[RTTY] More GRITTY observations

[Kok Chen]

On Apr 27, 2015, at 8:41 AM, David G3YYD wrote:

> One thing I noticed is some transmissions that always send a ltrs shift
> after a space character. What a waste of transmission time and the extra
> unnecessary characters adds to the potential for errors. Anyone know which
> software/hardware is doing this?

There is actually a rational reason for this.  Especially outside a contest, where the millisecond counters don't thread :-).

If you are sending USOS, and the other end receives with a non-USOS decoder, the extra LTRS shift avoids the infinite loop of "AGN? AGN? from people who don't know how to interpret "TOOQWE."  

The extra LTRS shift makes the sender compatible with both USOS and non-USOS receivers.  It might be the only way to ensure interoperability between USOS and non-USOS (though I haven't spent that much time in the past to come up with other solutions).

Perhaps a more optimal way to ensure USOS interoperability is to send extra LTRS only when repeating an exchange to the same caller.

If I were using USOS, I would use the extra LTRS when calling a DXpedition.  Who knows what they are using.

73
Chen, W7AY