Using Antenna Extension Cables

In some Wireless Control System installations antenna extension cables are needed between the transmitter or receiver and the antennas being used. This is mainly because the antennas need to be mounted higher off the ground, or out of the way of physical obstructions to obtain a clearer line-of-site for the RF signal path.

The one draw back in using antenna extension cables is the resulting signal loss. Signal loss through a length of coaxial cable is primarily a function of two things: Length and Frequency. The longer the length of a piece of coaxial cable, the more signal is lost. The higher the frequency of the signal passing through the coaxial cable, the higher the loss over a given length. Coaxial cable loss is normally specified in dB loss per foot of cable.

The cables we use for antenna extension cables are made from RG174 Coaxial 

Estimated Signal Loss Table for RG174 Cable

 Cable Length
At 900 MHz At 2.4 GHz
6 ft 1.88 3.61
9 ft 2.83 5.42
12 ft 3.77 7.23
15 ft 4.72 9.04