Re: 1984 Chrysler AM Radio Repair

The AM in my car's AM-FM radio works much better now that I've
gotten new tires. I'll leave it to my readers here to figure out why.

I'm going to guess--based on things I've heard discussed on the 'net
before--that this might have something to do with grounding or the steel
belts in the tire. Am I close?

William

It was indeed static from the tires. I don't think it has anything to
do with the steel belts, for both original and replacement tires have
those, and they're not grounded. But the conductivity of rubber
varies quite widely, even among similar products. I believe my old
tires had low conductivity. Therefore, when I'd be on asphalt
pavement for a long period, static charge would build up on the car
body and discharge to wherever it discharged to, presumably the road,
and make lots of electronic noise doing so. On concrete, the static
sound would disappear.

I found that on asphalt (British use is 'macadam,' I think) roads
whose cracks had been sealed with whatever black compound Ohio uses
for the purpose, I found that the signal improved when the car rolled
over one of these networks of sealed cracks; presumably the sealer is
conductive. On rainy days, the signal was fine except for
interference from lightning.

I got so used to compensating for the various signal levels in my
daily drives that I couldn't quite figure out what had happened when I
replaced the faithful old wheelskins at Wal-mart one day and never got
a whisper of road static thereafter.

M Kinsler

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