Selecting Antennas / Coaxial Cable
Normally antennas and cable types are selected following a radio test for a proposed installation.
The test will be done with specific antennas and cables and the results of the test will indicate whether higher gain antennas or lower-loss cables are required.
For Example:
- If a test yields a fade margin of 5dB, then you know that by inserting an extra 5dB antenna gain, or removing 5dB coaxial loss, will increase the fade margin to 10dB. The gain can be inserted at either the transmitter or receiver end, or both.
- If a test shows that net antenna/cable gain of 6 dB is required for reliable operation on a line-of-sight path, and a cable length of 10 metres is required at both ends of the link to give line-of-sight, then you can select which cable to use, and then select the antennas to give a net gain of 6dB.