[wsjt-devel] Compound callsigns

[Joe T. <jo...@pr...>]

Hi all,

Over the weekend I made some changes to the way WSJT-X generates 
suggested user messages when a compound callsign is involved.  I also 
made a minor change in the way the encoder decides when to use the 
free-text format in a message.  These changes are intended to make 
compound callsigns more convenient, when needed.

The original specification of the JT65 protocol included a list of 339 
DXCC prefixes, supposedly the most commonly used ones, plus 12 common 
single-character suffixes.  As described in Section 7.3 of the WSJT-X 
User Guide, they can be used to make "Type 1" compound callsigns.  Other 
arbitrary prefixes (up to 4 characters) and suffixes (up to 3 
characters) may be used in "Type 2" compound callsigns, with different 
restrictions in usage.

WSJT-X generates suggested messages automatically when the user clicks 
"Generate Std Msgs" on Tab 1 or one of the six buttons on Tab 2.  Here's 
a brief summary of what messages are affected by compound-callsign usage.

1. When "MyCall" is a Type 1 compound callsign, messages 1 and 6 contain 
the compound callsign as the second word.  Examples:

	K1ABC ZL/W9XYZ  (Tx1, also "Grid" button on Tab 2)
	CQ ZL/W9XYZ     (Tx6, also "CQ" button on Tab 2)

All other messages use the base callsigns only (no prefix/suffix).

2. When "MyCall" is a Type 2 compound callsign, messages 2, 5, and 6 
contain the compound callsign as the second word.  Examples:

	DE W9XYZ/VE1       (Tx2)
	DE W9XYZ/VE1 73    (Tx5, also "73" on Tab 2)
	CQ W9XYZ/VE1 FN75  (Tx6, also "CQ" on Tab 2)

Message numbers 1 ("Grid" on Tab 2), 3 ("R+dB") , and 4 ("RRR") use the 
base callsigns only.

3. When "HisCall" is a Type 1 compound callsign, message 1 uses it as 
the first word.  Example:

	ZL/K1ABC W9XYZ     (Tx1, also "Grid" on Tab 2)

All other messages use the base callsigns only.

4. When "HisCall" is a Type 1 compound callsign, message 5 uses it as 
the first word.  Example:

	K1ABC/VE1 73       (Tx5, also "73" on Tab 2)

All other messages use the base callsigns only.

[In the rare case where both MyCall and HisCall are compound, automatic 
message generation is not very useful.  Operators will need to edit 
messages manually, to be sure they will both know the full callsign of 
the station being worked.]

What happens if a user tries to send a message similar to the one in 
item #3 above, but with a prefix or suffix NOT in the short list?  For 
example, suppose the message is "XL/K1ABC W9XYZ".  Since "XL" is not in 
the short list, "XL/K1ABC" is a Type 2 compound callsign.  But the first 
word in a message with a Type 2 compound callsigns must be CQ, QRZ, or 
DE.  Since the attempted message fails to satisfy either Type 1 or Type 
2 criteria, subroutine packmsg() encodes the first 13 characters as free 
text and sends "XL/K1ABC W9XY".  This procedure may be useful for those 
with short callsigns.


These changes were made in the development branch, .../branches/wsjtx.

Should they be merged back into wsjtx-1.4?  This is a policy question, 
and I'm not sure or the proper answer.  The changes don't exactly fix a 
bug in v1.4-rc2; rather, they correct a perceived flaw in the way that 
version chose to generate messages automatically.

Your views on this matter would be welcome.  I would also appreciate any 
comments on whether you think the new code makes the best possible 
compromises for handling compound callsigns.

	-- 73. Joe, K1JT