How to Calibrate a CB Radio in Only 5 Easy Steps

After mounting your CB, you need to tune the antenna and calibrate the radio so it can perform correctly. The process involves four steps:

Calibrating CB antenna only takes five minutes once you learn how to calibrate a CB radio properly. So, dive in!

What You Need

  • SWR Meter
  • Antenna

Steps to Calibrate a Cb Radio

Before you begin, make sure to park your truck on vacant land. There should be no trees, mountains, or buildings within 15 meters. Also, close your truck’s doors and windows.

Step 1. Set up the antenna

If you already have your antenna set up, feel free to skip this step. Otherwise, prepare two ring washers, one lock washer, and one four-inch spring. The spring will bend to lower the impact of trees or wind on your antenna, preventing it from breaking. Follow the product instruction to install the antenna system.

Then, run the coax cable from your antenna to the CB radio. The cable should be completely straight; any cable coils can cause interference. Remember that the shorter the cable length is, the better the audio performance.

Step 2. Install the SWR Meter (Optional)

Most CB radio has a built-in SWR meter. But if you want to upgrade your system with a separate one, make sure to set it up in this step.

Each CB radio has 40 channels. You should start the CB radio calibration with the first frequency.

Step 3. Calibrate on Channel 1

To calibrate a Cobra CB radio, you must turn your radio on. Then, turn up the volume until you can hear the background chatter, set it to Channel 1, and follow these steps:

  • Flip the S/RF SWR CAL switch to CAL, which indicates calibration mode
  • Key the microphone button
  • Roll the SWR CAL knob until the SWR meter turns to the right and stays under the symbol CAL
  • Keep pressing down the microphone button, switch it back to SWR, and take note of the number on the SWR meter.

Repeat the same steps for Channel 40.

Step 4. Adjust the antenna

Now, compare the two SWR numbers that you have.

  • If the number of channel 40 SWR is higher than that of channel 1 SWR, you should shorten your antenna.
  • If the number of channel 1 SWR is higher than that of channel 40, you should lengthen your antenna.

SWR stands for Standing Ratio Wave, which is the differential between the transmitter and the antenna signals. Ideally, this ratio should be 1 for zero mismatches.

For a correct SWR calibration, readings should be similar and lower than two.

Step 5. Double-check on Channel 19

When you finish adjusting the CB antenna, double-check everything on most truckers’ favorite channel – Channel 19.

  • Set to Channel 19
  • Flip the switch to CAL for calibration
  • Key the microphone
  • Flip the switch back to SWR
  • Check if the SWR meter is under two. If not, you must readjust the antenna.

This video will give you more tips:

What About Other Settings?

At this point, you have finished calibrating the CB radio. You can tune in to your favorite channel and listen to the content. But for better audio quality, you need to adjust other CB settings.

  1. Switchable ANL/NB: This switch filters out ignition and engine noise, but it also suppresses weak signals. So, switch it off when you don’t find any signals on your radio.
  2. RF Gain: RF Gain controls the signal range that your radio can pick up. The more you turn this knob to the right, the further the signals your CB can receive. You should keep it at its maximum.
  3. Squelch: When you turn on your radio, slowly roll the squelch to the right until the radio picks up clear signals. When there are no incoming signals and all you can hear is static, turn off the squelch.
  4. Dynamike: The Dynamike Gain controls the microphone volume.
  5. CB/PA switch: This switch lets you communicate on PA (public address) instead of limiting you to CB (citizen’s band).
  6. Delta Tune switch: Delta Tune helps filter out incoming signals.
  7. Channel 9 switch: This switch allows instant access to Channel 9 – the channel of emergencies.


Our guide works perfectly for both the Cobra 29 LTD Classic and Cobra 29 WX NW. Now that you know how to calibrate a CB radio, you can get your wheel rolling and enjoy the best audio quality on the road.

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