Robert11 wrote:
Hello:

About a quarter of a mile from my house, in a direct line, there's a Ham
operator with a massive mast of what must be pushing 100 feet in height.
Almost the kind you would see for a small commercial station. Has all sorts
of antenna and beams mounted to it.
I have no idea what freq's he operates at, and really don't want to ask him.

He would probably be quite happy to tell you.

This is obviously a chap who takes his hobby seriously, and probably
radiates at the max allowable power levels, I would guess.

Is there any possibility that if he points his array at my house, it might
radiate enough power to cause my problem ?

Yes it is quite possible.

As someone else said, ask him to run a test.

You could also test for RFI yourself by wrapping it in metal foil
(tinfoil). That would make a good Faraday cage and would stop any RF
reaching it - not only his of course.

Of course, that assumes you could hear the alarm.

However, if it is his transmitter that is causing your alarms to go off,
you can be 100% it is a fault on your alarm(s). They should not be
responding to the RF. Unfortunately, although things have improved over
the years, consumer items are not very immune to RF - it costs a few
cents more to add decent RF protection.

It would probably be fairly easy to harden one against RF. Covering the
solid parts of the case with metal paint would help a lot.

If not, any thoughts on what else might be causing these chirps from two
different mfg's., and several models ?

RFI seems quite a likely cause, but it could be very local, such as
something arcing in your house.

As I say, screening the alarms would tell you if its RFI.

Much thanks,
Bob




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