[GreenKeys] M28 half vs full duplex? One loop or two?

[Chris Elmquist]

On Monday (07/02/2012 at 11:17AM -0400), Nick England wrote:
> Here's my understanding of how the Navy did it -
> 
> TT-176B's were wired with keyboard and printer in the same loop so you
> could see what you were typing and have a complete printed record of
> the communication.
> They were interfaced to two types of systems, TONE or CFS -
> The TONE TU (mainly for UHF transceivers) would switch into transmit
> automatically when you typed. The CFS system (HF) had separate rcv
> converter and xmt keyer - you manually used an external rcv-xmt
> switch. Shipboard, a C-1004/SG control box would have been associated
> with the TT-176
> http://www.navy-radio.com/rtty/c1004.htm
> 
> Hams usually had/have TU boxes hooked to a transceiver and run the
> equivalent of TONE operation.

Thanks Nick.  That helps.

For the Altair 680 application, I guess everything can be in series
since it can ignore incoming data while it is sending.  It then just
has to flush the last character received before it takes actual input,
since the last character received would also be the last that it sent.
But after that, half duplex should work.

Chris N0JCF

-- 
Chris Elmquist