| Author |
Message |
    
Jameslarson
Junior Member
Username: Jameslarson
Post Number: 13
Registered: 4-2006
| | Posted on Wednesday, April 12, 2006 - 1:05 pm: | 
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OK. Hear me out. About 15 years ago, when I was really into the whole CB thing (Had a moonraker, big stick, 1kw, etc). I was causing crazy interference to my 2 neighbors. We tried everyting in the book, and nothing really helped. Finally, as a last ditch effort, I wrapped aluminum foil around all the power cords of my neighbors TV's, telephone cords, and radios, and even wrapped aluminum foil around the cable coming into their house from the cable company. Would you believe it eliminated all the TVI? I couldn't believe it.
Now fast forward 15 years. I am installing a cb in my vehicle, and have the typical "whine" engine noise coming into the radio. I've tried everyting (Filters, grounding, straps, narrowing it down, etc..). What are your thoughts of me wrapping aluminum foil aorund all coax, all power leads (including the texas star power leads)? Would this actually cause more noise because it is now acting like an antenna? Thanks. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1164
Registered: 6-2004
| | Posted on Wednesday, April 12, 2006 - 5:50 pm: |
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Using aluminum foil as a Faraday shield is dangerous because it could just as easily short out whatever you were wrapping it around. It would also allow heat to build up and cause possible damage.
Does this whine change speed as your car does, or is it always the same? Does it go away when the antenna coax is unplugged? |
Jameslarson
Junior Member
Username: Jameslarson
Post Number: 15
Registered: 4-2006
| | Posted on Wednesday, April 12, 2006 - 6:40 pm: |
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Yes, the whine does change speed as the engine is changing speed as well. It stays even when the antenna is gone and coax disconnected. |
Tech237
Moderator
Username: Tech237
Post Number: 271
Registered: 4-2004
| | Posted on Wednesday, April 12, 2006 - 7:53 pm: |
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The aluminium becomes a shorted turn and with high power may even get hot enough to start a fire.
A better bet would be to replace the coax with one that has a better braided shield on it as I suspect that the leak trhu is due to a poor shield on the coax. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1165
Registered: 6-2004
| | Posted on Wednesday, April 12, 2006 - 9:40 pm: |
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If the whine happens with the antenna disconnected then it's coming through the power wires, and a power filter should eliminate it completely. I've used the high power model from Rat Shack and it works well - if they still sell one. I'm sure Copper sells one too. You could even use a capacitor near the radio if you have space to mount it.
Alternately, you could use a bypass capacitor at the source of the whine which is probably the alternator. The capacitor will shunt the A/C RF noise to ground before it can be radiated. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1419
Registered: 9-2004
| | Posted on Wednesday, April 12, 2006 - 10:40 pm: |
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i agree that better coax will help the problem.
the biggest help would be to filter the noise at its source, which is the alternator.
use a feed thru capacitor on the power lead of the alternator, and if that doesnt cure it, buy a noise filter for the power lead going into the radio.
those steps should cure the problem,
matt |
Allagator
Advanced Member
Username: Allagator
Post Number: 739
Registered: 9-2002
| | Posted on Monday, May 22, 2006 - 6:13 pm: |
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LOL ! the foil will work if your coax runs over the top of the phone line ! just wrap the phone line and run a strap to a groundrod ! i had a problem with my radios over the phone and tried everything ! then some one told me to try foil ! so i did on the phone line only and it worked !
after a year it will fall off but who ever used speaker wire for the phone line needs to be shot !
but your truck is a diff thing !
Allagator
CEF 115 |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 804
Registered: 11-2002
| | Posted on Thursday, June 15, 2006 - 12:04 am: |
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I agree with Hollowpoint...hmmm, that's spooky huh?
Na, just kiddin' man. It's the alternator causing the problem just like HP said. But a filter for the powerline and it'll go away. If it being picked up on the antenna/coax it would go away when you unhook the antenna or coax.
Since you still have it, then it's coming in on the power source. Do you have it grounded to the battery? A battery will usually help filter stuff like that out, but not always and not always all of it.
Copper sells the Magnum filter and I hear it's really good. Never heard anyone say anything bad about it. |
Dale
Intermediate Member
Username: Dale
Post Number: 474
Registered: 12-2002
| | Posted on Thursday, June 15, 2006 - 2:44 pm: |
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maybe i just lucky.i had my car tuned up with new plugs,wires,distribator,cap,rotar,also put in a alt. almost all noise is gone not enough noise that im gonna worry about.when was your last tune up? |
