Keep That HT Antenna Vertical

The previous post introduced you to the handheld transceiver (HT) and suggested that it had limitations.

One of the HTs weaknesses is that because it is hand held, the operator must maintain the antenna pointing up for maximum performance, as shown below.

DSCN4227

This is because repeater and mobile antennas are always vertically oriented and the handheld antenna should match orientation for maximum power transfer.

Antennas are polarized according to the electric field orientation, which is parallel to the antenna element.  So antenna polarization follows the physical orientation of the antenna with respect to the earth.  A vertical antenna is vertically polarized.  A horizontal antenna is horizontally polarized.  More details on antenna polarization can be found in the presentation on Understanding Antennas.

Unfortunately there is a natural reflex to hold the HT at an angle when speaking into the built-in microphone.

DSCN4224

However, this angle really reduces your signal as received at another radio or repeater.  A 45° tilt loses about half its signal strength (3dB).  Because this happens quite naturally we need to be thinking about antenna orientation and force ourselves to keep the antenna pointed up.

Turned completely sideways where the polarization is perpendicular (90°), the signal attenuation is much worse: 20dB loss or about one-hundred times less power received!

DSCN4226

It may look cool and you may see people doing this in movies and on TV shows but that’s not real life.

Of course, if you’re communicating directly with another radio and they have their antenna sideways, you would want yours to be sideways also.  But you would also have to be parallel to their antenna, not perpendicular.  That’s not easy to determine unless you can see them.  Good practice is to just keep your antenna pointing up.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s