On 11/27/2024 6:03 PM, Bob WA2SQQ wrote:
Replacing the custom cable
with the original one or omitting it did remove the interference, but why
did previously work? Charlie reached out to Verizon who sent a tech out.
I suspect that Verizon's installation, whatever it is, may have
exploited a vulnerability in the way the cable was built and/or wired.
The first question I would ask is for a detailed description of that
cable. How many conductors, are they twisted pairs or parallel wires,
does each circuit have it's own return? Is it shielded? Where is the
shield connected on each end?
The keys to something like this working or being problematic is whether
or not the signals are carried on transmission lines or on wires, and
where the returns (if there are any) are connected. CAT5, for example,
is NOT 8 wires, it is four tightly twisted pairs. Twisted pair is FAR
more resistant to interference and crosstalk than constructions like zip
cord, regardless of of the size.
73, Jim K9YC
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