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			502 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Fortran
		
	
	
	
	
	
			
		
		
	
	
			502 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Fortran
		
	
	
	
	
	
| subroutine ft8b(dd0,newdat,nQSOProgress,nfqso,nftx,ndepth,nzhsym,lapon,     &
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|      lapcqonly,napwid,lsubtract,nagain,ncontest,iaptype,mycall12,hiscall12, &
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|      f1,xdt,xbase,apsym,aph10,nharderrors,dmin,nbadcrc,ipass,               &
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|      msg37,xsnr,itone)
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| 
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|   use crc
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|   use timer_module, only: timer
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|   use packjt77
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|   include 'ft8_params.f90'
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|   parameter(NP2=2812)
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|   character*37 msg37
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|   character*12 mycall12,hiscall12
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|   character*77 c77
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|   real a(5)
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|   real s8(0:7,NN)
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|   real s2(0:511)
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|   real bmeta(174),bmetb(174),bmetc(174),bmetd(174)
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|   real llra(174),llrb(174),llrc(174),llrd(174),llrz(174)           !Soft symbols
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|   real dd0(15*12000)
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|   real ss(9)
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|   integer*1 message77(77),message91(91),apmask(174),cw(174)
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|   integer apsym(58),aph10(10)
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|   integer mcq(29),mcqru(29),mcqfd(29),mcqtest(29),mcqww(29)
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|   integer mrrr(19),m73(19),mrr73(19)
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|   integer itone(NN)
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|   integer icos7(0:6),ip(1)
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|   integer nappasses(0:5)  !Number of decoding passes to use for each QSO state
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|   integer naptypes(0:5,4) ! (nQSOProgress, decoding pass)  maximum of 4 passes for now
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|   integer ncontest,ncontest0
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|   logical one(0:511,0:8)
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|   integer graymap(0:7)
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|   integer iloc(1)
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|   complex cd0(0:3199)
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|   complex ctwk(32)
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|   complex csymb(32)
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|   complex cs(0:7,NN)
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|   logical first,newdat,lsubtract,lapon,lapcqonly,nagain,unpk77_success
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|   data icos7/3,1,4,0,6,5,2/  ! Flipped w.r.t. original FT8 sync array
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|   data     mcq/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0/
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|   data   mcqru/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,1,0,0,1,1,0,0/
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|   data   mcqfd/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,1,0,0,0,1,0/
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|   data mcqtest/0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,1,0,1,0,1,1,1,1,1,1,0,0,1,0/
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|   data   mcqww/0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,1,1,0,1,1,1,1,0/
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|   data    mrrr/0,1,1,1,1,1,1,0,1,0,0,1,0,0,1,0,0,0,1/
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|   data     m73/0,1,1,1,1,1,1,0,1,0,0,1,0,1,0,0,0,0,1/
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|   data   mrr73/0,1,1,1,1,1,1,0,0,1,1,1,0,1,0,1,0,0,1/
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|   data first/.true./
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|   data graymap/0,1,3,2,5,6,4,7/
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|   save nappasses,naptypes,ncontest0,one
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| 
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|   if(first.or.(ncontest.ne.ncontest0)) then
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|      mcq=2*mcq-1
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|      mcqfd=2*mcqfd-1
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|      mcqru=2*mcqru-1
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|      mcqtest=2*mcqtest-1
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|      mcqww=2*mcqww-1
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|      mrrr=2*mrrr-1
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|      m73=2*m73-1
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|      mrr73=2*mrr73-1
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|      nappasses(0)=2
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|      nappasses(1)=2
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|      nappasses(2)=2
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|      nappasses(3)=4
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|      nappasses(4)=4
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|      nappasses(5)=3
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| 
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| ! iaptype
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| !------------------------
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| !   1        CQ     ???    ???           (29+3=32 ap bits)
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| !   2        MyCall ???    ???           (29+3=32 ap bits)
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| !   3        MyCall DxCall ???           (58+3=61 ap bits)
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| !   4        MyCall DxCall RRR           (77 ap bits)
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| !   5        MyCall DxCall 73            (77 ap bits)
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| !   6        MyCall DxCall RR73          (77 ap bits)
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| 
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|      naptypes(0,1:4)=(/1,2,0,0/) ! Tx6 selected (CQ)
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|      naptypes(1,1:4)=(/2,3,0,0/) ! Tx1
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|      naptypes(2,1:4)=(/2,3,0,0/) ! Tx2
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|      naptypes(3,1:4)=(/3,4,5,6/) ! Tx3
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|      naptypes(4,1:4)=(/3,4,5,6/) ! Tx4
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|      naptypes(5,1:4)=(/3,1,2,0/) ! Tx5
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| 
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|      one=.false.
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|      do i=0,511
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|        do j=0,8
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|          if(iand(i,2**j).ne.0) one(i,j)=.true.
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|        enddo
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|      enddo
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|      first=.false.
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|      ncontest0=ncontest
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|   endif
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| 
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|   dxcall13=hiscall12  ! initialize for use in packjt77
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|   mycall13=mycall12
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| 
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|   max_iterations=30
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|   nharderrors=-1
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|   fs2=12000.0/NDOWN
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|   dt2=1.0/fs2
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|   twopi=8.0*atan(1.0)
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|   delfbest=0.
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|   ibest=0
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| 
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|   call timer('ft8_down',0)
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|   call ft8_downsample(dd0,newdat,f1,cd0)   !Mix f1 to baseband and downsample
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|   call timer('ft8_down',1)
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| 
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|   i0=nint((xdt+0.5)*fs2)                   !Initial guess for start of signal
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|   smax=0.0
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|   do idt=i0-10,i0+10                         !Search over +/- one quarter symbol
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|      call sync8d(cd0,idt,ctwk,0,sync)
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|      if(sync.gt.smax) then
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|         smax=sync
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|         ibest=idt
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|      endif
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|   enddo
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| 
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| ! Now peak up in frequency
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|   smax=0.0
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|   do ifr=-5,5                              !Search over +/- 2.5 Hz
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|     delf=ifr*0.5
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|     dphi=twopi*delf*dt2
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|     phi=0.0
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|     do i=1,32
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|       ctwk(i)=cmplx(cos(phi),sin(phi))
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|       phi=mod(phi+dphi,twopi)
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|     enddo
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|     call sync8d(cd0,ibest,ctwk,1,sync)
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|     if( sync .gt. smax ) then
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|       smax=sync
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|       delfbest=delf
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|     endif
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|   enddo
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|   a=0.0
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|   a(1)=-delfbest
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|   call twkfreq1(cd0,NP2,fs2,a,cd0)
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|   f1=f1+delfbest                           !Improved estimate of DF
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| 
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|   call timer('ft8_down',0)
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|   call ft8_downsample(dd0,.false.,f1,cd0)   !Mix f1 to baseband and downsample
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|   call timer('ft8_down',1)
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| 
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|   smax=0.0
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|   do idt=-4,4                         !Search over +/- one quarter symbol
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|      call sync8d(cd0,ibest+idt,ctwk,0,sync)
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|      ss(idt+5)=sync
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|   enddo
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|   smax=maxval(ss)
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|   iloc=maxloc(ss)
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|   ibest=iloc(1)-5+ibest
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|   xdt=(ibest-1)*dt2
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|   sync=smax
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| 
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|   do k=1,NN
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|     i1=ibest+(k-1)*32
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|     csymb=cmplx(0.0,0.0)
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|     if( i1.ge.0 .and. i1+31 .le. NP2-1 ) csymb=cd0(i1:i1+31)
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|     call four2a(csymb,32,1,-1,1)
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|     cs(0:7,k)=csymb(1:8)/1e3
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|     s8(0:7,k)=abs(csymb(1:8))
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|   enddo  
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| 
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| ! sync quality check
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|   is1=0
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|   is2=0
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|   is3=0
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|   do k=1,7
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|     ip=maxloc(s8(:,k))
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|     if(icos7(k-1).eq.(ip(1)-1)) is1=is1+1
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|     ip=maxloc(s8(:,k+36))
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|     if(icos7(k-1).eq.(ip(1)-1)) is2=is2+1
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|     ip=maxloc(s8(:,k+72))
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|     if(icos7(k-1).eq.(ip(1)-1)) is3=is3+1
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|   enddo
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| ! hard sync sum - max is 21
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|   nsync=is1+is2+is3
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|   if(nsync .le. 6) then ! bail out
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|     nbadcrc=1
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|     return
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|   endif
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| 
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|   do nsym=1,3
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|     nt=2**(3*nsym)
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|     do ihalf=1,2
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|       do k=1,29,nsym
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|         if(ihalf.eq.1) ks=k+7
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|         if(ihalf.eq.2) ks=k+43
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|         amax=-1.0
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|         do i=0,nt-1
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|           i1=i/64
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|           i2=iand(i,63)/8
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|           i3=iand(i,7)
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|           if(nsym.eq.1) then
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|             s2(i)=abs(cs(graymap(i3),ks))
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|           elseif(nsym.eq.2) then
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|             s2(i)=abs(cs(graymap(i2),ks)+cs(graymap(i3),ks+1))
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|           elseif(nsym.eq.3) then
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|             s2(i)=abs(cs(graymap(i1),ks)+cs(graymap(i2),ks+1)+cs(graymap(i3),ks+2))
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|           else
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|             print*,"Error - nsym must be 1, 2, or 3."
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|           endif
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|         enddo
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|         i32=1+(k-1)*3+(ihalf-1)*87
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|         if(nsym.eq.1) ibmax=2 
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|         if(nsym.eq.2) ibmax=5 
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|         if(nsym.eq.3) ibmax=8 
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|         do ib=0,ibmax
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|           bm=maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)) - &
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|              maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib))
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|           if(i32+ib .gt.174) cycle
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|           if(nsym.eq.1) then
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|             bmeta(i32+ib)=bm
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|             den=max(maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)), &
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|                     maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib)))
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|             if(den.gt.0.0) then
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|               cm=bm/den
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|             else ! erase it
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|               cm=0.0
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|             endif
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|             bmetd(i32+ib)=cm
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|           elseif(nsym.eq.2) then
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|             bmetb(i32+ib)=bm
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|           elseif(nsym.eq.3) then
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|             bmetc(i32+ib)=bm
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|           endif
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|         enddo
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|       enddo
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|     enddo
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|   enddo
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|   call normalizebmet(bmeta,174)
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|   call normalizebmet(bmetb,174)
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|   call normalizebmet(bmetc,174)
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|   call normalizebmet(bmetd,174)
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| 
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|   scalefac=2.83
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|   llra=scalefac*bmeta
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|   llrb=scalefac*bmetb
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|   llrc=scalefac*bmetc
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|   llrd=scalefac*bmetd
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| 
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|   apmag=maxval(abs(llra))*1.01
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| 
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| ! pass #
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| !------------------------------
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| !   1        regular decoding, nsym=1 
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| !   2        regular decoding, nsym=2 
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| !   3        regular decoding, nsym=3 
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| !   4        regular decoding, nsym=1, bit-by-bit normalized 
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| !   5        ap pass 1, nsym=1
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| !   6        ap pass 2
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| !   7        ap pass 3
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| !   8        ap pass 4
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| 
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|   if(lapon.or.ncontest.eq.7) then !Hounds always use AP
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|      if(.not.lapcqonly) then
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|         npasses=4+nappasses(nQSOProgress)
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|      else
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|         npasses=5 
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|      endif
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|   else
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|      npasses=4
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|   endif
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|   if(nzhsym.lt.50) npasses=4
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|   
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|   do ipass=1,npasses 
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|      llrz=llra
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|      if(ipass.eq.2) llrz=llrb
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|      if(ipass.eq.3) llrz=llrc
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|      if(ipass.eq.4) llrz=llrd
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|      if(ipass.le.4) then
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|         apmask=0
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|         iaptype=0
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|      endif
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|      if(ipass .gt. 4) then
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|         llrz=llra
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|         if(.not.lapcqonly) then
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|            iaptype=naptypes(nQSOProgress,ipass-4)
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|         else
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|            iaptype=1
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|         endif
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| 
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| ! ncontest=0 : NONE
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| !          1 : NA_VHF
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| !          2 : EU_VHF
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| !          3 : FIELD DAY
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| !          4 : RTTY
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| !          5 : WW_DIGI 
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| !          6 : FOX
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| !          7 : HOUND
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| !
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| ! Conditions that cause us to bail out of AP decoding
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|         if(ncontest.le.5 .and. iaptype.ge.3 .and. (abs(f1-nfqso).gt.napwid .and. abs(f1-nftx).gt.napwid) ) cycle
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|         if(ncontest.eq.6) cycle                     ! No AP for Foxes
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|         if(ncontest.eq.7.and.f1.gt.950.0) cycle     ! Hounds use AP only for signals below 950 Hz
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|         if(iaptype.ge.2 .and. apsym(1).gt.1) cycle  ! No, or nonstandard, mycall 
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|         if(ncontest.eq.7 .and. iaptype.ge.2 .and. aph10(1).gt.1) cycle
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|         if(iaptype.ge.3 .and. apsym(30).gt.1) cycle ! No, or nonstandard, dxcall
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| 
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|         if(iaptype.eq.1) then ! CQ or CQ RU or CQ TEST or CQ FD
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|            apmask=0
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|            apmask(1:29)=1  
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|            if(ncontest.eq.0) llrz(1:29)=apmag*mcq(1:29)
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|            if(ncontest.eq.1) llrz(1:29)=apmag*mcqtest(1:29)
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|            if(ncontest.eq.2) llrz(1:29)=apmag*mcqtest(1:29)
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|            if(ncontest.eq.3) llrz(1:29)=apmag*mcqfd(1:29)
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|            if(ncontest.eq.4) llrz(1:29)=apmag*mcqru(1:29)
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|            if(ncontest.eq.5) llrz(1:29)=apmag*mcqww(1:29)
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|            if(ncontest.eq.7) llrz(1:29)=apmag*mcq(1:29)
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|            apmask(75:77)=1 
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|            llrz(75:76)=apmag*(-1)
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|            llrz(77)=apmag*(+1)
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|         endif
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| 
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|         if(iaptype.eq.2) then ! MyCall,???,??? 
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|            apmask=0
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|            if(ncontest.eq.0.or.ncontest.eq.1.or.ncontest.eq.5) then
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|               apmask(1:29)=1  
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|               llrz(1:29)=apmag*apsym(1:29)
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|               apmask(75:77)=1 
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|               llrz(75:76)=apmag*(-1)
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|               llrz(77)=apmag*(+1)
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|            else if(ncontest.eq.2) then
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|               apmask(1:28)=1  
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|               llrz(1:28)=apmag*apsym(1:28)
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|               apmask(72:74)=1
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|               llrz(72)=apmag*(-1)
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|               llrz(73)=apmag*(+1)
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|               llrz(74)=apmag*(-1)
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|               apmask(75:77)=1 
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|               llrz(75:77)=apmag*(-1)
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|            else if(ncontest.eq.3) then
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|               apmask(1:28)=1  
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|               llrz(1:28)=apmag*apsym(1:28)
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|               apmask(75:77)=1 
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|               llrz(75:77)=apmag*(-1)
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|            else if(ncontest.eq.4) then
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|               apmask(2:29)=1  
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|               llrz(2:29)=apmag*apsym(1:28)
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|               apmask(75:77)=1 
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|               llrz(75)=apmag*(-1)
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|               llrz(76:77)=apmag*(+1)
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|            else if(ncontest.eq.7) then ! ??? RR73; MyCall <Fox Call hash10> ???
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|               apmask(29:56)=1  
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|               llrz(29:56)=apmag*apsym(1:28)
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|               apmask(57:66)=1
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|               llrz(57:66)=apmag*aph10(1:10)
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|               apmask(72:77)=1 
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|               llrz(72:73)=apmag*(-1)
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|               llrz(74)=apmag*(+1)
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|               llrz(75:77)=apmag*(-1)
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|            endif
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|         endif
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| 
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|         if(iaptype.eq.3) then ! MyCall,DxCall,??? 
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|            apmask=0
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|            if(ncontest.eq.0.or.ncontest.eq.1.or.ncontest.eq.2.or.ncontest.eq.5.or.ncontest.eq.7) then
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|               apmask(1:58)=1  
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|               llrz(1:58)=apmag*apsym
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|               apmask(75:77)=1 
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|               llrz(75:76)=apmag*(-1)
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|               llrz(77)=apmag*(+1)
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|            else if(ncontest.eq.3) then ! Field Day
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|               apmask(1:56)=1  
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|               llrz(1:28)=apmag*apsym(1:28)
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|               llrz(29:56)=apmag*apsym(30:57)
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|               apmask(72:74)=1 
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|               apmask(75:77)=1 
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|               llrz(75:77)=apmag*(-1)
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|            else if(ncontest.eq.4) then 
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|               apmask(2:57)=1  
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|               llrz(2:29)=apmag*apsym(1:28)
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|               llrz(30:57)=apmag*apsym(30:57)
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|               apmask(75:77)=1 
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|               llrz(75)=apmag*(-1)
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|               llrz(76:77)=apmag*(+1)
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|            endif
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|         endif
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| 
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|         if(iaptype.eq.5.and.ncontest.eq.7) cycle !Hound
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|         if(iaptype.eq.4 .or. iaptype.eq.5 .or. iaptype.eq.6) then  
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|            apmask=0
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|            if(ncontest.le.5 .or. (ncontest.eq.7.and.iaptype.eq.6)) then
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|               apmask(1:77)=1   ! mycall, hiscall, RRR|73|RR73
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|               llrz(1:58)=apmag*apsym
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|               if(iaptype.eq.4) llrz(59:77)=apmag*mrrr 
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|               if(iaptype.eq.5) llrz(59:77)=apmag*m73 
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|               if(iaptype.eq.6) llrz(59:77)=apmag*mrr73 
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|            else if(ncontest.eq.7.and.iaptype.eq.4) then ! Hound listens for MyCall RR73;...
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|               apmask(1:28)=1
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|               llrz(1:28)=apmag*apsym(1:28)
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|               apmask(57:66)=1
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|               llrz(57:66)=apmag*aph10(1:10)
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|               apmask(72:77)=1
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|               llrz(72:73)=apmag*(-1)
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|               llrz(74)=apmag*(1)
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|               llrz(75:77)=apmag*(-1)
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|            endif             
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|         endif
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|      endif
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| 
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|      cw=0
 | |
|      dmin=0.0
 | |
|      norder=2
 | |
|      maxosd=2
 | |
|      if(ndepth.eq.1) maxosd=-1  ! BP only
 | |
|      if(ndepth.eq.2) maxosd=0   ! uncoupled BP+OSD
 | |
|      if(ndepth.eq.3 .and.         &
 | |
|         (abs(nfqso-f1).le.napwid .or. abs(nftx-f1).le.napwid .or. ncontest.eq.7)) then
 | |
|         maxosd=2
 | |
|      endif
 | |
|      call timer('dec174_91 ',0)
 | |
|      Keff=91
 | |
|      call decode174_91(llrz,Keff,maxosd,norder,apmask,message91,cw,  &
 | |
|                        ntype,nharderrors,dmin)
 | |
|      if(nharderrors.ge.0) message77=message91(1:77)
 | |
|      call timer('dec174_91 ',1)
 | |
| 
 | |
|      msg37='                                     '
 | |
|      nbadcrc=1
 | |
|      if(nharderrors.lt.0 .or. nharderrors.gt.36) cycle
 | |
|      if(count(cw.eq.0).eq.174) cycle           !Reject the all-zero codeword
 | |
|      write(c77,'(77i1)') message77
 | |
|      read(c77(72:74),'(b3)') n3
 | |
|      read(c77(75:77),'(b3)') i3
 | |
|      if(i3.gt.5 .or. (i3.eq.0.and.n3.gt.6)) cycle
 | |
|      if(i3.eq.0 .and. n3.eq.2) cycle
 | |
|      call unpack77(c77,1,msg37,unpk77_success)
 | |
|      if(.not.unpk77_success) cycle
 | |
|      nbadcrc=0  ! If we get this far: valid codeword, valid (i3,n3), nonquirky message.
 | |
|      call get_ft8_tones_from_77bits(message77,itone)
 | |
|      if(lsubtract) then
 | |
|         call timer('sub_ft8a',0)
 | |
|         call subtractft8(dd0,itone,f1,xdt,.false.)
 | |
|         call timer('sub_ft8a',1)
 | |
|      endif
 | |
|      xsig=0.0
 | |
|      xnoi=0.0
 | |
|      do i=1,79
 | |
|         xsig=xsig+s8(itone(i),i)**2
 | |
|         ios=mod(itone(i)+4,7)
 | |
|         xnoi=xnoi+s8(ios,i)**2
 | |
|      enddo
 | |
|      xsnr=0.001
 | |
|      xsnr2=0.001
 | |
|      arg=xsig/xnoi-1.0 
 | |
|      if(arg.gt.0.1) xsnr=arg
 | |
|      arg=xsig/xbase/3.0e6-1.0
 | |
|      if(arg.gt.0.1) xsnr2=arg
 | |
|      xsnr=10.0*log10(xsnr)-27.0
 | |
|      xsnr2=10.0*log10(xsnr2)-27.0
 | |
|      if(.not.nagain) then
 | |
|        xsnr=xsnr2
 | |
|     endif
 | |
|     if(nsync.le.10 .and. xsnr.lt.-24.0) then    !bail out, likely false decode
 | |
|        nbadcrc=1
 | |
|        return
 | |
|     endif
 | |
|     if(xsnr .lt. -24.0) xsnr=-24.0
 | |
|     return
 | |
|   enddo
 | |
|   return
 | |
| end subroutine ft8b
 | |
| 
 | |
| subroutine normalizebmet(bmet,n)
 | |
|   real bmet(n)
 | |
| 
 | |
|   bmetav=sum(bmet)/real(n)
 | |
|   bmet2av=sum(bmet*bmet)/real(n)
 | |
|   var=bmet2av-bmetav*bmetav
 | |
|   if( var .gt. 0.0 ) then
 | |
|      bmetsig=sqrt(var)
 | |
|   else
 | |
|      bmetsig=sqrt(bmet2av)
 | |
|   endif
 | |
|   bmet=bmet/bmetsig
 | |
|   return
 | |
| end subroutine normalizebmet
 | |
| 
 | |
| 
 | |
| function bessi0(x) 
 | |
| ! From Numerical Recipes
 | |
|    real bessi0,x
 | |
|    double precision p1,p2,p3,p4,p5,p6,p7,q1,q2,q3,q4,q5,q6,q7,q8,q9,y
 | |
|    save p1,p2,p3,p4,p5,p6,p7,q1,q2,q3,q4,q5,q6,q7,q8,q9
 | |
|    data p1,p2,p3,p4,p5,p6,p7/1.0d0,3.5156229d0,3.0899424d0,1.2067492d0, &
 | |
|       0.2659732d0,0.360768d-1,0.45813d-2/
 | |
|    data q1,q2,q3,q4,q5,q6,q7,q8,q9/0.39894228d0,0.1328592d-1,           &
 | |
|       0.225319d-2,-0.157565d-2,0.916281d-2,-0.2057706d-1,               &
 | |
|       0.2635537d-1,-0.1647633d-1,0.392377d-2/
 | |
| 
 | |
|    if (abs(x).lt.3.75) then 
 | |
|       y=(x/3.75)**2
 | |
|       bessi0=p1+y*(p2+y*(p3+y*(p4+y*(p5+y*(p6+y*p7))))) 
 | |
|    else
 | |
|       ax=abs(x)
 | |
|       y=3.75/ax 
 | |
|       bessi0=(exp(ax)/sqrt(ax))*(q1+y*(q2+y*(q3+y*(q4         &
 | |
|            +y*(q5+y*(q6+y*(q7+y*(q8+y*q9))))))))
 | |
|    endif
 | |
|    return
 | |
| end function bessi0
 |