Lydia Gregoret (lydia@rosa.mit.edu) writes:
> We hear lots of static pops and crackles from our cassette player when
> our car is *running*. [...] It also seems that the popping intensifies
> the longer we drive as if there is some sort of charge buildup (i.e.
> it's not bad for the first few blocks). [...] We just got new Blaupunkt
> speakers and we don't want to destroy them.
First of all, I wouldn't worry about the speakers; they're only playing
what comes through the amplifier, be it scratches, pops or rap music, and
the amplifier would have to suffer some sort of meltdown before it elec-
trocuted the speakers. (O.K. It *could* happen...) Anyway, unless you can
identify precisely one type of noise to attack (e.g. popping spark plug
noise, generator whine), you should be able to just hang a noise suppressor
on the power lead to the cassette deck, such as, umm... (pause to consult
Rat Shack catalog...) Noise Eliminator kit 270-030. Low co$t.
Basically, you either attack the noise problem at its source (if you can
identify which component it is, there is probably a noise suppressor de-
signed to fit it), or block the noise at the point where it gets into the
sound system, which is usually the power lead.
Putting a choke coil like the above part number in the power lead worked
wonders on the spouse's car. Actually it WAS in there when we bought it.
I removed it during repairs to the sloppy PO installation, but when I
played the tape deck, I heard the same rubbishy noises as you did. "Yuck.
So THAT's what that thing was for." Quickly reinstalled it and regained
peace and quiet for tape playing. Your mileage may vary... good luck.
Andrew C. Green
Datalogics, Inc. Internet: acg@dlogics.com
441 W. Huron UUCP: ..!uunet!dlogics!acg
Chicago, IL 60610 FAX: (312) 266-4473
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