Pass hints to fst240sim, genfst240, and packjt77::pack77 on WSPR msgs

Due to  an ambiguity with  message encodings between 77-bit  QSO modes
and 50-bit  beacon modes with message  types 13.n3 4.0 and  0.6 a hint
needs to be  passed to ensure the right encoding  is emitted. The hint
only  effects  ambiguous messages,  others  will  be encoded  strictly
according to the message content.

lib/77bit/packjt77.f90

@@ -124,12 +124,14 @@ subroutine pack77(msg0,i3,n3,c77)
   integer ntel(3)
 
   msg=msg0
-  if(i3.eq.0 .and. n3.eq.5) go to 5
+  i3_hint=i3
+  n3_hint=n3
+  i3=-1
+  n3=-1
+  if(i3_hint.eq.0 .and. n3_hint.eq.5) go to 5
 
 ! Convert msg to upper case; collapse multiple blanks; parse into words.
   call split77(msg,nwords,nw,w)
-  i3=-1
-  n3=-1
   if(msg(1:3).eq.'CQ ' .or. msg(1:3).eq.'DE ' .or. msg(1:4).eq.'QRZ ') go to 100
 
 ! Check 0.1 (DXpedition mode)
@@ -160,7 +162,7 @@ subroutine pack77(msg0,i3,n3,c77)
      go to 900
   endif
 
-100 call pack77_06(nwords,w,i3,n3,c77)
+100 call pack77_06(nwords,w,i3,n3,c77,i3_hint,n3_hint)
   if(i3.ge.0) go to 900
 
 ! Check Type 1 (Standard 77-bit message) or Type 2, with optional "/P"
@@ -414,7 +416,7 @@ subroutine unpack77(c77,nrx,msg,unpk77_success)
         n28=n22+2063592
         call unpack28(n28,call_1,unpk28_success) 
         if(.not.unpk28_success) unpk77_success=.false.
-        call to_grid6(igrid6,grid6)
+        call to_grid(igrid6,grid6)
         msg=trim(call_1)//' '//grid6
 
 
@@ -938,7 +940,7 @@ subroutine pack77_03(nwords,w,i3,n3,c77)
 end subroutine pack77_03
 
 
-subroutine pack77_06(nwords,w,i3,n3,c77)
+subroutine pack77_06(nwords,w,i3,n3,c77,i3_hint,n3_hint)
 
   character*13 w(19)
   character*77 c77
@@ -955,13 +957,14 @@ subroutine pack77_06(nwords,w,i3,n3,c77)
        grid4(3:3).ge.'0' .and. grid4(3:3).le.'9' .and.               &
        grid4(4:4).ge.'0' .and. grid4(4:4).le.'9'
 
-  is_grid6(grid6)=len(trim(grid6)).eq.6 .and.                        &
+  is_grid6(grid6)=(len(trim(grid6)).eq.6.or.len(trim(grid6)).eq.4).and. &
        grid6(1:1).ge.'A' .and. grid6(1:1).le.'R' .and.               &
        grid6(2:2).ge.'A' .and. grid6(2:2).le.'R' .and.               &
        grid6(3:3).ge.'0' .and. grid6(3:3).le.'9' .and.               &
        grid6(4:4).ge.'0' .and. grid6(4:4).le.'9' .and.               &
-       grid6(5:5).ge.'A' .and. grid6(5:5).le.'X' .and.               &
+       (len(trim(grid6)).eq.4.or.                                    &
-       grid6(6:6).ge.'A' .and. grid6(6:6).le.'X'
+       (grid6(5:5).ge.'A' .and. grid6(5:5).le.'X' .and.              &
+       grid6(6:6).ge.'A' .and. grid6(6:6).le.'X'))
 
   is_digit(c)=c.ge.'0' .and. c.le.'9'
 
@@ -1033,8 +1036,13 @@ subroutine pack77_06(nwords,w,i3,n3,c77)
      go to 900
   endif
 
-  if(nwords.eq.2 .and. m1.ge.5 .and. m1.le.12 .and. m2.le.6) then
+  if(i3_hint.eq.0.and.n3_hint.eq.6.and.nwords.eq.2 .and. m1.ge.5  &
+       .and. m1.le.12 .and. m2.le.6) then
 ! WSPR Type 3
+
+     !n3_hint=6 and i3_hint=0 is a hint that the caller wanted a
+     !50-bit encoding rather than the possible alternative n3=4 77-bit
+     !encoding
      if(index(w(1),'<').lt.1 .or. index(w(1),'>').lt.1) go to 900
      grid6=w(2)(1:6)
      if(.not.is_grid6(grid6)) go to 900
@@ -1042,13 +1050,17 @@ subroutine pack77_06(nwords,w,i3,n3,c77)
      n3=6
      call pack28(w(1),n28)
      n22=n28-2063592
-     k1=(ichar(grid6(1:1))-ichar('A'))*18*10*10*24*24
+     k1=(ichar(grid6(1:1))-ichar('A'))*18*10*10*25*25
-     k2=(ichar(grid6(2:2))-ichar('A'))*10*10*24*24
+     k2=(ichar(grid6(2:2))-ichar('A'))*10*10*25*25
-     k3=(ichar(grid6(3:3))-ichar('0'))*10*24*24
+     k3=(ichar(grid6(3:3))-ichar('0'))*10*25*25
-     k4=(ichar(grid6(4:4))-ichar('0'))*24*24
+     k4=(ichar(grid6(4:4))-ichar('0'))*25*25
-     k5=(ichar(grid6(5:5))-ichar('A'))*24
+     if (grid6(5:6).eq.'  ') then
+        igrid6=k1+k2+k3+k4+24*25+24
+     else
+        k5=(ichar(grid6(5:5))-ichar('A'))*25
         k6=(ichar(grid6(6:6))-ichar('A'))
         igrid6=k1+k2+k3+k4+k5+k6
+     endif
      write(c77,1030) n22,igrid6,2,0,n3,i3
 1030 format(b22.22,b25.25,b3.3,b21.21,2b3.3)
   endif
@@ -1523,4 +1535,31 @@ subroutine to_grid6(n,grid6)
   return
 end subroutine to_grid6
 
+subroutine to_grid(n,grid6)
+  ! 4-, or 6-character grid
+  character*6 grid6
+
+  j1=n/(18*10*10*25*25)
+  n=n-j1*18*10*10*25*25
+  j2=n/(10*10*25*25)
+  n=n-j2*10*10*25*25
+  j3=n/(10*25*25)
+  n=n-j3*10*25*25
+  j4=n/(25*25)
+  n=n-j4*25*25
+  j5=n/25
+  j6=n-j5*25
+  grid6=''
+  grid6(1:1)=char(j1+ichar('A'))
+  grid6(2:2)=char(j2+ichar('A'))
+  grid6(3:3)=char(j3+ichar('0'))
+  grid6(4:4)=char(j4+ichar('0'))
+  if (j5.ne.24.or.j6.ne.24) then
+     grid6(5:5)=char(j5+ichar('A'))
+     grid6(6:6)=char(j6+ichar('A'))
+  endif
+
+  return
+end subroutine to_grid
+
 end module packjt77

lib/fst240/fst240sim.f90

@@ -6,6 +6,7 @@ program fst240sim
    use packjt77
    include 'fst240_params.f90'               !Set various constants
    type(hdr) h                                !Header for .wav file
+   logical*1 wspr_hint
    character arg*12,fname*17
    character msg37*37,msgsent37*37,c77*77
    complex, allocatable :: c0(:)
@@ -18,10 +19,11 @@ program fst240sim
 
 ! Get command-line argument(s)
    nargs=iargc()
-   if(nargs.ne.9) then
+   if(nargs.ne.10) then
-      print*,'Need 9 arguments, got ',nargs
+      print*,'Need 10 arguments, got ',nargs
-      print*,'Usage:    fst240sim "message"        TRsec f0   DT  h fdop del nfiles snr'
+      print*,'Usage:    fst240sim "message"        TRsec f0   DT  h fdop del nfiles snr W'
-      print*,'Examples: fst240sim "K1JT K9AN EN50"  60  1500 0.0  1  0.1 1.0   10   -15'
+      print*,'Examples: fst240sim "K1JT K9AN EN50"  60  1500 0.0  1  0.1 1.0   10   -15 F'
+      print*,'W (T or F) argument is hint to encoder to use WSPR message when there is abiguity'
       go to 999
    endif
    call getarg(1,msg37)                   !Message to be transmitted
@@ -41,6 +43,8 @@ program fst240sim
    read(arg,*) nfiles                     !Number of files
    call getarg(9,arg)
    read(arg,*) snrdb                      !SNR_2500
+   call getarg(10,arg)
+   read(arg,*) wspr_hint                  !0:break ties as 77-bit 1:break ties as 50-bit
 
    nfiles=abs(nfiles)
    twopi=8.0*atan(1.0)
@@ -72,12 +76,18 @@ program fst240sim
    sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*snrdb)
    if(snrdb.gt.90.0) sig=1.0
 
+   if(wspr_hint) then
+      i3=0
+      n3=6
+   else
       i3=-1
       n3=-1
+   endif
    call pack77(msg37,i3,n3,c77)
+   if(i3.eq.0.and.n3.eq.6) iwspr=1
    call genfst240(msg37,0,msgsent37,msgbits,itone,iwspr)
    write(*,*)
-   write(*,'(a9,a37,a7,i2)') 'Message: ',msgsent37,' iwspr:',iwspr
+   write(*,'(a9,a37,a3,L2,a7,i2)') 'Message: ',msgsent37,'W:',wspr_hint,' iwspr:',iwspr
    write(*,1000) f00,xdt,hmod,txt,snrdb
 1000 format('f0:',f9.3,'   DT:',f6.2,'   hmod:',i6,'   TxT:',f6.1,'   SNR:',f6.1)
    write(*,*)

lib/fst240/genfst240.f90

@@ -5,7 +5,8 @@ subroutine genfst240(msg0,ichk,msgsent,msgbits,i4tone,iwspr)
 !   - ichk     if ichk=1, return only msgsent
 !   - msgsent  message as it will be decoded
 !   - i4tone   array of audio tone values, {0,1,2,3}
-!   - iwspr    0: (240,101)/crc24, 1: (240,74)/crc24
+!   - iwspr    in: 0: FST240 1: FST240W
+!              out 0: (240,101)/crc24, 1: (240,74)/crc24
 !
 ! Frame structure:
 ! s8 d30 s8 d30 s8 d30 s8 d30 s8
@@ -43,6 +44,10 @@ subroutine genfst240(msg0,ichk,msgsent,msgbits,i4tone,iwspr)
 
    i3=-1
    n3=-1
+   if(iwspr.eq.1) then
+      i3=0
+      n3=6
+   endif
    call pack77(message,i3,n3,c77)
    call unpack77(c77,0,msgsent,unpk77_success) !Unpack to get msgsent
    msgbits=0

widgets/mainwindow.cpp

@@ -3875,6 +3875,7 @@ void MainWindow::guiUpdate()
             char fst240msgbits[101];
             QString wmsg;
             if(m_mode=="FST240W") {
+              iwspr = 1;
               wmsg=WSPR_message();
               ba=wmsg.toLatin1();
               ba2msg(ba,message);