On Thu, 11 Sep 2008 17:45:11 -0400, ml wrote:
previously i can say there was no chokes power went right into the
unit

today we installed the line filters they have some chokes


i noticed that line, in the manual, not really sure what it means
the power as supplied by con ed is rock solid as far as volts etc
power here is great

Hi Myles,

I'm not sure what that specification line means either, but choking is
a standard term for reducing the influence of inductive kick,
something those motors are going to do aggressively and spread RF
trash throughout the spectrum.

However, in the context of motor controllers, solid state triacs can
also be quite noisy and inject trash into the line. This has nothing
to do with Consolidated Edison, except that they, too, could become
annoyed with noise. However, they have a large industrial customer
base that they serve, and they deal with it.

Returning to your desire to add covers, mesh, and the rest. I suspect
that the metal casing already does what it should and requires no
further attention. Instead, it is a matter of the lines that emerge
from those cases that are carrying the noise. They are passing it
along to you through two possible means: radiation or conduction.

If your rig shares the same power line, noise may arrive through that
shared conduction path. This would be part of a ground loop. Barring
that explanation, those lines are radiating like antennas, and their
proximity to your antenna provides over-the-air coupling. This means
you have to reduce that radiation (again, some form of choking, in
this case ferrites) or you move to increase distance and enjoy the
square law (10 times the separation pushes down the noise from S-9 to
S-7 or something like that). Obviously, in your situation, choking is
the simpler, and more effective solution. This will be choking that
is an entirely separate issue from that one line in the manual.

73's
Richard Clark, KB7QHC