Radio Static

Old Henry said:
Funny thing is that the static is greatest when the engine is first started and decreases over time and speed (20-30 minutes/miles) until it's all gone until I pull into the garage again at idle and it's back.
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That sounds like the static is related to charging. After you start the car it is charging a lot but as you drive it the charging slows down as the battery reaches full charge.

So I'd suspect either the generator or the voltage regulator.

If you plug headphones directly into your CD player do you hear the static?

Tom
 
Mike B said:
Used to get the filters, looked like a coil wound thing with metal over the top to mount it (kinda like a small electric fuel pump without fittings) and run them inline to to power to our stereos to eliminate Alt noise when we had amps/etc, turned on.

Radio shack and every car stereo place had them, they did the job.
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Mentioning this one more time...eliminate the noise into the unit, maybe all you need:)
 
47COE said:
That sounds like the static is related to charging. After you start the car it is charging a lot but as you drive it the charging slows down as the battery reaches full charge.

So I'd suspect either the generator or the voltage regulator.

If you plug headphones directly into your CD player do you hear the static?

Tom
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Could have to do with charging. I've put a condenser on the regulator and the generator to no benefit. What else?

The CD player and mp3 player don't pick up the static on their own with headphones attached. The static is being picked up by the amp even without either the CD player or mp3 player attached.
 
Old Henry:
In past posts you needed Generator attention,which you did fix!
Did you have Radio static before the Generator problem?
 
Old Henry, You say its only the amplifier that seems to pick up the static. Try this, Grab your roll of cooking silver foil and wrap the amp up all over with two or three layers. Trouble with amps like that they are domestic units and not built for cars and as such don't have anti static radio interference circuits built in. See how you go. Regards, Kevin.
 
This may not make much sense, but my father bought a 47 Ford new. He ended up putting a ground wire from the hood to the body and that stopped his noise. The radio sounded great, but if you raised the hood all you heard was engine noise etc.
 
Back when we all used non-resistance plug wires, often all it took to get rid of the ignition noise in the Ford radios was to tie a knot in the coil wire. There was also a black bakelite inline coil resistor that worked well if you didn't know about the knot trick. The coil wire was cut and the wire ends screwed into the resistor. ..B.
 
Old Henry said:
Could have to do with charging. I've put a condenser on the regulator and the generator to no benefit. What else?

The CD player and mp3 player don't pick up the static on their own with headphones attached. The static is being picked up by the amp even without either the CD player or mp3 player attached.
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Where does the output of the amplifier go? Do you still get the noise if the amplifier feeds a headphone or a small speaker that is only connected to the amplifier and nothing else (such as the car's chassis)?

I would try a short circuit on the amplifier's input. From what you've said, the noise would probably still be there. In that case it is probably radiated electrical noise rather than noise conducted into the amplifier from the input. Shielding the amplifier by putting it into a grounded metal box might take care of the problem.

Or to track down the noise source, since the amplifier, battery pack, and a small speaker or headphones would be portable, I'd move it around to see where the noise was strong. Various places inside the car around the dash as well as under the hood.

That would help track down the source.
 
koates said:
Old Henry, You say its only the amplifier that seems to pick up the static. Try this, Grab your roll of cooking silver foil and wrap the amp up all over with two or three layers. Trouble with amps like that they are domestic units and not built for cars and as such don't have anti static radio interference circuits built in. See how you go. Regards, Kevin.
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Tried that. Didn't help but thanks anyway.
(I did get my amp gauge today so will be testing that which you have been helping me with.)
 
47COE said:
Where does the output of the amplifier go? Do you still get the noise if the amplifier feeds a headphone or a small speaker that is only connected to the amplifier and nothing else (such as the car's chassis)?
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The amp output goes to the DPDT switch that switches the speaker between that amp and the radio.

I disconnected that wire to the speaker switch and plugged in headphones - still static. I unplugged the amp from the large "D" battery pack I made and hooked up just a small 9 volt battery as it came with - still static. All of this with nothing plugged into the amp input.

47COE said:
I would try a short circuit on the amplifier's input. From what you've said, the noise would probably still be there. In that case it is probably radiated electrical noise rather than noise conducted into the amplifier from the input.
Click to expand...

Tried that. No change.

47COE said:
Shielding the amplifier by putting it into a grounded metal box might take care of the problem.
Click to expand...

Tried that. No change.

47COE said:
Or to track down the noise source, since the amplifier, battery pack, and a small speaker or headphones would be portable, I'd move it around to see where the noise was strong. Various places inside the car around the dash as well as under the hood.
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The sound is loudest inside toward the front, less toward the rear but still there even in the trunk. Outside it's less the further I get from the front end. In the engine compartment is the loudest.

Here's a little video clip of the sound playing through the speaker as the engine is revved up. Same sound in the headphones.

http://www.youtube.com/watch?v=SXzQvDwPPeM&feature=youtu.be
 
Marv said:
This may not make much sense, but my father bought a 47 Ford new. He ended up putting a ground wire from the hood to the body and that stopped his noise. The radio sounded great, but if you raised the hood all you heard was engine noise etc.
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Thanks for the idea.
Hood is grounded. The hood ornament light runs through that ground.
Opened and shut the hood. No change. But, thanks anyway.
I'm still desperate and bewildered enough to try anything.
 
BILL WZOREK said:
Old Henry:
In past posts you needed Generator attention,which you did fix!
Did you have Radio static before the Generator problem?
Click to expand...

I've used this amp for several years with virtually none of the static I now have. It has come since I replaced the brushes and armature in the generator but not immediately after. If this gives any ideas for a cure let me know. I did put the condenser on the generator armature terminal grounded to the generator body as instructed. Didn't help.
 
Old Henry said:
The sound is loudest inside toward the front, less toward the rear but still there even in the trunk. Outside it's less the further I get from the front end. In the engine compartment is the loudest.

Here's a little video clip of the sound playing through the speaker as the engine is revved up. Same sound in the headphones.
Click to expand...

Varying with engine speed like that makes me think it isn't the regulator. It seems more likely the source is the generator or spark.

You could temporarily disconnect all wires from the generator, or remove the belt driving the generator. That will narrow it down to spark vs. generator.

Tom
 
Old Henry>>>I'm still desperate and bewildered enough to try anything.>>>

Go to Amazon. Try a few other headphone amps.

Jack E/NJ
 
Jack E/NJ said:
Old Henry>>>I'm still desperate and bewildered enough to try anything.>>>

Go to Amazon. Try a few other headphone amps.

Jack E/NJ
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I had that thought too. Something may have gone bad in my amp and I just need a new one. It cost $100.00 so I'm a little hesitant to spring for a new one too quickly. All headphone amps are not created equal. The one I have is the most powerful one made at the time I bought it. Other weaker ones I tried were too weak to play the speaker loud enough.
 
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