I happen to have the receiver half of a Video Rabbit.  All
it is is a down converter from 902 to 928 MHZ whose IF output is
Channel 3 which, in the American and Japanese channel allocation
scheme is 60-66 MHZ.  If I recall correctly, it inverts so that
carriers near the high end of the input pass band come out at the
low end of the output pass band.  There is a pot that probably
modulates a varactor diode which tunes the local oscillator over
the 902-928 MHZ band so you can get away from your neighbor's
Rabbit or other interference.

        I assume the transmitter has a similar control so you can
walk up and down the band with them.

        Since the output of the receiver half is the IF output of
the converter, it connects directly to a television set or VCR.
The oscillator doesn't need to be rock steady and, believe me, it
isn't.

        I don't know what the transmitter looks like, but it
easily could be built very much like the receiver except that you
feed channel 3 in to the input and it comes out inverted in the
33 CM ham band.

        In my neighborhood, are several cordless phones and
remote loud speakers and wireless headsets, etc.  Some of the
cordless phones are digital and they constantly generate little
bursts of noise as they hop about the band.

        My town is classified as a small city of about 40,000 and
I am sure that a larger city such as Tulsa, Oklahoma City, Dallas
or Houston would be just full of stuff in that frequency
range.


Martin McCormick WB5AGZ  Stillwater, OK
OSU Center for Computing and Information Services Data Communications Group