Many users don’t give a second thought to antennas, but antennas are a crucial part of any two way radio system. They are the important link between the two way radio and the outside world.
When transmitting, they convert electrical current into radio waves, and on receive they convert radio waves into electrical current.
Antennas are also tuned to work on a specific frequency.
Factors such as corrosion, damage to feeder cable or faulty connectors can severely affect antenna system performance.
Even the very best two way radio can’t work properly without an efficient antenna system.
Different types of antenna vary in performance. This is due to something called “gain”.
There is a standard theoretical perfect antenna, known as a “unity gain” antenna.
This standard can be used to compare antennas which have better or worse performance or gain.
A high gain antenna is more efficient, but will not usually give better range.
A good rule of thumb is that a higher gain antenna will clean up weak signals which were originally difficult to understand.
Generally, for higher gain, a longer antenna is needed. There are restrictions to this, because the antenna length must also be tuned to the frequency in use.
The length of an antenna usually isn’t a problem when vehicle mounted, but the length can become an issue on hand portable equipment.
Hand portable antennas tend to be helically wound (coiled up) to make them less cumbersome.
“Compressed” antennas are also available with an even shorter profile than normal.
The biggest factor affecting hand portable antennas is the human body. It tends to shield the antenna.
The worst scenario for this is usually when a remote speaker or headset is used with a portable two way radio. The tendency is to attach the radio to the user’s belt.
As you can imagine, being up against the body, the antenna will be subjected to maximum shielding.
Also, the proximity to the body will affect the tuning of the antenna, making it far less efficient.
There are specialist antennas available, designed for specific tasks.
A directional antenna is designed to have extremely high gain in a specific direction.
A multiband antenna is designed to be resonant on multiple frequencies.
As the title of the article suggests, one of the best ways to keep your two way radio at peak performance is to look after your antenna.
Most problems, such as physical damage will be evident on close inspection.
Dodgy connectors, or damaged feeder can be more difficult to spot.
You could just pop in to Radphone and have us check things out for you.