Seriously, only give solid facts.

Log Time

AF5NP Emergency Communications (EmComm), GMT, Log, Time, UTC/UCT, Zulu

Keeping a record of contacts is important in amateur radio.  While no longer required by the FCC in the United States, logging is definitely encouraged.

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For the common, everyday VHF/UHF radio chatter we participate in on a local repeater, contacts are rarely logged.  This is fine, since logging of these would be a tedious nuisance.  Logging of all other contacts is highly recommended.

G2D09

Besides frequency, call sign and signal report, date and time of contact are logged.  Time should be when contact begins, not when completed.

In practice, active hams live in two time zones. The first is their local time, which is when they join a net or sign off a contact because dinner is being served.

Local time is what should be recorded in emergency communication (EmComm) logs when participating in drills or actual disaster deployments where local time is more meaningful.

The second zone hams more frequently use for logging is Zulu time, the current time at the Prime Meridian of the World running through Greenwich, England.  Zulu time (Z)  is also known as Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC or sometimes UCT).   If it’s coordinated Universal Time, why is it Called UTC and not CUT?

Standard_World_Time_Zones

Technically GMT is a time zone while UTC is a time standard (details) but practically speaking they are the same thing and in the aviation, military and telecommunications world it’s Zulu time.

Why the name Zulu?  There are 25 integer World Time Zones from -12 through 0 (GMT) to +12. Each one is 15° of Longitude as measured East and West from the Prime Meridian.  These are given alphabetic designations A-Z, less the letter J.  Z (ITU phonetic Zulu) corresponds to the prime meridian at 0° longitude.  Zulu time.

When logging all but EmComm contacts, hams should use Zulu, not their local time.  Then both parties in a logged contact have the same (universal) time and date recorded (date will change at midnight between 2359z and 0000z).  This becomes important when confirming contacts and getting awards.

Going Mobile

AF5NP Amateur Radio, Antenna, Emergency Communications (EmComm), Ham Radio, HT (Handheld Transceiver), Mobile, Transceiver

The Who had a hit tune entitled Going Mobile that may be playing in your head right now.  While the song celebrates the joy of living in a mobile home and traveling caravan-style in the UK, going mobile to hams means using radio equipment in your vehicle.

While some hams have HF radio setups in their cars, mobile predominantly means local VHF/UHF communication.  Besides bring able to talk to our ham buddies while driving around, 2m/70cm capability is particularly useful in case of disaster or other emergency communication (EmComm) situations.  It is perfect for storm spotting and certain public service events.

Mobile operation is popular and important enough that there are a number of US license exam questions involving the topic as you will see below.

Installing and using amateur radio equipment in one’s personal vehicle is too large a topic to cover here so we’ll simply advise you to research details on your own.  Talk to fellow hams and see what/how/why they installed their own gear.

The internet is also a vast resource for [mostly good] info .  One noteworthy site dedicated to mobile ham operation is managed by Alan Applegate, K0BG, and is located here.   It contains exceptionally useful info on most topics presented below.  We encourage you to use this site as a primary reference for your own mobile radio installation and operation.  The ABCs topic is the best place to start.

Before embarking on any of this yourself, there are several important points to consider:

  • Radio type
  • Radio control location
  • Radio mounting
  • Radio power wiring
  • Antenna type and mounting
  • Radio audio/speaker
  • Transmitting while driving
  • Hands-free/Distracted driving laws
  • Noise and interference

We will scratch the surface of each of these topics here:

Radio type-  Choose a mobile radio that best fits your needs, desires, and budget based on several factors:

  • Brand– quality/reliability and/or familiarity/loyalty
  • Transmit power (Watts)
  • Features– Auto power-off, APRS, dual-channel, remote head, cross-band, packet
  • VHF/UHF (V/U) or HF?
  • FM only, or multi-mode?
  • Single-band, dual-band, tri-band, or quad-band?
  • Analog or digital communication, or both?
  • New, reconditioned, or used?

Note that while a hand-held transceiver (HT) can be used in a car, it is significantly limited by its antenna and transmit power.  Both can be improved (linear amplifier and external antenna) but if you really want good mobile performance you should consider a purpose-specific mobile radio.

Radio control location-  Modern mobile transceivers typically feature removable front panels where the operator controls can be positioned in a more convenient, ergonomic, and safe location using a smaller footprint. Continue reading →

Ham Radio License Plates

AF5NP Amateur Radio, License Plate, Tag

If you are a new ham (or an aspiring one) you have probably noticed Radio Operator license plates (tags) on vehicles in your area and perhaps elsewhere.

hamplates

According to a Wikipedia topic, “All U.S. states offer specialized license plates for licensed amateur radio operators, in many cases at no extra charge or at a discount compared to standard vanity plates. Among the stated reasons in various state statutes for providing special amateur radio plates are to recognize amateur radio operators for their service, and to enhance visibility of amateur radio operators in an emergency. The owner’s radio call sign is used instead of a standard-issue serial.”

In addition to the USA, many other countries also issue specialty vehicle registration plates to licensed amateur radio operators,  purportedly to facilitate their movement during an emergency.  Notably, ham plates are not issued in continental Europe; please advise if this is incorrect or has changed.  One commenter from the UK has reported that they are available but expensive there.

Before you elect to get ham radio license plates for your own vehicle(s), consider the pros and cons of having them.

There are several advantages in having radio operator plates on your vehicle:

  • A fun form of specialty plate and the number is easy to remember (your call sign)
  • Helps other hams identify you
  • Opportunity to discuss amateur radio with a curious public
  • Possibly give you more credibility when driving into a disaster area
  • Likely at lower cost than any other form of vanity plate

And some disadvantages:

  • Makes it easier for the public to locate you if they want to, if you are sensitive to this issue (alternative is to give the government a PO box instead of a street address)
  • Negative publicity for ham radio if you are a bad driver
  • Potentially makes vehicle contents more attractive to thieves
  • You need to get new plates if you change your call sign

Interestingly, in Texas and at least three other US states, radio amateurs are permitted to have their call sign on the license plates of multiple vehicles that they own, in effect Continue reading →

Packet Radio

AF5NP Emergency Communications (EmComm), Message, Packet, TNC, Winlink

If you’re exposed to ham radio for any length of time you are sure to hear some discussion of packet radio.

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Without going into much detail, we’ll present a big-picture description here.  Just enough for you to have a basic grasp of what’s involved and give you some idea of how it might apply to you.

Packet radio is a generalized term for a digital communication mode where data is sent in bite-sized chunks (packets) via radio.  The transmission and receipt of packet data is largely automated and features data error correction for reliable messaging.

t8d08

Packet radio (sometimes shortened to just packet) blends radio and computer technologies together.  Sounds complicated but it really isn’t.  All you need besides your normal ham radio transceiver is a household computer and an interface between the two.  The heart of this interface is a Terminal Node Controller (TNC) which is an intelligent modem that converts text to audio tones and vice versa.

hal-with-tnc

Reprinted with permission, 2013 Handbook; copyright ARRL

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Packet radio can be used between hams directly in real-time (peer-to-peer or keyboard-to-keyboard) but is more commonly used to send messages that can be retrieved on demand.  This operates more like email or mobile phone text messaging.

Slow data rates (typically 1200 baud) make large messages impractical, so packet messages should be relatively short and not have any large files attached.  120KB is the max message size accepted by some big message servers.  A 4KB message will transfer in 2-2.5 minutes under ideal conditions at 1200 baud.

Particularly useful for emergency communication (EmComm) messages, packet radio is predominately used on VHF radios (more local) but can be sent over HF bands Continue reading →

National Simplex Calling Frequency

AF5NP Band Plan, FM (Frequency Modulation), Frequency, National, Simplex

A national calling frequency in the USA is a radio frequency that is widely accepted and understood to be a place to start communicating with other hams.

This frequency is established for each RF band under the voluntary US band plan and is not regulated by the FCC.  It is routinely monitored by any number of radio amateurs and is likely to result in a response when calling CQ or Mayday or SOS.

The US band plan shows calling frequencies for various modes (CW, SSB, FM, AM, digital) in different bands.  A calling frequency list includes not only the modes but adds specific activities (expeditions, power levels) as commonly practiced.

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For new hams who are likely to get started in local VHF/UHF operation, the national calling frequencies to be concerned with are 2m and 70cm FM simplex (non-repeater).  These are 146.520MHz and 446.000MHz, respectively, and should be included in your radio’s scanned channels.  If you regularly use 1.25m, 33cm and/or 23cm bands, there are national simplex calling frequencies defined per the band plan for you to look up.

Be aware that the national calling frequency for whatever mode and activity is only a place to start communicating.  Protocol and common courtesy require that once contact is established, you move to another frequency (QSY) to leave the calling frequency open for others to use.

The national simplex calling frequency is sort of a universal (within the USA) place to make contact when you are not sure where to start.  It is particularly useful Continue reading →

Ham Humor

AF5NP Humor

Amateur radio operators are not all serious business; some of us actually have a sense of Yuma (and fondness for puns).  It may be obscure and occasionally off-color, but some of it is pretty funny.

You can find bits of amateur radio-related humor on various ham websites.

For our part we have created a new Ham Humor page here which contains links and a selection of favorite clean ham radio humor which will grow as new material is discovered.  You can always access this page from the NewHams.info site menu just below the top banner.

Antenna Gain

AF5NP Antenna, dB, Decibel, Dipole, Efficiency, Gain

Newer amateur radio operators may read or hear some discussion of antenna gain.  The gist of it usually involves how much stronger signals are with a particular type of antenna.

This concept of antenna gain can be confusing or misleading to new hams because it sort of suggests that some antennas actually amplify received or transmitted RF signals.  Not so.

Like the decibel (dB), antenna ‘gain’ is always relative.  So when we speak of antenna gain it refers to a performance improvement compared to a different type of antenna.

More commonly, gain is used to compare highly directional antennas (beams, dishes) to monopoles or dipoles.

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While antenna gain usually emphasizes directivity it may also be used to compare two similar types with different characteristics, as efficiency is another contributing factor.  For example, we can observe and measure the relative gain of a stubby “rubber duck” handheld radio antenna (pathetic) vs. a 5/8-wave whip (much better) even though they are both vertical monopoles with the same directivity.

The two types of antennas usually referenced against are isotropic and the simple dipole.  When measuring performance of other antennas, they will often be compared to one of these two.

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If the gain improvement is relative to the theoretical isotropic antenna, the units should specify the gain as dBi.  If measured against a dipole antenna, the gain should indicate dBd.  Any other comparisons should mention the reference antenna in the text.

Some good references for antenna gain are given below: Continue reading →

Mic Fright and Your First Contact

AF5NP Anxiety, Contact, Elmer, Emergency Communications (EmComm), Experience, First, Listen(ing), Mic (rophone), Practice

Mic fright is a general term for anxiety leading to freezing, choking or hesitating when speaking into a microphone (mic).  The physiological response of worrying about saying the right thing to an audience large or small is very natural and expected.

micfright

Mic fright or shyness is a reality in public speaking, stage performance and similar situations.  Of course, it’s an important topic to new amateur radio operators so let’s provide some perspective and encouragement here.

Making that first voice contact over the radio can be an anxious moment for many new hams.  This can also carry over into the first several radio contacts where you worry about saying the right thing and following the rules.

First off, don’t let the “rules” make you nervous.  It mainly comes down to proper identification which means giving your call sign every 10 minutes during an exchange and at the end of your last transmission (USA rules, other countries vary).  That’s pretty easy to remember.

Second, every ham was a newbie once and remembers what it was like not knowing exactly what they were doing.  Most will be patient and helpful, giving coaching and gentle reminders along the way as needed.

For general phone (voice) contacts, there are no real procedures and formalities to worry about; it’s more conversational, much like a phone call.  While radio amateurs often use jargon, abbreviation and technical terms (see our Ham-Speak topic), this is not mandatory.  Hopefully that takes some of the pressure off to make you more relaxed for your first few contacts.

A starting point for getting on the air the first time is to listen in on the local (VHF/UHF) repeaters and HF SSB bands for a few hours to learn what people say and how they say it.  If you follow these examples you are almost certain to be successful when transmitting on your radio.

An excellent way to get past mic fright and performance anxiety is to ease into it with Continue reading →

dB, or not dB…

AF5NP dB, Decibel

…what was the question?

Whether ’tis nobler in the mind to understand dB or just plod along wondering what the heck other hams, publications and spec sheets are talking about is up to you.  With all due respect to Shakespeare’s Hamlet, decibels (dB) are a frequent subject in ham radio.  All three US license class exams have questions involving dB in their pools.

g5b01

Hams new and old don’t have to be technical experts but all should at least be familiar with the decibel.  To that end we will give a simplified explanation here.

Decibels (dB) are a convenient and standardized way of measuring a change or difference between two conditions.  In audio,  radio work and electronics in general, we are often dealing with very large or very small numbers and the difference between them can be many digits long.  To make the numbers more manageable, expressing ratios of large and small values is better done using a non-linear logarithmic scale.  Logarithms are based on orders of magnitude (10,100,1000,10000… and 1/10, 1/100, 1/1000, 1/10000…).

The human ear responds to sound logarithmically so decibels are a natural fit to measuring sound levels.  Similarly, radio work behaves non-linearly in some ways so the logarithmic approach works well here.  We’re stuck with dBs, like it or not.  In amateur radio the dB is commonly used in context of amplification, feedline loss, antenna gain, filter bandwidth and RF signal strength.

Technically the decibel is a ratio between one state and another; it’s not an absolute measurement, it’s relative.  Always ask, dB relative to what?, because this is a ctitical factor.

More practically it often comes down to the amount of amplification or attenuation.  In amateur radio it almost always involves power changes so we will focus on this aspect.  Decibels can also apply to other units such as voltage but this gets a little more complicated and not as widely used in ham radio.

A power ratio is simply comparing two Continue reading →

RF Connector Types

AF5NP BNC, Connector, N-Type, PL-259, RF, SMA

The plug that is used for terminating cables between the receiver, transmitter or transceiver and the antenna is generally referred to as the RF connector because it carries the Radio Frequency signal to/from the equipment.

In addition to mating the radio to the antenna via a transmission line (usually a coaxial cable) it may also used on RF test equipment (antenna analyzer, power and SWR meters, spectrum analyzer) and dummy loads.  All hams should be familiar with different RF connectors so we’ll give a brief high-level description here.

Good news!  There are only four common types of RF connector used in ham radio:

PL-259

220px-uhf_pl_connector     250px-uhf-connector

By far the most common RF connector, the PL-259 is used to connect most all modern HF transceivers and VHF/UHF mobile rigs to the antenna.  The PL designation stands for plug and the 259 is an old US Signal Corps assignment.  It has a male center pin and female thread.

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The mating  receptacle found on the radios and equipment is known as a SO-239.  SO for socket, it features a female center receptacle and has male threads.

so-239

The PL-259 and SO-239 combination (details here) is frequently referred to as a “UHF connector” although this designation comes from the 1930s when UHF was considered anything above 30MHz.  It has performance limitations above 100MHz so other connector types are more suitable for true UHF use.

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N-type Continue reading →

How Far Can I Communicate?

AF5NP Antenna, Distance, DX, HF (High Frequency), Signal, VHF/UHF

One of the more interesting questions a new or prospective ham will have is, “how far can I communicate?”  The frustrating answer is, “it depends…” (don’t you hate hearing that?)

dx-map

There are many factors involved in the limits to distance of radio communication.  Carrier frequency is the huge one, followed by operating mode, antenna characteristics and transmit power. Time of day, solar activity and the season (spring, summer, autumn, winter) also have a big impact on range.  Natural (thunderstorms, aurora, geologic, cosmic) and man-made (crowded band, power lines, noisy electronics) interference can also limit or disrupt a radio contact.  Also factor in the use of repeaters (terrestrial and space satellites) or reflective objects (structures, moon, meteor showers), plus unusual weather conditions and you have a lot to consider.

Since many hams get started using VHF/UHF radios for local communication, let’s talk about this first.  VHF/UHF radio wave propagation is normally limited to line-of-sight, meaning the antennas at each end must have a clear path between them (no obstructions such as buildings, trees, and particularly, the earth).

3-20 miles is a realistic range for VHF/UHF hand-held radios on the ground, depending mainly on a clear path and relative height of the two parties.  Throw in a repeater with a high antenna and that range extends considerably.  Raising your own antenna up higher Continue reading →

Public Service Events

AF5NP Emergency Communications (EmComm), HT (Handheld Transceiver), Public Service, QST

Are you a new ham who wants to practice radio communication?

Just getting started in amateur radio and want to learn about emergency communications (EmComm)?

Are you a ham who wants to make better use of your hobby?

If you answered yes to any of these, consider helping with a local public service event (PSE). Public Service Events provide an excellent chance to practice your EmComm radio skills.  Not only is it fun and interesting, but you will gain valuable experience in radio communications similar to a real disaster scenario, without the stress and urgency of a life and death situation.

pse-hams

Ham radio operators are often invited to assist with PSEs to provide primary or supplementary communication.  PSEs typically involve parades, races or large gatherings.  They normally use VHF/UHF radios so you don’t need any fancy equipment or big antennas.

Participants may be stationary  or mobile, depending on the nature of the event.  You may be sitting or standing or walking around.

Because hams supporting a PSE will often use a handheld transceiver (HT) it’s a good idea to have a few recommended HT accessories.  First would be a quality 1/4-wave antenna in place of the poorly-performing factory “rubber duck”.  Second is a spare battery pack for your radio.  Third would be headphone(s).

A must-read for new hams is Continue reading →

Don’t Settle for Just a HT

AF5NP Amateur Radio, Amplifier, Antenna, HT (Handheld Transceiver), Mic (rophone), Rat Tail, Repeater, VHF/UHF, Yagi

zys-ft-60r

Often a new ham’s first radio is a handheld transceiver (HT).  A HT represents the lowest-cost entry point to amateur radio and is relatively easy to set up and use.  Your first on-air experience as a licensed ham may involve a HT on a local VHF/UHF repeater, and that’s fine.

But don’t settle for just a HT as supplied by the manufacturer for your early ham radio experience.  You are almost certainly going to be frustrated and disappointed at its performance to the point of giving up on ham radio and wondering why all these hams are so enthusiastic about the hobby.

Don Keith N4KC makes this point eloquently  in his ‘HT Trap’ article where he discusses how easily a new ham can get discouraged with amateur radio because of the limitations of a stock HT.  I have observed this as well while helping new hams get set up in a local EmComm organization.

Huge improvements in HT performance or ease of use can be accomplished with three accessories.

First and foremost is the Continue reading →

Change of Address

AF5NP FCC, License, QTH

Have you moved since you got your amateur radio license?  This is a common concern for renters or apartment-dwelling hams and revocation or suspension of your license is the ultimate consequence of failing to notify the FCC.

If you have relocated your QTH from one place to another, or if you have otherwise changed your mailing address, you are obliged to update your postal address with the FCC in the United States.  The FCC needs to know where to reach you by mail for either operator or station license questions or issues.

It’s also common courtesy to other hams who want to send QSL cards or just to know where you are located based on your call sign.

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US Code of Federal Regulations 47 C.F.R Section 97.21 requires you to file timely for an update of the license as necessary to show your correct mailing address, name, club name, license trustee or custodian name. Revocation of your station license or suspension of your operator license may result when correspondence from the FCC is returned as undeliverable because you failed to provide the correct mailing address.

In the US you can update your address online (filing electronically) at Continue reading →

ARRL Membership

AF5NP Amateur Radio, ARRL, Membership, QST

arrl-logo The American Radio Relay League (ARRL) is is the largest membership association of amateur radio enthusiasts in the USA and it represents the interests of hams before federal regulatory bodies, provides technical advice and assistance to amateur radio enthusiasts, supports a number of educational programs and sponsors emergency communications service throughout the country.

The ARRL is the primary representative of amateur radio operators to the US government, lobbying Congress and the Federal Communications Commission on various issues of importance to ham radio.  The ARRL has a significant international membership and influence as well, serving as the secretariat of the International Amateur Radio Union, which performs a similar role internationally, advocating for amateur radio interests before the International Telecommunications Union and the World Administrative Radio Conference.

The ARRL’s underpinnings as Amateur Radio’s witness, partner and forum are defined by five pillars: Public Service, Advocacy, Education, Technology, and Membership.

ARRL’s Vision Statement–  As the national association for Amateur Radio in the United States, ARRL:

  • Supports the awareness and growth of Amateur Radio worldwide;
  • Advocates for meaningful access to radio spectrum;
  • Strives for every member to get involved, get active, and get on the air;
  • Encourages radio experimentation and, through its members, advances radio technology and education; and
  • Organizes and trains volunteers to serve their communities by providing public service and emergency communications.

For all the above reasons it is good to support the ARRL with membership at $49 per year. As a bonus, and for many it is reason alone to be a member, the ARRL publishes the monthly magazine QST.  Each issue is a source of equipment reviews, technical tips, projects, news and many other ham-related topics.

Regular columns address specific interests:

  • Amateur Radio World-  International ham radio news and info
  • Classic/Vintage  Radio- Fun look at older receivers, transmitters and transceivers
  • The Doctor is In-  Authoritative answers to interesting technical questions
  • Eclectic Technology- Discussion on new or unusual technology in ham radio
  • Hands-On Radio- Practical technical discussion of interest to DIY hams
  • Hints & Kinks- Ideas, tips, and related handy suggestions on all things ham
  • How’s DX?-  Long-distance (DX) communication news or issues
  • Public Service- Ham radio for emergency communication and/or events
  • The World Above 50 MHz- Ham radio at VHF and higher frequencies

There’s something for everyone in QST.  A new ham will be exposed to the Continue reading →

Powerpole® Connectors

AF5NP DC Power, Emergency Communications (EmComm), Power Supply, Powerpole®

The Anderson Power Products Company makes a family of electrical connectors with the registered trademark name of Powerpole®.  Now that we have established that, we’ll skip the ® symbol from now on.

Powerpole connectors come in several sizes and colors.  Housing size depends on current rating, from 15A  up to monstrous 350A and supporting wire sizes from 20AWG wire up to heavy 3/0 cable using different connector contacts.

powerpole-family

Hams in the US, and particularly within EmComm groups such as ARES, have adopted the 15-45A  Powerpole product as the de facto standard for 12VDC  power interconnect for amateur radio equipment.  These connectors are gaining popularity world-wide as well, so you will see more and more usage of this flavor of Powerpole connector being used everywhere.

powerpoles

Besides the convenience of a high-current quick-connect, having a standard means one ham’s equipment can be plugged into another’s  power source.  This is particularly important in emergency communication situations.  Additionally, a standard drives greater availability of commercial products that support it.

One reason Powerpole connectors are growing in popularity is that they have some unique advantages over other electrical connectors: Continue reading →

Get on the Air Now!

AF5NP Amateur Radio, Antenna, Book, Ham Radio, Ham-Speak, HF (High Frequency), HT (Handheld Transceiver), Recommended Reading, Terminology, Vocabulary

An outstanding resource for amateur radio operators, and new or prospective hams in particular, is a paperback book by Don Keith N4KC entitled, GET ON THE AIR…NOW!

    

There is something for everyone here: Folks who are interested in ham radio, those who just got a license, experienced hams who lose interest, and long-time hams who are looking for something to share with newbies. N4KC covers most of what current and prospective ham radio operators need to know and he does a great job of selling the hobby/interest. And no, he’s not pushing Morse code, although CW operation is one of the more interesting aspects of amateur radio.

The main emphasis of the book is encouraging licensees to actually get on the air and experience real ham radio, not to get frustrated with bad experiences and limited equipment and then give up on our hobby.  He addresses some of the common discouragements and steers us to realistic remedies.  Chapter five is a practical discussion of antennas and I particularly appreciate chapter six with Don’s concise description of what to expect on the HF bands.

gotan TOC

The second half of the book is a comprehensive dictionary of “ham-speak”–amateur radio terms, abbreviations and slang, useful to all hams, new and old.

About $19 with a Kindle version for $9.  Highly recommended and the first item listed on a new site page entitled Recommended Reading.

EmComm Toolbox

AF5NP ARES, ARRL, Directed Net, Emergency Communications (EmComm), Etiquette, FCC, Ham-Speak, Language, Training

Many new hams get involved in emergency communications (EmComm) and it may even be their primary focus or purpose for getting an amateur radio license.  Emergency communications is the first of five basic principles spelled out by the FCC for the existence of the licensed amateur radio service in Part 97:

Section 97.1(a): Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications.

In fact, by accepting an FCC operator/primary station license grant under these rules, USA amateurs are obliged to provide emergency communications as needed.  Not that you’ll get thrown in the slammer if you don’t help, but all licensed hams with the equipment and experience should help out in case of disaster or other EmComm situation, and most do so.

Having said all that, I would encourage all hams to join a local or regional EmComm group (such as ARES or RACES in the USA) and train and drill with them to get some experience.  It’s not enough to know how to talk on a repeater or social net; things get more serious in an EmComm situation.

There are more formal radio operating practices and language used in EmComm which is almost always conducted as a directed net.  You need to learn when and how to communicate and with whom and what to say and why things are done a certain way.  Participating in EmComm drills and public service events is important training, as is listening in on EmComm training nets. Taking EmComm courses such as the ARRL’s Introduction to Emergency Communication Course EC-001 is also of great benefit.

To familiarize you with the Who/What/When/Where/Why/How of EmComm, attached here Continue reading →

Kerchunking

AF5NP Ham-Speak, ID, Identify/Identification, Illegal, Key, Mic (rophone), PTT (push to talk), Repeater
The practice of briefly keying a microphone (hitting the push-to-talk/PTT button) to see if a repeater responds with a courtesy tone is commonly known as kerchunking (or ker-chunking) in ham-speak.
handmic     Kerchunk2
Don’t do it!  Don’t be a kerchunker, even though it’s often a quick and convenient way of verifying that you can hit a repeater.
For one, it is technically illegal.  All transmissions must be identified (with rare exceptions).
T2A06-2018
Just because you hear it happening and the probability of getting caught is very low doesn’t make it right.
Kerchunk
However, the main reason not to key a mic without identifying yourself is that it
is both annoying and disruptive.  It’s bad etiquette and almost always discouraged in published guidelines by the repeater owner.
Kerchunk3
If you really want to test your connection to a repeater, take the extra second to speak your call sign into the mic. Or say “testing”, followed by your call sign.  Or ID and ask for a signal report, which will give you even more info than just to hear a courtesy tone.
On a related note, if you want to test transmit power or SWR or something like that, consider using a simplex frequency to avoid tying up a repeater.

Call Sign Variations

AF5NP Call (Call Sign), FCC, Format, Vanity Call

New hams listening in on a repeater are likely to hear a wide variety of call signs.  They may be confused and question some of them.  Repeaters near an international border can get pretty interesting with call sign variations in both countries.   EchoLink and IRLP open many repeaters up to access from anywhere the internet can reach.  Call sign variations are even more evident on HF bands where communication distances can be much greater.  New ham KG5XYZ may wonder why not everybody else is a KG5 like them.

It is important for new hams to be familiar with call sign variations and legal call signs for logging, message handling and just scribbling down a call sign when communicating with another ham.  “Did I just hear KMG365?” Comment if you get this reference. 🙂

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First it is essential to understand that ham radio call signs (AKA call letters or just plain call) have a prefix followed by a numeric digit followed by a suffix.  The prefix is determined by the country in which the license is granted, most always one or two alphabetic letters. The digit following the prefix has significance within individual countries, such as geographic zones.  The alphabetic suffix following the number is generally meaningless other than to distinguish between calls sharing the same prefix and number.

There are variations in prefixes, not only by country but often also in number of alpha characters.  The number in a call sign is almost always a single digit.  The suffix may legally be anywhere from one to five alpha characters, depending on governing authority.

This arrangement of prefix-number-suffix is referred to as its format and is useful for describing a call sign. The format system counts the number of characters in both the prefix and the suffix.  It is usually termed the “p by s” system or pxs in writing where p represents the number of characters in the prefix and s is the number of suffix characters.  Using USA example call signs, W3MRC is a 1×3 call while KF5ZFD is a 2×3.  KL7AA and AF5NP are both 2×2 call signs.  NA6M is a 2×1 and W1AW is a 1×2.  One by three (1×3) and two by three (2×3) are by far the most common call formats in the US, followed by 2×2 and then 1×2 and 2×1.  Because they are relatively uncommon, even seasoned hams sometimes pause at a 2×1 call to register with their brain as legitimate.

1×1 call signs are legal in the US but are assigned only to organizations for special events and only for a limited time.  Details on special event call signs can be found at this FCC site.

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Valid prefixes in the USA are K, N, and W (one letter),  and AA-AL, KA-KZ, NA-NZ, and WA-WZ (two letters).  Complete details can be found here.

Below is a small sample of international prefixes a US ham might run across, mainly on HF bands: Continue reading →

Your QRZ Profile

AF5NP Database, Profile, QRZ, Reference

The previous post introduced you to a very useful and popular ham website called QRZ.    QRZ lets you look up details on a fellow ham you have interacted with over the air or in person, or perhaps just a call sign you have heard and wonder about.

As mentioned, the information on QRZ may be minimal.  Lacking any user-supplied detail, QRZ will show only the licensee’s name, address and license class, license expiration, map location and distance from your station.  This is derived from government amateur radio license info which is public record.

Like it or not, if you have a ham license you automatically have a QRZ page so why not make it useful?

I find that fewer than half the people on the air have any personal detail added so I would encourage you to create a free account on QRZ and add a photo and some personal information to your profile.  You can share as little or as much as you want.  I’ve seen pages that are huge with lots of graphics and photos and text and some with just a couple of sentences.  Add some detail about yourself for us to know you better, as much as you are comfortable with.

It’s nice to put a face to the callsign and you get to choose the photo.  Tell us just a little about yourself– things like hobbies and job and maybe what is your history with or interest in ham radio.  An email address is also helpful for people to contact you that way.

Of course, if you’re really cautious with how much personal info is on the web, then maybe this isn’t for you.  Remember that if you Continue reading →

QRZ

AF5NP Brevity, Call (Call Sign), Database, FCC, Q-Codes, QRZ, Reference

Old-timers are already familiar with it but new or prospective hams may not be aware of a wonderful online callsign reference called QRZ.

The ham radio brevity code QRZ means, “who is calling me?” if you’re not sure or didn’t catch their complete callsign.

QRZ is a very powerful and popular callsign database that is located at qrz.com  The QRZ site takes its name from the Q-code question, who is calling me?  It’s particularly useful to look up a fellow ham you’re having a QSO with or have heard about or met in person.

If they have a callsign, you can look up their FCC registered address, license class, license expiration, exact location including the important Maidenhead grid square and a map of their location with exact distance from your station.  It’s also useful for learning their previous callsigns if they have changed from what the FCC originally assigned them.

If the other ham has added info about themselves, you can see photos of them and their equipment, a biography, specific interests or whatever else they choose to share, including  an email address.  Hams can also use QRZ as a contact log if they choose to do so.

The database is updated daily from the FCC main file so it’s up to date and accurate.  You can search by call sign, partial call, name, address or grid locator.  If you look yourself up on the map you can see all the hams in your immediate vicinity; you might be surprised at how many there are.

I like to use QRZ to put a face to the name of people who are on Emcomm nets, the local repeaters, or during my HF QSOs and know a little more about them.

The QRZ database includes international hams so if you want to look up call signs around the world you can do that, too.  I found a distant relative fellow ham in Germany just by searching my family name.

By the way, QRZ is properly pronounced, “Cue Are Zed” as we  learned in the post on how to pronounce the letter Z.

QRZ has at least one major competitor, HamCall, plus a copycat with the confusing name of QRZCQ.

Before personal computers and the internet became common, hams relied on large printed books to look up the name and address associated with a particular callsign.  The main one was the Radio Amateur Callbook with the Pegasus (winged horse) mascot.  It is still available  on CD-ROM and/or USB memory stick.  Old print copies can be found on eBay and Amazon.

So check out QRZ and start using it.  I’m sure it will become a bookmarked browser favorite of yours.

Q-Codes

AF5NP Abbreviation, Ham-Speak, Jargon, Lingo, Q-Codes, QRM, QRN, QRP, QRT, QRZ, QSB, QSL, QSO, QSY, QTH, Terminology

Back in the ham-speak topic we noted that ham radio vocabulary includes plenty of jargon and lingo.  As mentioned there, it is best to not use too much ham-speak on the air, since plain language is preferred for voice modes (phone) but in reality you still hear many code words and abbreviations being used.

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You will run across many terms on the air as well as in books and magazines and perhaps in email that are cryptic to the new or prospective ham.  To help you with this we will present the topic of Q-codes here.

The Q code (or Q-code) is a standardized collection of three-letter codes, all of which start with the letter Q, where each code has a particular meaning. These brevity codes were originally developed for commercial radiotelegraph use but were quickly  adopted by amateur radio operators.  Although Q codes were created when radio used Morse code exclusively, they continued to be employed after the introduction of voice transmissions. Some history on Q-codes can be found here and here and here.

Listed below are ten Q-codes the average ham is most likely to hear (in the author’s opinion), along with their meaning and common usage:

  • QRM- Man-made interference, interference from other stations.
  • QRN- Natural interference, typically static or crashing from thunderstorms.
  • QRP- Low power transmit, generally 5W or less.
  • QRT- Quitting; stopping transmission or shutting down station.
  • QRZ- Who is calling me?
  • QSB- Fading signal.
  • QSL- I acknowledge receipt; also confirmation of contact.
  • QSO- Conversation, radio contact and exchange.
  • QSY- Change frequency.
  • QTH- Location.

You should be familiar with at least these and perhaps some others as well.  Comprehensive lists of Q-codes can be found here and here and here and here.t21b10

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The main point here is not for you to learn Q-codes to use them, but to understand them when you inevitably hear them.

That’s all for now so 73 and I’ll be QRT.

Stuck Microphone

AF5NP Directed Net, HT (Handheld Transceiver), Mic (rophone), Mobile, Net (work), PTT (push to talk), Repeater

While it’s mainly a local VHF/UHF communications issue, stuck microphones can be a real problem.

A stuck mic situation is when a radio operator inadvertently transmits for an extended time because they have unintentionally triggered the push to talk or transmit switch on their radio.  Consequences of a stuck mic range from being a nuisance to a life-threatening disruption. At best a stuck mic ties up a repeater or simplex frequency with dead air or noise.  At worst it blocks urgent communication during a disaster net or public service event.

One common stuck mic situation involves a mobile unit with the hand-held mic loose in the vehicle where it might get wedged into the seat to trigger the PTT button.  Best practice here is to keep the mic clipped into a hanger when not being used to minimize inadvertent transmission.

mobilemicclipped
Keeping a mobile mic secure in clip minimizes chance of inadvertent keying.

Another common situation involves mic accessories with HTs during a public service event or emergency deployment.  When using a speaker-mic or headset, ensure that the PTT button is protected from accidental triggering.  Also, the Yaesu FT-60 is a wonderful handheld radio and many hams have them, but they (and others like them) have a squirrely speaker/mic jack that is prone to false triggers when the connector is not seated completely.  So make sure your accessory is connected securely and not prone to pulling out when the radio is clipped to your belt or in a pocket or something like that.

yaesu-spkr-mic
External mic or headset prone to false PTT triggers because of plug design on certain HTs.

In any case, awareness is our first line of defense.  Be aware that a stuck mic is a problem and that you might be the culprit.

stuckmicmeme
Don’t be this guy!

Keep an eye on your transmit light to make sure it’s not on when Continue reading →

Radio Shack

AF5NP Ham-Speak, Operator, Radio Shack®, Shack, Station

When you hear the term Radio Shack, readers over 30 years old will automatically think of the electronics retail giant that had a presence in nearly every city and town across the US.  Indeed, Radio Shack® was sometimes the only local source of electronics, parts and supplies.

In ham radio lingo (ham-speak) the term radio shack or even just the shack refers at least to the operator station, typically a desk or bench or table.  The ham shack may also refer to the room in which the radio gear is used (den, office, bedroom, garage) or even a purpose-specific building for such equipment and use.  The shack often includes an electronics workbench or similar area for building and tinkering and storing parts and accessories.

The radio shack may be somewhat stealthy to blend in with a living area such as my own:

af5np-shack

Or it may be a large and luxurious setup such as shown below:

shack-ve3jw-s

If you want to see some really complicated and fancy (dare I suggest outrageous?) ham shacks, check this out for fun.

When setting up your own shack you need to do what’s best for you (and the spouse!) so it will range from super-simple to elaborate dream; most likely something in between these extremes.  An excellent guide with 17 suggestions and considerations in setting up a new radio shack is found here.

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The term radio shack likely derives its name from the earliest days of radio Continue reading →

Practical Skills For the Radio Amateur

AF5NP Antenna, ARRL, DIY, Elmer, Kit, Multimeter, Practical, Skills, Technique

While not every ham is technically inclined or particularly handy, amateur radio operators tend to be do-it-yourself (DIY) kind of people who often build, install, and fix their gear and other things.  In many ways hams are some of the original “Makers” and experimenters who have actually helped further the art and science of radio and communications technology.

To encourage and further this historic reputation, consider developing in yourself some of the practical skills that ham radio operators are stereotyped to possess.  While the list rightly could be more extensive, we will suggest four basic ones here:

  • Electronic soldering
  • Using a multimeter
  • Stripping and terminating different kinds of wire and cable
  • Drilling and cutting material (fabrication)

We can’t go into details on these here, so the reader will need to learn about these skills on their own.  Besides researching them on the web, how can you develop these skills and techniques?  As always, consult your Elmer for some guidance on any or all of these topics.  On your own you can also read up on different subjects in books, magazines and on the internet. The ARRL Handbook has plenty of info on these subjects and is a highly recommended reference.  QST magazine is also a good resource.

Building an electronic kit is a wonderful experience that will teach you a lot about components and soldering.  Local clubs may also host training/practice sessions in some of these areas.  A VHF antenna build is another great way to gain experience with stripping, terminating and soldering and may also involve a multimeter.

Feel free to chime in with your own suggestions for practical skills in the comments below.

Know Your Radio

AF5NP Configuration, Emergency Communications (EmComm), HT (Handheld Transceiver), Mobile, Radio, Settings

Do you know how to change the settings on all of your radios?  You should, particularly with the VHF/UHF rigs that would be used in an emergency situation in case of a local disaster.

It may seem silly to ask this question when such knowledge is often assumed.  But consider these factors:

  • Many of the modern radios can be configured via software on a PC, often including memory channels for local repeaters.  Did you actually set up your radio manually, or was it cloned or computer configured?
  • Many hams have multiple transceivers- handhelds (HTs), mobile, and base station rigs.  Configuration of these is likely different for each model, even with the same manufacturer.
  • Hams may have different makes of the same type of radio as well, each with very different configuration procedures.  If you have both Yaesu and  Baofeng HTs, the procedures will be quite different.

Consequently some hams only know how to turn the radio on and off, adjust the volume and squelch, and then select a memory channel to work a local repeater.  This is OK when you want to chat with a buddy, since little can go wrong and there are no real consequences.

But during a drill, public service event or EmComm deployment, we have to be flexible and prepared to change things up.  There are many reasons things don’t go as planned, and you may have to change a setting on your radio.  Even something as simple as communicating outside the local area will require different repeater access tones.  Some events use a portable repeater that you may not have programmed into your radio.  Many of us have been embarrassed in the field when Continue reading →

License Training & Study

AF5NP Amateur Radio, Ham Radio, HamTestOnline, License, Study

So you are interested in ham radio and want to get a license.  Thats’s great!  Now how should you study for the exam?

Let’s present some basic information first. Breathe a sigh of relief to know that Morse code is no longer required to be a licensed US amateur radio operator.  Also unlike the days of old, you no longer have to travel to a FCC office to be examined.  Many of us old timers recall having to demonstrate our skills at sending and receiving Morse and taking a tough written test at a FCC office in a large city.

License exams are now conducted by local hams who are accredited by an authorized organization to certify that examinees have passed the written exam.  These volunteer examiners then process the paperwork necessary to get passing candidates their license.  You can find the nearest exam dates and locations at the ARRL website.

License exam questions are all multiple-choice and are managed by the exam coordinator organizations.  There are question pools for each of the three license grades and these pools change somewhat every four years.  The question pool for the Technician class license consists of about 425 possible questions while the General exam has around 460.  The Tech and General exams both have  35 questions and a passing grade is 26 correct answers (74%, 9 wrong).  The Extra class license is much more extensive with over 700 questions in the pool and consists of 50 questions with a passing grade of 37 correct answers (74%, 13 wrong).  Each license class has questions about Rules/Regulations,  Operating Procedures, Radio Fundamentals, Practices, Electrical/Electronic Principles/Components, Equipment, Modes/Methods, Radio Wave Behavior, Antennas/Feedlines, and Safety.  As you might expect the questions become more involved and difficult as you progress from Technician to Extra license classes.  Every exam will have a certain number of questions from each of these general categories.

The Technician license exam is relatively easy to pass and is where most people start.  The General class exam is more challenging but is still doable for most people, being moderately or somewhat difficult to learn.  The Extra class exam is truly difficult and requires extensive learning and study to pass.  You can proceed from Technician to General and on to Extra in one exam session if you are really eager and prepared or just settle for Tech or General that day, as most people do.

Because you won’t know which questions will be on any given exam, you need to understand most (at least 75%) of the entire question pool for whichever exam you are attempting to pass.  So this requires some study in advance of taking the exam.

While it is possible for a reasonably intelligent and technically-minded person Continue reading →

New Topics Coming

AF5NP Amateur Radio

Sorry that it’s been several months  since any new topics have been posted.  The site manager  had a major stroke in April that put him in the hospital for four weeks and Jim has been recovering since.

Now that AF5NP is doing much better and has regained most of his functionality and energy we can think about writing and posting new material.  Still don’t have full use of the left hand, which makes typing awkward.  But we hope to roll a few things out in the near future even if he has to type one-handed.

Here are some of the topics on Jim’s list to prepare:

  • Practical skills for the radio amateur
  • Don’t settle for just a HT
  • Using a multi-meter
  • Your QRZ profile
  • License study
  • Call sign variations
  • Guide to using PowerPole® connectors
  • Packet radio
  • Dummy loads
  • Public service events
  • Radio craft language
  • Ham radio license plates
  • ARRL membership

We will also add a page of recommended reading to share publications that are particularly useful.

What Will My New Call Sign Be?

AF5NP Amateur Radio, Call (Call Sign), FCC

Of particular interest to prospective hams just finishing their study and preparing for their license exam, there is a great way to get a basic idea of the call letters they will be assigned, at least in the USA.  First they must know the FCC region they reside in based on the address they gave on the license application form.  The FCC divides the US into ten geographic regions with a numeric designation for each one;  a quick reference is found here.  For example, the table shows a numeral 5 for Texas so all New Texas licensees will have a 5 in their call sign as originally assigned.  By the way, this can be changed later but that will be a future topic.

From here you can refer to the Hamdata FCC info website and look for the most recent sequentially assigned call signs in your numeric region.  You can estimate that your assigned prefix (the letters before the number) will likely be the same as the most recent one issued for your region (unless it is at the end of the alphabet already), and your suffix (the letters after the number) will be the next one or two alpha characters subsequent to the most recent one issued for your region. All of this applies, assuming you take your exam in the next two or three weeks. If you test further out, you will need to check the database again to see the current stats.

73 What?

AF5NP 73, Abbreviation, Jargon, Lingo, Terminology, Vocabulary

Usually near the end of an amateur radio conversation (QSO) the phrase “seven three” or “seventy three” will be heard.  New hams or unlicensed listeners will probably wonder, 73 what?  Here is more of that ham-speak stuff we are learning about and this terminology has a very particular meaning.

73

73 simply means, “Best Regards”.  It is a very common phrase used on the radio in voice, Morse code (CW), and data communication modes and is often used in emails and handwritten notes between hams.  73 is considered a polite and friendly way of signing off all forms of communications between hams or as a general show of respect.

The origins of 73 are not absolutely certain, but the prevailing idea Continue reading →

Listen and Learn

AF5NP Amateur Radio, Ham Radio, Listen(ing), Repeater

Prospective hams or hams in training may wonder what they will do or say over the radio when they get their license.  There is all that lingo/jargon that hams use and there are rules about identifying and phonetics and whatnot; it can be confusing and intimidating to non-hams who haven’t had much exposure to amateur radio.

The best way to learn how hams speak on the air and what kinds of things they talk about is to listen in.  No license is required to listen; you can monitor radio traffic 24/7 if you like.  Listen and learn.  Just keep your finger off the transmit control (usually a push-to-talk [PTT] button) until your have a license.

Start by listening in on the local Continue reading →

Signal Reports

AF5NP QSO, Report, RST, S-Meter, Signal

One of the most basic features of an amateur radio contact (ham-speak=QSO) is an exchange of signal reports so each participant knows how well they are coming through.  If either end has a poor signal then usually the exchange is minimized to avoid the frustration of trying to copy the other ham.  Conversely, a good signal report means you are likely to have a good QSO and can exchange a lot of information if you want to.

Signal reports vary with operating mode and other factors.  We will look at three basic types: CW (Morse code), general phone (voice), and repeater use (very different here).

The complete standard ham radio signal report is a three number code representing Continue reading →

eHam Product Reviews

AF5NP eHam.net, Reviews

Want to buy a transceiver but aren’t sure which one to get?  How about an antenna or a DC power supply or a microphone or some other ham radio accessory?

Get reviews on all sorts of ham radio products at eHam.net.

This site provides an extensive list of reviews by real hams on everything imaginable in the world of amateur radio.

Besides product reviews, eHam.net has lots of information, references, forums, classified ads, and more.  It’s a great resource.

Because eHam product reviews are so beneficial, I have added the URL to a new page called Links.  Will be adding many more useful web links to that page in the future as well.

DC Power Supply Ratings

AF5NP DC Power, Electromagnetic Interference (EMI), Linear, Mobile, Power Supply, Ratings/Specifications, Regulator/Regulated, SMPS

Except for handheld transceivers (HTs), most modern ham radio gear uses 12V DC power.  You may find vintage radios and more recent designs that require AC main power, but the VHF/UHF mobile radios and the latest HF transceivers run off of 12-13.5VDC.   Nearly all of the modern all-band transceivers use 12VDC power as well so that they can be operated mobile or portable.

T5A06

If you want to install a mobile radio in your home instead of your vehicle (an excellent idea, by the way, if you don’t have an all-band rig) you will need a DC power supply for it.  Same goes for the latest HF transceivers; they require 12VDC power but don’t often include the power supply.  Additionally, many radio accessories require 12V nominal power.

Astron RS-35M 35 Amp DC Power Supply with Meters 120V AC in / 13.8 Volts DC Out     MFJ 4230MVP 30 AMP Switching Power Supply With Meter, 4-16 Volts & Power Poles    NEW Pyramid PS8KX AC to DC 8 Amp 12V Fully Regulated Low Ripple Power Supply     NEW QJE PS50SWIII 50 Amp Switching Power Supply with Volt/Amp Meter     JETSTREAM JTPS30LCD - 9 ~ 12 Volt 30 AMP Max Switching Power Supply w/ LCD Meter

Examples of ham gear DC power supplies.

The 50W mobile radios and 100W transceivers need a lot of current at 12V to operate at full output power.  Sizing a DC power supply for these plus accessories isn’t quite as straightforward as it would seem.

For one, you cannot simply take radio output power and divide by 12V to get amperes. Continue reading →

Directed Net

AF5NP ARES, Directed Net, Double, Emergency Communications (EmComm), Net (work)

An amateur radio net (ham-speak for network) is an organized gathering of at least three hams on the air for a specific purpose.  It is usually on a regular schedule (e.g., 9pm local on Wednesdays) and specific frequency (e.g., 146.900 repeater).  Nets are organized for various reasons, usually conforming to one of two categories: hobby/pleasure and utilitarian.  Nets may be impromptu and unscheduled, such as during severe weather when a net may be quickly organized, or following a local emergency or disaster.

While there are CW (Morse code) and voice (phone) nets on the HF bands, most ham nets are found on VHF/UHF repeaters to serve area organizations such as a club or emergency communication group. EmComm organizations such as ARES typically have weekly training nets so it’s likely that one is in your area.

Radio nets can be formal or informal.  You are most likely to encounter formal nets which have a more structured feel.

When joining a more formal net, you are likely to hear the phrase, “directed net.”  This means that one operator is in charge of the net, and this person is Continue reading →

Disable Yaesu WIRES Feature

AF5NP DTMF, Echolink, Emergency Communications (EmComm), IRLP, Transceiver, VoIP, WIRES, Yaesu

Yaesu makes some of the best and most popular transceivers for amateur radio use.  In some locations, Yaesus are the majority of radios working local VHF/UHF repeaters.

One of the few criticisms of Yaesu is the WIRES™ feature.  WIRES is an acronym for Wide-coverage Internet Repeater Enhancement System and is unique to this brand of transceiver.  The system can link compatible repeaters together via Voice over Internet Protocol (VoIP).  WIRES-equipped radios using these linked repeaters can communicate over great distances since they use the internet as a pathway.  It’s a hybrid communication scheme combining short-distance radio and long-distance internet.

This sounds like a good idea but is popular only on Yaesu’s home turf in Japan.  While some can be found outside of Japan, WIRES™-compatible repeaters are not common in the rest of the world.   The Internet Repeater Linking Project (IRLP) and Echolink are similar systems more widely adopted and prolific.

So what’s the problem with WIRES™?  It uses a dual-tone multi-frequency (DTMF) signal to identify a Yaesu transceiver to a WIRES-compatible repeater.  Unfortunately, when a non-compatible repeater see DTMF signals it Continue reading →

Microphone Technique

AF5NP Mic (rophone)

Amateur radio operators have numerous modes available for communication but the most common one is voice transmission (phone). This is particularly true for new hams and those involved in EmComm.  Whether you’re using FM, SSB or AM phone, getting your voice clearly heard on the receiving end involves proper microphone (mic) technique.

 

Shure_mikrofon_55S

No matter whether you are using a hand mic, desk mic, boom mic, or built-in mic, there are are two primary concerns with microphone technique: distance and angle.

Keep the mic 1-2″ (25-50mm) away from your mouth.  Any closer and it picks up wet mouth sounds and/or noise from your face/beard/lips brushing against the mic.  These are mainly annoying to the listener but in the extreme may obscure your voice.

In extreme cases with FM radios, it can actually result in over-deviation, which sounds distorted.

T7B01-2018

If your mouth is too far from the mic, the audio level drops significantly and you may become unintelligible, particularly if there is noise at either end.  You also begin to lose some of the Continue reading →

Antenna Lightning Protection

AF5NP Antenna, Coax (ial Cable), Feedline, Lightning, Protection

Many hams have a VHF/UHF radio and antenna for local communication, especially if they are involved in EmComm.  Ideally you have an exterior antenna up high for best performance with your radio. The downside to that is that vertically-oriented VHF/UHF  monopole antennas are a juicy target for lightning strikes.  Basically, they look like a lightning rod.

Lightning Antenna

Lightning wants to go to ground and if the best path is through your antenna and feed line, your radio is likely to be destroyed.  And if you’re right near the radio when it happens, you might be injured, or a fire might be started by the lightning strike.  Bottom line, bad things can happen with an outdoor antenna during a thunderstorm.

W0ZUX lightning damage
Lightning damage in W0ZUX shack

Lightning protection is important to have.  There are numerous sources of arresters available, mostly for coaxial cable (feed line).  Some simple and cheap, others complex and costly.  How much is your radio and even your house worth to you?

Here are some commonly available coaxial cable lightning arresters:

Arrestor4     Arrestor3     Arrestor2

Even better than these stand-alone arresters with separate ground wires is to group them on a plate that is well-grounded.

T0a07-2018

Special ground rods with arrester mounting plates are available for this:

Arrestor1

Common lightning arresters on your antenna feed line help only with minor stray lightning bolts.  A direct strike on your antenna cannot be stopped by a simple arrester; there is too much energy involved to dissipate.  The radio will be destroyed in such a case, along with possible damage and injury.

So what can you do to protect yourself and your radio from lightning?  In addition to using arresters the best way is to Continue reading →

Who’s Your Elmer?

AF5NP Amateur Radio, Elmer, Ham Radio, Training

Elmer is what hams affectionately call an experienced amateur radio operator who acts as a mentor, guide, or encourager to new or prospective hams.  They coach and help prepare for license exams. They help new hams obtain equipment and accessories and get on the air.  They advise how to work the radio and what to say on the air.  They spend time showing new hams how things are done.  They practice communicating on the air to get over mic fright.  They demonstrate new or different modes or aspects of ham radio.  Elmers do all this and more.

So who is your Elmer?  Few people jump into ham radio cold on their own; they probably saw it in action by a relative, friend, or neighbor.  So  that person is your most likely Elmer.  But maybe that person is no longer around or available.  Who do you turn to? Continue reading →

When All Else Fails…

AF5NP ARES, Emergency Communications (EmComm)

Whatever your interest and motivation for getting into ham radio, the hobby has one undeniable benefit when things go terribly wrong in the local community: it may be the only means of communication in case of natural or man-made disaster when commercial radio, television, and phone systems are down.

Even if landline and mobile phones are functional, government and disaster response agencies have priority to use these channels of communication, which means personal calls are unlikely to get through.  The internet may also be disabled or compromised.  In this situation where personal communication is difficult at best, ham radio is the only practical means of getting messages across town and even farther.

Unfortunately this scenario is real too many times and has led to the emergency communications (EmComm) slogan, “When All Else Fails…Amateur Radio.”

WhenAllElseFails

Hams have a reputation for getting radios and antennas set up quickly without commercial power and organizing EmComm networks for Continue reading →

Ham-Speak

AF5NP Abbreviation, Ham-Speak, Jargon, Lingo, Terminology, Vocabulary

Amateur radio operators have quite an interesting vocabulary.  This “ham-speak” may be called terminology, lingo, or jargon and it often includes many abbreviations.  If you don’t understand a term, just ask the person using ham-speak to explain it.  Don’t worry, you will figure these out over time.

A lot of the words are technical because hams use radios and electronics and antennas and cables and power supplies and meters and…well, quite a few gizmos that involve big and fancy words.

Other forms of ham-speak are more cryptic and non-technical.  Hams are equal-opportunity obfuscators; we can make an unintelligible mess out of anything!  Just kidding– there is often good reason for all of this terminology and abbreviation.

The technology part of ham-speak is largely unavoidable; there are no good alternatives for transceiver, impedance, modulation, propagation, and such terms.  There are, however, slang terms for some of these technical words and plenty of abbreviations.  For example, the word Continue reading →