Tuning a CB Aerial

Tuning a CB Aerial

If you're reading this, you are probably already ready to install your CB Radio.  Before you get started though there's something else to do that can make or break the success you have with your radio and that is to tune in your aerial.

Tuning your aerial means adjusting it to the correct height so that the radio puts out signals as efficiently as possible.

That varies, according to the specific vehicle, the place on the vehicle where you've installed it and the ground plane that it has.

First, you measure how the radio is performing currently with an SWR meter, and then you adjust the antenna length or location to improve the signal output.

CB antenna tuning means that you're trying to get the lowest SWR reading possible. You do that by increasing or decreasing the length of the antenna (depending on the SWR meter readings) in very small increments of about 1/4 inch, then retesting.

 how to get started

You'll need to run your swr meter between the cb radio and the aerial using a patch lead.  Connect the patch lead between te cb radio and your swr meter and connect the aerial to the other end of the swr meter.

1. Turn on the CB Radio.
2. Set the CB CB Radio to channel 1.
3. Set the SWR meter to the FWD position.
4. Key the microphone by pressing the talk button and turn knob on the SWR Meter until the needle hovers on the "set" position. Unkey the microphone by letting up on the talk button.
5. Flip the SWR meter to the "reflect" position.
6. Key the microphone and look at the reading on the SWR meter. The lower the reading, the better. If the meter reading is in the red zone, DO NOT operate the CB. Recheck your connections.
7. Turn CB to channel 40. Follow instructions 7-10 again.

How to adjust your aerial

• If the reading on channel 1 is higher than the reading on channel 40, you need to lengthen your aerial. Alternately, if the reading on 40 is higher, your aerial is too long.
• If the meter reading on channel 1 is 1.2 and the reading on channel 40 is 2.3, you'll need to shorten the aerial to get better efficiency. You can do that by turning the tuning tip or the adjusting ring, or you can take the aerial mast out and trim it about 1/4 inch, and place it back firmly against the coil. Remember, it's easier to cut a little more off the aerial than to have to add some length.
• If your reading is 2.6 on channel 1 and 1.3 on channel 40, your antenna is too short. The solutions are to add a spring, raise the aerial, or reposition the aerial.
• If any adjustments are needed, they should be made in small increments. Re-check after each adjustment. Be sure to have all components on the aerial when testing, including the tip if there is one.

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 Tuning a CB Aerial

Other Posts

Getting set up on a CB Radio

Setting the SWR on the CB in the car
CB Car Set up

Setting up a Homebase CB Aerial
Why is SWR? Important