[RTTY] Tinyfsk, 2Tone and USOS

[Charles Lind]

Why is it if I transmit using MMTTY/simple transistor interface I get no
requests for repeats, and checking with another rig on receive loaded only
with MMTTY it prints correctly when I send "599 05 NY NY", but when I
switch to 2Tone/Tinyfsk I get numerous requests for repeats of the state
and it prints " ,6 ,6 " on the other end with MMTTY receive.  The only
change has been in the transmitted signal.  What is different between the
exchange sent by MMTTY/simple interface vs. 2Tone/Tinyfsk?????

Chuck, N8CL



On Tue, Sep 29, 2015 at 5:45 PM, Kok Chen <chen at mac.com> wrote:

>
> On Sep 29, 2015, at 9:52 AM, V. Sidarau wrote:
>
> > Another guy has just sent me a part of his MixW decoding log. In a
> string of
> > QSOs a BIG contester sends like, 599 05 .- .- (that's <dit><dot>)
> instead of
> > the state of MA.
>
> In LTRS shift, a full stop (.) is an M.  Similarly, a dash (-) is an A.
>  So, ".-" in FIGS is "MA" in LTRS.
>
> The encoder (transmitter) was probably in USOS state, so it, properly,
> does not send an explicit LTRS character before the "MA."  The decoder was
> probably in "non-USOS" state, and did not shift to LTRS mode after it saw
> the space.
>
> If the sender had sent 599-MA, it would have transmitted an explicit FIGS
> after the "-", and the receiver would receive 599-MA.
>
> That said, don't ever send MA-MA.  You only slow things down, and more
> characters mean more potential for errors.
>
> When I used to participate in contests, my preferred state exchange was
> "599-OR OR."
>
> The dash makes the transmission compatible with both USOS and non-USOS
> receivers since the transmitter always transmits a LTRS after the dash.
> The space between two "OR" adds the robustness to USOS systems, while not
> screwing up non-USOS printers.
>
> The only disadvantage is an extra LTRS that is transmitted right after the
> dash when compared to "599 OR OR" in USOS.
>
> 73
> Chen, W7AY
>
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