CB problem - Appreciate Thoughts ??????

[mangojk]

Ok, I installed my CB in my JK and its not working properly and I need help trying to diagnose problem ! My CB is a Cobra DX 19 subcompact and is mounted inside console my antenna (fire stick)is mounted on my Spare tire rack and coax cable is mounted through rubber grommet through rear door and runs up right-side behind panels and under carpets and crosses at the back of right side rear floor pan into console approx. 12'-14' feet long. If vehicle is running and stereo is on I get voice through rear sub/amp, it also triggers all dash lights on and sometimes even wipers.I have check for shorts in the antenna and it is OK. I had it check today for RF signal and is very high around 3 almost 4. I took a second antenna coax cable about 16' long and ran from center console and ran out the passenger door along outside of Jeep in screwed it into the antenna " works fine" checked RF and is around 1 maybe a little lower on channel (1) and 1-1.25 or so on channel (20).I then took the coax that gives me good RF and run it through inside of Jeep and out between tailgate and window test CB problem still there and when engine is running. The only thing that I can figure out but doesn't make sense to me is my power feed runs up right side of Jeep to rear Amp/Sub. The coax is a shield cable and I even wrapped Amp power cables in foil to see if it would make difference no change

[dartjeep]

NOT being a smartass but your post reminds me of the old joke.... guy goes to see his doctor and says " doctor, it hurts when I do this..." doctor says "then stop doing that". lol.

sorry.... I guess you have your answer, re-run your coax away from ALL power lines and maybe even check that the "radio" part of your cb is away from stuff too. What's in the console next to the radio box? it's obviously leaking RF all over your wiring so re-route it.

Again, not being a smartass but I think your answer is clear based on your post. good luck


edit: extreme SWR will do that too. So after routing your coax down the other side of the jeep away from power and speaker wires, tune your swr so that it's as close to flat as you can get it. Take good care to get good grounds, don't share grounds with other devices. Your antenna should be grounded good, not mounted on plastic without a ground wire going to clean steel.

[mangojk]

Thanks for info smart ass ! I figured I was setting myself for the reply. Already removed Coax tonight and was planning to run up opposite side , hopefully that should fix the issue ..... lol . Because there is a power outlet in console , should I relocate CB ?

[dartjeep]

Mar 19, 2012 21:55:32 GMT -4 mangojk said:

Because there is a power outlet in console , should I relocate CB ?

If re-routing your coax doesn't solve it completely, I would, yes.

You should be able to key up 250 watts or more and not have your wipers turn on by themselves. The radio itself could be feeding interference into your power outlet beside it. Maybe try a different radio if the re-routing doesn't fix it.

[mangojk]

Thks for info, I will see what happens tomorrow and will update progress .

[00tansahara]

also i fought with mine alot too!!! originally i had mine hooked up to a aux wire behind glove box, had interferance with my radio and it screaming everytime i keyed the mic.... to fix that i ran my power and ground wire directly to my battery... then i faced the problem of high swr up to 3 and higher!!! so sanded off my antenna bracket and made sure that the antenna threaded adaptor had the lock washer, insulating washer in the right posistions!! tested again around 1.25 swr... still wasn't good enough for me though lol... so took my spare tire bracket off when i got out to my parents tackled it with a cut off wheel to make sure it was completely grounded off!! and my bracket was bent so i straighted that out but accidently jammed the coax in the tailgate!! so then i needed a new coax cable wasn't getting anything anymore.... got that fixed and now i'm at 1 swr!!

[The Garagemahal]

You know you can tune the antenna to get the swr down

[mangojk]

I still cannot figure out what is going on with mine, I have removed and reinstalled my coax up opposite side of Jeep away from power and RCA's for sub/amp and measured RF and is still quite high. I checked the antenna bracket and I figured it didn't have good enough ground so I ran a separate ground it may be a bit better but still not satisfied with the overall performance. I seems to work better with stereo shut-off. Does anyone know anybody that works on these things ? Car audio installers don't seem to be up on this stuff.

[The Garagemahal]

You may need an inline noise reducer , Its a small box that goes on the power supply
Do you have the plastic isolator / washer on the ant ?

[00tansahara]

if you were closer i'd say stop by and i'd have a look at it

[mangojk]

I do have the plastic isolater on there. Will the noise reducer take the feed back I am getting at the sub when I key the Mic ?

[dartjeep]

Do you have a friend near you with a CB that you could put in yours for a quick test if all else fails? I'm wondering if it isn't the radio itself.

[mangojk]

There is a guy I have been talking to in New Glasgow that sells CB's and accessories but unfortunately he doesn't install them anymore. We did talk about swapping my Radio out for one of his to try just to see if it makes the difference he sells Uniden. I agree because my radio is new doesn't mean its good. He did bench test before I installed it and thought it was good radio....... He tells me the RF is to high but is running out of ideas on how to fix it. When you research such CB problems it seems to always refer back to grounds.

[mangojk]

Problem resolved, I reinstalled my antenna after putting new bumpers and rear carrier on and then tested CB , the SWR was reading high but wasn't turning the lights on my dash board like a Christmeas tree. The guy was looking over my work like he had before and noticed that the teflon washer was in wrong place therefore antenna was not getting proper ground, correct the problem and measured the SWR and tested it with a CBer and it was crystal clear. Glad to have it finally working.

[mangojk]

After many conversations,trouble shooting,including changing to clean power, replacing coax cable , shielding coax cable,relocating antenna, running separate grounds,always to arrive back to same issue, approximately 3 years later problem is now fixed ! ........ FYI - anyone that installs after an market stereo and wantt to keep everything O.E. Meaning steering wheel controls they require a module to do that. I just went back to the guy that installed my stereo oiriginal and even though he said there was something wrong with my computer,CB radio, grounds etc; I asked him to humor me and remove modules for steering control . Problem fixed. Every time I keyed mimic it was leaking through module and getting into can bust system ! FIXED !!!!