future_sailor100

Ok so I just hooked up an older Uniden CB in my 1996 F150 I have the antenna hooked up to a bracket me and my grandpa made on the passenger mirror holder. I can use my CB while the truck is off NO problems. When I start the truck I hear a repetative noise. I know it has to be the antenna because I hooked the radio up to an alternative power supply other than the cig. lighter and the noise was still there. I looked all over the internet to find an anwer and all I found was get a noise filter but I have no idea if it is my alternator or what. Also NO MATTER WHERE I put the antenna on the truck it still makes the darn noise. Please help.

UPDATE: We tried a different radio and a different antenna both on an external power supply and we still got the engine/spark plug noise. We also hooked the radio up directly to the battery and NO SOLUTION.

4Crawler

iTrader: (3)

Some things I found useful below:
- http://www.4crawler.com/4x4/CheapTri...na.shtml#Power

future_sailor100

I actually read that earlier and I ran the CB directly to the battery or as the article says independant wiring and it still did not work. No matter what I do I am getting sound. I can move the CB around change the CB change the antenna move the antenna etc. but I still get the noise I need something that can stop the noise or at least muffle it a little bit.

4Crawler

iTrader: (3)

Did you run both power AND ground to the battery? Picking up ground from the body somewhere can give an access path for noise to get in, at least from what I found. I did that plus run an active noise filter on mine and I can hardly tell when the engine is running.

Also is the antenna properly grounded?
- http://www.firestik.com/Tech_Docs.htm

future_sailor100

I did run both the power and ground to the battery. I do not know much about noise filters but from many years of being a mechanic with my dad I would think something like that could hurt an electric ignition. No matter how many mechanics tricks I use the darn sound will not go away. Could you please tell me more about the sound filter, how it works and possibly where to get one? I am pretty sure the auto parts store does not have them.

4Crawler

iTrader: (3)

As noted on the web page above, I ran twisted power and ground wires from the battery back to the passenger compartment where I installed an electrical noise filter:
- http://www.jcwhitney.com/electronic-.../p2001587.jcwx

then from there to the various radios, including the CB. THe filter is on the power/ground wires feeding the CB, nothing to do with the engine or EFI or anything. I also made sure to run those power wires as far away from the ignition parts as that is the primary source or noise.

Now you might find that some CBs just let in too much noise, no matter what you do. I did have one CB (part of an AM/FM/CB setup, that was noisy no matter what. I ended up putting it into my VW diesel and it worked perfect there, no ignition, no electronics, nothing. Only thing with that CB is that if a gas engine vehicle pulls up next to me at a stop light, I can pick up there ignition noise in the radio, it gets loud.

future_sailor100

So your saying I need to run the wires directly to the battery through my firewell on the passenger side, and twist them together. Also put a noise filter on it and that should pretty much solve my problem? The reason I ask is because I know it is not the radio because I swapped radios three different times.

4Crawler

iTrader: (3)

Just saying that is what I did and it works for me, at least on 2 out of 3 CBs that I have used over the years.

future_sailor100

Ok well thank you for all the help I will try it out and see if it works out for me. I will send you a message if it does. Thanks again for all the help.

xxxtreme22r

subscribed. My Uniden Grant is doing the same thing.

future_sailor100

Have you found anything to help solve the problem. I have a Uniden too.

xxxtreme22r

well, I took another lok at mine and it doesn't seem to be coming from the power connectors. I have mine tapped into the same wire as the stereo. I Have a cheap magnet mount antenna and if i lift it off the body then the noise goes away as well as disconnecting the antenna cable from the cb. no noise.

future_sailor100

That is the problem I am having too I know it is the antenna. But temporarily I just turn the RF gain down so the noise is not as bad. I can still talk to people while I am on the highway. I did some research and Uniden Radios are very sensitive, so maybe were just missing something. But turning the RF gain down helps out a heck of a lot.

4Crawler

iTrader: (3)

My old radio was a Uniden GrantXL and it was a great radio, just a little large. It had a switch for noise filtering and that did reduce the little noise that did come in with the engine running:


On it's highest setting, there was almost no ignition/alternator noise.

xxxtreme22r

heh, nice radio. mine is just about that big I think it's the standard grant, I also have a Uniden PC-244 that does the same thing. Alot of noise. The switch your talking about isn't the NB/ANL switch is it? I knew I should not have gone with the mag mount, but it sounds like going with a standard bolt in mount, I would have the same problems? How to fix though since its not that easy to attach a noise filter to antenna cable. Interesting place to mount the radio too. not sure if I'd want mine there in the case of a deep water crossing though haha.

future_sailor100

The switch that I am talking about in RF I do not know what your radio looks like so I would not be able to tell you which one.

xxxtreme22r

last post was meant for 4crawler. Got rid of mine by turning the NB/ANL switch on. Still have static but the ign noise is gone.

4Crawler

iTrader: (3)

Yep, that was the switch I was referring to.

A good grounded bolt-in mount also helps, and it needs to be a good ground:
- http://www.4crawler.com/4x4/CheapTri....shtml#Antenna

I used to use my bumper/swing out tire carrier, but I guess all the combined resistance of the bumper-frame mounts and the carrier swing-out pivot added up to a poor ground, at least at RF frequencies (measured 0.0 ohms on my DC meter). Now is bolted/riveted to bare sheet metal and works perfect:

xxxtreme22r

Yeah I figured my magnet mount isn't working as well as it should. Good SWR's now that I cut about an incha nad a half off it ll. Gonna wait till I decide to either go with dual 4' FIRESTICK II's (maybe an adjustable 4' wilson) or a single 102" whip.

Tbeck792

I would also vote for a bad grounded antenna. As 4Crawler said, it really can make all the difference. If not that then It seems that your alternator or something in your electrical system is making the distortion in the ground.
This can happen with commercial sound systems where you will have everything hooked up to a circuit that has a common ground and you will get cross noise between systems.
Good luck!!