Another important point I forgot to mention. Virtually all problems
with RF actually getting into the cable system (and showing up on
the center conductor of the coax) are caused by poorly crimped F-
connectors, or other forms of poor termination, like a non-technical
user trying to extend his cable wiring.
One good way to check for this kind of problem is to tune a 2M
talkie to the range between 145.41 and 145.47 and probe around the
cable system coax listening for carriers. These carriers are the pix
carrier and horizontal sync modulation for one of their analog
channels (18, if I remember correctly). When these carriers are
strong, you've found a bad connection that is letting that RF escape
and will also let RF get onto the coax.
Jim Brown K9YC
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