When selecting a site for the roof antenna, find an outdoor location that provides full 360-degree visibility of the horizon. In most cases, this means locating the antenna as high as possible, such as on the roof. Any obstructions may degrade unit performance by blocking the satellite signals. Blocked signals can increase the time for satellite acquisition, or prevent acquisition altogether.
A short mounting mast and hose clamps are provided with the roof antenna to mount the antenna to a pole or the peak of a building. The antenna mounting mast and clamps are well suited to attach the antenna to a vent pipe or mast affixed to the roof. The pipe must be rigid and able to withstand high winds without flexing.
- Ensure to use high quality Antenna Cables from well known manufacturers.
- GPS operates on frequency 1575.42 MHz. Please consider this frequency for all cable attenuation calculations.
- Avoid using RG-58 cable for GPS Antenna connections due to the higher loss (~30dB loss at 50m length).
- Recommended cables are CNT 400 / LMR 400 (~16dB loss at 100m length) or 1/2 Inch Coaxial cable (~8dB loss at 100m length ) and limit the length to no more than 100m.
- If longer lengths than 100m are needed, use an In-line Amp, but install it close to the antenna as possible. Typical In-line Amps need a minimum of +6dV input to function properly. it is recommended to test the setup before installation.
For Cable attenuation calculator, following link may be used - RF Transmission Line Loss Calculator