On Sat, 04 Jan 2003 15:26:48 -0500, Carter Grabarczyk wrote:
>He is sending his (your) serial number, the exchange. It is in alpha
>because he is inadvertently using "unshift on space".
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You're half right - it is the serial number, but the problem is
not caused by using USOS. USOS is the default mode for nearly
all TNCs and soundcard programs, and does not cause this
particular error. Unless someone has intentionally turned USOS
off, they are probably operating with it on whether they realize
it or not.
I haven't seen the CO station's print myself, but if he is
consistently sending unshifted numbers, then somehow he is going
from LTRS mode to FIGS mode without sending a FIGS shift
character ahead of the numbers. Perhaps he is using a homebrew
software program which contains an error. I can't think of any
setting in the usual programs or hardware which would cause this,
but perhaps there might be one.
A properly operating machine will send a FIGS shift character
when going from letters to numbers regardless of whether USOS is
turned on or not. The only thing that USOS does differently is
to return to LTRS mode whenever it detects a space (both TX and
RX), and, if the next character is a number, the TX sends a FIGS
shift character first. This greatly increases the probability of
the TX and RX remaining in sync with each other as to which shift
is in use. The only drawback is a slight slowing down caused by
the extra FIGS character - approximately 167 ms each time one is
sent, but only when a space is followed by a number.
To anyone who is new to RTTY, this will probably seem to be the
next thing to meaningless, but a little time spent pondering the
subject will cause one to realize what a clever idea USOS is.
All hams should have USOS enabled in their equipment.
For more information, please see my "RTTY Basics" section in the
MMTTY help files. MMTTY, including the help files, is available
at: http://www.qsl.net/mmhamsoft/
73, Bill W7TI
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