On Jan 28, 6:27 pm, "Henry Kolesnik"
wrote:
I sure see lots of retired cell phones and wonder why I haven't seen any
homebrew projcts to make something useful out of old outdated ones.
I realize that the last few years may be too complex and small but how about
the old analog shoe phones?

Some of the analog shoebox and suitcase phones have separate VCO
modules and IF strips. The chips used were sometimes well-documented
(I'm thinking of the Signetics and Motorola stuff) and the datastreams
for microprocessor control you could figure out.

But you have to go back to the early 90's to find equipment of that
era. There were some ham magazine articles at the time these were
going surplus. Some of the equipment had diagnostic modes that let you
turn them into simplex receivers - not very good quality but OK and
their reach outside the cellphone spectrum was nearly nonexistent.

Just to make you jealous: I work just two blocks from where the
original actual shoe phone now resides :-). I am trying to persuade my
company to get it from them on inter-agency loan...

Tim.