CB Odd Static Issue

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Josey1972

Josey1972

Joined
Oct 28, 2016
Threads
84
Messages
872
Location
Indiana
I have a Cobra 18x. It worked fine in my other truck so I know its not a radio issue. I have a 4' Firestick running to the Slee rear bumper swing out. I have an 18'cable running between the antenna and the radio. The cable, radio and antenna were in my old Land Cruiser. It wall worked just fine.

I don't use the CB at all. I plan to eventually but I travel alone mostly. I do use the WX feature a lot. It has a lot of static. So, I figure I have a ground problem. I ran a new 12ga ground wire directly to the engine. That does not to seem to help.

I have checked the conncections at both the antenna and the radio. All is good. The cable was good from my previous truck.

The ODD part: When I unscrew the coax from the radio and move it around the reception improves.

I'm clueless. I don't know what the issue is.

Any help is appreciated.
 
Presumably static when the engine is running, yes?

Turn off various accessories, including lights etc (especially some LED lights that have very noisy electronic drivers).

Make sure you antenna coax is all good (ground shield and core). Connectors are good. Run you coax away from noisy sources (inside the fender if possible versus through the engine bay.

I presume you have a squelch, you will likely need to raise it up above the background noise level.

The + AND - power leads of the CB should go straight to the battery to minimise noise pickup, i.e. don't pick the + from some ignition switched etc source inside the cab.

Anyhow, just a few random thoughts...

cheers,
george.
 
george_tlc said:
Presumably static when the engine is running, yes?

Turn off various accessories, including lights etc (especially some LED lights that have very noisy electronic drivers).

Make sure you antenna coax is all good (ground shield and core). Connectors are good. Run you coax away from noisy sources (inside the fender if possible versus through the engine bay.

I presume you have a squelch, you will likely need to raise it up above the background noise level.

The + AND - power leads of the CB should go straight to the battery to minimise noise pickup, i.e. don't pick the + from some ignition switched etc source inside the cab.

Anyhow, just a few random thoughts...

cheers,
george.
Click to expand...

I hadn't thought of that. I have the CB run to my AUX panel mounted in the engine bay. Its a good Blue Sea. I will run the power to the battery and see what happens. The cable runs from the passenger corner rear. Through the hatch, under the seats and comes up to the drivers side of the center console.
 
Your cable should be exactly 1/2 wavelength. It should not be coiled or looped like a rope or hose, and no sharp bends like kinks. Run a hard ground from the CB to the battery. Ensure that the cable connector is tight at both end.
 
ferg said:
Your cable should be exactly 1/2 wavelength. It should not be coiled or looped like a rope or hose, and no sharp bends like kinks. Run a hard ground from the CB to the battery. Ensure that the cable connector is tight at both end.
Click to expand...
Ok. I'll do all of the above. Thank you.
 
The 'exact' 1/2 wavelength of coax cable is myth. Looping excess cable not a good idea. But of course the optimum is to cut the cable to the right length in the first place to not have excess to deal with. Basically the optimum cable length is the length necessary to get from the rig to the antenna (ignoring fancy phased antenna arrays etc - which are irrelevant to CB stuff).

cheers,
george.
 
george_tlc said:
The 'exact' 1/2 wavelength of coax cable is myth. Looping excess cable not a good idea. But of course the optimum is to cut the cable to the right length in the first place to not have excess to deal with. Basically the optimum cable length is the length necessary to get from the rig to the antenna (ignoring fancy phased antenna arrays etc - which are irrelevant to CB stuff).

cheers,
george.
Click to expand...

The 18' cable is just about right length wise.
 
That's fine if you need 18', but it won't make any difference. The shorter you make it, the better you will transmit and receive since you will be reducing coax signal losses. My comment was that the so called 1/2 wavelength cable length is a myth that has been propagated from early CB days. Besides, 18' is wrong since you need to use the velocity factor of the cable (hint the signal travels quite a bit slower than the speed of light - which is what the 18' is based on....).

I'd focus on the power and ground feeds to your rig (go to the battery, uses fuses there), run the coax away from noisy sources, ensure connectors are tight and good connection is being made, use good quality coax (50 ohm), etc. Basically what I first posted up top. Make sure all the factory ground straps to/from engine are in place and good.

cheers,
george.
 
Yes. The device that anchors the antenna through the hole in the swing out was making contact with the metal. I put in a rubber grommet and problem solved. I had thought about it earlier but discounted it as a possibility. Then a friend suggested it and what do you know!
 
If you're running the CB from a properly installed aux fuse box, which is most likely connected directly to the battery via heavy gauge wiring ( and isn't ign switched), you're not likely to see much difference when connecting directly to the battery.

Have your measured SWR?

Check your coax, as mentioned: no excess, loops or sharp turns. Check to see if you're running it by some heavy power cables or similar (maybe audio amps or something?) and check to see that both ends are properly soldered.

Is your antenna mount/bumper properly grounded? Check this out: The importance of grounded mounts

Your coax is a part of your antenna, so reception should change if you move it around
 
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