CB purchase

So when you key it up it makes a whining sound?

Did you check you SWR?

Well when my Cobra 148GTL did that, I had to replace the coax cable from the stock one connected the the AM/FM radio to it's own coax cable and with a correctly Shielded Copper coax cable.

DO NOT USE the cheap aluminum junk coax.

It was Squealing over the AM/FM radio Speakers and not grounded correctly with the stock equipment that came with the truck.

Also make sure the power and ground are direct to the battery with a 8 to 6 gage wire(fused on both sides just in case)

Make sure your antennas have a really good ground and use extra grounding wires or grounding straps if needed from mounts to the body and to the battery.

Copper is the best to use. If you want to you can use a flexible plastic dip on the grounding wires or grounding straps to keep them from going green over time.

Silicon and petroleum jelly are good in the areas where water may cause a problem later at connection points.

I personal also use soldering and glued heat shrink and plastic wire armor with hockey/duck tape to make sure the wires are sealed and protected from water, dirt , rubbing wires or exposed metal.

If you going to build it right, Over Build IT !!!

 

This is the starting place.

Grounding Properly is very important

Stock Cobra radio you can easily run it on 12 to 14 gauge. You can ground it to the body, use a eyelet connector , connect it to the wire using a dimple crimper or solder, to the body using a sheet metal screw and 2 internal/external lock washers 1 on each side. You can run to the batteries for 12+, install a fuse at the battery end of the wire, never go futher than 4 to 6 inches from the power source before adding the fuse. The fuse is there to protect the truck, not to proect the radio..

This is all good ideas, save later heartache.

Never use petroleum jelly on a electrical circuit, it will melt and cause future problems like intermitant or a voltage drop.
RTV Silicon is good, I use a conductive lub available at industrial supplies, be very careful it is conductive. wrap in 3m splicing tape and cover with Scotch's coat Scotch® Electrical Moisture Sealant 06147/06149, it is a electrical selant. You now have a water proof connection you will never mess with again.

This is good, but what I use to protect wires is the outside jacket from coax scraps, Im all for wire armor preventing abrasions, cuts and shorts of the future.

I apologise for the slice and dice.

Grounding properly is most important for chasing noise.

The radio is just showing you there are problems, its not necessarily the problem.

You could also have bad diodes in the alternator. they are what changes the ac in the alternator to dc for the battery system. the whine can be traces of ac wandering about thru the wires.

 

I get my CB's from Amazon.com. I use a Cobra 29 barefoot with an Astatic Road Devil amplified mic. Cheap, but effective.