diff --git a/Modulator/Modulator.cpp b/Modulator/Modulator.cpp
index 3a33c42f1..f267022e0 100644
--- a/Modulator/Modulator.cpp
+++ b/Modulator/Modulator.cpp
@@ -92,20 +92,8 @@ void Modulator::start (unsigned symbolsLength, double framesPerSymbol,
     if(delay_ms >= mstr) m_silentFrames = m_ic + 0.001*(delay_ms-mstr)*m_frameRate;
   }
 
-  // Special case for FST280:
-//  qDebug() << "aa" << m_ic << m_silentFrames << m_symbolsLength << m_nsps;
-  if(m_nsps==800 or m_nsps==1680 or m_nsps==3888 or m_nsps==8200 or m_nsps==21168) {
-    m_ic = m_ic + 48000 - 2*m_nsps + 9600;             //The 9600 is empirical
-    m_silentFrames = m_silentFrames - 2*m_nsps;
-  }
-  if(m_silentFrames<0) {
-    m_ic = m_ic - m_silentFrames;
-    m_silentFrames = 0;
-  }
-//  qDebug() << "bb" << m_ic << m_silentFrames;
-//  qDebug() << "cc" << QDateTime::currentDateTimeUtc().toString("hh:mm:ss.zzz")
-//           << delay_ms << mstr << m_silentFrames << m_ic;
-
+//  qDebug() << "aa" << QDateTime::currentDateTimeUtc().toString("hh:mm:ss.zzz")
+//           << delay_ms << mstr << m_silentFrames << m_ic << m_symbolsLength;
 
   initialize (QIODevice::ReadOnly, channel);
   Q_EMIT stateChanged ((m_state = (synchronize && m_silentFrames) ?
@@ -317,14 +305,18 @@ qint64 Modulator::readData (char * data, qint64 maxSize)
             m_amp=32767.0;
             sample=qRound(m_amp*foxcom_.wave[m_ic]);
           }
-
+/*
+          if((m_ic<1000 or (4*m_symbolsLength*m_nsps - m_ic) < 1000) and (m_ic%10)==0) {
+            qDebug() << "cc" << QDateTime::currentDateTimeUtc().toString("hh:mm:ss.zzz") << m_ic << sample;
+          }
+*/
           samples = load(postProcessSample(sample), samples);
           ++framesGenerated;
           ++m_ic;
         }
 
 //        qDebug() << "dd" << QDateTime::currentDateTimeUtc().toString("hh:mm:ss.zzz")
-//                 << m_ic << m_amp << foxcom_.wave[m_ic];
+//                 << m_ic << i1 << foxcom_.wave[m_ic] << framesGenerated;
 
         if (m_amp == 0.0) { // TODO G4WJS: compare double with zero might not be wise
           if (icw[0] == 0) {
diff --git a/lib/fst240/gen_fst240wave.f90 b/lib/fst240/gen_fst240wave.f90
index 3005968b2..43170638d 100644
--- a/lib/fst240/gen_fst240wave.f90
+++ b/lib/fst240/gen_fst240wave.f90
@@ -8,13 +8,11 @@ subroutine gen_fst240wave(itone,nsym,nsps,nwave,fsample,hmod,f0,    &
   real, allocatable :: dphi(:)
   integer hmod
   integer itone(nsym)
-!  integer*8 count0,count1,clkfreq
   logical first
   data first/.true./
   data nsps0/-99/
   save first,twopi,dt,tsym,nsps0,ctab
 
-!  call system_clock(count0,clkfreq)
   if(first) then
      twopi=8.0*atan(1.0)
      do i=0,NTAB-1
@@ -68,7 +66,7 @@ subroutine gen_fst240wave(itone,nsym,nsps,nwave,fsample,hmod,f0,    &
   enddo
 
 ! Compute the ramp-up and ramp-down symbols
-  kshift=nsps-nint(fsample)
+  kshift=nsps
   if(icmplx.eq.0) then
      wave(1:nsps)=0.0
      wave(nsps+1:nsps+nsps/4)=wave(nsps+1:nsps+nsps/4) *                      &
@@ -89,10 +87,11 @@ subroutine gen_fst240wave(itone,nsym,nsps,nwave,fsample,hmod,f0,    &
      cwave=cshift(cwave,kshift)
   endif
 
-!  call system_clock(count1,clkfreq)
-!  tt=float(count1-count0)/float(clkfreq)
-!  write(*,3001) tt
-!3001 format('Tgen:',f8.3)
-  
+!  do i=1,nwave
+!     write(71,3071) i,i/48000.0,wave(i)
+!3071 format(i10,2f15.9)
+!  enddo
+  wave(nsps*nsym:)=0.                !Kill a stray spike ??
+
   return
 end subroutine gen_fst240wave
diff --git a/widgets/mainwindow.cpp b/widgets/mainwindow.cpp
index 269fdc75f..e7042b59a 100644
--- a/widgets/mainwindow.cpp
+++ b/widgets/mainwindow.cpp
@@ -3542,7 +3542,7 @@ void MainWindow::guiUpdate()
     if(m_TRperiod==30)  txDuration=1.0 + 160*1680/12000.0;
     if(m_TRperiod==60)  txDuration=1.0 + 160*3888/12000.0;
     if(m_TRperiod==120) txDuration=1.0 + 160*8200/12000.0;
-    if(m_TRperiod==300) txDuration=1.0 + 160*21168/12000.0;
+    if(m_TRperiod==300) txDuration=1.0 + 160*21504/12000.0;
   }
   if(m_modeTx=="ISCAT" or m_mode=="MSK144" or m_bFast9) {
     txDuration=m_TRperiod-0.25; // ISCAT, JT9-fast, MSK144
@@ -3886,14 +3886,13 @@ void MainWindow::guiUpdate()
             if(m_TRperiod==30) nsps=1680;
             if(m_TRperiod==60) nsps=3888;
             if(m_TRperiod==120) nsps=8200;
-            if(m_TRperiod==300) nsps=21168;
+            if(m_TRperiod==300) nsps=21504;
             nsps=4*nsps;                           //48000 Hz sampling
-            int nsym=164;
+            int nsym=160;
             float fsample=48000.0;
             float dfreq=hmod*fsample/nsps;
             float f0=ui->TxFreqSpinBox->value() - m_XIT + 1.5*dfreq;
-//            int nwave=(nsym+2)*nsps;
-            int nwave=48000 + 166*nsps;
+            int nwave=(nsym+2)*nsps;
             int icmplx=0;
             gen_fst240wave_(const_cast<int *>(itone),&nsym,&nsps,&nwave,
                     &fsample,&hmod,&f0,&icmplx,foxcom_.wave,foxcom_.wave);
@@ -7170,7 +7169,7 @@ void MainWindow::transmit (double snr)
     if(m_TRperiod==30) nsps=1680;
     if(m_TRperiod==60) nsps=3888;
     if(m_TRperiod==120) nsps=8200;
-    if(m_TRperiod==300) nsps=21168;
+    if(m_TRperiod==300) nsps=21504;
     int hmod=int(pow(2.0,double(m_nSubMode)));
     double dfreq=hmod*12000.0/nsps;
     double f0=ui->TxFreqSpinBox->value() - m_XIT + 1.5*dfreq;