GSM-noise "buzz" issue

[Joerg Reisenweber]

[oops, sorry for delayed post]
Am So  21. September 2008 schrieb Werner Almesberger:
> Joerg Reisenweber wrote:
> > Clock-harmonics and the like are a completely different story, and also 
the 
> > clock frequency itself could create noise if a clocked component is placed 
> > inside audio can, not only it's harmonics.
> 
> Yes, that's what I meant: noise we generate in the CPU can sneaking
> out and, say, hitting GPS. Given the current poor RF design, this is
> probably already happening, it's just not bad enough that it would
> lead to something clearly visible as a failure.
ACK


> 
> We could actually test this: rework a device such that only GPS is
> powered and communicate with GPS
[editor: create a link from a GPS-app on an auxiliary device to chipset on 
DUT]

> from a remote system (over a 
> properly exorcised cable). Then compare the performance between this
> system and a regular device.
...in a way I mentioned xx times, named A/B-double-blind test

> 
> Ah, so many ideas, so little time ... and so few devices to
> slaughter ;-)
> 
> - Werner
> 


a brilliant idea, even better than (or as good as) doing a plot of emitted 
(rogue) frequencies in a RF-clean room (Faraday-room), in the range from 1MHz 
to 2500. (exactly what I recently asked a German guy to do, in one of my last 
msgs ;).
Werner, we're not short on devices to gain decent results (the type of results 
we couldn't gain knowledge about from simple reading of ABS.MAX.Ratings in 
datasheets). Argentina customs is a different issue.
Tell me what you like to do exactly and I'll see whether I can set up a test 
environment :-). Actually got some spare devices.

cheers
jOERG
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