CB Radio Antenna

Thread Starter


Joined Apr 14, 2017
I wanted to make an Antenna for my CB Radio that is in my Bedroom.

I got this Cable.

Then at one End I put this Splitter.

The Splitter just gives you 2. Terminals for you to put your Left Wire Lead and your Right Wire Lead.

So Internally the Center Conductor of the cable is going to 1. Terminal and the Shield of the cable is going to the other Terminal.

To make my Left Wire Lead and Right Wire Lead I take 22 AWG.

I cut 8. and a Half Feet for the Left Wire Lead and Right Wire Lead.

I have 1. LWire Lead going to each Terminal.

I go into my CB Radios SWR Setting and yes I know how to Set it up.

I should get a Rating between 1.0 and 1.5 I got 9.00 this is way to High.

I do have this on a Rod on the Top of my Bedroom Ceiling.

Can anybody help?

Thread Starter


Joined Apr 14, 2017
The Adaptor takes the cable and at one End and gives you 2. Terminals.

What are the 2. Terminals for then if they are not giving you 1. for the Center Conductor and the 1. for the Shield?


Joined Jan 27, 2019
A balun (for balanced-unbalanced) is a device that converts a balanced line to an unbalanced one. The dipole antenna you are making has a characteristic impedance that varies based on the distance from the ground.

It is nominally and impedance 72Ω but can range from less than 50Ω to more than 100Ω for a λ/4 (¼ wave) antenna like the one you are trying to construct. The balun has a transformer inside it which is to prevent the shield of the cable from becoming part of the antenna.

The coax you are using has an impedance of 50Ω. The antenna may not be a very good match at all if it is too close to the ground or the wrong length—or both. Additionally, CB radio uses a vertical polarization so if you use a horizontal dipole it will not be very effective on the band.

The length is very critical. Measuring it approximately is not enough. Many things can affect the electrical length of an antenna. The physical length of the wires is just one factor. You are very unlikely to get a good result using the antenna you have made, but if you want to try to make it work it will have to be hung vertically and fairly high off the ground.

This is probably not practical, so the best bet is to buy something like this mobile antenna and attach it to a large piece of metal for a image antenna, that is, the other half of the antenna system that is created by the ground. Something like a file cabinet will work pretty well—or you can fabricate a mild steel bracket and provide 1 to 4 λ/4 radials electrically connected to it. This could one in the form of wires. Ideally they would be at a 45° angle but even without that you can probably make it work.

One more thing that is probably a good idea is to get an antenna tuner to match the antenna to the radio. This is because you are probably going to have a hard time tuning the antenna with just length adjustment.

The right way to solve this is to buy a proper outdoor antenna. There are no shortcuts and a good antenna is going to be much longer than you can fit in your room.