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Old May 6th 07, 02:40 PM posted to alt.ham-radio,alt.ham-radio.vhf-uhf,alt.radio.scanner,rec.radio.scanner
DougSlug DougSlug is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 27
Default PC speaker buzz from Cingular GSM cellphones

"Sarge" wrote in message
...

"DougSlug" wrote in message
...
In my office we often experience instances of a "galloping" sort of buzz
periodically coming from the PC speakers near co-workers who have
Cingular GSM cell phones. A preliminary Web search turns up many
instances of this problem. My understanding is that these phones
periodically communicate with the network, and during these brief bursts
the carrier is modulated at around 200 Hz resulting is a clear,
repeatable buzz pattern. How is this buzz getting into the PC speaker
amplifier, and, more importantly, how can it be prevented?

Thanks,
Doug


every so often all gsm phones communicate with the tower. Thats when the
rf interferes with stuff or when its about to ring. Just keep a little
farther away from other appliances.


Thanks, but you basically just re-stated the problem. I was hoping to get a
more technical explanation of the mechanism by which the noise is coupled
with the goal of using that information to determine what techniques might
be used to prevent it. Keeping it a little farther away isn't usually an
option because the owner keeps it clipped on his belt, and it isn't
practical for him to remove it when he is at his workstation since he comes
and goes all day. I'm figuring that use of a ferrite on the amplified
speaker power cord is likely to be the most effective solution.