Joe, is it possible to use one of the extra FT8 bits as a flag that you are
transmitting in contest mode or not? Would that be useful to keep the program
on the receiving end from being confused?
73 Jay KA9CFD
Sent from my U.S.Cellular© Smartphone
-------- Original message --------From: Joe Taylor <j...@princeton.edu> Date:
5/31/18 10:34 (GMT-06:00) To: WSJT software development
<wsjt-devel@lists.sourceforge.net> Subject: Re: [wsjt-devel] working stations
over 10000 km on 6m
Hi Jay, Ned, and all,
On 5/30/2018 8:57 PM, Jay Hainline KA9CFD wrote:
> We had a big opening to JA today on 6m. Some of the contacts were over
> 10,000 km and I have heard some ops report their WSJT-X software would hang
> up asking if they want to switch to contest mode. Apparently the program
> sees the grid from JA and thinks they are in contest mode? I don't have much
> more details. Maybe someone can chime in or advise if this would be a bug
> that needs fixed.
>
> Jay Hainline KA9CFD
Ned AA7A wrote:
> This happened to me at the most inopportune time. I was sending a signal
> report to DS4AOW for a ATNO on 6m and it sent a NA Contest TX3 exchange
> instead of what was expected. The only way I could clear the problem was to
> change the mode to to anything other than FT8 and then back to get the right
> TX3 message. While I was sorting that all out, the band faded and I did not
> complete.
>
> It's rare to hear stations over 10 KM, so this is a hard thing to test.
Jay KA9CFD wrote:
> Hopefully the developers will have some insight. I never have like the idea
>of using the opposite side of the world grid to represent an R-grid contest
>report. Causes confusion for non-contesters, and some bad side effects
>apparently. :-)
Contesters pleaded for an easy way to send "R+grid" rather than "R+rpt"
in the message sequence. They wanted this feature in both MSK144 and
FT8. FT8 has three extra information bits in its message payload, not
all of which are (yet) used. MSK144 does not have these extra bits.
There is no foolproof, satisfy-everybody, mode-independent way to
squeeze "R+grid" messages along with all other standard message features
in a 72-bit packet.
We therefore decided to use the "antipode grid" method of conveying
"R+grid". QSOs on VHF bands over distances greater than 10,000 kkm
using MSK144 and FT8 are expected to be rare.
When you're lucky enough to be working East Asia on 6m, using WSJT-X
v1.9, just hit "No" when asked if you should be in contest mode.
In any future (or possibly enhanced) modes we will most likely reserve a
few additional bits for message types that solve this problem (as well
as Rover callsigns and a few other nagging issues of message structure)
in a better way. The necessary price will be a small (less than 1 dB)
loss of sensitivity.
-- 73, Joe, K1JT
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