From 5e0265a5ab7c2c0e7859eeabba3d551d8b993643 Mon Sep 17 00:00:00 2001
From: Joe Taylor <k1jt@arrl.org>
Date: Fri, 7 Jul 2017 15:27:15 +0000
Subject: [PATCH] Minor tweaks to FT8 decoder, including norder=3 if ndepth=3.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7805 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
---
 lib/fsk4hf/ft8b.f90  | 7 +++++--
 lib/fsk4hf/sync8.f90 | 8 ++++----
 lib/ft8_decode.f90   | 6 +++---
 mainwindow.cpp       | 1 +
 4 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/fsk4hf/ft8b.f90 b/lib/fsk4hf/ft8b.f90
index 11a9b3731..0091d2046 100644
--- a/lib/fsk4hf/ft8b.f90
+++ b/lib/fsk4hf/ft8b.f90
@@ -1,4 +1,5 @@
-subroutine ft8b(dd0,newdat,nfqso,f1,xdt,nharderrors,dmin,nbadcrc,message,xsnr)
+subroutine ft8b(dd0,newdat,nfqso,ndepth,icand,sync0,f1,xdt,nharderrors,   &
+     dmin,nbadcrc,message,xsnr)
 
   use timer_module, only: timer
   include 'ft8_params.f90'
@@ -19,13 +20,13 @@ subroutine ft8b(dd0,newdat,nfqso,f1,xdt,nharderrors,dmin,nbadcrc,message,xsnr)
 
   max_iterations=40
   norder=2
+  if(ndepth.eq.3 .and. abs(nfqso-f1).lt.10.0) norder=3
   fs2=12000.0/NDOWN
   dt2=1.0/fs2
   twopi=8.0*atan(1.0)
   delfbest=0.
   ibest=0
 
-!  if(abs(nfqso-f1).lt.10.0) norder=3
   call timer('ft8_down',0)
   call ft8_downsample(dd0,newdat,f1,cd0)   !Mix f1 to baseband and downsample
   call timer('ft8_down',1)
@@ -141,6 +142,8 @@ subroutine ft8b(dd0,newdat,nfqso,f1,xdt,nharderrors,dmin,nbadcrc,message,xsnr)
      if( xnoi.gt.0 .and. xnoi.lt.xsig ) xsnr=xsig/xnoi-1.0
      xsnr=10.0*log10(xsnr)-27.0
      if( xsnr .lt. -24.0 ) xsnr=-24.0
+!     write(50,3050) icand,sync0,f1,xdt,nharderrors,dmin,message
+!3050 format(i3,3f10.3,i5,f10.3,2x,a22)
   endif
 
 900 continue
diff --git a/lib/fsk4hf/sync8.f90 b/lib/fsk4hf/sync8.f90
index 1fcd368e3..35c402f58 100644
--- a/lib/fsk4hf/sync8.f90
+++ b/lib/fsk4hf/sync8.f90
@@ -8,8 +8,8 @@ subroutine sync8(dd,nfa,nfb,nfqso,s,candidate,ncand)
   real x(NFFT1)
   real sync2d(NH1,-JZ:JZ)
   real red(NH1)
-  real candidate0(3,100)
-  real candidate(3,100)
+  real candidate0(3,200)
+  real candidate(3,200)
   real dd(NMAX)
   integer jpeak(NH1)
   integer indx(NH1)
@@ -88,12 +88,12 @@ subroutine sync8(dd,nfa,nfb,nfqso,s,candidate,ncand)
   do i=1,100
      n=ia + indx(iz+1-i) - 1
      if(red(n).lt.syncmin) exit
-     k=k+1
+     if(k.lt.200) k=k+1
      candidate0(1,k)=n*df
      candidate0(2,k)=(jpeak(n)-1)*tstep
      candidate0(3,k)=red(n)
   enddo
-  ncand=min(100,k)
+  ncand=k
 
 ! Put nfqso at top of list, and save only the best of near-dupe freqs.  
   do i=1,ncand
diff --git a/lib/ft8_decode.f90 b/lib/ft8_decode.f90
index 72380dc39..460302f47 100644
--- a/lib/ft8_decode.f90
+++ b/lib/ft8_decode.f90
@@ -32,7 +32,7 @@ contains
     class(ft8_decoder), intent(inout) :: this
     procedure(ft8_decode_callback) :: callback
     real s(NH1,NHSYM)
-    real candidate(3,100)
+    real candidate(3,200)
     real dd(15*12000)
     logical, intent(in) :: newdat, nagain
     character*12 mycall, hiscall
@@ -52,7 +52,6 @@ contains
     call timer('sync8   ',1)
 
     syncmin=2.0
-!    rewind 51
     do icand=1,ncand
        sync=candidate(3,icand)
        if(sync.lt.syncmin) cycle
@@ -60,7 +59,8 @@ contains
        xdt=candidate(2,icand)
        nsnr0=min(99,nint(10.0*log10(sync) - 25.5))    !### empirical ###
        call timer('ft8b    ',0)
-       call ft8b(dd,newdat,nfqso,f1,xdt,nharderrors,dmin,nbadcrc,message,xsnr)
+       call ft8b(dd,newdat,nfqso,ndepth,icand,sync,f1,xdt,nharderrors,   &
+            dmin,nbadcrc,message,xsnr)
        nsnr=xsnr  
        xdt=xdt-0.6
        call timer('ft8b    ',1)
diff --git a/mainwindow.cpp b/mainwindow.cpp
index d062f8a99..674ea54ed 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1788,6 +1788,7 @@ void MainWindow::keyPressEvent (QKeyEvent * e)
     case Qt::Key_Minus:
       if(e->modifiers() & Qt::ControlModifier) {
         int f=ui->TxFreqSpinBox->value()/50;
+        if((ui->TxFreqSpinBox->value() % 50) == 0) f=f-1;
         ui->TxFreqSpinBox->setValue(50*f);
         return;
       }