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Useful advices / The CB Antennas / Adjustment of SWR

THE S.W.R. (Standing Wave Ratio)

All President antennas are delivered pre-adjusted. Nevertheless the environment and the location selected for the installation are as many factors liable to make vary the S.W.R. So it is important to check if your antenna is perfectly connected before using your CB radio. Transmission with a non adjusted antenna, a damaged antenna cable or a disconnected antenna can cause important damages on your transceiver.


This adjustment, which has to be done accurately, improves the performance of your installation and avoids damage of your transceiver (a transceiver damaged by a maladjusted S.W.R. is not covered by the guarantee). This operation has to be done imperatively during a changing of the antenna. This adjustment has to be made in a free and open location.


Cable PL / PL


The S.W.R.-meter (President TOS-1 or TOS-2) is connected between the CB radio (TX) and the antenna, as close as possible to the transceiver (use a cable of max. 35 cm like CA-2C).


  1. Check all connections.
  2. Set the CB radio on channel 20.
  3. Set the switch of the S.W.R.-meter on position FWD (gauging).
  4. Press the key of the microphone to pass into transmission and keep it in this position.
  5. Bring the needle of the S-meter on the pointer , ∞ or SET with the gauging button [CAL].
  6. Put the switch in position REF (reading of the SWR value). The value read on the S-meter must be close to 1. In the opposite case, readjust your antenna (by sliding the radiant) until you obtain a value as close as possible to 1 (a S.W.R. value between 1 and 1,5 is acceptable).
  7. In some cases, it may be necessary to shorten the radiant of your antenna of some millimetres in order to obtain a correct value.
  8. It’s necessary to gauge the S.W.R. meter again between each adjustment of the antenna.
    Your CB radio is now ready to function.