dykesc wrote in
:

....
Yes, but I am specifically interested in what's going on near my
operating position. Have had some problems with computer peripherals
when transmitting on 80m.

Well, doing is learning.

My own view is that common mode current meters are seen as a magic
bullet. It is true that if you make a single measurement and you observe
substantial current (meaning you have some absolute calibration), then
you know there is a problem.

The problem is that if you don't observe current in that single
measurement, you cannot infer that there is not a common mode current
problem.

Some things that you might do may just move the standing wave pattern.
Again, measurements at a single point are a very limited perspective.

The best countermeasure is design of antenna *systems* for low common
mode current.

Nevertheless, we need to make some compromises on suburban blocks and
physical symmetry can be one of the sacrifices.

Take a leaf from the books of lightning protection. They usually firstly
try to shunt the undesired current to ground rather than trying to impede
its flow through the equipment room.

If that isn't enough, then impede its flow into the equipment room so
that more of it is shunted via the ground path.

Owen