"rkhalona" wrote in message
oups.com...

Robert11 wrote:
Can someone please explain the major differences between simplex, half
duplex, full duplex, etc. ?

See
http://eserver.bell.ac.uk/mirrors/dc100www/dc_014.htm


What is there inherent in the theory that prevents two way conversation,
like on a phone line, in the simplex mode (such as in maritime VHF/fm
ship
to shore conversations) ?

There is nothing inherent in the theory that prevents this. It's just
part of the communication system design.

RK


This would require a lot more hardware. Modern transceivers share much of
the circuitry- so it cannot be used simultaneously for TX and RX.
From a logistics standpoint you would obviously need 2 channels of
sufficient separation to allow reasonable filters to isolate the TX from the
RX- and likely separate antennas- although a single antenna may be used if
more complex filters are incorporated.
All in all, a lot more complexity and $$ for little benefit.
Dale W4OP