2-place aircraft intercom based on notes from David E Allen posted to a 
mailing list in 1997.  His description is in intercom{1,2,3}.txt.

EAGLE board, schematic and library files were created by Henry Hallam and
are released into the public domain as of Nov 23, 2011.  No rights reserved, no warranty expressed or implied.  If you build this, expect it to set your aircraft on fire.

This has been working great in my VariEze for three years.


-- Henry Hallam, intercom@pericynthion.org, 2011-11-23