Top posted because it's Brian.

Looping speaker leads though ferrite clip-on block may fix that entry
route. You may find something similar plus more careful earthing or/and a
filtered mains block would help.

You'd need to say more about the details of your "Low level circuits" for
me to give more specific suggestions. e.g. a 100pF rf cap shunt may help,
but larger caps would be a problem for some inputs like "turntables" (sic).
Maybe you've not tried caps that remain caps at UHF and above?

Diodes might simply make it worse by spraying the energy across into other
frequency bands and pulling more current.

Jim


In article , Brian-Gaff
wrote:
With the proliferisation of mobile devices running on the mobile phone
network its getting increasingly a annoying to listen to things on a
good old fashioned or even new fangled radio, without the noise
occurring at some point. Even from next door one can get it getting into
the audio chain. Anyone know if there is an easy way to stop it. In the
old days a few capacitors got rid of Radio China or Vatican City, but
due to the high frequencies of the phones and the spiky nature of the
handshaking noise, this seems not to work much. What is the mechanism.
they cannot be tuned to the r frequencies, so is it just straight diode
type detection due to the huge signal level?

Low level circuits like turntables, microphone inputs etc, seem to be
the worst, but I've also proved my Denon is picking it up from its
speaker cables.

Brian

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