"Bill" <connelly.bill from gmail.com> a écrit:
> frequency. i.e. the amplitude and timing is random. We work in Faraday
> cages. All cell phones are turned off. And it is still there even if a
> rig is run off a battery.
>> Anyone got any thoughts?
May be your power supply. Ensure your PS is sharing the same
ground level than your Faraday cages.
Computers also generate a lot of waves as well any cell phones.
http://en.wikipedia.org/wiki/TEMPEST
Of course, you don't care about any secrets, but I think they can
compromise a clean recording.