> My new Nokia 6010 has an interesting and somewhat annoying habit. If
>> it's anywhere within a 5 foot radius of my PC speakers, I can hear it
>> periodically transmitting something (sort of a rhythmic
>> dum-diddy-dum-diddy-dum-dum-dum). Sounds like static, but definitely
>> with a paced rhythm. I haven't timed the intervals exactly, but it
>> seems to take place every 17-20 minutes. In a related activity, I
>> hear a big burst of static on my PC speakers, and then some rhythmic
>> noise, about 5-7 seconds before the cell phone begins to ring.
>> This is the first cell phone I've had that caused these noises. Do I
>> have a mutant phone? Is this anything to be concerned about?
> It's not just the Nokia 6010. *Any* GSM will exhibit the
> characteristics you refer to. It's the phone communicating with the
> system periodically...
True. I was told by a contact at ETSI (the organisation that defined many of the GSM standards) that this was originally an oversight -- they had not realised that the modulation scheme was effectively 100% amplitude modulation, which would be "detected" by any rectifying circuit nearby. It caused a lot of consternation in the early days.
The "solution" they eventually agreed was to reduce the power transmitted by the phones by a factor of 10. This had been proposed anyway, to reduce the cell size and hence increase system capacity (also to increase battery life).
Phil McKerracher
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