diff --git a/lib/ft4/ft4d.f90 b/lib/ft4/ft4d.f90
index 7cb1cac01..fa7c8045a 100644
--- a/lib/ft4/ft4d.f90
+++ b/lib/ft4/ft4d.f90
@@ -11,7 +11,7 @@ program ft4d
    character*4  cqstr
    real*8 fMHz
    integer ihdr(11)
-   integer*2 iwave(180000)                !15*12000
+   integer*2 iwave(240000)                !20*12000
 
    fs=12000.0/NDOWN                       !Sample rate
    dt=1/fs                                !Sample interval after downsample (s)
diff --git a/lib/ft4/getcandidates4.f90 b/lib/ft4/getcandidates4.f90
index 9ce4d8e70..23da3d394 100644
--- a/lib/ft4/getcandidates4.f90
+++ b/lib/ft4/getcandidates4.f90
@@ -27,7 +27,7 @@ subroutine getcandidates4(id,fa,fb,syncmin,nfqso,maxcand,savg,candidate,   &
 ! Compute symbol spectra, stepping by NSTEP steps.  
   savg=0.
   tstep=NSTEP/12000.0                         
-  df=12000.0/NFFT1                            !5.86 Hz
+  df=12000.0/NFFT1                            
   fac=1.0/300.0
   do j=1,NHSYM
      ia=(j-1)*NSTEP + 1
@@ -55,22 +55,31 @@ subroutine getcandidates4(id,fa,fb,syncmin,nfqso,maxcand,savg,candidate,   &
   indx=0
   call indexx(savsm(n300:n2500),np,indx)
   xn=savsm(nfa+indx(nint(0.3*np)))
-  savsm=savsm/xn
-
   ncand=0
+  if(xn.le.1.e-8) return 
+  savsm=savsm/xn
+!  call ft4_baseline(savg,nfa,nfb,sbase)
+!  savsm=savsm/sbase
+
   f_offset = -1.5*12000/512
   do i=nfa+1,nfb-1
-    if(savsm(i).ge.savsm(i-1) .and. savsm(i).ge.savsm(i+1) .and. savsm(i).ge.syncmin) then
-!      del=0.5*(savsm(i-1)-savsm(i+1))/(savsm(i-1)-2*savsm(i)+savsm(i+1))
-      del=0. 
-      fpeak=(i+del)*df+f_offset
-      speak=savsm(i) - 0.25*(savsm(i-1)-savsm(i+1))*del
-      ncand=ncand+1
-      candidate(1,ncand)=fpeak
-      candidate(2,ncand)=-99.99
-      candidate(3,ncand)=speak
-      if(ncand.eq.maxcand) exit
-    endif
+     if(savsm(i).ge.savsm(i-1) .and. savsm(i).ge.savsm(i+1) .and.      &
+          savsm(i).ge.syncmin) then
+        den=savsm(i-1)-2*savsm(i)+savsm(i+1)
+        del=0.
+        if(den.ne.0.0)  del=0.5*(savsm(i-1)-savsm(i+1))/den
+        fpeak=(i+del)*df+f_offset
+        speak=savsm(i) - 0.25*(savsm(i-1)-savsm(i+1))*del
+        ncand=ncand+1
+        if(ncand.gt.maxcand) then
+           ncand=maxcand
+           exit
+        endif
+        candidate(1,ncand)=fpeak
+        candidate(2,ncand)=-99.99
+        candidate(3,ncand)=speak
+        if(ncand.eq.maxcand) exit
+     endif
   enddo
 
 return