Georgia Trail Riders Forum

MEMBERS DISCUSSION AREA => General Discussion => Topic started by: OscarMike2.0 on January 16, 2015, 08:14:55 PM

Title: CB radio help!!
Post by: OscarMike2.0 on January 16, 2015, 08:14:55 PM
I have a Cobra 75 cb radio and I installed it about a year ago, it had been working fine until about a month ago when it would start to make noises out of the left tweeter whenever I spoke (I could hear perfectly clear) and now I went to test it out again because I am going for a FS ride tomorrow and not just the left tweeter but both now make a horrible noise whenever I press the talk button on the cb (I can still hear others clearly)

HELP!!
Title: Re: CB radio help!!
Post by: ranier1315 on January 16, 2015, 08:28:29 PM
We'll see what we can do with it in the morning. Get there early. Doesn't sound like a normal problem though so not sure what we will be able to do.

first check and make sure you don't have coax crossing any of the stereo wires. That could cause crossover noise. Other than that, not sure what could be going on.
Title: Re: CB radio help!!
Post by: DOUG on January 16, 2015, 08:30:58 PM
Turn radio off and ok?  Radio issue not cb issue?

Maybe coax rubbed thru?

Don't know.
Title: Re: CB radio help!!
Post by: OscarMike2.0 on January 16, 2015, 08:32:16 PM
We'll see what we can do with it in the morning. Get there early. Doesn't sound like a normal problem though so not sure what we will be able to do.

first check and make sure you don't have coax crossing any of the stereo wires. That could cause crossover noise. Other than that, not sure what could be going on.

Alright thanks
Title: Re: CB radio help!!
Post by: OscarMike2.0 on January 16, 2015, 08:33:17 PM
Turn radio off and ok?  Radio issue not cb issue?

Maybe coax rubbed thru?

Don't know.

No even when the stereo is off it makes the noise.  The stereo system is fine  when i dont have the CB on..
Title: Re: CB radio help!!
Post by: cru9 on January 16, 2015, 08:41:07 PM
Sounds like a poor ground
Title: Re: CB radio help!!
Post by: OscarMike2.0 on January 16, 2015, 08:44:32 PM
Sounds like a poor ground
Already checked ground thats not it.
Title: Re: CB radio help!!
Post by: cru9 on January 16, 2015, 08:46:20 PM
Do you have a separate ground or just using antenna mount? Do you get dame noise if Jeep running motor  and with it just turned on Accessory power?
Title: Re: CB radio help!!
Post by: OscarMike2.0 on January 16, 2015, 09:06:26 PM
Do you have a separate ground or just using antenna mount? Do you get dame noise if Jeep running motor  and with it just turned on Accessory power?
Separate ground. And yes it makes the noise even if the car is completely off and I turn on the cb.
Title: Re: CB radio help!!
Post by: Cannonballkev on January 16, 2015, 09:57:50 PM
Bad mic?
Title: Re: CB radio help!!
Post by: OscarMike2.0 on January 16, 2015, 09:58:01 PM
I think I will just show up early and see if anyone is willing to help me.
Title: Re: CB radio help!!
Post by: OscarMike2.0 on January 16, 2015, 10:01:32 PM
Bad mic?
I dont think so but tomorrow I will switch just mics with my buddy whos has the same CB to see if that could be it
Title: Re: CB radio help!!
Post by: Jango on January 16, 2015, 10:39:53 PM
We used my swr meter and did the full test ( ch 1 , ch 19, ch 40) each test gave me a reading right between 2 and 3 which was in the red zone on my meter.
This is what i found from a cb radio website about the readings..

"If SWR is in the "red zone" on all channels, you probably have an electrical short in your coax connectors, or your mounting stud was installed incorrectly and is shorted. Do not operate your radio until the problem is found, serious damage can occur to your radio."

We both could not detect any sort of short in the coax cable on either ends or in the middle.The "brain" is grounded down on the body inside the cab. The power wire for the CB is ran to the fuse box i believe, due to the cb only working when key is turned to battery.  And the antenna is grounded only on its mount (no other ground wire off the antenna). checked the mount fittings under the antenna and those were perfect.

 After all of this I could still not have any idea what in the world is going on with Oscar!!
Title: Re: CB radio help!!
Post by: ranier1315 on January 17, 2015, 05:09:59 AM
CB to the fuse box probably answers the interference problem. RF can back feed through the power cable. The SWR's are probably a whole other problem.