January 2007: The HeyPhone documentation on this site
derives, for the most part, from material produced during the period 2002-2004.
Although still largely correct, documentation may go out-of-date with respect
to corrections, obsolete components, updated techniques and peripheral
Occasionally, updates to this web site may be produced but,
as time goes on, this will become less likely. To find out the current status
of the project you should subscribe to the CREG discussion forum where you can
share your requests and experiences with the wider caving community (assuming,
of course, that it reads the forum).
Please note: the HeyPhone project is
not actively supported by CREG. CREG has no
brochures, no circuit boards, no components and
no built units for sale. The HeyPhone is entirely a
"build-it-yourself" project. The only support available is the
documentation on this web site, and any "public" help you may receive in
response to posting a message to the CREG