Re: what is the best wire for a perimeter alarm

"Sue" wrote in message
My brother-in-law, who is an electrical engineer, would wake up from a nap
in his easy chair and walk to the kitchen thru the beam of his PIR only to
have his alarm start wailing. "Wait", he said to himself, "I didn't arm
the system!" After this happened several times, he began to wonder, what
in the heck is going on that could arm my alarm? One evening immediately
after this happened, he mosied outdoors, and lo and behold he could hear
his neighbor talking on his ham radio. Said neighbor had antennas all
over the outside of his house. Ron had not used shielded wire for his
alarm system. He re-wired that weekend, and problem was solved.


I had a problem with a TV remote extender not working (Operate the TV remote
from another room). So I enclosed the transmitter in a metal box, receiver
in another metal box (Faraday cages), leaving small holes for the light to
go through, then connected a shielded coax cable between them. Then it
worked just fine.

The receiver had a light which indicated it was receiving a signal from the
transmitter. Well this light was going almost constantly even though the
transmitter was off! And this was jamming the real signals so the extender
could not work. After I shielded everything (from external RF), the light on
the receiver stayed dark unless the transmitter was activated.

Anyway lots of RF around - at least where I live...


.

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