Yes, a CB antenna can totally be used for FM. You do need to shop wisely, though, if you have any expectation whatsoever regarding how you want the CB to work.
It started back in the late 70s when manufacturers decided to connect a device to the FM antenna. They named it a 3-way antenna. This was a good idea on a surface level, as it prevented theft, and you were good to go without needing another antenna.
But it was only on the ‘receiving’ end, meaning you could not connect to others. Nowadays, you can easily use a CB antenna for FM radio. Read on to find out how to connect one to your radio.
How to Connect CB Antenna to FM Radio
If you have a radio, it is crucial that you match the CB base station antenna perfectly, as otherwise, you might damage the radio. Setting up the antenna wrongly can result in the radio getting poor signals as well.
Make sure to install the radio first and attach the CB antenna correctly to it. Now you are ready to set up the Standing Wave Ratio or SWR.
How to Set up the SWR Meter?
Setup is easy but has to be done right. Read carefully, get all of the steps right, and you’ll be good to go.
Put the radio function to SWR. The knob is generally labeled as SWR/CAL/R. Make sure that the knob is put to the right function and then look at the meter.
Press on the microphone key next. Keep an eye on the meter in the meantime. The SWR should be in the range of 1.1 or lower, which is the desired range. You can try this on both channel 1 and channel 40.
If, by any chance, the reading is above 1.1 on either of the channels, stop pressing on the microphone key. When the reading on Channel 1 is higher than that of Channel 40, make the antenna a bit shorter. For the opposite scenario, you will have to raise the antenna.
Based on the readings, you can adjust the antenna either up or down. Some CB antennas come with a set screw, and it is easier to adjust. CB antennas come with a pair of rings as well, which helps to adjust the length of the antenna by moving it up or down.
Repeat step 2 to recheck the standing wave. If it is correct, it means you are done setting up the SWR meter. In case it is still out of range, repeat step 4.
How to Read the SWR Meter?
Many people struggle with the reading, even if they get the setup right. Follow these steps here to learn how to do it.
Make sure that the SWR meter is attached. You can disconnect the antenna and plug in the SWR meter. Then attach the antenna to the SWR meter where it says ‘Antenna’.
Bring the switch on the meter to FWD. Press on the microphone key to switch the knob to the ‘Set’ option. The meter will then move to the set mark. Flip over the switch to the ‘SWR’ option while you are still pressing down the microphone key.
Repeat this process for both Channel 1 and Channel 40. If the reading is at 1.1 or lower for both channels, go back to step 3, as mentioned above.
Based on the readings, you can adjust the antenna up or down now. As mentioned in step 4 above, you can now move it up or down till it sets up just right.
Now recheck to see the standing wave by doing what we did in step 2 of ‘How to Read the SWR Meter’. If the standing wave stands correct, you are then done with the process. In case of discrepancy, repeat moving the antenna up or down till the range is correct.
Tip: Do not use a CB antenna without setting up the standing wave first, as this can potentially damage the radio.
Use a CB Antenna for FM Radio and Enjoy!
With a CB antenna attached to the FM radio, you should be able to enjoy connecting to many channels on the FM wavelength. Looking for a CB antenna should be a fun endeavor as well. There are a huge number of CB antenna reviews online.
They are available in many online shops, as well as junkyards. Getting a CB antenna for your FM radio can certainly elevate the quality of your radio signals.