Ok totally CB newbie. Buddy and I just installed Cobra ultra 19 CB's with Firestick firefly antennas. I got mine tuned to ~1.6-1.7 on both 1 and 40 and middle channels are down around 1.1-1.2 range. My buddies SWR numbers are a little higher but 1 and 40 are under 2 and middle mid 1's. We can talk about a mile away in an urban setting with lots of buildings etc. Problem is when he is done talking and lets off the mic I get a short annoying sqreetch high pitched noise. He said on his end he gets more of just a scratchy interference squelch noise when I am done. Any ideas? Headed to Moab on the 27th of this month and it will drive me crazy if I don't get it to stop. thanks

 

Did you both use a SWR meter while tuning your firefly antenna (have to remove the red cap on top)? Have you adjusted the squelch control knob? Did you use high quality coax cable? And last how are you powering your CB? Best to connect directly to the battery by going through the firewall. Just make sure you use an inline fuse near the battery connection. You may have already tried all these. Give us a little more info.

 

Is it the same noise as when you manually open the squelch? If so, welcome the the world of HF communications. If not, it could be something near you causing it. Try listening from a different location.

Finally, it could be something distant that you hear because of skip. This is a cyclical thing (11 year period), and it has been especially bad and annoying the past year or so. The solar cycle just peaked last year and is now on decline.

Bear in mind CB is not a cell phone. It isn't VHF or higher, where things are more quiet. It is HF where 5 watts is enough to literally go around the world in the right conditions (that solar peak last year). And it is AM modulation, which is especially susceptible to noise.

 

yes we adjusted both antennas with a SWR meter (fireflies both had black caps and both were put on after each adjusment and retested with cap back in place) Radio Shacks best CB cable 20' and properly laid out the excess not coiled etc. I am not batter direct but using a cigarette plug as I won't be leaving it in the jeep when not off road. Squelch is turned down just past where it is open. voice sound was clear on both ends when mic was keyed but the noise happens when unkeying the mic. Not sure what high knob is. thanks

 

it is on his end he says it sounds like squelch. On my end it is much sharper and higher pitch. It is only there for a second or two after he is done keying the mic.

 

Well, that is about how long before squelch should cut noise off. But, you may have a problem in the radio. You might try swapping radios with him to test it.

Also, is your engine running? If so, try a radio check with just the battery (ignition to accessory, engine off). You could be picking up noise off the alternator. Engine off test will help test that. If noise goes away, you could try changing where your power wires run and hook up. There are also filters you can put on the power leads to eliminate alternator noise. I will let you Google that.

Finally, you could have some obscure interference generated by something else. Stereo. AC fan. Seat heaters. Test turning all of that stuff off and see if you can isolate noise generator.

Tracking down noise can be frustrating, but it is possible by a process of elimination. Good luck!

 

my vehicle was running as I was driving I am not sure if his was off or on. car radio was turned off but defroster was on so fan was running. heated seats off. thanks. We relieve each other at work so I won't see him again until 6pm and will give these ideas a try. thanks.