I was out playing with my CB last night and realized that with my truck off when I key up the CB it applies power to my Stereo. If I rememebr correctly when I hooked this up it wasn't connected to the Stereo in ANY WAY. I have also noticed that there is some "noise" in the radio when the truck is running. I'm sure it has been posted on here many times but what do I need to remove the "noise" and why the heck is it turning on my radio.

 

thats wierd ive never had any of those problems with mine
you want a better radio? mine is for sell

 

No thast ok I'll stick with my Wal-Mart CB. It doesn't really bother me that bad I only use it for off-roading. I don't want my CB to cost more than my truck.

 

It is probably just RF leaking into the stereo's electronics. It's fairly common to have it effect something somehow. For example, in our utility truck, the low band fire radio would turn on the siren in the truck and turn off the stereo.

Suggestions are rerouting the coax and making sure you don't have a boat load of SWR.

 

maybe also the coax cable sheilding failed and try another one

 

i got a coax for sell to

 

Dude figure it out I'm not going to buy anything from you and with you post whoring my thread that has a legit question in it nobody else is either.

I'm not trying to be a jerk but seriously. You don't see me in your F/S thread saying I have Emeregency Lights for you to buy.

 

What is SWR? That is pretty funny about the Low Band in your utility. Is there anything I can install in the 12v Power Wire to reduce the RF Leak into the Stereo.

 

It's nothing on your power circuit. It is most likely just being radiated from the antenna and pissing off something in the radio.

SWR is standing wave ratio. It is power being reflected back at the radio due to in improperly tuned antenna. You need an SWR meter to test it.

 

You know I haven't tried it since I got the new Antenna last night. I only tried it with the truck off. i will try it again today with the truck running. I don't remember it doing that before the old antenna was broken. The Stereo thing is my main wonder.

 

Dude, Radio shack has one of those tuners for SWR for like 35 bucks. I'll go halves with ya...

 

Yeah using a CB without a properly tuned antenna will produce a boat load of SWR and with that it could burn up your transmitter. You may also try a ground loop isolator. That helped a lot with mine. I still get a lot of electronic noise through the CB tho.

 

I might have access to a SWR Meter. If I can get it how about would I go about tuning the Antenna. I have a 4' Fiberglass Whip

 

either the tip of the antenna is tunable or you can do it by shortening the length of the antenna wire. I would wait for Griggs or the guy from out west with the truck like mine. THey both know their stuff. Also how do you have it grounded? The antenna mount needs to be grounded an the antenna isolated from it.

 

whenever i roll up or down y windows with the cb on it changes the channel to 9.

 

I don't have it grounded. What I have is a ground and power going to the CB the Antenna wire then comes out of the CB and goes to the mount which is located on my tool box.

So what you are saying is I need to put a ground wire between the antenna and the mount.

It already has a plastic insert on the underside of the mount.

 

To attain good SWR readings and removing stray RF; ground the radio and system.... There are several ways to accomplish this.... First run a braided ground strap from the radio chassis to the vehicles metal ground, then run a grounding strap from the antenna mount to the vehicles frame (for best ground) and you can also strip a little insulation off the coax and twist the shield together and attach this to the vehicles ground.... This should help some with the stray RF...
I would also suggest upgrading the coax from the RG 58 to LMR 240 for double shielding... to help with stray RF.

The only reason why the radio will change channels to the default CH 9 when rolling the windows up would be that the memory power source is attached to the same source as the main power. When rolling up the windows the voltage drops for the main power and since there is no memory backup it reverts back to the default channel 9.

Using a Radio Shack SWR meter will only get you in the ball park... To tune your antenna ACCURATELY.... the best way is to use an Antenna Bridge Tuner... which allows you to measure SWR for whatever frequency you want right down to 1.0 IF you have a quality antenna and the grounding allows.

The shielding on a trucks stereo system and wiring is VERY poor and stray RF makes radio components reactive and find its way in on the incoming wiring. Even after shielding the radio and applying chokes to the incoming wiring..... your system can still react to the stray RF.

OR 4x4

 

The braid of the coax should be attached to the antenna mount. The center conductor of the coax would go through the mount, usually with a plastic isolator so it isn't touching the mount itself.

If the antenna mount is attached to a metal tool box, the most you might want to do is put a ground strap from the tool box to the body or frame. Tool boxes sometimes don't have the greatest ground continuity when attached with a few little screws or clamps.

I made a little picture to illustrate it.

 

I never said the radio reverts to channel 9. What happens is that the Car Stereo turns on when the truck is off and I key up the CB.

 

I also thinks it's a ground issue... That's what I'd try first. A bad, or missing ground can screw all kinds of things up on a DC System.

Don

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Mike,

My apologies..... I was responding to a couple different posts.... and the response about Ch 9 problem was for FX 4 Rangerman.

Staying up all night talking DX on the radio doesn't do much for thinking clearly the following day. Coffee does wonders for clearing brain FOG....
Does the radio actually power up when you key up the CB? OR are you hearing your CB audio (RF) thru the stereo system speakers when you key up the radio ?
IF the problem is that your radio does turn on when you keyup the CB... Not sure how that could happen since if the power wires were some how shorted or back feeding the stereo would be on all the time.... Do you have relay in the system somewhere? The stray RF could be enough to energize a relay in the system and power up the radio.
IF the problem actually is the CB audio coming thru the radio speakers then the CB RF is leaking into the stereo system by using something in the stereo system as an antenna.
You can try using shielded speaker wiring, wrapping the radio in shielding and grounding out the radio case. When RF leaks your stereo system... it can be difficult to track down and remove.

OR 4x4