Confused about Antennas?

Choosing the right antenna is as important as choosing the right speakers for your stereo. You can have the best radio in the world but if your antenna isn't doing the job you'll be no better off...

There are number of factors to consider; Where is the antenna to be mounted, will it look good, is it too high, will the vehicle be used primarily on or off road. Most of the time all these things will be under consideration when an installer is choosing an antenna. In the end it will all come down to compromise. Compromise involves getting the best possible performance without detracting from vehicle looks or operation.

Antenna Gain:
The saying "big is beautiful" unfortunately won't help selecting the right antenna. Generally the bigger the antenna the more gain the antenna has; but lots of gain can be a two edged sword. In flat open areas more gain can mean more range, however in undulating or mountainous terrain more gain will probably get you less coverage or at least coverage where its wanted. It's a bit counter intuitive until you look at what's happening.
Referring to the diagram above it can be seen that the 3db gain antenna exhibits a round shaped radiation pattern, conversely the 9dB exhibits a much flatter pattern. The radio RF power is the same for both antennas but the energy is radiated in a different way.

Looking at the next diagram it can be seen that the higher gain antenna is radiating more power into the sky than along the terrain, while the lower gain antenna is giving much better coverage by penetrating the valley. The diagram shows the difference between a 3dB and 6db antenna, imagine the effect of a 9dB antenna.

Antenna Mounting:
Antenna mounting position is probably as important as having the correct antenna because how the antenna is mounted will have a direct effect on performance. Incorrect positioning or mounting affects radiation pattern and overall gain so spending the time getting right is time well spent.

Depending on the vehicle there are four main mounting positions:

1). Bull bar mount
2). Guard mount
3). Roof Mount
4). Gutter Mount

Other common configurations are mirror mount, magnetic base and glass mount.
As a rough rule of thumb ground independent antennas should be used on Bull bars, mirror and gutter mounts.
Depending on weight, they can be used on guard mounts as well.
For roof mount, guard mount and magnetic base mounts 1/4 wave whip or phased whips antennas should be used.

There's a bit of jargon happening here... So what does it all mean?
If you are trying to choose an antenna for use with a UHF CB radio we recommend that you download this brochure and have a good look through it. It will take you through all the different antennas available in the GME range or if you just want to cut to the chase, Click Here and we will make a recommendation for you based on your installation...

For commercial two way radio applications please EMAIL or phone us for advice.