subroutine packcall(callsign,ncall,text)

C  Pack a valid callsign into a 28-bit integer.

      parameter (NBASE=37*36*10*27*27*27)
      character callsign*6,c*1,tmp*6
      logical text

      text=.false.

C  Work-around for Swaziland prefix:
      if(callsign(1:4).eq.'3DA0') callsign='3D0'//callsign(5:6)

      if(callsign(1:3).eq.'CQ ') then
         ncall=NBASE + 1
         if(callsign(4:4).ge.'0' .and. callsign(4:4).le.'9' .and. 
     +      callsign(5:5).ge.'0' .and. callsign(5:5).le.'9' .and. 
     +      callsign(6:6).ge.'0' .and. callsign(6:6).le.'9') then
            read(callsign(4:6),*) nfreq
            ncall=NBASE + 3 + nfreq
         endif
         return
      else if(callsign(1:4).eq.'QRZ ') then
         ncall=NBASE + 2
         return
      else if(callsign(1:3).eq.'DE ') then
         ncall=267796945
         return
      endif

      tmp='      '
      if(callsign(3:3).ge.'0' .and. callsign(3:3).le.'9') then
         tmp=callsign
      else if(callsign(2:2).ge.'0' .and. callsign(2:2).le.'9') then
         if(callsign(6:6).ne.' ') then
            text=.true.
            return
         endif
         tmp=' '//callsign(:5)
      else
         text=.true.
         return
      endif

      do i=1,6
         c=tmp(i:i)
         if(c.ge.'a' .and. c.le.'z') 
     +     tmp(i:i)=char(ichar(c)-ichar('a')+ichar('A'))
      enddo

      n1=0
      if((tmp(1:1).ge.'A'.and.tmp(1:1).le.'Z').or.tmp(1:1).eq.' ') n1=1
      if(tmp(1:1).ge.'0' .and. tmp(1:1).le.'9') n1=1
      n2=0
      if(tmp(2:2).ge.'A' .and. tmp(2:2).le.'Z') n2=1
      if(tmp(2:2).ge.'0' .and. tmp(2:2).le.'9') n2=1
      n3=0
      if(tmp(3:3).ge.'0' .and. tmp(3:3).le.'9') n3=1
      n4=0
      if((tmp(4:4).ge.'A'.and.tmp(4:4).le.'Z').or.tmp(4:4).eq.' ') n4=1
      n5=0
      if((tmp(5:5).ge.'A'.and.tmp(5:5).le.'Z').or.tmp(5:5).eq.' ') n5=1
      n6=0
      if((tmp(6:6).ge.'A'.and.tmp(6:6).le.'Z').or.tmp(6:6).eq.' ') n6=1

      if(n1+n2+n3+n4+n5+n6 .ne. 6) then
         text=.true.
         return 
      endif

      ncall=nchar(tmp(1:1))
      ncall=36*ncall+nchar(tmp(2:2))
      ncall=10*ncall+nchar(tmp(3:3))
      ncall=27*ncall+nchar(tmp(4:4))-10
      ncall=27*ncall+nchar(tmp(5:5))-10
      ncall=27*ncall+nchar(tmp(6:6))-10

      return
      end