JKT100@psuvm.psu.edu (JKT) (09/08/90)
I made a rather startling discovery by mistake today....
I've known for a while that my Amiga 2000HD puts out a LOT of
radio interference on the FM bands. I can't watch TV channels 2-8
in the next room, my stereo in my computer room is "fuzzy" on FM,
etc. The interference seems to diminish when the CPU is working
and increases when it is "idling." But I've learned to live with
it. But anyway, on to the discovery:
I happened to unplug the telephone cord from my Supra 2400zi internal
modem today, and voila! All the interference on my stereo disappeared!
Plugged it back in just to be sure, and yep, the interference returned.
I assume the telephone cable is acting as an antenna for the static
the computer is broadcasting. Can anyone offer opinions as to whether
they agree or disagree with this diagnosis?
Also, I'd appreciate input as to why the interference diminishes when
the CPU is under a load. What I mean by this is if workbench is just
sitting there with no programs running, the interference is strong as
strong as ever. If I load a program, you can here the interference
get stronger and weaker at the same time as the hard drive light
flashes. If I put a constant workload on the CPU (such as run A-Max)
the interference goes away for the most part.
My system is a 2000HD with an old CMI processor accelerator running
at 14 MHz, and a Supra 2400zi. The interference does not change at
all if I slow the processor to 7 MHz. I have not tried removing the
processor, for it would be a semi-major operation. Ideas anyone?
Kurt
--
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|| Kurt Tappe (215) 363-9485 || Amigas, Macs, IBM's, C-64's, NeXTs, ||
|| 184 W. Valley Hill Rd. || Apple ]['s.... I use 'em all. ||
|| Malvern, PA 19355-2214 || (and in that order too! ;-) ||
|| jkt100@psuvm.psu.edu --------------------------------------||
|| jkt100@psuvm.bitnet jkt100%psuvm.bitnet@psuvax1 QLink: KurtTappe ||
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