[GreenKeys] SELCAL, etc.

[wa2hwj@att.net]

ZCZC

As a "TTY Traditionalist" I'd like to stick with the codes
that were used in the good old RTTY days. ZCZC as a start of
message and NNNN as an end of message code are pretty much
standard. In fact, I have seen those codes still used in my
snooping for RTTY on the shortwave freqs. Using our call
letters is the best way to differentiate the specific
person's TTY address (whether or not we decode all of the
characters or just a subset). FIGS H LTRS is used as the
deselect code just to set everything to the beginning, so
to speak. 
I have an old Frederick "solid state" sequence selector
which has been set up with my call and the NNNN sequence for about 20 years (never used). And, with my recently-constructed Model
28 sequence selector, the sender could even select which machine
in the shack he wants to send to (!). My plan for the sequence selector is to use it as a switch to pick the machine that gets traffic (and to obviously turn it on). By blinding the loop to the machines, I can
let them time out and shut down; startup would be with the good old 
line-operated motor control relay often found in the back of 28's (the one that shuts the motor off with a stuntbox code and starts up when it sees loop activity).
Great discussions...it seems this topic has really awakened the Greenkeys gang.
73,
Jack WA2HWJ

NNNN