"whit3rd" wrote in message
...
On Tuesday, February 12, 2013 12:31:27 AM UTC-8, N_Cook wrote:
Arfa Daily wrote in message

...

I have a current transformer on one leg of the input to my dummy load /
power meter. This allows me to monitor ...

I suspect a current transformer would affect any PA/speaker/Zobell
resonance/interaction effect.

A properly loaded currrent transformer can be ten millliohms, or a few
hundred microohms. There needn't be any significant effect on the system
being measured.


Quite. The one that I use is completely non-invasive to the system it's
monitoring - in this case an output stage into a dummy load. It's just a
fully encapsulated winding with a hole through the middle. One leg of the
input to my tester passes through this hole. The winding is terminated with
a couple of k, and my scope hooks directly across it, fully isolated from
the unit under test. It has zero measurable effect on the amplifier or any
networks connected in the amp's output circuit. I would not have designed it
in, and been using it without issue for some years, if it did ...

This is the exact one

http://ww.sourcingmap.co.uk/020a-inp...-p-133281.html

Arfa