Here you will find answers to some common questions about our range of GMRS Antennas.
No.
Different sized antennas offer different performance benefits based on a number of different factors including construction type, installation location on your overlanding vehicle, and the gain of the antenna.
Technically the gain (when measured in dBi) of any given antenna is the performance compared to an isotropic radiator (a theoretical antenna that radiates equally in all directions). Hence the “i” in dBi.
The gain of a ½ wave dipole is universally accepted as 2.1dBi.
So the important thing to remember is that gain is not an absolute value of power but the ability of the antenna to radiate more or less in any direction compared to a theoretical antenna.
Without getting too technical, the gain in dB is a logarithmic (base 10) scale and as a rule of thumb:
- 3dB = 2 x power gain
- 6dB = 4 x power gain
- 10dB = 10 x power gain
- 13dB = 20 x power gain
- 16dB = 40 x power gain
If using two antennas on a vehicle, it is recommended to have a minimum of 300mm separation distance between the antennas to ensure no interference.
The AE4705B-U has 6.6dBi gain, and the AE4704B-U has 2.1dBi gain.
For more information on the range of GME GMRS Radome antennas, see here
Ground Dependent antennas require a ground-plane (usually a large metal surface) to operate effectively, where Ground Independent antennas feature an elevated-feed assembly, meaning they do not require a ground-plane.
The full range of GME GMRS Radome antennas are Ground Independent.
While there are a number of 3rd-party antenna switches available on the market, GME does not recommend the use of these products as any potential performance gains will be offset by loss through the splitter, sometimes as much as 1dB.
A preferable solution is an interchangeable whip antenna system such as the AE4700 series of GMRS antennas.