Re: RF Immunity in Smoke Detectors

[Eyeball Kid <jimbo1@xxxxxxx>]

I'm still waiting to hear from the customer in person (the probelm was
forwarded to me from our service dispatchers) one of the questions I had
  for him was what freq is he using to make it trip consistently and how
much power is he puttinginto the antenna and where the antenna is
located in relation to the smoke (and it's wiring).  I'd like to arrange
a site visit to see for myself.

Rewring an existing system with shielded wire seems a little impractical
and my first thought was to try an eliminate the problem by adding a
combination of caps and or chokes at both ends of the wire (at the panel
and at the smoke)

One of the questions I want to ask the customer is when he manages to
trip the system does the sounder in the smoke go off or just just the
siren (in which case he is just tripping the zone on the panel (I
suspect it's an Ademco Vista but I haven't pulled the file)

Years ago I had a problem with a customer/ham who was able to arm and
diarm his system by keying his mike.  It was an old DSC CP-10 style
panel (arming/diarming by mom contact in this case a DCU-20 Keypad) and
I solved that one by taking the excess wire at the panel end of the
arming input and wrapping it around the shaft of my instrument
screwdriver to form a poor man's inductor.

Hopefuly this one is as easy.

It strikes me as curious that RFI is a commom spec on motions but
unheard of on smokes....