[Phil Allison]

"flipper"
Ian Bell


Indeed. However, I would have expected the transformer to attenuate
noise in the 1Hz region

You have a couple of dubious assumptions here with the first being
it's a 'separate' signal. It's more likely riding on the AC with the
AC acting as, essentially, a carrier.

The second is that the AC 'noise' has the same frequency component as
your filtered measurement.


** Maybe it is time someone explained what "de-modulation" is to the
congenital Ian Bell FOOL.




..... Phil