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> From: Timothy D. Gray <timgray@LAMBDANET.COM>
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: Simplify xmit/recv RF codes
> Date: Friday, June 26, 1998 4:26 AM
>
> (although anyone can jam a rf based secirity system easily unless the
> transmitters are spread spectrum.)
>

Incidentally, anyone can also jam a hard wired security system, without
even entering the house.  The high frequency starter on a TIG welder
produces sufficient noise for the long runs of unshielded, untwisted alarm
sensor wire to bring the alarm controller to its knees.

The rf based units would probably actually work better in a noisy
environment,
since the designers of those systems have at least given momentary
consideration
to the possibility of jamming.