I usually send everything once, especially if the exchange is
something simple, like "DAVE AZ."
I participate in a lot of contests, and most people already know
that I am DAVE AZ. Serious RTTY contesters should also be
running a call history. The Arizona Outlaws Contest Club web
site is a good source of these call histories. You should also
be doing verification of the copy by listening to signal strength
of the signal in your headphones, correlating that with copy on
the screen. If the signal goes into a fade, trust the copy less.
If the signal is solid, once is enough. I try to be loud, so
once is enough most of the time. If you are using a call
history, and the signal goes into a fade, and you copy "MAVE RZ,"
and your call history says DAVE AZ, go with it. It is not a
moral failing to do this. You may lose the QSO if you are wrong,
which is an appropriate penalty for your slipshod behavior, but
you are not getting condemned to hell for eternity. Shannon's
communications theory points out that, if the message is
predictable, reliability of the communication is much improved,
because random hits have low impact. Call history improves
predictability.
In sending the exchange just once, I also minimize the use of
FIGS/LTRS shifts. For example, I send "599-356 AZ" where the
dash between the 599 and 356 keeps that whole sequence in FIGS
mode, rather than interjecting a FIGS/LTRS or LTRS/FIGS shift.
(Dash is a FIGS character.) There is a downside to this
procedure, but over the years I have found that it is more
reliable to use this technique, especially with more and more
people using 2Tone. For some reason, based on my experience,
2Tone copies FIGS slightly better than MMTTY.
Dave Hachadorian, K6LL
Big Bear Lake, CA
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