diff --git a/CMakeLists.txt b/CMakeLists.txt
index 99dc533a1..5d39c437d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -360,6 +360,7 @@ set (wsjt_FSRCS
   lib/jt65_decode.f90
   lib/jt65_mod.f90
   lib/ft8_decode.f90
+  lib/ft4_decode.f90
   lib/jt9_decode.f90
   lib/options.f90
   lib/packjt.f90
@@ -517,9 +518,9 @@ set (wsjt_FSRCS
   lib/msk144sim.f90
   lib/mskrtd.f90
   lib/nuttal_window.f90
+  lib/ft4/ft4b.f90
   lib/ft4/ft4sim.f90
   lib/ft4/ft4sim_mult.f90
-  lib/ft4/ft4_decode.f90
   lib/ft4/ft4_downsample.f90
   lib/77bit/my_hash.f90
   lib/wsprd/osdwspr.f90
diff --git a/Modulator.cpp b/Modulator.cpp
index 8811d16a3..725de9e42 100644
--- a/Modulator.cpp
+++ b/Modulator.cpp
@@ -92,11 +92,9 @@ void Modulator::start (unsigned symbolsLength, double framesPerSymbol,
   if (synchronize && !m_tuning && !m_bFastMode)	{
     m_silentFrames = m_ic + m_frameRate / (1000 / delay_ms) - (mstr * (m_frameRate / 1000));
   }
-  if((symbolsLength==103 or symbolsLength==105) and framesPerSymbol==512
+  if(symbolsLength==105 and framesPerSymbol==512
      and (toneSpacing==12000.0/512.0 or toneSpacing==-2.0)) {
 //### FT4 parameters
-    delay_ms=100;
-    mstr=5000;
     m_ic=0;
     m_silentFrames=0;
   }
@@ -159,6 +157,8 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
   qint16 * end (samples + numFrames * (bytesPerFrame () / sizeof (qint16)));
   qint64 framesGenerated (0);
 
+//  if(m_ic==0) qDebug() << "Modulator::readData" << 0.001*(QDateTime::currentMSecsSinceEpoch() % (1000*m_TRperiod));
+
   switch (m_state)
     {
     case Synchronizing:
@@ -180,8 +180,7 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
     case Active:
       {
         unsigned int isym=0;
-//        qDebug() << "Mod A" << m_toneSpacing << m_frequency << m_nsps
-//                 << m_ic << m_symbolsLength << icw[0];
+
         if(!m_tuning) isym=m_ic/(4.0*m_nsps);            // Actual fsample=48000
         bool slowCwId=((isym >= m_symbolsLength) && (icw[0] > 0)) && (!m_bFastMode);
         if(m_TRperiod==3) slowCwId=false;
@@ -192,6 +191,8 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
         if(m_bFastMode and (icw[0]>0) and (tsec>(m_TRperiod-5.0))) fastCwId=true;
         if(!m_bFastMode) m_nspd=2560;                 // 22.5 WPM
 
+//        qDebug() << "Mod A" << m_ic << isym << tsec;
+
         if(slowCwId or fastCwId) {     // Transmit CW ID?
           m_dphi = m_twoPi*m_frequency/m_frameRate;
           if(m_bFastMode and !bCwId) {
@@ -263,10 +264,10 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
         }
 
         qint16 sample;
+
         for (unsigned i = 0; i < numFrames && m_ic <= i1; ++i) {
           isym=0;
-          if(!m_tuning and m_TRperiod!=3) isym=m_ic / (4.0 * m_nsps);         //Actual
-                                                                              //fsample=48000
+          if(!m_tuning and m_TRperiod!=3) isym=m_ic/(4.0*m_nsps);   //Actual fsample=48000
           if(m_bFastMode) isym=isym%m_symbolsLength;
           if (isym != m_isym0 || m_frequency != m_frequency0) {
             if(itone[0]>=100) {
@@ -278,8 +279,6 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
                 m_toneFrequency0=m_frequency + itone[isym]*m_toneSpacing;
               }
             }
-//            qDebug() << "Mod B" << m_bFastMode << m_ic << numFrames << isym << itone[isym]
-//                     << m_toneFrequency0 << m_nsps;
             m_dphi = m_twoPi * m_toneFrequency0 / m_frameRate;
             m_isym0 = isym;
             m_frequency0 = m_frequency;         //???
@@ -302,10 +301,10 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
           sample=qRound(m_amp*qSin(m_phi));
 
 //Here's where we transmit from a precomputed wave[] array:
-          if(!m_tuning and (m_toneSpacing < 0)) sample=qRound(m_amp*foxcom_.wave[m_ic]);
-//          if(m_ic < 10) qDebug() << "Mod Tx" << m_ic << m_amp
-//                                  << foxcom_.wave[m_ic] << sample
-//                                  << m_toneSpacing;
+          if(!m_tuning and (m_toneSpacing < 0)) {
+            m_amp=32767.0;
+            sample=qRound(m_amp*foxcom_.wave[m_ic]);
+          }
 
           samples = load(postProcessSample(sample), samples);
           ++framesGenerated;
@@ -322,9 +321,9 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
         }
 
         m_frequency0 = m_frequency;
-        // done for this chunk - continue on next call
-//        qint64 ms1=QDateTime::currentMSecsSinceEpoch() - m_ms0;
-//        if(m_ic>=4*144*160) qDebug() << "Modulator finished" << m_ic << 0.001*ms1;
+// done for this chunk - continue on next call
+
+//        qDebug() << "Mod B" << m_ic << i1 << 0.001*(QDateTime::currentMSecsSinceEpoch() % (1000*m_TRperiod));
 
         while (samples != end)  // pad block with silence
           {
diff --git a/lib/decoder.f90 b/lib/decoder.f90
index 218a6cbf7..37ca5b1bd 100644
--- a/lib/decoder.f90
+++ b/lib/decoder.f90
@@ -7,6 +7,7 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
   use jt65_decode
   use jt9_decode
   use ft8_decode
+  use ft4_decode
 
   include 'jt9com.f90'
   include 'timer_common.inc'
@@ -27,6 +28,10 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
      integer :: decoded
   end type counting_ft8_decoder
 
+  type, extends(ft4_decoder) :: counting_ft4_decoder
+     integer :: decoded
+  end type counting_ft4_decoder
+
   real ss(184,NSMAX)
   logical baddata,newdat65,newdat9,single_decode,bVHF,bad0,newdat,ex
   integer*2 id2(NTMAX*12000)
@@ -40,6 +45,7 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
   type(counting_jt65_decoder) :: my_jt65
   type(counting_jt9_decoder) :: my_jt9
   type(counting_ft8_decoder) :: my_ft8
+  type(counting_ft4_decoder) :: my_ft4
 
   !cast C character arrays to Fortran character strings
   datetime=transfer(params%datetime, datetime)
@@ -53,6 +59,7 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
   my_jt65%decoded = 0
   my_jt9%decoded = 0
   my_ft8%decoded = 0
+  my_ft4%decoded = 0
 
   single_decode=iand(params%nexp_decode,32).ne.0
   bVHF=iand(params%nexp_decode,64).ne.0
@@ -142,6 +149,15 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
      go to 800
   endif
 
+  if(params%nmode.eq.5) then
+     call timer('decft4  ',0)
+     call my_ft4%decode(ft4_decoded,id2,params%nQSOProgress,params%nfqso,    &
+          params%nutc,params%nfa,params%nfb,params%ndepth,ncontest,          &
+          mycall,hiscall)
+     call timer('decft4  ',1)
+     go to 800
+  endif
+
   rms=sqrt(dot_product(float(id2(300000:310000)),            &
        float(id2(300000:310000)))/10000.0)
   if(rms.lt.2.0) go to 800
@@ -258,7 +274,8 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
 !$omp end parallel sections
 
 ! JT65 is not yet producing info for nsynced, ndecoded.
-800 ndecoded = my_jt4%decoded + my_jt65%decoded + my_jt9%decoded + my_ft8%decoded
+800 ndecoded = my_jt4%decoded + my_jt65%decoded + my_jt9%decoded +       &
+         my_ft8%decoded + my_ft4%decoded
   write(*,1010) nsynced,ndecoded
 1010 format('<DecodeFinished>',2i4)
   call flush(6)
@@ -561,4 +578,44 @@ contains
     return
   end subroutine ft8_decoded
 
+  subroutine ft4_decoded (this,sync,snr,dt,freq,decoded,nap,qual)
+    use ft4_decode
+    implicit none
+
+    class(ft4_decoder), intent(inout) :: this
+    real, intent(in) :: sync
+    integer, intent(in) :: snr
+    real, intent(in) :: dt
+    real, intent(in) :: freq
+    character(len=37), intent(in) :: decoded
+    character c1*12,c2*12,g2*4,w*4
+    integer i0,i1,i2,i3,i4,i5,n30,nwrap
+    integer, intent(in) :: nap 
+    real, intent(in) :: qual 
+    character*2 annot
+    character*37 decoded0
+    
+    decoded0=decoded
+
+    annot='  ' 
+    if(ncontest.eq.0 .and. nap.ne.0) then
+       write(annot,'(a1,i1)') 'a',nap
+       if(qual.lt.0.17) decoded0(37:37)='?'
+    endif
+
+    write(*,1001) params%nutc,snr,dt,nint(freq),decoded0,annot
+1001 format(i6.6,i4,f5.1,i5,' ~ ',1x,a37,1x,a2)
+    write(13,1002) params%nutc,nint(sync),snr,dt,freq,0,decoded0
+1002 format(i6.6,i4,i5,f6.1,f8.0,i4,3x,a37,' FT8')
+    
+    call flush(6)
+    call flush(13)
+    
+    select type(this)
+    type is (counting_ft4_decoder)
+       this%decoded = this%decoded + 1
+    end select
+
+    return
+  end subroutine ft4_decoded
 end subroutine multimode_decoder
diff --git a/lib/ft4/ft4b.f90 b/lib/ft4/ft4b.f90
new file mode 100644
index 000000000..d425277ef
--- /dev/null
+++ b/lib/ft4/ft4b.f90
@@ -0,0 +1,489 @@
+subroutine ft4b(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
+   iwave,ndecodes,mycall,hiscall,cqstr,line,data_dir)
+
+   use packjt77
+   include 'ft4_params.f90'
+   parameter (NSS=NSPS/NDOWN)
+
+   character message*37,msgsent*37,msg0*37
+   character c77*77
+   character*61 line,linex(100)
+   character*37 decodes(100)
+   character*512 data_dir,fname
+   character*17 cdatetime0
+   character*12 mycall,hiscall
+   character*12 mycall0,hiscall0
+   character*6 hhmmss
+   character*4 cqstr,cqstr0
+
+   complex cd2(0:NMAX/NDOWN-1)                  !Complex waveform
+   complex cb(0:NMAX/NDOWN-1)
+   complex cd(0:NN*NSS-1)                       !Complex waveform
+   complex ctwk(2*NSS),ctwk2(2*NSS,-16:16)
+   complex csymb(NSS)
+   complex cs(0:3,NN)
+   real s4(0:3,NN)
+
+   real bmeta(2*NN),bmetb(2*NN),bmetc(2*NN)
+   real a(5)
+   real llr(2*ND),llra(2*ND),llrb(2*ND),llrc(2*ND),llrd(2*ND)
+   real s2(0:255)
+   real candidate(3,100)
+   real savg(NH1),sbase(NH1)
+
+   integer apbits(2*ND)
+   integer apmy_ru(28),aphis_fd(28)
+   integer icos4a(0:3),icos4b(0:3),icos4c(0:3),icos4d(0:3)
+   integer*2 iwave(NMAX)                 !Raw received data
+   integer*1 message77(77),rvec(77),apmask(2*ND),cw(2*ND)
+   integer*1 hbits(2*NN)
+   integer graymap(0:3)
+   integer ip(1)
+   integer nappasses(0:5)    ! # of decoding passes for QSO States 0-5
+   integer naptypes(0:5,4)   ! nQSOProgress, decoding pass
+   integer mcq(29)
+   integer mrrr(19),m73(19),mrr73(19)
+
+   logical nohiscall,unpk77_success
+   logical one(0:255,0:7)    ! 256 4-symbol sequences, 8 bits
+   logical first, dobigfft
+
+   data icos4a/0,1,3,2/
+   data icos4b/1,0,2,3/
+   data icos4c/2,3,1,0/
+   data icos4d/3,2,0,1/
+   data graymap/0,1,3,2/
+   data msg0/' '/
+   data first/.true./
+   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/
+   data    mrrr/0,1,1,1,1,1,1,0,1,0,0,1,0,0,1,0,0,0,1/
+   data     m73/0,1,1,1,1,1,1,0,1,0,0,1,0,1,0,0,0,0,1/
+   data   mrr73/0,1,1,1,1,1,1,0,0,1,1,1,0,1,0,1,0,0,1/
+   data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, &
+      1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, &
+      0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
+   save fs,dt,tt,txt,twopi,h,one,first,linex,apbits,nappasses,naptypes, &
+      mycall0,hiscall0,msg0,cqstr0,ctwk2
+   
+   call clockit('ft4_deco',0)
+   hhmmss=cdatetime0(8:13)
+
+   if(first) then
+      fs=12000.0/NDOWN                !Sample rate after downsampling
+      dt=1/fs                         !Sample interval after downsample (s)
+      tt=NSPS*dt                      !Duration of "itone" symbols (s)
+      txt=NZ*dt                       !Transmission length (s) without ramp up/down
+      twopi=8.0*atan(1.0)
+      h=1.0
+      one=.false.
+      do i=0,255
+         do j=0,7
+            if(iand(i,2**j).ne.0) one(i,j)=.true.
+         enddo
+      enddo
+
+      do idf=-16,16
+         a=0.
+         a(1)=real(idf)
+         ctwk=1.
+         call clockit('twkfreq1',0)
+         call twkfreq1(ctwk,2*NSS,fs/2.0,a,ctwk2(:,idf))
+         call clockit('twkfreq1',1)
+      enddo
+
+      mrrr=2*mod(mrrr+rvec(59:77),2)-1
+      m73=2*mod(m73+rvec(59:77),2)-1
+      mrr73=2*mod(mrr73+rvec(59:77),2)-1
+      nappasses(0)=2
+      nappasses(1)=2
+      nappasses(2)=2
+      nappasses(3)=2
+      nappasses(4)=2
+      nappasses(5)=3
+
+! iaptype
+!------------------------
+!   1        CQ     ???    ???           (29 ap bits)
+!   2        MyCall ???    ???           (29 ap bits)
+!   3        MyCall DxCall ???           (58 ap bits)
+!   4        MyCall DxCall RRR           (77 ap bits)
+!   5        MyCall DxCall 73            (77 ap bits)
+!   6        MyCall DxCall RR73          (77 ap bits)
+!********
+      naptypes(0,1:4)=(/1,2,0,0/) ! Tx6 selected (CQ)
+      naptypes(1,1:4)=(/2,3,0,0/) ! Tx1
+      naptypes(2,1:4)=(/2,3,0,0/) ! Tx2
+      naptypes(3,1:4)=(/3,6,0,0/) ! Tx3
+      naptypes(4,1:4)=(/3,6,0,0/) ! Tx4
+      naptypes(5,1:4)=(/3,1,2,0/) ! Tx5
+
+      mycall0=''
+      hiscall0=''
+      cqstr0=''
+      first=.false.
+   endif
+
+   if(cqstr.ne.cqstr0) then
+      i0=index(cqstr,' ')
+      if(i0.le.1) then 
+         message='CQ A1AA AA01'
+      else
+         message='CQ '//cqstr(1:i0-1)//' A1AA AA01'
+      endif
+      i3=-1
+      n3=-1
+      call pack77(message,i3,n3,c77)
+      call unpack77(c77,1,msgsent,unpk77_success)
+      read(c77,'(29i1)') mcq
+      mcq=2*mod(mcq+rvec(1:29),2)-1
+      cqstr0=cqstr
+   endif
+
+   l1=index(mycall,char(0))
+   if(l1.ne.0) mycall(l1:)=" "
+   l1=index(hiscall,char(0))
+   if(l1.ne.0) hiscall(l1:)=" "
+   if(mycall.ne.mycall0 .or. hiscall.ne.hiscall0) then
+      apbits=0
+      apbits(1)=99
+      apbits(30)=99
+      apmy_ru=0
+      aphis_fd=0
+
+      if(len(trim(mycall)) .lt. 3) go to 10 
+
+      nohiscall=.false.
+      hiscall0=hiscall
+      if(len(trim(hiscall0)).lt.3) then
+         hiscall0=mycall  ! use mycall for dummy hiscall - mycall won't be hashed.
+         nohiscall=.true.
+      endif
+      message=trim(mycall)//' '//trim(hiscall0)//' RR73'
+      i3=-1
+      n3=-1
+      call pack77(message,i3,n3,c77)
+      call unpack77(c77,1,msgsent,unpk77_success)
+      if(i3.ne.1 .or. (message.ne.msgsent) .or. .not.unpk77_success) go to 10 
+      read(c77,'(77i1)') message77
+      apmy_ru=2*mod(message77(1:28)+rvec(2:29),2)-1
+      aphis_fd=2*mod(message77(30:57)+rvec(29:56),2)-1
+      message77=mod(message77+rvec,2)
+      call encode174_91(message77,cw)
+      apbits=2*cw-1
+      if(nohiscall) apbits(30)=99
+
+10    continue
+      mycall0=mycall
+      hiscall0=hiscall
+   endif
+   candidate=0.0
+   ncand=0
+   syncmin=1.2
+   maxcand=100
+
+   fa=nfa
+   fb=nfb
+   call clockit('getcand4',0)
+   call getcandidates4(iwave,fa,fb,syncmin,nfqso,maxcand,savg,candidate,   &
+      ncand,sbase)
+   call clockit('getcand4',1)
+
+   ndecodes=0
+   dobigfft=.true.
+   do icand=1,ncand
+      f0=candidate(1,icand)
+      snr=candidate(3,icand)-1.0
+      if( f0.le.10.0 .or. f0.ge.4990.0 ) cycle
+      call clockit('ft4_down',0)
+      call ft4_downsample(iwave,dobigfft,f0,cd2)  !Downsample from 512 to 32 Sa/Symbol
+      if(dobigfft) dobigfft=.false.
+      call clockit('ft4_down',1)
+
+      sum2=sum(cd2*conjg(cd2))/(real(NMAX)/real(NDOWN))
+      if(sum2.gt.0.0) cd2=cd2/sqrt(sum2)
+! Sample rate is now 12000/16 = 750 samples/second
+      do isync=1,2
+         if(isync.eq.1) then
+            idfmin=-12
+            idfmax=12
+            idfstp=3
+            ibmin=0
+            ibmax=216                     !Max DT = 216/750 = 0.288 s
+            ibstp=4
+         else
+            idfmin=idfbest-4
+            idfmax=idfbest+4
+            idfstp=1
+            ibmin=max(0,ibest-5)
+            ibmax=min(ibest+5,NMAX/NDOWN-1)
+            ibstp=1
+         endif
+         ibest=-1
+         smax=-99.
+         idfbest=0
+         do idf=idfmin,idfmax,idfstp
+
+            call clockit('sync4d  ',0)
+            do istart=ibmin,ibmax,ibstp
+               call sync4d(cd2,istart,ctwk2(:,idf),1,sync)  !Find sync power
+               if(sync.gt.smax) then
+                  smax=sync
+                  ibest=istart
+                  idfbest=idf
+               endif
+            enddo
+            call clockit('sync4d  ',1)
+
+         enddo
+      enddo
+      f0=f0+real(idfbest)
+      if( f0.le.10.0 .or. f0.ge.4990.0 ) cycle
+
+      call clockit('ft4down ',0)
+      call ft4_downsample(iwave,dobigfft,f0,cb) !Final downsample with corrected f0
+      call clockit('ft4down ',1)
+      sum2=sum(abs(cb)**2)/(real(NSS)*NN)
+      if(sum2.gt.0.0) cb=cb/sqrt(sum2)
+      cd=cb(ibest:ibest+NN*NSS-1)
+      call clockit('four2a  ',0)
+      do k=1,NN
+         i1=(k-1)*NSS
+         csymb=cd(i1:i1+NSS-1)
+         call four2a(csymb,NSS,1,-1,1)
+         cs(0:3,k)=csymb(1:4)
+         s4(0:3,k)=abs(csymb(1:4))
+      enddo
+      call clockit('four2a  ',1)
+
+! Sync quality check
+      is1=0
+      is2=0
+      is3=0
+      is4=0
+      do k=1,4
+         ip=maxloc(s4(:,k))
+         if(icos4a(k-1).eq.(ip(1)-1)) is1=is1+1
+         ip=maxloc(s4(:,k+33))
+         if(icos4b(k-1).eq.(ip(1)-1)) is2=is2+1
+         ip=maxloc(s4(:,k+66))
+         if(icos4c(k-1).eq.(ip(1)-1)) is3=is3+1
+         ip=maxloc(s4(:,k+99))
+         if(icos4d(k-1).eq.(ip(1)-1)) is4=is4+1
+      enddo
+      nsync=is1+is2+is3+is4   !Number of correct hard sync symbols, 0-16
+      if(smax .lt. 0.7 .or. nsync .lt. 8) cycle
+
+      do nseq=1,3             !Try coherent sequences of 1, 2, and 4 symbols
+         if(nseq.eq.1) nsym=1
+         if(nseq.eq.2) nsym=2
+         if(nseq.eq.3) nsym=4
+         nt=2**(2*nsym)
+         do ks=1,NN-nsym+1,nsym  !87+16=103 symbols.
+            amax=-1.0
+            do i=0,nt-1
+               i1=i/64
+               i2=iand(i,63)/16
+               i3=iand(i,15)/4
+               i4=iand(i,3)
+               if(nsym.eq.1) then
+                  s2(i)=abs(cs(graymap(i4),ks))
+               elseif(nsym.eq.2) then
+                  s2(i)=abs(cs(graymap(i3),ks)+cs(graymap(i4),ks+1))
+               elseif(nsym.eq.4) then
+                  s2(i)=abs(cs(graymap(i1),ks  ) + &
+                     cs(graymap(i2),ks+1) + &
+                     cs(graymap(i3),ks+2) + &
+                     cs(graymap(i4),ks+3)   &
+                     )
+               else
+                  print*,"Error - nsym must be 1, 2, or 4."
+               endif
+            enddo
+            ipt=1+(ks-1)*2
+            if(nsym.eq.1) ibmax=1
+            if(nsym.eq.2) ibmax=3
+            if(nsym.eq.4) ibmax=7
+            do ib=0,ibmax
+               bm=maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)) - &
+                  maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib))
+               if(ipt+ib.gt.2*NN) cycle
+               if(nsym.eq.1) then
+                  bmeta(ipt+ib)=bm
+               elseif(nsym.eq.2) then
+                  bmetb(ipt+ib)=bm
+               elseif(nsym.eq.4) then
+                  bmetc(ipt+ib)=bm
+               endif
+            enddo
+         enddo
+      enddo
+
+      bmetb(205:206)=bmeta(205:206)
+      bmetc(201:204)=bmetb(201:204)
+      bmetc(205:206)=bmeta(205:206)
+
+      call clockit('normaliz',0)
+      call normalizebmet(bmeta,2*NN)
+      call normalizebmet(bmetb,2*NN)
+      call normalizebmet(bmetc,2*NN)
+      call clockit('normaliz',1)
+
+      hbits=0
+      where(bmeta.ge.0) hbits=1
+      ns1=count(hbits(  1:  8).eq.(/0,0,0,1,1,0,1,1/))
+      ns2=count(hbits( 67: 74).eq.(/0,1,0,0,1,1,1,0/))
+      ns3=count(hbits(133:140).eq.(/1,1,1,0,0,1,0,0/))
+      ns4=count(hbits(199:206).eq.(/1,0,1,1,0,0,0,1/))
+      nsync_qual=ns1+ns2+ns3+ns4
+      if(nsync_qual.lt. 20) cycle
+
+      scalefac=2.83
+      llra(  1: 58)=bmeta(  9: 66)
+      llra( 59:116)=bmeta( 75:132)
+      llra(117:174)=bmeta(141:198)
+      llra=scalefac*llra
+      llrb(  1: 58)=bmetb(  9: 66)
+      llrb( 59:116)=bmetb( 75:132)
+      llrb(117:174)=bmetb(141:198)
+      llrb=scalefac*llrb
+      llrc(  1: 58)=bmetc(  9: 66)
+      llrc( 59:116)=bmetc( 75:132)
+      llrc(117:174)=bmetc(141:198)
+      llrc=scalefac*llrc
+
+      apmag=maxval(abs(llra))*1.1
+      npasses=3+nappasses(nQSOProgress)
+      if(ncontest.ge.5) npasses=3  ! Don't support Fox and Hound
+      do ipass=1,npasses
+         if(ipass.eq.1) llr=llra
+         if(ipass.eq.2) llr=llrb
+         if(ipass.eq.3) llr=llrc
+         if(ipass.le.3) then
+            apmask=0
+            iaptype=0
+         endif
+
+         if(ipass .gt. 3) then
+            llrd=llrc
+            iaptype=naptypes(nQSOProgress,ipass-3)
+
+! ncontest=0 : NONE
+!          1 : NA_VHF
+!          2 : EU_VHF
+!          3 : FIELD DAY
+!          4 : RTTY
+!          5 : FOX
+!          6 : HOUND
+!
+! Conditions that cause us to bail out of AP decoding
+            napwid=50
+            if(ncontest.le.4 .and. iaptype.ge.3 .and. (abs(f0-nfqso).gt.napwid) ) cycle
+            if(iaptype.ge.2 .and. apbits(1).gt.1) cycle  ! No, or nonstandard, mycall
+            if(iaptype.ge.3 .and. apbits(30).gt.1) cycle ! No, or nonstandard, dxcall
+
+            if(iaptype.eq.1) then  ! CQ or CQ TEST or CQ FD or CQ RU or CQ SCC
+               apmask=0
+               apmask(1:29)=1
+               llrd(1:29)=apmag*mcq(1:29)
+            endif
+
+            if(iaptype.eq.2) then ! MyCall,???,???
+               apmask=0
+               if(ncontest.eq.0.or.ncontest.eq.1) then
+                  apmask(1:29)=1
+                  llrd(1:29)=apmag*apbits(1:29)
+               else if(ncontest.eq.2) then
+                  apmask(1:28)=1
+                  llrd(1:28)=apmag*apbits(1:28)
+               else if(ncontest.eq.3) then
+                  apmask(1:28)=1
+                  llrd(1:28)=apmag*apbits(1:28)
+               else if(ncontest.eq.4) then
+                  apmask(2:29)=1
+                  llrd(2:29)=apmag*apmy_ru(1:28)
+               endif
+            endif
+
+            if(iaptype.eq.3) then ! MyCall,DxCall,???
+               apmask=0
+               if(ncontest.eq.0.or.ncontest.eq.1.or.ncontest.eq.2) then
+                  apmask(1:58)=1
+                  llrd(1:58)=apmag*apbits(1:58)
+               else if(ncontest.eq.3) then ! Field Day
+                  apmask(1:56)=1
+                  llrd(1:28)=apmag*apbits(1:28)
+                  llrd(29:56)=apmag*aphis_fd(1:28)
+               else if(ncontest.eq.4) then ! RTTY RU
+                  apmask(2:57)=1
+                  llrd(2:29)=apmag*apmy_ru(1:28)
+                  llrd(30:57)=apmag*apbits(30:57)
+               endif
+            endif
+
+            if(iaptype.eq.4 .or. iaptype.eq.5 .or. iaptype.eq.6) then
+               apmask=0
+               if(ncontest.le.4) then
+                  apmask(1:91)=1   ! mycall, hiscall, RRR|73|RR73
+                  if(iaptype.eq.6) llrd(1:91)=apmag*apbits(1:91)
+               endif
+            endif
+
+            llr=llrd
+         endif
+         max_iterations=40
+         message77=0
+         call clockit('bpdecode',0)
+         call bpdecode174_91(llr,apmask,max_iterations,message77,     &
+            cw,nharderror,niterations)
+         call clockit('bpdecode',1)
+         if(sum(message77).eq.0) cycle
+         if( nharderror.ge.0 ) then
+            message77=mod(message77+rvec,2) ! remove rvec scrambling
+            write(c77,'(77i1)') message77(1:77)
+            call unpack77(c77,1,message,unpk77_success)
+            idupe=0
+            do i=1,ndecodes
+               if(decodes(i).eq.message) idupe=1
+            enddo
+            if(ibest.le.10 .and. message.eq.msg0) idupe=1   !Already decoded
+            if(idupe.eq.1) exit
+            ndecodes=ndecodes+1
+            decodes(ndecodes)=message
+            if(snr.gt.0.0) then
+               xsnr=10*log10(snr)-14.0
+            else
+               xsnr=-20.0
+            endif
+            nsnr=nint(max(-20.0,xsnr))
+            freq=f0
+            tsig=mod(tbuf + ibest/750.0,100.0)
+
+            write(line,1000) hhmmss,nsnr,tsig,nint(freq),message
+1000        format(a6,i4,f5.1,i5,' + ',1x,a37)
+            l1=index(data_dir,char(0))-1
+            if(l1.ge.1) data_dir(l1+1:l1+1)="/"
+            fname=data_dir(1:l1+1)//'all_ft4.txt'
+            open(24,file=trim(fname),status='unknown',position='append')
+            write(24,1002) cdatetime0,nsnr,tsig,nint(freq),message,    &
+               nharderror,nsync_qual,ipass,niterations,iaptype,nsync
+            if(hhmmss.eq.'      ') write(*,1002) cdatetime0,nsnr,             &
+               tsig,nint(freq),message,nharderror,nsync_qual,ipass,    &
+               niterations,iaptype
+1002        format(a17,i4,f5.1,i5,' Rx  ',a37,6i4)
+            close(24)
+            linex(ndecodes)=line
+            if(ibest.ge.ibmax-15) msg0=message         !Possible dupe candidate
+            exit
+         endif
+      enddo !Sequence estimation
+   enddo    !Candidate list
+   call clockit('ft4_deco',1)
+   call clockit2(data_dir)
+   call clockit('ft4_deco',101)
+   return
+
+ entry get_ft4msg(idecode,line)
+   line=linex(idecode)
+   return
+
+ end subroutine ft4b
diff --git a/lib/ft4/ft4d.f90 b/lib/ft4/ft4d.f90
index fa7c8045a..a63e3e0a6 100644
--- a/lib/ft4/ft4d.f90
+++ b/lib/ft4/ft4d.f90
@@ -67,7 +67,7 @@ program ft4d
       do n=1,nsteps
          i0=(n-1)*istep + 1
          tbuf=(i0-1)/12000.0
-         call ft4_decode(cdatetime,tbuf,nfa,nfb,nQSOProgress,ncontest,    &
+         call ft4b(cdatetime,tbuf,nfa,nfb,nQSOProgress,ncontest,           &
               nfqso,iwave(i0),ndecodes,mycall,hiscall,cqstr,line,data_dir)
          do idecode=1,ndecodes
             call get_ft4msg(idecode,line)
diff --git a/lib/ft4/ft4sim.f90 b/lib/ft4/ft4sim.f90
index 1481840c8..6b5d01599 100644
--- a/lib/ft4/ft4sim.f90
+++ b/lib/ft4/ft4sim.f90
@@ -6,18 +6,19 @@ program ft4sim
   use packjt77
   include 'ft4_params.f90'               !Set various constants
   parameter (NWAVE=NN*NSPS)
+  parameter (NZZ=18*3456)                !62208
   type(hdr) h                            !Header for .wav file
   character arg*12,fname*17
   character msg37*37,msgsent37*37
   character c77*77
-  complex c0(0:NMAX-1)
-  complex c(0:NMAX-1)
-  real wave(NMAX)
-  real dphi(0:NMAX-1)
+  complex c0(0:NZZ-1)
+  complex c(0:NZZ-1)
+  real wave(NZZ)
+  real dphi(0:NZZ-1)
   real pulse(3*NSPS)               
   integer itone(NN)
   integer*1 msgbits(77)
-  integer*2 iwave(NMAX)                  !Generated full-length waveform
+  integer*2 iwave(NZZ)                  !Generated full-length waveform
   integer icos4(4)
   data icos4/0,1,3,2/
   
@@ -100,7 +101,8 @@ program ft4sim
   phi=0.0
   c0=0.0
   dphi=dphi+twopi*f0*dt
-  do j=0,NMAX-1
+!  do j=0,NMAX-1                          !### ??? ###
+  do j=0,(NN+2)*NSPS-1
      c0(j)=cmplx(cos(phi),sin(phi))
      phi=mod(phi+dphi(j),twopi)
   enddo 
@@ -109,22 +111,19 @@ program ft4sim
   c0((NN+1)*NSPS:(NN+2)*NSPS-1)=c0((NN+1)*NSPS:(NN+2)*NSPS-1)*(1.0+cos(twopi*(/(i,i=0,NSPS-1)/)/(2.0*NSPS) ))/2.0
   c0((NN+2)*NSPS:)=0.
 
-  k=nint((xdt+0.14)/dt)
+  k=nint((xdt+0.5)/dt)
   c0=cshift(c0,-k)
-  ia=k
 
   do ifile=1,nfiles
      c=c0
-     if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c,NMAX,NWAVE,fs,delay,fspread)
+     if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c,NZZ,NWAVE,fs,delay,fspread)
      c=sig*c
-  
-     ib=k
      wave=real(c)
-     peak=maxval(abs(wave(ia:ib)))
+     peak=maxval(abs(wave))
      nslots=1
    
      if(snrdb.lt.90) then
-        do i=1,NMAX                   !Add gaussian noise at specified SNR
+        do i=1,NZZ                   !Add gaussian noise at specified SNR
            xnoise=gran()
            wave(i)=wave(i) + xnoise
         enddo
@@ -140,15 +139,14 @@ program ft4sim
      endif
      if(any(abs(wave).gt.32767.0)) print*,"Warning - data will be clipped."
      iwave=nint(wave)
-     h=default_header(12000,NMAX+2208)
+     h=default_header(12000,NZZ)
      write(fname,1102) ifile
 1102 format('000000_',i6.6,'.wav')
      open(10,file=fname,status='unknown',access='stream')
      write(10) h,iwave                !Save to *.wav file
-     iwave(1:2208)=0
-     write(10) iwave(1:2208)          !Add 0.5 s of zeroes
      close(10)
      write(*,1110) ifile,xdt,f0,snrdb,fname
 1110 format(i4,f7.2,f8.2,f7.1,2x,a17)
-  enddo    
+  enddo
+  
 999 end program ft4sim
diff --git a/lib/ft4/ft4sim_mult.f90 b/lib/ft4/ft4sim_mult.f90
index bc696e814..065b2a76b 100644
--- a/lib/ft4/ft4sim_mult.f90
+++ b/lib/ft4/ft4sim_mult.f90
@@ -6,7 +6,7 @@ program ft4sim_mult
   use packjt77
   include 'ft4_params.f90'               !FT4 protocol constants
   parameter (NWAVE=NN*NSPS)
-  parameter (NZZ=15*12000)               !Length of .wav file, 180,000 i*2 samples
+  parameter (NZZ=65760)                  !Length of .wav file (4.48+1.0)*12000
   type(hdr) h                            !Header for .wav file
   character arg*12,fname*17,cjunk*4
   character msg37*37,msgsent37*37,c77*77
@@ -26,20 +26,19 @@ program ft4sim_mult
      go to 999
   endif
   call getarg(1,arg)
-  read(arg,*) nsigs                      !Number of signals
+  read(arg,*) nsigs               !Number of signals
   call getarg(2,arg)
-  read(arg,*) nfiles                     !Number of files
+  read(arg,*) nfiles              !Number of files
 
   twopi=8.0*atan(1.0)
-  fs=12000.0                             !Sample rate (Hz)
-  dt=1.0/fs                              !Sample interval (s)
-  hmod=1.0                               !Modulation index (0.5 is MSK, 1.0 is FSK)
-  tt=NSPS*dt                             !Duration of unsmoothed symbols (s)
-  baud=1.0/tt                            !Keying rate (baud)
-  txt=NZ*dt                              !Transmission length (s) without ramp up/down
+  fs=12000.0                      !Sample rate (Hz)
+  dt=1.0/fs                       !Sample interval (s)
+  hmod=1.0                        !Modulation index (0.5 is MSK, 1.0 is FSK)
+  tt=NSPS*dt                      !Duration of unsmoothed symbols (s)
+  baud=1.0/tt                     !Keying rate (baud)
+  txt=NZ*dt                       !Transmission length (s) without ramp up/down
   bandwidth_ratio=2500.0/(fs/2.0)
   txt=NN*NSPS/12000.0
-  xdtmax=10.0 - 0.086
   open(10,file='messages.txt',status='old',err=998)
 
   do ifile=1,nfiles
@@ -57,7 +56,7 @@ program ft4sim_mult
         if(isnr.lt.-16) isnr=-16
         f0=ifreq*93.75/50.0
         call random_number(r)
-        xdt=r*xdtmax
+        xdt=r-0.5
 ! Source-encode, then get itone()
         i3=-1
         n3=-1
@@ -66,7 +65,7 @@ program ft4sim_mult
         nwave0=(NN+2)*NSPS
         call gen_ft4wave(itone,NN,NSPS,12000.0,f0,wave0,nwave0)
 
-        k0=nint(xdt/dt)
+        k0=nint((xdt+0.5)/dt)
         if(k0.lt.1) k0=1
         tmp(:k0-1)=0.0
         tmp(k0:k0+nwave0-1)=wave0
diff --git a/lib/ft4/ft4_decode.f90 b/lib/ft4_decode.f90
similarity index 84%
rename from lib/ft4/ft4_decode.f90
rename to lib/ft4_decode.f90
index 83287e1e9..500cdd081 100644
--- a/lib/ft4/ft4_decode.f90
+++ b/lib/ft4_decode.f90
@@ -1,13 +1,39 @@
-subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
-   iwave,ndecodes,mycall,hiscall,cqstr,line,data_dir)
+module ft4_decode
+  
+  type :: ft4_decoder
+     procedure(ft4_decode_callback), pointer :: callback
+   contains
+     procedure :: decode
+  end type ft4_decoder
 
-   use packjt77
-   include 'ft4_params.f90'
-   parameter (NSS=NSPS/NDOWN)
+  abstract interface
+     subroutine ft4_decode_callback (this,sync,snr,dt,freq,decoded,nap,qual)
+       import ft4_decoder
+       implicit none
+       class(ft4_decoder), intent(inout) :: this
+       real, intent(in) :: sync
+       integer, intent(in) :: snr
+       real, intent(in) :: dt
+       real, intent(in) :: freq
+       character(len=37), intent(in) :: decoded
+       integer, intent(in) :: nap 
+       real, intent(in) :: qual 
+     end subroutine ft4_decode_callback
+  end interface
 
+contains
+
+  subroutine decode(this,callback,iwave,nQSOProgress,nfqso,    &
+       nutc,nfa,nfb,ndepth,ncontest,mycall,hiscall)
+    use timer_module, only: timer
+    use packjt77
+    include 'ft4/ft4_params.f90'
+    class(ft4_decoder), intent(inout) :: this
+    procedure(ft4_decode_callback) :: callback
+    parameter (NSS=NSPS/NDOWN)
+    parameter (NZZ=18*3456)
    character message*37,msgsent*37,msg0*37
    character c77*77
-   character*61 line,linex(100)
    character*37 decodes(100)
    character*512 data_dir,fname
    character*17 cdatetime0
@@ -16,8 +42,8 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
    character*6 hhmmss
    character*4 cqstr,cqstr0
 
-   complex cd2(0:NMAX/NDOWN-1)                  !Complex waveform
-   complex cb(0:NMAX/NDOWN-1)
+   complex cd2(0:NZZ/NDOWN-1)                  !Complex waveform
+   complex cb(0:NZZ/NDOWN-1+NN*NSS)
    complex cd(0:NN*NSS-1)                       !Complex waveform
    complex ctwk(2*NSS),ctwk2(2*NSS,-16:16)
    complex csymb(NSS)
@@ -34,7 +60,7 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
    integer apbits(2*ND)
    integer apmy_ru(28),aphis_fd(28)
    integer icos4a(0:3),icos4b(0:3),icos4c(0:3),icos4d(0:3)
-   integer*2 iwave(NMAX)                 !Raw received data
+   integer*2 iwave(NZZ)                 !Raw received data
    integer*1 message77(77),rvec(77),apmask(2*ND),cw(2*ND)
    integer*1 hbits(2*NN)
    integer graymap(0:3)
@@ -62,12 +88,11 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
    data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, &
       1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, &
       0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
-   save fs,dt,tt,txt,twopi,h,one,first,linex,apbits,nappasses,naptypes, &
+   save fs,dt,tt,txt,twopi,h,one,first,apbits,nappasses,naptypes, &
       mycall0,hiscall0,msg0,cqstr0,ctwk2
-   
-   call clockit('ft4_deco',0)
-   hhmmss=cdatetime0(8:13)
 
+    this%callback => callback
+    hhmmss=cdatetime0(8:13)
    if(first) then
       fs=12000.0/NDOWN                !Sample rate after downsampling
       dt=1/fs                         !Sample interval after downsample (s)
@@ -86,9 +111,7 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
          a=0.
          a(1)=real(idf)
          ctwk=1.
-         call clockit('twkfreq1',0)
          call twkfreq1(ctwk,2*NSS,fs/2.0,a,ctwk2(:,idf))
-         call clockit('twkfreq1',1)
       enddo
 
       mrrr=2*mod(mrrr+rvec(59:77),2)-1
@@ -183,23 +206,21 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
 
    fa=nfa
    fb=nfb
-   call clockit('getcand4',0)
+   call timer('getcand4',0)
    call getcandidates4(iwave,fa,fb,syncmin,nfqso,maxcand,savg,candidate,   &
       ncand,sbase)
-   call clockit('getcand4',1)
+   call timer('getcand4',1)
 
    ndecodes=0
    dobigfft=.true.
    do icand=1,ncand
       f0=candidate(1,icand)
       snr=candidate(3,icand)-1.0
-      if( f0.le.10.0 .or. f0.ge.4990.0 ) cycle
-      call clockit('ft4_down',0)
-      call ft4_downsample(iwave,dobigfft,f0,cd2)  !Downsample from 512 to 32 Sa/Symbol
+      call timer('ft4_down',0)
+      call ft4_downsample(iwave,dobigfft,f0,cd2)  !Downsample to 32 Sam/Sym
+      call timer('ft4_down',1)
       if(dobigfft) dobigfft=.false.
-      call clockit('ft4_down',1)
-
-      sum2=sum(cd2*conjg(cd2))/(real(NMAX)/real(NDOWN))
+      sum2=sum(cd2*conjg(cd2))/(real(NZZ)/real(NDOWN))
       if(sum2.gt.0.0) cd2=cd2/sqrt(sum2)
 ! Sample rate is now 12000/16 = 750 samples/second
       do isync=1,2
@@ -208,22 +229,21 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
             idfmax=12
             idfstp=3
             ibmin=0
-            ibmax=216                     !Max DT = 216/750 = 0.288 s
+            ibmax=800
             ibstp=4
          else
             idfmin=idfbest-4
             idfmax=idfbest+4
             idfstp=1
             ibmin=max(0,ibest-5)
-            ibmax=min(ibest+5,NMAX/NDOWN-1)
+            ibmax=min(ibest+5,NZZ/NDOWN-1)
             ibstp=1
          endif
          ibest=-1
          smax=-99.
          idfbest=0
+         call timer('sync4d  ',0)
          do idf=idfmin,idfmax,idfstp
-
-            call clockit('sync4d  ',0)
             do istart=ibmin,ibmax,ibstp
                call sync4d(cd2,istart,ctwk2(:,idf),1,sync)  !Find sync power
                if(sync.gt.smax) then
@@ -232,20 +252,20 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
                   idfbest=idf
                endif
             enddo
-            call clockit('sync4d  ',1)
-
          enddo
+         call timer('sync4d  ',1)
       enddo
       f0=f0+real(idfbest)
       if( f0.le.10.0 .or. f0.ge.4990.0 ) cycle
-
-      call clockit('ft4down ',0)
-      call ft4_downsample(iwave,dobigfft,f0,cb) !Final downsample with corrected f0
-      call clockit('ft4down ',1)
+!      write(*,3002) smax,ibest/750.0,f0
+!3002  format('b',3f8.2)
+      call timer('ft4down ',0)
+      call ft4_downsample(iwave,dobigfft,f0,cb) !Final downsample, corrected f0
+      call timer('ft4down ',1)
       sum2=sum(abs(cb)**2)/(real(NSS)*NN)
       if(sum2.gt.0.0) cb=cb/sqrt(sum2)
       cd=cb(ibest:ibest+NN*NSS-1)
-      call clockit('four2a  ',0)
+      call timer('four2a  ',0)
       do k=1,NN
          i1=(k-1)*NSS
          csymb=cd(i1:i1+NSS-1)
@@ -253,7 +273,7 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
          cs(0:3,k)=csymb(1:4)
          s4(0:3,k)=abs(csymb(1:4))
       enddo
-      call clockit('four2a  ',1)
+      call timer('four2a  ',1)
 
 ! Sync quality check
       is1=0
@@ -322,11 +342,9 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
       bmetc(201:204)=bmetb(201:204)
       bmetc(205:206)=bmeta(205:206)
 
-      call clockit('normaliz',0)
       call normalizebmet(bmeta,2*NN)
       call normalizebmet(bmetb,2*NN)
       call normalizebmet(bmetc,2*NN)
-      call clockit('normaliz',1)
 
       hbits=0
       where(bmeta.ge.0) hbits=1
@@ -432,10 +450,10 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
          endif
          max_iterations=40
          message77=0
-         call clockit('bpdecode',0)
+         call timer('bpdec174',0)
          call bpdecode174_91(llr,apmask,max_iterations,message77,     &
             cw,nharderror,niterations)
-         call clockit('bpdecode',1)
+         call timer('bpdec174',1)
          if(sum(message77).eq.0) cycle
          if( nharderror.ge.0 ) then
             message77=mod(message77+rvec,2) ! remove rvec scrambling
@@ -455,35 +473,15 @@ subroutine ft4_decode(cdatetime0,tbuf,nfa,nfb,nQSOProgress,ncontest,nfqso, &
                xsnr=-20.0
             endif
             nsnr=nint(max(-20.0,xsnr))
-            freq=f0
-            tsig=mod(tbuf + ibest/750.0,100.0)
-
-            write(line,1000) hhmmss,nsnr,tsig,nint(freq),message
-1000        format(a6,i4,f5.1,i5,' + ',1x,a37)
-            l1=index(data_dir,char(0))-1
-            if(l1.ge.1) data_dir(l1+1:l1+1)="/"
-            fname=data_dir(1:l1+1)//'all_ft4.txt'
-            open(24,file=trim(fname),status='unknown',position='append')
-            write(24,1002) cdatetime0,nsnr,tsig,nint(freq),message,    &
-               nharderror,nsync_qual,ipass,niterations,iaptype,nsync
-            if(hhmmss.eq.'      ') write(*,1002) cdatetime0,nsnr,             &
-               tsig,nint(freq),message,nharderror,nsync_qual,ipass,    &
-               niterations,iaptype
-1002        format(a17,i4,f5.1,i5,' Rx  ',a37,6i4)
-            close(24)
-            linex(ndecodes)=line
+            xdt=ibest/750.0 - 0.5
+            call this%callback(sync,nsnr,xdt,f0,message,iaptype,qual)
             if(ibest.ge.ibmax-15) msg0=message         !Possible dupe candidate
             exit
          endif
       enddo !Sequence estimation
    enddo    !Candidate list
-   call clockit('ft4_deco',1)
-   call clockit2(data_dir)
-   call clockit('ft4_deco',101)
-   return
 
- entry get_ft4msg(idecode,line)
-   line=linex(idecode)
-   return
+  return
+  end subroutine decode
 
-end subroutine ft4_decode
+end module ft4_decode
diff --git a/lib/jt9.f90 b/lib/jt9.f90
index ff548b46e..7b3b0181e 100644
--- a/lib/jt9.f90
+++ b/lib/jt9.f90
@@ -23,7 +23,7 @@ program jt9
   integer :: arglen,stat,offset,remain,mode=0,flow=200,fsplit=2700,          &
        fhigh=4000,nrxfreq=1500,ntrperiod=1,ndepth=1,nexp_decode=0
   logical :: read_files = .true., tx9 = .false., display_help = .false.
-  type (option) :: long_options(25) = [ &
+  type (option) :: long_options(26) = [ &
     option ('help', .false., 'h', 'Display this help message', ''),          &
     option ('shmem',.true.,'s','Use shared memory for sample data','KEY'),   &
     option ('tr-period', .true., 'p', 'Tx/Rx period, default MINUTES=1',     &
@@ -48,10 +48,11 @@ program jt9
     option ('fft-threads', .true., 'm',                                      &
         'Number of threads to process large FFTs, default THREADS=1',        &
         'THREADS'),                                                          &
-    option ('jt65', .false., '6', 'JT65 mode', ''),                          &
-    option ('jt9', .false., '9', 'JT9 mode', ''),                            &
-    option ('ft8', .false., '8', 'FT8 mode', ''),                            &
     option ('jt4', .false., '4', 'JT4 mode', ''),                            &
+    option ('ft4', .false., '5', 'FT4 mode', ''),                            &
+    option ('jt65', .false.,'6', 'JT65 mode', ''),                          &
+    option ('ft8', .false., '8', 'FT8 mode', ''),                            &
+    option ('jt9', .false., '9', 'JT9 mode', ''),                            &
     option ('qra64', .false., 'q', 'QRA64 mode', ''),                        &
     option ('sub-mode', .true., 'b', 'Sub mode, default SUBMODE=A', 'A'),    &
     option ('depth', .true., 'd',                                            &
@@ -76,7 +77,7 @@ program jt9
   nsubmode = 0
 
   do
-     call getopt('hs:e:a:b:r:m:p:d:f:w:t:9864qTL:S:H:c:G:x:g:X:',      &
+     call getopt('hs:e:a:b:r:m:p:d:f:w:t:98654qTL:S:H:c:G:x:g:X:',      &
           long_options,c,optarg,arglen,stat,offset,remain,.true.)
      if (stat .ne. 0) then
         exit
@@ -113,6 +114,8 @@ program jt9
            mode = 164
         case ('4')
            mode = 4
+        case ('5')
+           mode = 5
         case ('6')
            if (mode.lt.65) mode = mode + 65
         case ('9')
diff --git a/samples/CMakeLists.txt b/samples/CMakeLists.txt
index cab1609cb..6be6a6df2 100644
--- a/samples/CMakeLists.txt
+++ b/samples/CMakeLists.txt
@@ -1,5 +1,5 @@
 set (SAMPLE_FILES
-  FT4/190106_000115.wav
+  FT4/190106_000112.wav
   FT8/181201_180245.wav
   ISCAT/ISCAT-A/VK7MO_110401_235515.wav
   ISCAT/ISCAT-B/K0AWU_100714_115000.wav
diff --git a/samples/FT4/190106_000112.wav b/samples/FT4/190106_000112.wav
new file mode 100644
index 000000000..2c6e0a9d4
Binary files /dev/null and b/samples/FT4/190106_000112.wav differ
diff --git a/samples/FT4/190106_000115.wav b/samples/FT4/190106_000115.wav
deleted file mode 100644
index cf23159f8..000000000
Binary files a/samples/FT4/190106_000115.wav and /dev/null differ
diff --git a/widgets/mainwindow.cpp b/widgets/mainwindow.cpp
index 3f195a416..8cc5bc330 100644
--- a/widgets/mainwindow.cpp
+++ b/widgets/mainwindow.cpp
@@ -169,11 +169,6 @@ extern "C" {
 
   void chkcall_(char* w, char* basc_call, bool cok, int len1, int len2);
 
-  void ft4_decode_(char* cdatetime, float* tbuf, int* nfa, int* nfb, int* nQSOProgress,
-                   int* nContest, int* nfqso, short int id[], int* ndecodes, char* mycall,
-                   char* hiscall, char* cqstr, char* line, char* ddir, int len1,
-                   int len2, int len3, int len4, int len5, int len6);
-
   void get_ft4msg_(int* idecode, char* line, int len);
 
 }
@@ -748,13 +743,6 @@ MainWindow::MainWindow(QDir const& temp_directory, bool multiple,
   connect(&m_guiTimer, &QTimer::timeout, this, &MainWindow::guiUpdate);
   m_guiTimer.start(100);   //### Don't change the 100 ms! ###
 
-
-  FT4_TxTimer.setSingleShot(true);
-  connect(&FT4_TxTimer, &QTimer::timeout, this, &MainWindow::stopTx);
-
-  FT4_WriteTxTimer.setSingleShot(true);
-  connect(&FT4_WriteTxTimer, &QTimer::timeout, this, &MainWindow::FT4_writeTx);
-
   ptt0Timer.setSingleShot(true);
   connect(&ptt0Timer, &QTimer::timeout, this, &MainWindow::stopTx2);
 
@@ -1333,7 +1321,9 @@ void MainWindow::fixStop()
     m_hsymStop=((int(m_TRperiod/0.288))/8)*8;
   } else if (m_mode=="FT8") {
     m_hsymStop=50;
-  }
+  } else if (m_mode=="FT4") {
+  m_hsymStop=18;
+}
 }
 
 //-------------------------------------------------------------- dataSink()
@@ -1341,8 +1331,7 @@ void MainWindow::dataSink(qint64 frames)
 {
   static float s[NSMAX];
   char line[80];
-
-  int k (frames);
+  int k(frames);
   QString fname {QDir::toNativeSeparators(m_config.writeable_data_dir ().absoluteFilePath ("refspec.dat"))};
   QByteArray bafname = fname.toLatin1();
   const char *c_fname = bafname.data();
@@ -1381,8 +1370,9 @@ void MainWindow::dataSink(qint64 frames)
   if(m_monitoring || m_diskData) {
     m_wideGraph->dataSink2(s,m_df3,m_ihsym,m_diskData);
   }
-  if(m_mode=="FT4") ft4_rx(k);
-  if(m_mode=="MSK144" or m_mode=="FT4") return;
+//  if(m_mode=="FT4") ft4_rx(k);
+//  if(m_mode=="MSK144" or m_mode=="FT4") return;
+  if(m_mode=="MSK144") return;
 
   fixStop();
   if (m_mode == "FreqCal"
@@ -1462,7 +1452,7 @@ void MainWindow::dataSink(qint64 frames)
 
     if(!m_diskData) {                        //Always save; may delete later
 
-      if(m_mode=="FT8") {
+      if(m_mode=="FT8" or m_mode=="FT4") {
         int n=now.time().second() % m_TRperiod;
         if(n<(m_TRperiod/2)) n=n+m_TRperiod;
         auto const& period_start=now.addSecs(-n);
@@ -1472,11 +1462,13 @@ void MainWindow::dataSink(qint64 frames)
         m_fnameWE=m_config.save_directory ().absoluteFilePath (period_start.toString ("yyMMdd_hhmm"));
       }
       m_fileToSave.clear ();
+      int samples=m_TRperiod*12000;
+      if(m_mode=="FT4") samples=18*3456;
 
       // the following is potential a threading hazard - not a good
       // idea to pass pointer to be processed in another thread
       m_saveWAVWatcher.setFuture (QtConcurrent::run (std::bind (&MainWindow::save_wave_file,
-            this, m_fnameWE, &dec_data.d2[0], m_TRperiod*12000, m_config.my_callsign(),
+            this, m_fnameWE, &dec_data.d2[0], samples, m_config.my_callsign(),
             m_config.my_grid(), m_mode, m_nSubMode, m_freqNominal, m_hisCall, m_hisGrid)));
       if (m_mode=="WSPR") {
         QString c2name_string {m_fnameWE + ".c2"};
@@ -1914,14 +1906,6 @@ void MainWindow::keyPressEvent (QKeyEvent * e)
       break;
     case Qt::Key_F1:
       if(bAltF1F5) {
-        if(m_mode=="FT4") {
-          if(e->modifiers() & Qt::ControlModifier) {
-            ft4_tx(1);
-          } else {
-            ft4_tx(6);
-          }
-          return;
-        }
         auto_tx_mode(true);
         on_txb6_clicked();
         return;
@@ -1931,10 +1915,6 @@ void MainWindow::keyPressEvent (QKeyEvent * e)
       }
     case Qt::Key_F2:
       if(bAltF1F5) {
-        if(m_mode=="FT4") {
-          ft4_tx(2);
-          return;
-        }
         auto_tx_mode(true);
         on_txb2_clicked();
         return;
@@ -1944,10 +1924,6 @@ void MainWindow::keyPressEvent (QKeyEvent * e)
       }
     case Qt::Key_F3:
       if(bAltF1F5) {
-        if(m_mode=="FT4") {
-          ft4_tx(3);
-          return;
-        }
         auto_tx_mode(true);
         on_txb3_clicked();
         return;
@@ -1957,10 +1933,6 @@ void MainWindow::keyPressEvent (QKeyEvent * e)
       }
     case Qt::Key_F4:
       if(bAltF1F5) {
-        if(m_mode=="FT4") {
-          ft4_tx(4);
-          return;
-        }
         auto_tx_mode(true);
         on_txb4_clicked();
         return;
@@ -1971,10 +1943,6 @@ void MainWindow::keyPressEvent (QKeyEvent * e)
       }
     case Qt::Key_F5:
       if(bAltF1F5) {
-        if(m_mode=="FT4") {
-          ft4_tx(5);
-          return;
-        }
         auto_tx_mode(true);
         on_txb5_clicked();
         return;
@@ -2720,7 +2688,8 @@ void MainWindow::diskDat()                                   //diskDat()
     float bw=m_config.RxBandwidth();
     if(db > 0.0) degrade_snr_(dec_data.d2,&dec_data.params.kin,&db,&bw);
     for(int n=1; n<=m_hsymStop; n++) {                      // Do the waterfall spectra
-      k=(n+1)*kstep;
+//      k=(n+1)*kstep;           //### Why was this (n+1) ??? ###
+      k=n*kstep;
       if(k > dec_data.params.kin) break;
       dec_data.params.npts8=k/8;
       dataSink(k);
@@ -2842,7 +2811,7 @@ void MainWindow::decode()                                       //decode()
   m_msec0=QDateTime::currentMSecsSinceEpoch();
   if(!m_dataAvailable or m_TRperiod==0) return;
   ui->DecodeButton->setChecked (true);
-  if(!dec_data.params.nagain && m_diskData && !m_bFastMode && m_mode!="FT8") {
+  if(!dec_data.params.nagain && m_diskData && !m_bFastMode && m_mode!="FT8" && m_mode!="FT4") {
     dec_data.params.nutc=dec_data.params.nutc/100;
   }
   if(dec_data.params.nagain==0 && dec_data.params.newdat==1 && (!m_diskData)) {
@@ -2852,7 +2821,7 @@ void MainWindow::decode()                                       //decode()
     imin=imin % 60;
     if(m_TRperiod>=60) imin=imin - (imin % (m_TRperiod/60));
     dec_data.params.nutc=100*ihr + imin;
-    if(m_mode=="ISCAT" or m_mode=="MSK144" or m_bFast9 or m_mode=="FT8") {
+    if(m_mode=="ISCAT" or m_mode=="MSK144" or m_bFast9 or m_mode=="FT8" or m_mode=="FT4") {
       QDateTime t=QDateTime::currentDateTimeUtc().addSecs(2-m_TRperiod);
       ihr=t.toString("hh").toInt();
       imin=t.toString("mm").toInt();
@@ -2902,7 +2871,8 @@ void MainWindow::decode()                                       //decode()
   if(m_modeTx=="JT65") dec_data.params.ntxmode=65;
   dec_data.params.nmode=9;
   if(m_mode=="JT65") dec_data.params.nmode=65;
-  if(m_mode=="JT65") dec_data.params.ljt65apon = ui->actionEnable_AP_JT65->isVisible () && ui->actionEnable_AP_JT65->isChecked (); 
+  if(m_mode=="JT65") dec_data.params.ljt65apon = ui->actionEnable_AP_JT65->isVisible () &&
+      ui->actionEnable_AP_JT65->isChecked ();
   if(m_mode=="QRA64") dec_data.params.nmode=164;
   if(m_mode=="QRA64") dec_data.params.ntxmode=164;
   if(m_mode=="JT9+JT65") dec_data.params.nmode=9+65;  // = 74
@@ -2911,8 +2881,10 @@ void MainWindow::decode()                                       //decode()
     dec_data.params.ntxmode=4;
   }
   if(m_mode=="FT8") dec_data.params.nmode=8;
-  if(m_mode=="FT8") dec_data.params.lft8apon = ui->actionEnable_AP_FT8->isVisible () && ui->actionEnable_AP_FT8->isChecked ();
+  if(m_mode=="FT8") dec_data.params.lft8apon = ui->actionEnable_AP_FT8->isVisible () &&
+      ui->actionEnable_AP_FT8->isChecked ();
   if(m_mode=="FT8") dec_data.params.napwid=50;
+  if(m_mode=="FT4") dec_data.params.nmode=5;
   dec_data.params.ntrperiod=m_TRperiod;
   dec_data.params.nsubmode=m_nSubMode;
   if(m_mode=="QRA64") dec_data.params.nsubmode=100 + m_nSubMode;
@@ -3057,7 +3029,7 @@ void MainWindow::readFromStdout()                             //readFromStdout
         // truncate before line ending chars
         line_read = line_read.left (p - line_read.constData ());
       }
-    if(m_mode!="FT8") {
+    if(m_mode!="FT8" and m_mode!="FT4") {
       //Pad 22-char msg to at least 37 chars
       line_read = line_read.left(43) + "               " + line_read.mid(43);
     }
@@ -3077,7 +3049,7 @@ void MainWindow::readFromStdout()                             //readFromStdout
       }
       return;
     } else {
-      if(m_mode=="JT4" or m_mode=="JT65" or m_mode=="QRA64" or m_mode=="FT8") {
+      if(m_mode=="JT4" or m_mode=="JT65" or m_mode=="QRA64" or m_mode=="FT8" or m_mode=="FT4") {
         int n=line_read.indexOf("f");
         if(n<0) n=line_read.indexOf("d");
         if(n>0) {
@@ -3137,10 +3109,10 @@ void MainWindow::readFromStdout()                             //readFromStdout
 //Right (Rx Frequency) window
       bool bDisplayRight=bAvgMsg;
       int audioFreq=decodedtext.frequencyOffset();
-      if(m_mode=="FT8") {
+      if(m_mode=="FT8" or m_mode=="FT4") {
         auto const& parts = decodedtext.string().remove("<").remove(">")
             .split (' ', QString::SkipEmptyParts);
-        if (parts.size () > 6) {
+        if (parts.size() > 6) {
           auto for_us = parts[5].contains (m_baseCall)
             || ("DE" == parts[5] && qAbs (ui->RxFreqSpinBox->value () - audioFreq) <= 10);
           if(m_baseCall==m_config.my_callsign() and m_baseCall!=parts[5]) for_us=false;
@@ -3218,7 +3190,7 @@ void MainWindow::readFromStdout()                             //readFromStdout
 
 //### I think this is where we are preventing Hounds from spotting Fox ###
       if(m_mode!="FT8" or (SpecOp::HOUND != m_config.special_op_id())) {
-        if(m_mode=="FT8" or m_mode=="QRA64" or m_mode=="JT4" or m_mode=="JT65" or m_mode=="JT9") {
+        if(m_mode=="FT8" or m_mode=="FT4" or m_mode=="QRA64" or m_mode=="JT4" or m_mode=="JT65" or m_mode=="JT9") {
           auto_sequence (decodedtext, 25, 50);
         }
 
@@ -3417,6 +3389,7 @@ void MainWindow::guiUpdate()
 
   if(m_TRperiod==0) m_TRperiod=60;
   txDuration=0.0;
+  if(m_modeTx=="FT4")  txDuration=0.35 + 105*512/12000.0;     // FT4
   if(m_modeTx=="FT8")  txDuration=1.0 + 79*1920/12000.0;      // FT8
   if(m_modeTx=="JT4")  txDuration=1.0 + 207.0*2520/11025.0;   // JT4
   if(m_modeTx=="JT9")  txDuration=1.0 + 85.0*m_nsps/12000.0;  // JT9
@@ -3588,7 +3561,8 @@ void MainWindow::guiUpdate()
       Q_EMIT m_config.transceiver_ptt (true);            //Assert the PTT
       m_tx_when_ready = true;
     }
-    if(!m_bTxTime and !m_tune and m_mode!="FT4") m_btxok=false;       //Time to stop transmitting
+//    if(!m_bTxTime and !m_tune and m_mode!="FT4") m_btxok=false;       //Time to stop transmitting
+    if(!m_bTxTime and !m_tune) m_btxok=false;       //Time to stop transmitting
   }
 
   if(m_mode.startsWith ("WSPR") and
@@ -3677,7 +3651,7 @@ void MainWindow::guiUpdate()
                                     22, 22);
 //        if(m_modeTx=="WSPR-LF") genwspr_fsk8_(message, msgsent, const_cast<int *> (itone),
 //                                    22, 22);
-        if(m_modeTx=="MSK144" or m_modeTx=="FT8") {
+        if(m_modeTx=="MSK144" or m_modeTx=="FT8" or m_modeTx=="FT4") {
           char MyCall[6];
           char MyGrid[6];
           strncpy(MyCall, (m_config.my_callsign()+"      ").toLatin1(),6);
@@ -3722,6 +3696,17 @@ void MainWindow::guiUpdate()
               }
             }
           }
+          if(m_modeTx=="FT4") {
+            int ichk=0;
+            genft4_(message, &ichk, msgsent, const_cast<int *>(itone), 37, 37);
+            int nsym=103;
+            int nsps=4*512;
+            float fsample=48000.0;
+            float f0=ui->TxFreqSpinBox->value() - m_XIT;
+            int nwave=(nsym+2)*nsps;
+            gen_ft4wave_(const_cast<int *>(itone),&nsym,&nsps,&fsample,&f0,foxcom_.wave,&nwave);
+          }
+
           if(SpecOp::EU_VHF==m_config.special_op_id()) {
             if(m_ntx==2) m_xSent=ui->tx2->text().right(13);
             if(m_ntx==3) m_xSent=ui->tx3->text().right(13);
@@ -3739,7 +3724,7 @@ void MainWindow::guiUpdate()
       }
     }
 
-    if(m_mode!="FT4") m_currentMessage = QString::fromLatin1(msgsent);
+    m_currentMessage = QString::fromLatin1(msgsent);
     m_bCallingCQ = CALLING == m_QSOProgress
       || m_currentMessage.contains (QRegularExpression {"^(CQ|QRZ) "});
     if(m_mode=="FT8" or m_mode=="FT4") {
@@ -3784,7 +3769,7 @@ void MainWindow::guiUpdate()
       if((m_config.prompt_to_log() or m_config.autoLog()) && !m_tune) logQSOTimer.start(0);
     }
 
-    bool b=(m_mode=="FT8") and ui->cbAutoSeq->isChecked();
+    bool b=(m_mode=="FT8" or m_mode=="FT4") and ui->cbAutoSeq->isChecked();
     if(is_73 and (m_config.disable_TX_on_73() or b)) {
       m_nextCall="";  //### Temporary: disable use of "TU;" messages;
       if(m_nextCall!="") {
@@ -3857,14 +3842,14 @@ void MainWindow::guiUpdate()
       m_msgSent0 = current_message;
     }
 
-    if(m_mode!="FT4") {
+//    if(m_mode!="FT4") {
       if(!m_tune) write_all("Tx",m_currentMessage);
 
       if (m_config.TX_messages () && !m_tune && SpecOp::FOX!=m_config.special_op_id()) {
         ui->decodedTextBrowser2->displayTransmittedText(current_message, m_modeTx,
              ui->TxFreqSpinBox->value(),m_bFastMode);
       }
-    }
+//    }
 
     switch (m_ntx)
     {
@@ -3928,12 +3913,14 @@ void MainWindow::guiUpdate()
       if(tHound >= 120 and m_ntx==1) auto_tx_mode(false);
     }
 
-    progressBar.setVisible(!(m_mode=="FT4"));
+//    progressBar.setVisible(!(m_mode=="FT4"));
+    progressBar.setVisible(true);
     if(m_auto and m_mode=="Echo" and m_bEchoTxOK) {
       progressBar.setMaximum(6);
       progressBar.setValue(int(m_s6));
     }
-    if(m_mode!="Echo" and m_mode!="FT4") {
+//    if(m_mode!="Echo" and m_mode!="FT4") {
+    if(m_mode!="Echo") {
       if(m_monitoring or m_transmitting) {
         progressBar.setMaximum(m_TRperiod);
         int isec=int(fmod(tsec,m_TRperiod));
@@ -4217,11 +4204,7 @@ void MainWindow::on_txb1_clicked()
     m_ntx=1;
     m_QSOProgress = REPLYING;
     ui->txrb1->setChecked(true);
-    if(m_mode=="FT4") {
-      ft4_tx(1);
-    } else {
-      if(m_transmitting) m_restart=true;
-    }
+    if(m_transmitting) m_restart=true;
   }
   else {
     on_txb2_clicked ();
@@ -4242,11 +4225,7 @@ void MainWindow::on_txb2_clicked()
     m_ntx=2;
     m_QSOProgress = REPORT;
     ui->txrb2->setChecked(true);
-    if(m_mode=="FT4") {
-      ft4_tx(2);
-    } else {
-      if(m_transmitting) m_restart=true;
-    }
+    if(m_transmitting) m_restart=true;
 }
 
 void MainWindow::on_txb3_clicked()
@@ -4254,11 +4233,7 @@ void MainWindow::on_txb3_clicked()
     m_ntx=3;
     m_QSOProgress = ROGER_REPORT;
     ui->txrb3->setChecked(true);
-    if(m_mode=="FT4") {
-      ft4_tx(3);
-    } else {
-      if(m_transmitting) m_restart=true;
-    }
+    if(m_transmitting) m_restart=true;
 }
 
 void MainWindow::on_txb4_clicked()
@@ -4266,11 +4241,7 @@ void MainWindow::on_txb4_clicked()
     m_ntx=4;
     m_QSOProgress = ROGERS;
     ui->txrb4->setChecked(true);
-    if(m_mode=="FT4") {
-      ft4_tx(4);
-    } else {
-      if(m_transmitting) m_restart=true;
-    }
+    if(m_transmitting) m_restart=true;
 }
 
 void MainWindow::on_txb4_doubleClicked()
@@ -4288,11 +4259,7 @@ void MainWindow::on_txb5_clicked()
     m_ntx=5;
     m_QSOProgress = SIGNOFF;
     ui->txrb5->setChecked(true);
-    if(m_mode=="FT4") {
-      ft4_tx(5);
-    } else {
-      if(m_transmitting) m_restart=true;
-    }
+    if(m_transmitting) m_restart=true;
 }
 
 void MainWindow::on_txb5_doubleClicked()
@@ -4306,11 +4273,7 @@ void MainWindow::on_txb6_clicked()
     m_QSOProgress = CALLING;
     set_dateTimeQSO(-1);
     ui->txrb6->setChecked(true);
-    if(m_mode=="FT4") {
-      ft4_tx(6);
-    } else {
-      if(m_transmitting) m_restart=true;
-    }
+    if(m_transmitting) m_restart=true;
 }
 
 void MainWindow::doubleClickOnCall2(Qt::KeyboardModifiers modifiers)
@@ -4349,7 +4312,7 @@ void MainWindow::doubleClickOnCall(Qt::KeyboardModifiers modifiers)
     }
     return;
   }
-  DecodedText message {cursor.block().text()};
+  DecodedText message {cursor.block().text().trimmed().remove("TU; ")};
   m_bDoubleClicked = true;
   processMessage (message, modifiers);
 }
@@ -4360,7 +4323,6 @@ void MainWindow::processMessage (DecodedText const& message, Qt::KeyboardModifie
   auto shift = modifiers.testFlag (Qt::ShiftModifier);
   auto ctrl = modifiers.testFlag (Qt::ControlModifier);
   // auto alt = modifiers.testFlag (Qt::AltModifier);
-
   // basic mode sanity checks
   auto const& parts = message.string ().split (' ', QString::SkipEmptyParts);
   if (parts.size () < 5) return;
@@ -4382,21 +4344,6 @@ void MainWindow::processMessage (DecodedText const& message, Qt::KeyboardModifie
         ui->TxFreqSpinBox->setValue(frequency); //Set Tx freq
       }
     }
-    if(m_mode=="FT4") {
-      int i0=message.string().indexOf(" +  ");
-      QString t=message.string().trimmed().mid(i0+4,-1);
-      int n=0;
-      if(t==ui->tx1->text()) n=1;
-      if(t==ui->tx2->text()) n=2;
-      if(t==ui->tx3->text()) n=3;
-      if(t==ui->tx4->text()) n=4;
-      if(t==ui->tx5->currentText()) n=5;
-      if(t==ui->tx6->text()) n=6;
-      if(n>0) {
-        if(ctrl) ui->TxFreqSpinBox->setValue(frequency);
-        ft4_tx(n);
-      }
-    }
     return;
   }
 
@@ -4587,6 +4534,7 @@ void MainWindow::processMessage (DecodedText const& message, Qt::KeyboardModifie
       } else {  // no grid on end of msg
         QString r=message_words.at (3);
         if(m_QSOProgress >= ROGER_REPORT && (r=="RRR" || r.toInt()==73 || "RR73" == r)) {
+          if(m_mode=="FT4" and r=="RR73") m_dateTimeRcvdRR73=QDateTime::currentDateTimeUtc();
           if(ui->tabWidget->currentIndex()==1) {
             gen_msg = 5;
             if (ui->rbGenMsg->isChecked ()) m_ntx=7;
@@ -4594,7 +4542,6 @@ void MainWindow::processMessage (DecodedText const& message, Qt::KeyboardModifie
           } else {
             m_bTUmsg=false;
             m_nextCall="";   //### Temporary: disable use of "TU;" message
-
             if(SpecOp::RTTY == m_config.special_op_id() and m_nextCall!="") {
 // We're in RTTY contest and have "nextCall" queued up: send a "TU; ..." message
               logQSOTimer.start(0);
@@ -4847,16 +4794,6 @@ void MainWindow::processMessage (DecodedText const& message, Qt::KeyboardModifie
       && !m_bDoubleClicked && m_mode!="FT4") {
     return;
   }
-  if(m_mode=="FT4" and ui->cbAutoSeq->isChecked()) {
-    if((m_ntx==4 or m_ntx==5) and !m_diskData) {
-      save_FT4();
-      logQSOTimer.start(0);  // Log the QSO
-    }
-    if((m_ntx==3 and ui->cbFirst->isChecked()) or m_ntx==4 or m_bDoubleClicked) {
-      QThread::msleep(600);  //Wait a bit.  ### Is this a good idea??? ###
-      ft4_tx(m_ntx);
-    }
-  }
   if(m_config.quick_call()) auto_tx_mode(true);
   m_bDoubleClicked=false;
 }
@@ -5039,7 +4976,8 @@ void MainWindow::genStdMsgs(QString rpt, bool unconditional)
         QDateTime now=QDateTime::currentDateTimeUtc();
         int sinceTx3 = m_dateTimeSentTx3.secsTo(now);
         int sinceRR73 = m_dateTimeRcvdRR73.secsTo(now);
-        if(m_bDoubleClicked and (qAbs(sinceTx3-12) <= 3) and (sinceRR73 < 5)) {
+//        qDebug() << "aa" << m_bDoubleClicked << sinceTx3 << sinceRR73;
+        if(m_bDoubleClicked and (sinceTx3 < 15) and (sinceRR73 < 3)) {
           t="TU; " + ui->tx3->text();
           ui->tx3->setText(t);
         }
@@ -5647,7 +5585,7 @@ void MainWindow::on_actionFT4_triggered()
 {
   m_mode="FT4";
   m_modeTx="FT4";
-  m_TRperiod=2147483647;
+  m_TRperiod=6;
   bool bVHF=m_config.enable_VHF_features();
   m_bFast9=false;
   m_bFastMode=false;
@@ -5656,7 +5594,7 @@ void MainWindow::on_actionFT4_triggered()
   m_nsps=6912;
   m_FFTSize = m_nsps/2;
   Q_EMIT FFTSize (m_FFTSize);
-  m_hsymStop=50;
+  m_hsymStop=18;
   setup_status_bar (bVHF);
   m_toneSpacing=12000.0/512.0;
   ui->actionFT4->setChecked(true);
@@ -5674,7 +5612,7 @@ void MainWindow::on_actionFT4_triggered()
   ui->label_7->setText("Rx Frequency");
   ui->label_6->setText("Band Activity");
   ui->decodedTextLabel->setText( "  UTC   dB   DT Freq    Message");
-  displayWidgets(nWidgets("011010000100111000010000100110001"));
+  displayWidgets(nWidgets("111010000100111000010000100110001"));
   ui->txrb2->setEnabled(true);
   ui->txrb4->setEnabled(true);
   ui->txrb5->setEnabled(true);
@@ -6793,18 +6731,17 @@ void MainWindow::setFreq4(int rxFreq, int txFreq)
 
 void MainWindow::handle_transceiver_update (Transceiver::TransceiverState const& s)
 {
-  // qDebug () << "MainWindow::handle_transceiver_update:" << s;
   Transceiver::TransceiverState old_state {m_rigState};
   //transmitDisplay (s.ptt ());
-  if (s.ptt () && !m_rigState.ptt ()) // safe to start audio
-                                      // (caveat - DX Lab Suite Commander)
-    {
-      if (m_tx_when_ready && g_iptt) // waiting to Tx and still needed
-        {
-          ptt1Timer.start(1000 * m_config.txDelay ()); //Start-of-transmission sequencer delay
-        }
-      m_tx_when_ready = false;
+  if (s.ptt () && !m_rigState.ptt ()) { // safe to start audio
+                                        // (caveat - DX Lab Suite Commander)
+    if (m_tx_when_ready && g_iptt) {    // waiting to Tx and still needed
+      int ms_delay=1000*m_config.txDelay();
+      if(m_mode=="FT4") ms_delay=20;
+      ptt1Timer.start(ms_delay); //Start-of-transmission sequencer delay
     }
+    m_tx_when_ready = false;
+  }
   m_rigState = s;
   auto old_freqNominal = m_freqNominal;
   if (!old_freqNominal)
@@ -6955,12 +6892,12 @@ void MainWindow::transmit (double snr)
   }
 
   if (m_modeTx == "FT4") {
-//    toneSpacing=12000.0/512.0;        //Generate Tx waveform from itone[] array
+    m_dateTimeSentTx3=QDateTime::currentDateTimeUtc();
     toneSpacing=-2.0;                     //Transmit a pre-computed, filtered waveform.
     Q_EMIT sendMessage (NUM_FT4_SYMBOLS,
            512.0, ui->TxFreqSpinBox->value() - m_XIT,
-           toneSpacing, m_soundOutput, m_config.audio_output_channel (),
-           true, false, snr, 2);
+           toneSpacing, m_soundOutput, m_config.audio_output_channel(),
+           true, false, snr, m_TRperiod);
   }
 
   if (m_modeTx == "QRA64") {
@@ -8677,7 +8614,7 @@ void MainWindow::write_all(QString txRx, QString message)
   t.sprintf("%5d",ui->TxFreqSpinBox->value());
   if(txRx=="Tx") msg="   0  0.0" + t + " " + message;
   auto time = QDateTime::currentDateTimeUtc ();
-  if(m_mode!="FT4") time = time.addSecs(-(time.time().second() % m_TRperiod));
+  time = time.addSecs(-(time.time().second() % m_TRperiod));
   t.sprintf("%10.3f ",m_freqNominal/1.e6);
   if(m_diskData) {
     line=m_fileDateTime + t + txRx + " " + m_mode.leftJustified(6,' ') + msg;
@@ -8700,221 +8637,6 @@ void MainWindow::write_all(QString txRx, QString message)
   }
 }
 
-void MainWindow::ft4_rx(int k)
-{
-  static int nhsec0=-1;
-  static bool wrapped=false;
-  short id[60000];
-  const int istep=3456;
-  const int k_enough=55296;  //4.608 s
-
-  if(k<m_kin0) m_kin0=0;
-  int nhsec=k/istep;
-  if(nhsec0>nhsec) nhsec0=-1;
-  if(nhsec==nhsec0) return;
-  if(k<k_enough and !wrapped) return;
-
-//Process FT4 data at intervals of istep/12000.0 = 0.288 seconds
-  int j=k/istep;
-  j=istep*j-k_enough;
-  if(j<0) j+=NRING;
-  float tbuf=j/12000.0;
-  for(int i=0; i<60000; i++) {
-    id[i]=dec_data.d2[j];
-    j++;
-    if(j>=NRING) {
-      j=j-NRING;
-      wrapped=true;
-    }
-  }
-  if(j>60000) wrapped=false;
-  if(m_saveAll and ((k-m_kin0)/12000.0 > 15.0) and !m_diskData) save_FT4();
-
-  if(k>=NRING) {
-    if(m_saveAll and !m_diskData) save_FT4();
-    //Wrap the ring buffer pointer
-    k=k-NRING;
-    dec_data.params.kin=k;
-  }
-
-  QByteArray ba;
-  if(m_diskData) {
-    ba=(m_fileDateTime + ".000").toLatin1();
-  } else {
-    auto time = QDateTime::currentDateTimeUtc ();
-    ba=time.toString("yyMMdd_hhmmss.sss").toLatin1();
-  }
-  char* cdatetime=ba.data();
-
-  strncpy(dec_data.params.mycall, (m_config.my_callsign()+"            ").toLatin1(),12);
-  char mycall[13];
-  strncpy(mycall,m_config.my_callsign().toLatin1(),12);
-  char hiscall[13];
-  strncpy(hiscall,m_hisCall.toLatin1(),12);
-
-  char line[61];
-  int nfqso=1500;
-  int ndecodes=0;
-  int nfa=m_wideGraph->nStartFreq();
-  int nfb=m_wideGraph->Fmax();
-  int nQSOProgress = static_cast<int> ( m_QSOProgress );
-  int nContest = static_cast<int> (m_config.special_op_id());
-  QString dataDir;
-  dataDir = m_config.writeable_data_dir ().absolutePath ();
-  char ddir[512];
-  strncpy(ddir,dataDir.toLatin1(), sizeof (ddir) - 1);
-  char cqstr[4];
-  strncpy(cqstr,"    ",4);
-  if(SpecOp::NA_VHF == m_config.special_op_id()) strncpy(cqstr,"TEST",4);
-  if(SpecOp::EU_VHF == m_config.special_op_id()) strncpy(cqstr,"TEST",4);
-  if(SpecOp::FIELD_DAY == m_config.special_op_id()) strncpy(cqstr,"FD",2);
-  if(SpecOp::RTTY == m_config.special_op_id()) {
-        if(m_config.RTTY_Exchange()!="SCC") strncpy(cqstr,"RU",2);
-        if(m_config.RTTY_Exchange()=="SCC") strncpy(cqstr,"SCC",3);
-  }
-  ft4_decode_(cdatetime,&tbuf,&nfa,&nfb,&nQSOProgress,&nContest,&nfqso,id,&ndecodes,&mycall[0],&hiscall[0],
-              &cqstr[0],&line[0],&ddir[0],17,12,12,4,61,512);
-  line[60]=0;
-  for (int idecode=1; idecode<=ndecodes; idecode++) {
-    get_ft4msg_(&idecode,&line[0],61);
-    line[60]=0;
-    QString sline{QString::fromLatin1(line)};
-    DecodedText decodedtext {sline.replace(QChar::LineFeed,"")};
-    ui->decodedTextBrowser->displayDecodedText (decodedtext,m_baseCall,m_mode,
-                   m_config.DXCC(),m_logBook,m_currentBand,m_config.ppfx());
-
-//Right (Rx Frequency) window
-//    int audioFreq=decodedtext.frequencyOffset();
-    auto const& parts = decodedtext.string().remove("<").remove(">")
-        .split (' ', QString::SkipEmptyParts);
-    if(parts.size() > 6) {
-      int iFirstCall=5;
-      if(parts[5]=="TU;") iFirstCall=6;
-      auto for_us = parts[iFirstCall].contains(m_baseCall);
-      if(m_baseCall==m_config.my_callsign() and m_baseCall!=parts[iFirstCall]) for_us=false;
-      if(m_bCallingCQ && !m_bAutoReply && for_us && ui->cbFirst->isChecked()) {
-        m_bDoubleClicked=true;
-        m_bAutoReply = true;
-        ui->cbFirst->setStyleSheet("");
-      }
-      if(for_us) {
-        ui->decodedTextBrowser2->displayDecodedText(decodedtext,m_baseCall,
-             m_mode,m_config.DXCC(),m_logBook,m_currentBand,m_config.ppfx());
-        if(decodedtext.string().trimmed().contains(m_inQSOwith)) processMessage(decodedtext);
-        m_QSOText = decodedtext.string().trimmed ();
-      }
-      if(for_us and parts[iFirstCall+2]=="RR73") m_dateTimeRcvdRR73=QDateTime::currentDateTimeUtc();
-      write_all("Rx",decodedtext.string().trimmed());
-    }
-  }
-  nhsec0=nhsec;
-  if(m_diskData and (k > (dec_data.params.kin-istep))) m_startAnother=m_loopall;
-  if(m_bNoMoreFiles) {
-    MessageBox::information_message(this, tr("Just one more file to open."));
-    m_bNoMoreFiles=false;
-  }
-}
-
-void MainWindow::ft4_tx(int ntx)
-{
-  if(g_iptt!=0) return;             //Already transmitting?
-  static char message[38];
-  static char msgsent[38];
-  QByteArray ba;
-  m_ntx=ntx;
-  setTxMsg(m_ntx);
-  if(m_ntx == 1) ba=ui->tx1->text().toLocal8Bit();
-  if(m_ntx == 2) ba=ui->tx2->text().toLocal8Bit();
-  if(m_ntx == 3) ba=ui->tx3->text().toLocal8Bit();
-  if(m_ntx == 4) ba=ui->tx4->text().toLocal8Bit();
-  if(m_ntx == 5) ba=ui->tx5->currentText().toLocal8Bit();
-  if(m_ntx == 6) ba=ui->tx6->text().toLocal8Bit();
-  QString msg = QString::fromLatin1(ba.data());
-  if(m_ntx==2 or m_ntx==3) m_inQSOwith=m_hisCall;
-  if(msg.trimmed().length()==0) return;   //Don't transmit a blank message, or ...
-  if(m_diskData) return;                  //... in response to a decode from disk
-  ba2msg(ba,message);
-  int ichk=0;
-  genft4_(message, &ichk, msgsent, const_cast<int *>(itone), 37, 37);
-  msgsent[37]=0;
-  m_currentMessage = QString::fromLatin1(msgsent).trimmed();
-  tx_status_label.setStyleSheet("QLabel{background-color: #ffff33}");
-  tx_status_label.setText("TX: " + m_currentMessage);
-  if(m_ntx==2 or m_ntx==3) {
-    QStringList t=ui->tx2->text().split(' ', QString::SkipEmptyParts);
-    int n=t.size();
-    m_xSent=t.at(n-2) + " " + t.at(n-1);
-  }
-  auto_tx_mode(true);                    //Enable Tx
-  icw[0]=0;
-  g_iptt = 1;
-  setRig ();
-  setXIT (ui->TxFreqSpinBox->value ());
-
-  int nsym=103;
-  int nsps=4*512;
-  float fsample=48000.0;
-  float f0=ui->TxFreqSpinBox->value() - m_XIT;
-  int nwave=(nsym+2)*nsps;
-  gen_ft4wave_(const_cast<int *>(itone),&nsym,&nsps,&fsample,&f0,foxcom_.wave,&nwave);
-  if(m_ntx==3) m_dateTimeSentTx3=QDateTime::currentDateTimeUtc();
-  Q_EMIT m_config.transceiver_ptt (true);            //Assert the PTT
-  m_tx_when_ready = true;
-  qint64 ms=QDateTime::currentMSecsSinceEpoch();
-  m_modulator->set_ms0(ms);
-  FT4_TxTimer.start(4600);      //Slightly more than FT4 transmission length
-
-  if (g_iptt == 1 && m_iptt0 == 0) {
-    auto const& current_message = QString::fromLatin1 (msgsent);
-    FT4_WriteTxTimer.start(100);  //Why is a delay necessary to ensure Tx after Rx in all.txt?
-    if (m_config.TX_messages () && !m_tune && SpecOp::FOX!=m_config.special_op_id()) {
-      ui->decodedTextBrowser2->displayTransmittedText(current_message, m_modeTx,
-           ui->TxFreqSpinBox->value(),m_bFastMode);
-    }
-
-    switch (m_ntx)
-    {
-    case 1: m_QSOProgress = REPLYING; break;
-    case 2: m_QSOProgress = REPORT; break;
-    case 3: m_QSOProgress = ROGER_REPORT; break;
-    case 4: m_QSOProgress = ROGERS; break;
-    case 5: m_QSOProgress = SIGNOFF; break;
-    case 6: m_QSOProgress = CALLING; break;
-    default: break;             // determined elsewhere
-    }
-    m_transmitting = true;
-    transmitDisplay (true);
-    statusUpdate ();
-  }
-  m_dateTimeQSOOn=QDateTime::currentDateTimeUtc();
-  if(!m_btxok && m_btxok0 && g_iptt==1) stopTx();
-  if(m_saveAll and !m_diskData) save_FT4();
-}
-
-void MainWindow::FT4_writeTx()
-{
-  write_all("Tx",m_currentMessage);
-}
-
-void MainWindow::save_FT4()
-{
-  double tsec=(dec_data.params.kin - m_kin0)/12000.0;
-  if(tsec<4.4) return;       //Saved data must be at least 4.4 seconds long.
-  auto time = QDateTime::currentDateTimeUtc ();
-  QString t=time.toString("yyMMdd_hhmmss");
-  m_fnameWE=m_config.save_directory().absoluteFilePath(t);
-
-// The following is potential a threading hazard - not a good
-// idea to pass pointer to be processed in another thread
-  int nsamples=dec_data.params.kin - m_kin0 + 1;
-  m_saveWAVWatcher.setFuture (QtConcurrent::run (std::bind (&MainWindow::save_wave_file,
-        this, m_fnameWE, &dec_data.d2[m_kin0], nsamples, m_config.my_callsign(),
-        m_config.my_grid(), m_mode, m_nSubMode, m_freqNominal, m_hisCall,
-        m_hisGrid)));
-
-  m_kin0=dec_data.params.kin;
-}
-
 void MainWindow::chkFT4()
 {
   if(m_mode!="FT4") return;
diff --git a/widgets/mainwindow.h b/widgets/mainwindow.h
index 8be317596..6bce17978 100644
--- a/widgets/mainwindow.h
+++ b/widgets/mainwindow.h
@@ -46,7 +46,7 @@
 #define NUM_MSK144_SYMBOLS 144             //s8 + d48 + s8 + d80
 #define NUM_QRA64_SYMBOLS 84               //63 data + 21 sync
 #define NUM_FT8_SYMBOLS 79
-#define NUM_FT4_SYMBOLS 103
+#define NUM_FT4_SYMBOLS 105
 #define NUM_CW_SYMBOLS 250
 #define TX_SAMPLE_RATE 48000
 #define N_WIDGETS 33
@@ -312,8 +312,6 @@ private slots:
   void on_comboBoxHoundSort_activated (int index);
   void not_GA_warning_message ();
   void checkMSK144ContestType();
-  void ft4_rx(int k);
-  void ft4_tx(int ntx);
   int  setTxMsg(int n);
   bool stdCall(QString const& w);
 
@@ -583,8 +581,6 @@ private:
   QTimer minuteTimer;
   QTimer splashTimer;
   QTimer p1Timer;
-  QTimer FT4_TxTimer;
-  QTimer FT4_WriteTxTimer;
 
   QString m_path;
   QString m_baseCall;
@@ -764,8 +760,6 @@ private:
   void foxTxSequencer();
   void foxGenWaveform(int i,QString fm);
   void writeFoxQSO (QString const& msg);
-  void FT4_writeTx();
-  void save_FT4();
 };
 
 extern int killbyname(const char* progName);