Regulars here may have followed my efforts to deal with noise
generated within
my own home. Along the way I read W1HIS's work on "Common Mode Noise"
and further study revealed differential noise becomes a problem when
it becomes
common mode noise.

W1HIS does a great job of describing how and where to use filters and
ferrite
to reduce noise from the home and to prevent noise from going up the
coax to
enter the antenna.

The exact method of DM conversion to CM has intrigued me. Reducing DM
is
the most useful tool for stopping self generated RFI. But you can't
get rid of all
of the DM noise. So I have been trying to decipher the riddle. I have
gathered a
lot of references and tried to develop a "ressonable" way to explain
the exact
conversion method.

In the process I have made a lot of measurements and wasn't have any
great
success at building a model to deal with this. My method of injecting
SM and
seeing where it becomes CM was useful but left gaps.

There are days I am so dense it amazes me I accomplish anything. A
net
search for another topic and found a article by Jasper Goebloed
entitled
"Reciprocity and EMC measurements".

It is so simple. Inject a Common Mode noise source and follow the
conversion to Differential Mode noise.
www.ieee.org/organizations/pubs/newsletters/emcs/summer03/jasper.pdf

This is a very useful tool that avoids the quasi legal use of my 10mW
3.58MHz,
80M ham band, RF source.

Assuming anyone else is trying to tame their self generated RFI is
interested,
this is a very useful method that allows us to inject CM noise, that
does not
radiate a significant amount of RF, IE I can't receive it 20' away
from the
power cable. I am using a home made ferrite toroid

Will will post this and the pdf in his stopRFI page in the near
future.

Terry