"Don Pearce" wrote in message
news:4a54e8a0.1490496031@localhost...

Pots is both balanced and unbalanced - that is how it manages full
duplex over a single pair.


Pardon? The line is balanced - period. Full duplex merely means that the
speech currents from each end combine in the line.

If you are thinking about anti-sidetone hybrids (which I guess you are from
other posts) then they are not necessary for full duplex, the telephone
industry did without them for decades, and they do not in any respect
involve unbalancing.

David.