[mod.telecom] Hands Free duplexing circuit.

marcus@EDDIE.MIT.EDU@ihlpl.UUCP (12/05/86)

I am interested in building a better home intercom system, or at least
planning it.  With the fairly great number of phones out in the world
with "hands free" features, it seems that a similar circuit could be
made for intercom use.  Many of the phones use a VOX circuit to switch
between half-duplex modes of operation.  I really don't care for that if
it could possibly be avoided.  What possibility is there for subtracting
the speaker's output from the microphone's input or something similar to
operate in a FDX mode?  Are there any ICs made for phones that would be
of much use here?  Any suggested circuits or sources?

Marcus Hall
..!ihnp4!ihlpl!marcus