I think if I were to have a security system installed these days, I'd specify
that all runs use Category 5e UTP. It has to be resistant to RFI in order to
work to Ethernet standard, so its eight conductors are twisted tight into
balanced-line pairs.
It is so common the price has dropped a great deal, and it's not very big. I
used some scrap to re-wire my phone system, and there's no RFI in it, that I
have discovered, in two years of operating. Keep the twist in the pairs right
up to the terminals, if possible -- or, better yet, use RJ45s wherever
possible. As a rule, if RF can't get in, it can't get out.
As to a system in place, I might try to get a good, low-impedance, RF ground on
the control panel chassis (good idea anyway), and bypass or choke the RF at the
sensor and control terminals, if possible, just as if I were trying to keep my
TX RF out of it. You have my sympathies. Sounds like you bought a house-full of
"incidental radiators." You might consider registering a complaint with the
FCC. After all, you're the one with the license, not the manufacturer.
Good luck,
Tom, KA5NEE
> 1. Home Security System RFI (Marc Ornstein)
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