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Old April 25th 07, 02:55 PM posted to alt.ham-radio.vhf-uhf,alt.radio.scanner,rec.radio.scanner
Jack Ricci Jack Ricci is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 62
Default PC speaker buzz from Cingular GSM cellphones


"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


Turning off the phones, the PC speakers, the computers or removing the
electrical supply to the building or city would work if there are no
provisions for backup power...But I have a suspicion that this was not the
answer you seek

You will notice that various noise is generated by any electronics
network utilising microprocessors, such as cell phones ( or any
transceivers ), phone switches/PBX, computer/FAX devices, and security
equipment, all of which emit or generate RF signals ,whether they are
super-imposed with audio frequencies or not. This usually includes most
micro-processor-controlled electronics...harmonics will bleed through into
your regular phones, TVs, scanners, PCs, any amplifiers, and AM/FM/LW/SW
radio equipment either internally or from being in close proximity to any
other electronics devices too.

That's why you aren't allowed to use cell phones of any type on any
network in hospitals where you might interfere with someone's pacemaker or
diagnostic equipment, and testing has provided facts to back up the claims
with viable statistics. The hospital administrations have decided that the
best way to cure the possibility of interference from
outside/inside/portable sources is to turn " OFF " the device which has the
potential to cause it. Portable cell phones provide an ever changing source
of interference with many variables involved as the carrier of the device
moves about, and this can cause unpredictable consequences.

If you're computers are not losing or misinterpreting data input/output,
then you might want to live with the slight noise problem and let the cell
phone industry survive and thrive.

Jack