I don't know if those units are like the IMTS mobile telephone
units here in the United States, but if so, they could probably be
pressed in to amateur radio service after a _lot_ of modification.
The IMTS or Improved Mobile Telephone Service units that were the
ultimate in car phones between the sixties and mid eighties were
full-duplex transceivers that operated mostly in the 150 MHZ or 450
MHZ ranges.  The system could  either operate automatically in pulse
dial mode via frequency-shift keying or could be switched in to manual
mode and operated by a push-to-talk button.

        I know these type mobile phones were or maybe still are used
in other countries besides the U.S, so one might find a few here and
there.

        If the transmitter and receiver are digitally synthesized, it
may be possible to convert them to amateur frequencies and a PIC would
probably excellent for controlling them.  You will have to do
something such as remove the diplexer and install some kind of TR
switch because the diplexer was what kept the transmitter signal from
frying the input to the receiver when the system was operated in
full-duplex mode.  This diplexer is apt to be several cavities that
act as band-pass filters for the receiver and also band-stop filters
to keep the transmitter signal out since both are using the same
antenna.

        I would say that you may end up with a good transmitter and
receiver unit, but you will have to totally rebuild the control and
antenna switching systems.  It's worth it if you get one for free, but
I sure wouldn't spend anything more than $5.00 or $10.00 because the
project will involve a major outlay of elbow grease to whip that beast
in to the form you want for two-way radio type use.


Martin McCormick WB5AGZ  Stillwater, OK
OSU Center for Computing and Information Services Data Communications Group
James Cameron writes:
>Travis wrote:
>> I've been thinking about making a couple of walkie talkies.  [...]
>
>What I'd love is a way to re-use the nearly obsolete analog mobile
>telephone units that will soon become fairly common garbage in
>Australia.
>
>--
>James Cameron                              (james.cameron@digital.com)
>Digital Equipment Corporation (Australia) Pty. Ltd. A.C.N. 000 446 800