That's a really fuzzy area.
Automated equipment on 2m must be controlled on a higher band, things
like repeaters can't be controlled entirely on 2m. So a higher band, 440
or 902 would be more appropriate.
Packet radio would work, there are some simple data modules that have
been published for sending balloon telemetry. A PIC chip and a little
glue and a radio. One way communications, is it broadcasting? APRS is
that way. Sending data about position and weather. You might install an
APRS weather station at the cabin, then use some status bits to indicate
burglar alarm switch status. Like change status from home to mobile...
Your controller need not cause transmissions often except when the
status changes.
Technically it can work. Legally is fuzzy. We do send alarm signals on
CW from our local repeater cabinet, but that's amateur radio equipment
its guarding. Your cabin isn't.
Being that it can be accomplished commercially, there is indirect
pecuniary gain, namely cost saving by doing it with amateur radio. How
that is different from using amateur radio to run a safety network for a
sporting event that is making money and saving on setting up
communications can be the basis for much debate, without any clear basis
in the FCC rules part 97 to back any sides to that debate.
9600 baud packet sounds much like noise, only carrier levels give it
away. Few have equipment for copying 9600 baud (and most of the rice
boxes that claim 9600 baud capability work poorly if at all) and fewer
tune around looking for stray activity.
I've considered doing much the same, though I wish for video from my
barn 8 miles from home. So far I've been too lazy to accomplish the
task. Better door security has kept losses from continuing.
73, Jerry, K0CQ
--
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.
|