[RTTY] More GRITTY observations

Kok Chen chen at mac.com
Mon Apr 27 16:17:40 EDT 2015

On Apr 27, 2015, at 12:56 PM, David G3YYD wrote:

> This [LTRS] is unnecessary whether USOS is
> on or off.

A USOS transmitter needs to send an explicit LTRS shift when sending certain sequences, if the receiver is not using USOS. Otherwise, a "599 OR" from the USOS transmitter will be received as "599 94" by a non-USOS receiver for example.

It is faster, and more error free (more redundant characters == more percentage errors) to not use USOS when exchanges are all (or mostly) numerical.  The way out with USOS is to use no delimiter (599001) or use the "-" delimiter between numbers (599-001).  

Chen, W7AY

More information about the RTTY mailing list