"GregS" wrote in message

In article
, "Arny
Krueger" wrote:
"Andy" wrote in message


I want to use an audio transformer to see if it helps to
reduce the ffect of an earth loop.

Go straight to Radio Shack and get their "Ground
Isolator".

I've tested them on the bench, and they aren't all that
bad.

I in the past have been using their 600 ohm 1:1
transformer
to make such a device, with much success. I still want
to measure it. Buying two transformers, a box, and wiring,
is much more complicated than purchashing this premade
"Ground Isolator"
I do have reservations of having the unit attenuate the
signal
voltage.

There are no doubt some losses.

Primary DCR = 136 ohms
Secondary DCR = 175 ohms

Turns ratio probably follows this pattern, IOW a slight step up perhaps to
minimize apparent loss.

I would guess its working impedance at around 3 K ohms. This is the range
where the resonance is nicely damped and the signal handling ability allows
for good dynamic range.