In message <199612100809.AAA26360@dfw-ix7.ix.netcom.com>, Andrew Warren writes:
>Does the fact that the
>transmitters in question only transmit at VERY low power make any
>difference?

        Yes it does.  I don't have any of this in front of me, but the rules
regarding unlicensed devices have been relaxed somewhat over the last
couple of years.  These devices can only use a few milliwatts of transmitter
power and they are sort of at the bottom of the electronic food chain in that
they may not interfere with licensed radio services and the people who use
them can not complain when some amateur or commercial transmitter
clobbers their receiver or causes their device to malfunction in any way.

        They are called Part 15 Devices after the subsection of
government regulations controlling their use.  There are many frequencies
that are now available for Part 15 devices.  Some are in the amateur radio
bands and others are not.  I am not sure whether the 434 MHZ frequency is
one that Part 15 devices can use, but there is a little extra complication.

        In the Northern tear of the 48 contiguous United States, the 70
CM amateur band only extends from 440 to 450 MHZ because the 420-440 MHZ
range was needed to provide extra spectrum space for business and public
safety users in the high population area around the U.S/Canadian border.
In other words, your system might be perfectly all right anywhere but
this area which is about 200 Miles wide and runs from New York to Michigan
and maybe even further West.

        The amateur radio magazine "QST" has had many articles about this
area of the country.  You might search for the expression "Line A" since
that is what the line is called that defines this region.


Martin McCormick 405 744-7572   Stillwater, OK
OSU Center for Computing and Information services Data Communications Group