Main > Write-ups

Coax Cable Selection

Coax Cable Selection & Installation

First off, there are a few cables and manufacturers out there. Indeed, some antennas will come with coax as a package. With the exception of magnet mount style of antennas (which most don't stay on Jeeps very well while off roading), this is fine if you want to use it. However, note the type you have so when you end up replacing it you'll know what not to get. Here are the most common types:

RG8U

RG8X

RG58U

(About ½" in diameter) Larger & stiff, not very flexible, and mostly used on base stations. Tends to be pricey, and not suited well with mobile use. Although it would work if that is what you have. It's just harder to use, that is all.

(About ¼" in diameter / commonly called RG mini 8) Preferred by most (including me). Flexible, small in diameter, reasonably priced, easy to work with, and reasonably strong.

(About ¼" in diameter) Commonly provided with antenna packages. Weaker than the above by far, especially on the center lead wire and shielding. Cheaper, but not near as strong in many ways.

Length(s) of coax to purchase:

First off, many say it is necessary to buy and use a full 18' of coax. Indeed, this is true If you were running hundreds of feet of coax. This debate will go on for a long time. However, I personally have never had a problem cutting my coax to size. In other words, if all you have is a 14' piece, then lets use it…provided you want to. The amount of resistance caused by a "non ½" wave" piece of coax is so negligible, that it's hardly worth discussing…especially on a mobile set up.

Remember, "We want to keep things simple, and inexpensive". So let's not fret about it. If you've purchase an antenna that has an 18' coax with connectors, no problem,. let's use it. Provided the coax is in good shape with no pinches that would cause a short, we're good to go. One simple hint though, if you have excess of coax left after we run it, do not coil it. This will create resistance, and reduce performance. Simply 'zig zagging' it and zip or wire tying the excess should be fine.

Coax to Radio connection;

The connector used to hook up your coax to the radio is called a PL-259 connector (UG175/176 adapters required with RG8X). This is important only if you didn't buy a prefabricated piece of coax. If your coax came with connectors then it is a matter of just plugging it into the back of the radio.

If you didn't buy a prefabricated piece of coax, no problem. You can pick up the connectors at any Radio Shack, most truck stops, and most certainly any CB or Ham radio outlet store.

There are a couple details we should look at prior to hooking up the coax. First off, I'd recommend considering running your coax in an area of the least amount of traffic in your vehicle (yet accessible), if you are running it inside the cab or tub that is. This is especially important if you are using the RG58U coax as it will not take a lot of abuse. Now is a good time to consider and formulate a plan for running your coax. If you are running it under the chassis, then make sure you secure the coax well (away from heat sources such as exhaust system) to keep it from snagging on branches, brush, rocks, etc. Usually you can find plenty of areas to run it and zip tie it.

Assuming you've come up with a plan, lets begin running our coax towards our antenna mount.

CB selection | Wiring Basics | Cable selection | Antenna Mount