This article is going to show you how to fix CB coax cable easily with some basic tools and household items.
Before starting you will need a few things…..
- A small pair of electrical cutters
- A small pair of pointy nose pliers
- A soldering iron and some solder
- A roll of standard household silver foil
- A sharp scalpel or craft knife
- A roll of electrical insulation tape (same color as the coax if possible)
- 1 foot of heat shrink tubing (optional)
- A hot air heat gun (optional)
The only skills you need to complete this task are to be able to solder and to handle a sharp blade.
Important If you are going to be using the heat shrink tubing and the coax has an antenna on one and a plug on the other, now is the time to put 8 inches of tubing over either piece of the coax. If it is not done now the joint will have to be taken apart again to fit tubing (I know this is common sense but I will admit to forgetting this some times and its a real pain to sort out).
A Breakdown of Coax
Here is a piece of coax that I have stripped and each section is labeled so you know what I am referring to in this article.
Preparing the Coax
If the ends of the coax are not flush or some wire is showing cut down the ends of the coax so no wires are showing.
Now with your scalpel carefully take off 2 inches of the outer insulation, making sure not to cut the screen underneath, if you just score the outer insulation all the way around you will be able to break it away by bending the coax, then pull the screen back an about an inch and twist into a point to keep it out of your way until needed.
Soldering the Core Wire
Now you have 1 inch of exposed inner insulation and core to work with, take your cutters and remove 1/2 inch of it by cutting through the inner insulation and the core.
Using the scalpel remove 1/4 inch of inner insulation by scoring all the way around like you did with the outer insulation, careful not to scratch the core too much or this will cause problems in the next step.
With your pointy nose pliers make little hooks out of the exposed core wire.
Now interlock the hooks together and squeeze tightly closed with your pliers to create a solid connection.
Next apply a generous amount of solder to the hooks and allow them to cool down completely.
When everything has cooled down, take the insulation tape and wrap it around the hooks to separate the core from the screen making sure none of the fine screen wires are trapped under the insulation tape and causing a short circuit.
Joining together the screen
Try to spread the screen wires out as much as possible and join by twisting them together with your fingers, don’t panic if its twisted up into a thin strand as the silver foil we put on next will solve this problem.
Lay the screen flat before soldering taking care not to melt the insulation tape covering the core hooks.
Let the screen joint cool and remove any sharp bits with the cutters paying close attention the underneath of the joint so nothing will pierce the insulation covering the core hooks.
Apply the Silver Foil
The screen plays an important part in the overall performance of the coax and because we have disturbed it we are going to cover the screen joint with a layer of silver foil to provide continuity.
Cut some silver foil to the approx width between both sides of the outer insulation and wrap it around the screen joint 2 or 3 times and secure in the middle with a little piece of insulation tape , don’t worry about trying to pull the silver foil tight at this point as it will be forced down onto the screen joint properly when we tape the whole connection off.
Taping up the Connection
Start at one end of the joint and wrap the tape around and around tightly all the way to the other side of the joint. Repeat this step 2 or 3 times to get a good layer of insulation over the whole joint.
Using the Heat Shrink Tubing (optional)
If your newly created joint in the coax is going to be outside, its a good idea to add better waterproofing as the tape used will last some time when exposed to the elements but will eventuality break down.
If you don’t have heat shrink tubing already be sure to measure the diameter of your coax before buying any or cut a inch or so off and take that to the store with you.
For a good fit the tubing should be about 5 millimeters bigger than the coax.
Slide the tubing over the new joint so it completely covers it with some of the tubing also covering the outside of the coax insulation on both ends.
Take heat gun and apply heat to tubing until it shrinks to fit over joint, please note that all the insulation on the coax is plastic and too much heat will melt it and cause a possible short circuit, so start with the heat gun at least 6 inches from the tubing.
You can shrink the tubing with the end of the soldering iron if no heat gun is available but this is not a very good method and can give mixed results with a reduction in levels of waterproofing.
And there you have it, a CB coax joint without the need for bulky connectors.
Knowing When to Repair or Replace Coax
Judging when the coax cable is just too far gone or the radio system its being used in makes a repair problematic or dangerous can be broken down into some very simple metrics.
Any join in coax that’s going to handle power levels above 100 watts (on whatever frequency) should always be done very carefully and to the highest standards. With power outputs in the region of 500 watts and above I would always completely replace the coax regardless of how well I could join the pieces together.
If you feel that any repairs you’ve made to coax is dragging down your whole CB setup in anyway its best to go ahead and replace it. This is very much a personal choice but if its a worry then its always going to make you think that things could be working that much better.
Keep in mind that even perfect coax loses signal over the length and any join (no matter how masterful) will only make this loss greater.