On 11/12/2018 01:41, Mike Maynard wrote:
So I installed v2.0 GA on my 'mobile' setup today. I no longer have a
grid square in my standard messages with /M on my callsign.
If I just put in my base callsign the grid square shows up fine. once
I change to K2GC/M the grid square drops out.
Tried it on my shack setup too (also 2.0GA) and it does the same thing.
this was a non-issue in 1.9.1 Did I miss something? or is this a bug?
--
Mike
K2GC
www.k2gc.net <http://www.k2gc.net>
Hi Mike,
in the new 77-bit payload FT8 and MSK144 messages the handling of
callsigns has been unified, there are three ways of inserting a callsign
into a standard form message, either a standard callsign, a complex
callsign, or a hash code representing the callsign. Complex callsigns
include compound callsigns, longer callsigns that don't fit the WSJT-X
standard callsign pattern and those including standard suffixes like /M.
Note that all of these complex callsigns are now treated uniformly,
there are no type-1 or type-2 compound callsigns with the 77-bit
messages. The CQ, QRZ and similar words count as a standard callsign.
The message can contain two callsigns and some extra information except
when one of the callsigns is a complex callsign. The extra information
can be a grid-square, a report, a R-report, RRR, RR73, or 73. So that
reports can be exchanged with both callsigns printed when a complex
callsign is involved, one callsign can be represented by a hash code
which uses less payload bits than the callsign in full, this leaves
space for one of a RRR, RR73, 73, report, R-report, or a grid, but note
that for the last three (reports or grid) the complex callsign must be
the one sent as a hash.
So, given the above, a CQ message with a complex callsign cannot include
a grid-square because the only way to do so would be to replace the
callsign with a hash code and that will not work as hash codes can only
be converted to callsigns at the receiving end if the callsign has
previously been decoded and even then there may be two or more callsigns
that map to the same hash code, the hash codes have a one to many
(actually one to few) relationship with the callsigns they represent and
where two or more callsigns of interest map to the same hash code is
what is known as a hash collision.
The bottom line is that special handling of basic suffixes like /M /P /A
/1 /2 ... /0 and other specified prefixes that had special encoding in
the 75-bit message format (type 1 compound callsigns) have been
sacrificed to allow message space for a uniform approach that works for
vastly more variations of complex callsigns including those originally
covered by type-1 special cases.
You can send a message to you QSO partner including your grid square but
it must be of the following form:
G4WJS <K2GC/M> FN03
this is fine once a QSO has started, you could sign off with it for
example, because your full call would have been sent earlier in the QSO
and your QSO partner and anyone listening will have the correct hash
code mapping to decode the message as shown above. Anyone not having the
hash code would receive the message above as:
G4WJS <...> FN03
which is not much good to them. In the same way that sending:
CQ <K2GC/M> FN03
would not be any use and in this case we even flag it as a bad message
and don't allow it to be sent.
Just to complete the picture with complex callsigns, there are a couple
of special cases for the NA and EU VHF contest modes that allow /R and
/P respectively since these are necessary for many stations in such
contests.
73
Bill
G4WJS.
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