How to Match a CB Antenna
By Pamela Gardapee
If you have a CB radio, you need to know how to match the CB antenna so that you do not damage the radio. If the antenna standing wave ratio is not set correctly, not only can you damage the radio, but you will have a poor radio signal and may not be able to hear or be heard by any listeners. After you have installed the radio and hooked up the CB antenna, you are ready to set the SWR (standing wave ratio).
CB Radio SWR Meter
Set the radio function knob to "SWR." The knob usually reads "SWR/CAL/R." Turn the knob to the right function and look at the meter.
Look at the meter as you press the microphone key. The standing wave ratio should be in the desired range of 1.1 or lower. Try this step on Channel 1 and then on Channel 40.
Stop keying the microphone and adjust the antenna if the meter reading was higher than 1.1 on either channel. If the reading you saw on Channel 1 was more than what it was on Channel 40, you will need to make the antenna shorter. If it was lower than Channel 40, you will raise the antenna.
Adjust the antenna to up or down, according to your readings. Some antennas have a set screw to loosen to adjust the length of the antenna. Some antennas have a pair of rings to loosen and move up or down to control the length of the antenna.
Recheck the standing wave by repeating Step 2. If the standing wave is correct, you are finished. If the CB standing wave is still out of range, repeat Step 4.
SWR Meter Reading
Hook up a SWR meter to the CB. Disconnect the antenna from the CB and plug in the SWR meter to the CB with the jumper. Then hook up the antenna to the SWR meter where it reads "Antenna."
Move the switch on the meter to "FWD." Press the microphone key and use the knob to switch to "Set." You will see the meter move to the set mark. Then flip the switch to '"SWR" while holding down the microphone key. Do this procedure on Channel 1 and Channel 40. The reading should be 1.1 or lower on both channels. If not, go to Step 3.
Adjust the antenna to up or down, according to your readings. Some antennas have a set screw to loosen to adjust the length of the antenna. Some antennas have a pair of rings to loosen and move up or down to control the length of the antenna. If the reading you saw on Channel 1 was more than what it was on Channel 40, you will need to make the antenna shorter. If it was lower than Channel 40, you will raise the antenna.
Recheck the standing wave by repeating Step 2. If the standing wave is correct, you are finished. If the standing wave is still out of range, repeat Step 3.
References
Warnings
- Never use a CB without setting the standing wave.
Writer Bio
Pamela Gardapee is a writer with more than seven years experience writing Web content. Being functional in finances, home projects and computers has allowed Gardapee to give her readers valuable information. She studied accounting, computers and writing before offering her tax, computer and writing services to others.