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Discussion Starter #1
for those of you still with the old school AM/FM radios, what is the primary cause of radio noise?

plugs, plug wires, coil, cheap radio, bad ground, crappy antenna? thanks-

billy
 

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Hood grounding, good plug wires, radio DC filter choke. Do all these and check back with any further problems (which I doubt you will have).

Regards,

Bob
 

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Discussion Starter #3
Hood grounding, good plug wires, radio DC filter choke. Do all these and check back with any further problems (which I doubt you will have).

Regards,

Bob
thanks Bob. now how about in english?

how does one ground the hood?

how do you define "good wires"?

what is a radio filter choke and where does it go?

thanks-
 

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You need to take a small jumper wire to "bond" the hood to the body - get a few small ring terminals crimp them on and screw them to hood/body. Quality plug wires are designed to reduce RF interference and should say so on the box. An RF choke is just a ferrite core that goes in near your radio around the wires to reduce radio frequency induced noise - sometime you can get away with making you own by coiling a wire around the wire and ground one end....http://www.carstereo.com/help/Articles.cfm?id=71
 

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Billy,

On the 69/70's, there is a copper plated spring clip with teeth that mounts at the top if the cowl, it grounds the hood when the hood is closed, not sure if 67/68's have them or not (and can't recall what year you own, put it in your sig maybe?).

Suppression wires as bad says.

On the radio choke, I was thinking more of the inline choke (radio shack should have these), it is a two-leaded transformer looking thing that the 12V feed to the radio goes into, the other lead goes to the radio. It "chokes" noise on the DC feed to the radio out.

Regards,

Bob
 

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Discussion Starter #6
Billy,

On the 69/70's, there is a copper plated spring clip with teeth that mounts at the top if the cowl, it grounds the hood when the hood is closed, not sure if 67/68's have them or not (and can't recall what year you own, put it in your sig maybe?).



Regards,

Bob
and there is one of the many reasons i ask all these silly questions! for thirty two years i have looked at that copper clip and wondered what the hell it does! just looked and it is still there, although it does not appear my hood is in contact with the clip when it's closed. guess i can just bend the clip up a bit. thanks Bob!
 

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Most radio noise is from ignition or alternator. A popping sound that increases with RPM is ignition and a whine that also increases with RPM is alternator noise. Resistor spark plug wires will take care of the ignition noise, you can't run solid core wires if you want to listen to the radio. Alternator whine is a grounding problem. Make sure your ground points are clean and make sure your radio has a good chassis ground. I ran a car stereo shop for years and we found the chokes and noise suppressors are not needed if the real cause is addressed.
 

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...Alternator whine is a grounding problem...
I don't think this is correct. The voltage/current that the alternator puts out is rectified AC and the frequency of the AC (and thus the noise) varies in frequency. Also, there is minimal filtering provided by the battery and no large capacitance or inductance to form a proper filter for that noise. As a result, the AC noise riding on the DC presented to the radio can end up causing noise in the audio output. Noise which a proper DC choke will eliminate by filtering it (not permitting it to pass the choke). Grounding is of course important (ground loops and differences in ground potential can cause plenty of problems), but it will not do anything to remove noise produced by the alternator.

Regards,

Bob
 

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In reference to grounds, On my car once it comes back, when I go to establish a ground should I go to bare metal or will the screw through the paint be sufficient? I sure don't want to be scraping off fresh paint everywhere. There were a ton of grounds on that car.
 

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Isn't there some wacky thing in the passenger side wheel bearing cap also for radio interference??? i saw it in a 68 manual, or is that the elusive flux capacitor
 

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Isn't there some wacky thing in the passenger side wheel bearing cap also for radio interference??? i saw it in a 68 manual, or is that the elusive flux capacitor
Recall seeing that somewhere along the line, it is a hub grounding hoosiewhat'sit's.
 

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In reference to grounds, On my car once it comes back, when I go to establish a ground should I go to bare metal or will the screw through the paint be sufficient? I sure don't want to be scraping off fresh paint everywhere. There were a ton of grounds on that car.
It it best to have clean metal to metal contact. I always use no-ox grease to keep it from corroding/rusting as well. Grounds are crucial to everything - make them clean/secure
 
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