diff --git a/map65/libm65/CMakeLists.txt b/map65/libm65/CMakeLists.txt
index ab40d521a..e7ea7d103 100644
--- a/map65/libm65/CMakeLists.txt
+++ b/map65/libm65/CMakeLists.txt
@@ -1,6 +1,7 @@
 set (libm65_FSRCS
 # Modules come first:
   wideband_sync.f90
+  wideband2_sync.f90
 
 # Non-module Fortran routines:
   afc65b.f90
@@ -135,6 +136,9 @@ target_link_libraries (m65 m65impl ${FFTW3_LIBRARIES})
 add_executable (mapsim mapsim.f90)
 target_link_libraries (mapsim m65impl ${FFTW3_LIBRARIES})
 
+add_executable (synctest synctest.f90)
+target_link_libraries (synctest m65impl ${FFTW3_LIBRARIES})
+
 install (
   TARGETS m65 mapsim
   RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT runtime
diff --git a/map65/libm65/decode0.f90 b/map65/libm65/decode0.f90
index 56057fb86..ae63c6f53 100644
--- a/map65/libm65/decode0.f90
+++ b/map65/libm65/decode0.f90
@@ -19,6 +19,11 @@ subroutine decode0(dd,ss,savg,nstandalone)
 
   call timer('decode0 ',0)
 
+!###
+!  npol=1 + 3*nxpol
+!  write(50) nutc,npol,ss(1:npol,:,:),savg(1:npol,:)
+!###
+  
   nkhz_center=nint(1000.0*(fcenter-int(fcenter)))
   ntone_spacing=2**(nmode/10)
   call timer('wb_sync ',0)
diff --git a/map65/libm65/synctest.f90 b/map65/libm65/synctest.f90
new file mode 100644
index 000000000..47a8f85dd
--- /dev/null
+++ b/map65/libm65/synctest.f90
@@ -0,0 +1,73 @@
+program synctest
+
+  use wideband2_sync
+  use timer_module, only: timer
+  use timer_impl, only: init_timer, fini_timer
+  parameter (MAX0=1000,MAX_CANDIDATES=20)
+  real ss(4,322,NFFT),savg(4,NFFT)
+  real candidate(MAX_CANDIDATES,5)             !snr1,f0,xdt0,ipol,flip
+  integer indx(NFFT)
+  logical skip
+  character*8 arg
+
+  open(50,file='50.a',form='unformatted',status='old')
+  call getarg(1,arg)
+  read (arg,*) iutc
+  
+  do ifile=1,999
+     read(50,end=999) nutc,npol,ss(1:npol,:,:),savg(1:npol,:)
+     if(nutc.eq.iutc) exit
+  enddo
+  close(50)
+
+  call init_timer('timer.out')
+  call timer('synctest',0)
+  
+  print*,nutc,npol
+  ntone_spacing=1
+  call timer('wb_sync ',0)
+  call wb2_sync(ss,savg,ntone_spacing)
+  call timer('wb_sync ',1)
+
+  df3=96000.0/NFFT
+  ia=nint(7000.0/df3)
+  ib=nint(89000.0/df3)
+  iz=ib-ia+1
+  do i=ia,ib
+     f0=0.001*i*df3
+     write(13,1000) f0,sync_dat(i,2:5)
+1000 format(3f10.3,2f5.0)
+  enddo
+
+  call timer('indexx  ',0)
+  call indexx(sync_dat(ia:ib,2),iz,indx)
+  call timer('indexx  ',1)
+
+  k=0
+  do i=1,MAX0
+     j=indx(iz+1-i) + ia - 1
+     f0=0.001*j*df3
+     snr1=sync_dat(j,2)
+     if(snr1.lt.3.0) exit
+     skip=.false.
+     do n=1,k
+        diffhz=1000.0*(f0-candidate(n,2))
+        if(diffhz.gt.-10.0 .and. diffhz.lt.108.0) skip=.true.
+     enddo
+     if(skip) cycle
+     k=k+1
+     candidate(k,1)=snr1                !snr1
+     candidate(k,2)=f0                  !f0
+     candidate(k,3)=sync_dat(j,3)       !xdt0
+     candidate(k,4)=sync_dat(j,4)       !ipol
+     candidate(k,5)=sync_dat(j,5)       !flip
+     write(*,1010) k,candidate(k,1:5)
+1010 format(i3,3f10.3,2f6.0)
+     if(k.ge.MAX_CANDIDATES) exit
+  enddo
+
+999 call timer('synctest',1)
+  call timer('synctest',101)
+  call fini_timer()
+
+end program synctest
diff --git a/map65/libm65/wideband2_sync.f90 b/map65/libm65/wideband2_sync.f90
new file mode 100644
index 000000000..a9e1fd9e9
--- /dev/null
+++ b/map65/libm65/wideband2_sync.f90
@@ -0,0 +1,103 @@
+module wideband2_sync
+
+  parameter (NFFT=32768)
+  integer isync(22)
+  integer nkhz_center
+  real sync_dat(NFFT,5)     !fkhz, ccfmax, xdt, ipol, flip
+
+  contains
+  
+subroutine wb2_sync(ss,savg,ntone_spacing)
+
+! Compute "orange sync curve" using the Q65 sync pattern
+
+  parameter (LAGMAX=30)
+  real ss(4,322,NFFT)
+  real savg(4,NFFT)
+  logical first
+  character*1 c1
+  integer isync0(22)
+  integer jsync0(63)
+! Q65 sync symbols
+  data isync0/1,9,12,13,15,22,23,26,27,33,35,38,46,50,55,60,62,66,69,74,76,85/
+  data jsync0/                                                         &
+       1,  4,  5,  9, 10, 11, 12, 13, 14, 16, 18, 22, 24, 25, 28, 32,  &
+       33, 34, 37, 38, 39, 40, 42, 43, 45, 46, 47, 48, 52, 53, 55, 57, &
+       59, 60, 63, 64, 66, 68, 70, 73, 80, 81, 89, 90, 92, 95, 97, 98, &
+       100,102,104,107,108,111,114,119,120,121,122,123,124,125,126/
+  data first/.true./
+  save first
+
+  do j=322,1,-1
+     if(sum(ss(1,j,1:NFFT)).gt.0.0) exit
+  enddo
+  jz=j
+
+  tstep=2048.0/11025.0        !0.185760 s: 0.5*tsym_jt65, 0.3096*tsym_q65
+  if(first) then
+     fac=0.6/tstep
+     do i=1,22                                !Expand the Q65 sync stride
+        isync(i)=nint((isync0(i)-1)*fac) + 1
+     enddo
+     do i=1,63
+        jsync0(i)=2*(jsync0(i)-1) + 1
+     enddo
+     first=.false.
+  endif
+
+  df=96000.0/NFFT
+  ia=nint(7000.0/df)          !Flat frequency range for WSE converters
+  ib=nint(89000.0/df)
+  lagbest=-1
+  ipolbest=-1
+
+  do i=ia,ib
+     ccfmax=0.
+     do ipol=1,4
+        do lag=0,LAGMAX
+
+           ccf=0.
+           do j=1,22
+              k=isync(j) + lag
+              ccf=ccf + ss(ipol,k,i+1) + ss(ipol,k+1,i+1) + ss(ipol,k+2,i+1) 
+           enddo
+           ccf=ccf - savg(ipol,i+1)*3*22/float(jz)
+           if(ccf.gt.ccfmax) then
+              ipolbest=ipol
+              lagbest=lag
+              ccfmax=ccf
+              flip=0.
+           endif
+
+           ccf=0.
+           do j=1,63
+              k=jsync0(j) + lag
+              ccf=ccf + ss(ipol,k,i+1) + ss(ipol,k+1,i+1)
+           enddo
+           ccf=ccf - savg(ipol,i+1)*2*63/float(jz)
+           if(ccf.gt.ccfmax) then
+              ipolbest=ipol
+              lagbest=lag
+              ccfmax=ccf
+              flip=1.0
+           endif
+
+        enddo  ! lag
+     enddo  !ipol
+
+     fkhz=0.001*i*df + nkhz_center - 48.0
+     xdt=lagbest*tstep-1.0
+     sync_dat(i,1)=fkhz
+     sync_dat(i,2)=ccfmax
+     sync_dat(i,3)=xdt
+     sync_dat(i,4)=ipolbest
+     sync_dat(i,5)=flip
+  enddo
+
+  call pctile(sync_dat(ia:ib,2),ib-ia+1,50,base)
+  sync_dat(ia:ib,2)=sync_dat(ia:ib,2)/base
+
+  return
+end subroutine wb2_sync
+
+end module wideband2_sync