How To Choose a UHF Antenna
When choosing an antenna you want to make sure it's going to be effective for your UHF needs and not just look good on the bull bar. Antenna gain is measured in dBi and is simply the measure of an antenna's ability to direct or concentrate radio frequency energy in a particular pattern or direction. dBi Gain is one of those things that's not just the bigger number is better.
Choosing the antenna can be confusing at first but if you know where you're primarily going to use your 4wd's UHF then it can be fairly simple. Are you using your 4WD for going bush? Up through the mountains? Down into rivers and valleys? Or are you wanting to use your UHF system primarily on the flat country roads? Figuring this out will help you choose the right antenna and get the most out of your purchase.
Simple rule of thumb for understanding dBi Gain:
- High Gain Antenna (8.1dBi) - This is ideal for flat country side with fewer obstacles in the signals path. This is good for touring the outback, heading up the Hume or playing i-spy with your mates on the treeless Nullarbor desert plains. The signal radiates in a straight narrow path.
- Medium Gain Antenna (5.1 - 6.6 dBi) - This is the go to antenna if you do a bit of everything. This antenna is ideally suited to those who drive around suburban and country areas. The medium gain antennas are less likely to be obstructed from buildings, trees or mountains.
- Unity gain (2.1 dBi) - This describes an antenna that outputs a signal the same level as the input. It works on a very broad pattern and is far less likely to be obstructed from buildings, trees, rugged terrain or mountains.