I have serviced alarm systems in the 27Mhz band, they were 5 watt
units made by Baldwin Hawkeye Systems. The frequency allocations were
mostly in between channels in the old RC "hole slots" or above channel 40.

Some of the car alarms also use CB bands for the pager units. My neigbors
kept going off so much that I sampled the signal and retransmitted it at
random 3-5am intervals until he stopped using the remote function of the
alarm. Same type of things found with the original auto cell phones hooked
to the horn.

cheers
skipp
http://sonic.ucdavis.edu

: Night Ranger wrote:
: Anyone have any idea what the many many many digital tone burst
: occuring on channel 23 are? I know that channel 23 was designated as
: a remote control channel even in the 1970s. I've heard remote control
: hobby airplanes there before, but in the last year or two there has
: been a substantial increase in these "packet radio" style tone burst
: on channel 23. I've heard them in Phoenix, AZ in South Carolina.
: The tone burst are present 24 hours a day, and are far too numerous
: and too frequent to be a person manually operating a remote controlled
: device such as a toy car or airplane. A remote control toy generates a
: constant carrier with varying tones, but these signals are occuring in
: short burts of tone sequences.

: Night Ranger