Radio Noise Suppression
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Radio Noise Suppression
A long time ago.....a thousand years B.C.,.....
Well, not that long ago of course, but when I first got this project, I found this "thing" in it.
I chucked it, and now I know why the previous owner had it.
I'm having a helluva time trying to get static-free radio operation in this '73 with the engine on. I've got 2 ground connections from the radio chassis (running directly to the battery) which helped some. and a 10 AMP RF Suppressor off the IGN Lead to the radio. And there's still noise so bad, it just makes the radio unlistenable.
There's an HEI Distributor with 9MM wires on the engine that I'm sure is "helping" the problem. I don't believe the stock ignition shield would fit over it. And if it did, would it even help?
Just looking for solutions you guys may have found.
Thanks.
Steve
Well, not that long ago of course, but when I first got this project, I found this "thing" in it.
I chucked it, and now I know why the previous owner had it.
I'm having a helluva time trying to get static-free radio operation in this '73 with the engine on. I've got 2 ground connections from the radio chassis (running directly to the battery) which helped some. and a 10 AMP RF Suppressor off the IGN Lead to the radio. And there's still noise so bad, it just makes the radio unlistenable.
There's an HEI Distributor with 9MM wires on the engine that I'm sure is "helping" the problem. I don't believe the stock ignition shield would fit over it. And if it did, would it even help?
Just looking for solutions you guys may have found.
Thanks.
Steve
The ORIGINAL and bestest
Joined: Oct 2000
Posts: 10,009
Likes: 240
From: Toronto Ontario
Toronto Events Coordinator
You could try an antenna noise filter, like this:
http://www.ebay.com/itm/usa-seller-C...-/281202246104
Some info on car audio noise:
http://www.crutchfield.com/S-2vi5BDG...ion_guide.html
http://www.ebay.com/itm/usa-seller-C...-/281202246104
Some info on car audio noise:
http://www.crutchfield.com/S-2vi5BDG...ion_guide.html
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
), it's not related to the antenna circuit. Noise is there even with the RIO Player using the AUX Input. Intermittent static AND cutout of audio, only when the engine is on.
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Disconnected Antenna Cable Lead from Radio: Static still present with MP3 Player/AUX operation.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
Static is most likely ignition noise. You also need to know how it is getting to the radio. Try connecting the radio to an independent power source. I usually get another car battery and wire the radio to it. If the noise is gone, you know the noise is coming through the power connections, and this is where you can focus your efforts. If its still present, its likely an ignition sheilding issue. I once had a Pioneer deck in my '79 that would exhibit a sporadic static 'pop'. I tried everything I know to eliminate it with no success. I finally solved the problem by swapping the deck for one from another manufacturer. I later installed that Pioneer deck in another vehicle and it works perfectly to this day. Go figure. Some things just defy explanation. Good luck.
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Thanks for more ideas!
I'm leaning towards a shielding fault. I don't think that the NOS distributor box will fit over the HEI distributor that's in there now. I do have some foil covered foam sheeting that I can cut and somewhat set up as a barrier between the radio and firewall. The independent power source is an excellent move in determining a power problem.
Thanks again.
Steve
I'm leaning towards a shielding fault. I don't think that the NOS distributor box will fit over the HEI distributor that's in there now. I do have some foil covered foam sheeting that I can cut and somewhat set up as a barrier between the radio and firewall. The independent power source is an excellent move in determining a power problem.
Thanks again.
Steve
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Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
If the noise is constant regardless of engine rpm, it's ignition noise. If the noise (whine) rises and lowers with engine rpm, it's alternator noise.
Also...the radio itself might not have sufficient built-in noise suppression. If the radio is Custom Auto Sound, that could be your problem...many have complained about the poor quality of those.
Also...the radio itself might not have sufficient built-in noise suppression. If the radio is Custom Auto Sound, that could be your problem...many have complained about the poor quality of those.
Team Owner
Joined: Jun 2000
Posts: 38,923
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From: Southbound
Cruise-In II Veteran
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
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From: San Diego California
THAT would do the Clampette's proud!Steve
Burning Brakes
Joined: Sep 2005
Posts: 1,050
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From: Lewes Delaware
The noise filter on my 73 is a large capacitor (purchased from one of the corvette vendors) hooked to the alternator + and ground (case). You want it as close to the power (noise) source as possible.
No noise on FM and very little on on AM.
Fran
No noise on FM and very little on on AM.
Fran
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
I found the yellow power wire that runs to the windshield washer pump (on the wiper motor) was resting up/against a spark plug lead. I moved it away from that lead, and although not totally gone (dammit), the radio was quieter.
I'm getting there. Thanks much.
Steve
I'm getting there. Thanks much.
Steve
The ORIGINAL and bestest
Joined: Oct 2000
Posts: 10,009
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From: Toronto Ontario
Toronto Events Coordinator
Is the ground wire for the stereo connected to the original stereo ground wire in the wiring harness? If it is, disconnect it and connect a new separate ground wire somewhere close to the stereo, keeping the wire as short as possible. See if that makes a difference.
BTW, are you also using a separate amplifier?
BTW, are you also using a separate amplifier?
Race Director
Joined: Oct 2008
Posts: 19,228
Likes: 1,672
From: Long Island
Is the ground wire for the stereo connected to the original stereo ground wire in the wiring harness? If it is, disconnect it and connect a new separate ground wire somewhere close to the stereo, keeping the wire as short as possible. See if that makes a difference.
BTW, are you also using a separate amplifier?
BTW, are you also using a separate amplifier?
Last edited by BLUE1972; Nov 13, 2014 at 07:34 PM.
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Is the ground wire for the stereo connected to the original stereo ground wire in the wiring harness? If it is, disconnect it and connect a new separate ground wire somewhere close to the stereo, keeping the wire as short as possible. See if that makes a difference.
BTW, are you also using a separate amplifier?
BTW, are you also using a separate amplifier?
No amplifier. Just radio.
Steve
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Easy ? this may help, get a relay and run 2 wires to the battery from the radio (along the handbrake ) for power. Cut the + (positive) and use the relay to have the key control the radio (if desired) . You can also add an RF choke filter from E bay or from the high power stereo shops $25 between the relay and the radio. Then put tinfoil behind the radio on the firewall that should solve all the problems. Worked on friends 70.
And the tin foil trick: Aye Aye sir!
Steve
The ORIGINAL and bestest
Joined: Oct 2000
Posts: 10,009
Likes: 240
From: Toronto Ontario
Toronto Events Coordinator
Some more good reading:
http://www.termpro.com/asp/pubs.asp?ID=121
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
That is where I would start. One single gound wire that is not part of the original wiring as short as possible as a test.
Some more good reading:
http://www.termpro.com/asp/pubs.asp?ID=121
Some more good reading:
http://www.termpro.com/asp/pubs.asp?ID=121
Another excellent article! Thanks so much.
Steve