diff --git a/CMakeLists.txt b/CMakeLists.txt
index f77a46033..6e295356c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -299,6 +299,7 @@ set (wsjt_FSRCS
   lib/badmsg.f90
   lib/bpdecode40.f90
   lib/bpdecode144.f90
+  lib/fsk4hf/bpdecode120.f90
   lib/fsk4hf/bpdecode168.f90
   lib/baddata.f90
   lib/ccf2.f90
@@ -324,6 +325,7 @@ set (wsjt_FSRCS
   lib/encode4.f90
   lib/encode_msk40.f90
   lib/encode_msk144.f90
+  lib/fsk4hf/encode120.f90
   lib/fsk4hf/encode168.f90
   lib/entail.f90
   lib/ephem.f90
@@ -390,6 +392,7 @@ set (wsjt_FSRCS
   lib/jt9_decode.f90
   lib/jt9fano.f90
   lib/ldpcsim144.f90
+  lib/fsk4hf/ldpcsim120.f90
   lib/fsk4hf/ldpcsim168.f90
   lib/ldpcsim40.f90
   lib/libration.f90
@@ -1084,10 +1087,13 @@ target_link_libraries (jt65 wsjt_fort wsjt_cxx)
 add_executable (ldpcsim40 lib/ldpcsim40.f90 wsjtx.rc)
 target_link_libraries (ldpcsim40 wsjt_fort wsjt_cxx)
 
+add_executable (ldpcsim120 lib/fsk4hf/ldpcsim120.f90 lib/crc.cpp wsjtx.rc)
+target_link_libraries (ldpcsim120 wsjt_fort wsjt_cxx)
+
 add_executable (ldpcsim144 lib/ldpcsim144.f90 wsjtx.rc)
 target_link_libraries (ldpcsim144 wsjt_fort wsjt_cxx)
 
-add_executable (ldpcsim168 lib/fsk4hf/ldpcsim168.f90 wsjtx.rc)
+add_executable (ldpcsim168 lib/fsk4hf/ldpcsim168.f90 lib/crc.cpp wsjtx.rc)
 target_link_libraries (ldpcsim168 wsjt_fort wsjt_cxx)
 
 add_executable (msk144sim lib/msk144sim.f90 wsjtx.rc)
diff --git a/lib/crc12.cpp b/lib/crc.cpp
similarity index 59%
rename from lib/crc12.cpp
rename to lib/crc.cpp
index 7077aaba7..c4dd12b90 100644
--- a/lib/crc12.cpp
+++ b/lib/crc.cpp
@@ -5,6 +5,8 @@ extern "C"
 {
    short crc12 (unsigned char const * data, int length);
    bool crc12_check (unsigned char const * data, int length);
+   short crc10 (unsigned char const * data, int length);
+   bool crc10_check (unsigned char const * data, int length);
 }
 
 // assumes CRC is last 16 bits of the data and is set to zero
@@ -18,3 +20,13 @@ bool crc12_check (unsigned char const * data, int length)
 {
    return !boost::augmented_crc<12, 0xc06> (data, length);
 }
+
+short crc10 (unsigned char const * data, int length)
+{
+    return boost::augmented_crc<10, 0x08f> (data, length);
+}
+
+bool crc10_check (unsigned char const * data, int length)
+{
+   return !boost::augmented_crc<10, 0x08f> (data, length);
+}
diff --git a/lib/crc.f90 b/lib/crc.f90
index 8ac68e051..6e5c262eb 100644
--- a/lib/crc.f90
+++ b/lib/crc.f90
@@ -16,5 +16,22 @@ module crc
       type (c_ptr), value :: data
       integer (c_int), value :: length
     end function crc12_check
+
+    function crc10 (data, length) bind (C, name="crc10")
+      use, intrinsic :: iso_c_binding, only: c_short, c_ptr, c_int
+      implicit none
+      integer (c_short) :: crc10
+      type (c_ptr), value :: data
+      integer (c_int), value :: length
+    end function crc10
+
+    function crc10_check (data, length) bind (C, name="crc10_check")
+      use, intrinsic :: iso_c_binding, only: c_bool, c_ptr, c_int
+      implicit none
+      logical (c_bool) :: crc10_check
+      type (c_ptr), value :: data
+      integer (c_int), value :: length
+    end function crc10_check
+
   end interface
 end module crc
diff --git a/lib/fsk4hf/bpdecode120.f90 b/lib/fsk4hf/bpdecode120.f90
new file mode 100644
index 000000000..de6450deb
--- /dev/null
+++ b/lib/fsk4hf/bpdecode120.f90
@@ -0,0 +1,306 @@
+subroutine bpdecode120(llr,apmask,maxiterations,decoded,niterations)
+!
+! A log-domain belief propagation decoder for the (120,60) code.
+!
+integer, parameter:: N=120, K=60, M=N-K
+integer*1 codeword(N),cw(N),apmask(N)
+integer  colorder(N)
+integer*1 decoded(K)
+integer Nm(7,M)  ! 5, 6, or 7 bits per check 
+integer Mn(3,N)  ! 3 checks per bit
+integer synd(M)
+real tov(3,N)
+real toc(7,M)
+real tanhtoc(7,M)
+real zn(N)
+real llr(N)
+real Tmn
+integer nrw(M)
+
+data colorder/    &
+  0,1,2,21,3,4,5,6,7,8,20,10,9,11,12,23,13,28,14,31, &
+  15,16,22,26,17,30,18,29,25,32,41,34,19,33,27,36,38,43,42,24, &
+  37,39,45,40,35,44,47,46,50,51,53,48,52,56,54,57,55,49,58,61, &
+  60,59,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79, &
+  80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99, &
+  100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119/
+
+data Mn/               &
+   1,  18,  48, &
+   2,   4,  51, &
+   3,  23,  47, &
+   5,  36,  42, &
+   6,  43,  49, &
+   7,  24,  55, &
+   8,  35,  60, &
+   9,  26,  30, &
+  10,  29,  45, &
+  11,  13,  46, &
+  12,  53,  54, &
+  14,  20,  57, &
+  15,  16,  58, &
+  17,  39,  44, &
+  19,  37,  41, &
+  21,  28,  34, &
+  22,  50,  59, &
+  25,  31,  52, &
+  27,  32,  38, &
+  33,  40,  56, &
+   1,  11,  47, &
+   2,  10,  16, &
+   3,  12,  27, &
+   4,  24,  28, &
+   5,  23,  60, &
+   6,  29,  39, &
+   7,  31,  54, &
+   8,  50,  56, &
+   9,  13,  14, &
+  15,  22,  41, &
+  17,  26,  40, &
+  18,  25,  45, &
+  19,  20,  55, &
+  21,  30,  36, &
+  32,  49,  59, &
+  33,  53,  58, &
+  34,  38,  46, &
+  29,  35,  57, &
+  37,  43,  48, &
+  42,  51,  52, &
+   7,  11,  44, &
+   1,  42,  58, &
+   2,  13,  49, &
+   3,  20,  40, &
+   4,  18,  56, &
+   5,  45,  55, &
+   6,  21,  31, &
+   8,  46,  52, &
+   9,  12,  48, &
+  10,  37,  38, &
+  14,  15,  25, &
+  16,  17,  60, &
+  19,  39,  53, &
+  22,  44,  51, &
+  23,  28,  41, &
+  24,  32,  35, &
+  26,  45,  59, &
+  27,  33,  36, &
+  30,  47,  54, &
+  34,  50,  57, &
+  33,  43,  55, &
+   1,  41,  57, &
+   2,  40,  54, &
+   3,   6,  24, &
+   4,  11,  59, &
+   5,  13,  56, &
+   7,  16,  34, &
+   8,  19,  26, &
+   9,  31,  58, &
+  10,  21,  53, &
+  12,  22,  60, &
+  14,  38,  51, &
+  15,  43,  46, &
+  17,  48,  50, &
+  18,  27,  39, &
+  20,  28,  44, &
+  23,  25,  49, &
+   4,  29,  36, &
+  30,  32,  52, &
+  35,  37,  47, &
+  39,  42,  59, &
+   1,  21,  40, &
+   2,  50,  55, &
+   3,   8,  10, &
+   5,  31,  37, &
+   6,  14,  60, &
+   7,  36,  49, &
+   9,  34,  39, &
+  11,  19,  25, &
+  12,  52,  57, &
+  13,  22,  29, &
+  15,  30,  56, &
+  16,  18,  20, &
+  17,  24,  46, &
+  23,  38,  58, &
+  26,  28,  43, &
+   2,  27,  41, &
+   5,  32,  44, &
+  33,  47,  51, &
+  35,  48,  53, &
+  42,  43,  54, &
+  34,  45,  47, &
+   1,   8,  49, &
+   3,  14,  59, &
+   4,  31,  46, &
+   6,  20,  50, &
+   7,  26,  53, &
+   9,  10,  36, &
+  11,  58,  60, &
+  12,  21,  45, &
+  13,  28,  33, &
+  15,  17,  35, &
+  16,  38,  52, &
+  18,  41,  54, &
+  19,  23,  32, &
+  22,  40,  55, &
+  24,  25,  42, &
+  26,  27,  56, &
+  29,  44,  54, &
+  30,  37,  55/
+
+data Nm/               &
+   1,  21,  42,  62,  82, 103, 0, &
+   2,  22,  43,  63,  83,  97, 0, &
+   3,  23,  44,  64,  84, 104, 0, &
+   2,  24,  45,  65,  78, 105, 0, &
+   4,  25,  46,  66,  85,  98, 0, &
+   5,  26,  47,  64,  86, 106, 0, &
+   6,  27,  41,  67,  87, 107, 0, &
+   7,  28,  48,  68,  84, 103, 0, &
+   8,  29,  49,  69,  88, 108, 0, &
+   9,  22,  50,  70,  84, 108, 0, &
+  10,  21,  41,  65,  89, 109, 0, &
+  11,  23,  49,  71,  90, 110, 0, &
+  10,  29,  43,  66,  91, 111, 0, &
+  12,  29,  51,  72,  86, 104, 0, &
+  13,  30,  51,  73,  92, 112, 0, &
+  13,  22,  52,  67,  93, 113, 0, &
+  14,  31,  52,  74,  94, 112, 0, &
+   1,  32,  45,  75,  93, 114, 0, &
+  15,  33,  53,  68,  89, 115, 0, &
+  12,  33,  44,  76,  93, 106, 0, &
+  16,  34,  47,  70,  82, 110, 0, &
+  17,  30,  54,  71,  91, 116, 0, &
+   3,  25,  55,  77,  95, 115, 0, &
+   6,  24,  56,  64,  94, 117, 0, &
+  18,  32,  51,  77,  89, 117, 0, &
+   8,  31,  57,  68,  96, 107, 118, &
+  19,  23,  58,  75,  97, 118, 0, &
+  16,  24,  55,  76,  96, 111, 0, &
+   9,  26,  38,  78,  91, 119, 0, &
+   8,  34,  59,  79,  92, 120, 0, &
+  18,  27,  47,  69,  85, 105, 0, &
+  19,  35,  56,  79,  98, 115, 0, &
+  20,  36,  58,  61,  99, 111, 0, &
+  16,  37,  60,  67,  88, 102, 0, &
+   7,  38,  56,  80, 100, 112, 0, &
+   4,  34,  58,  78,  87, 108, 0, &
+  15,  39,  50,  80,  85, 120, 0, &
+  19,  37,  50,  72,  95, 113, 0, &
+  14,  26,  53,  75,  81,  88, 0, &
+  20,  31,  44,  63,  82, 116, 0, &
+  15,  30,  55,  62,  97, 114, 0, &
+   4,  40,  42,  81, 101, 117, 0, &
+   5,  39,  61,  73,  96, 101, 0, &
+  14,  41,  54,  76,  98, 119, 0, &
+   9,  32,  46,  57, 102, 110, 0, &
+  10,  37,  48,  73,  94, 105, 0, &
+   3,  21,  59,  80,  99, 102, 0, &
+   1,  39,  49,  74, 100, 0,   0, &
+   5,  35,  43,  77,  87, 103, 0, &
+  17,  28,  60,  74,  83, 106, 0, &
+   2,  40,  54,  72,  99, 0,   0, &
+  18,  40,  48,  79,  90, 113, 0, &
+  11,  36,  53,  70, 100, 107, 0, &
+  11,  27,  59,  63, 101, 114, 119, &
+   6,  33,  46,  61,  83, 116, 120, &
+  20,  28,  45,  66,  92, 118, 0, &
+  12,  38,  60,  62,  90, 0,   0, &
+  13,  36,  42,  69,  95, 109, 0, &
+  17,  35,  57,  65,  81, 104, 0, &
+   7,  25,  52,  71,  86, 109, 0/
+
+data nrw/   &
+6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, &
+6,6,6,6,6,7,6,6,6,6,6,6,6,6,6,6,6,6,6,6, &
+6,6,6,6,6,6,6,5,6,6,5,6,6,7,7,6,5,6,6,6/ 
+
+ncw=3
+
+toc=0
+tov=0
+tanhtoc=0
+!write(*,*) llr
+! initialize messages to checks
+do j=1,M
+  do i=1,nrw(j)
+    toc(i,j)=llr((Nm(i,j)))
+  enddo
+enddo
+
+ncnt=0
+
+do iter=0,maxiterations
+
+! Update bit log likelihood ratios (tov=0 in iteration 0).
+  do i=1,N
+    if( apmask(i) .ne. 1 ) then
+      zn(i)=llr(i)+sum(tov(1:ncw,i))
+    else
+      zn(i)=llr(i)
+    endif
+  enddo
+
+! Check to see if we have a codeword (check before we do any iteration).
+  cw=0
+  where( zn .gt. 0. ) cw=1
+  ncheck=0
+  do i=1,M
+    synd(i)=sum(cw(Nm(1:nrw(i),i)))
+    if( mod(synd(i),2) .ne. 0 ) ncheck=ncheck+1
+!    if( mod(synd(i),2) .ne. 0 ) write(*,*) 'check ',i,' unsatisfied'
+  enddo
+!write(*,*) 'number of unsatisfied parity checks ',ncheck
+  if( ncheck .eq. 0 ) then ! we have a codeword - reorder the columns and return it
+    niterations=iter
+    codeword=cw(colorder+1)
+    decoded=codeword(M+1:N)
+    return
+  endif
+
+  if( iter.gt.0 ) then  ! this code block implements an early stopping criterion
+    nd=ncheck-nclast
+    if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
+      ncnt=0  ! reset counter
+    else
+      ncnt=ncnt+1
+    endif
+!    write(*,*) iter,ncheck,nd,ncnt
+    if( ncnt .ge. 3 .and. iter .ge. 5 .and. ncheck .gt. 10) then
+      niterations=-1
+      return
+    endif
+  endif
+  nclast=ncheck
+
+! Send messages from bits to check nodes 
+  do j=1,M
+    do i=1,nrw(j)
+      ibj=Nm(i,j)
+      toc(i,j)=zn(ibj)  
+      do kk=1,ncw ! subtract off what the bit had received from the check
+        if( Mn(kk,ibj) .eq. j ) then  
+          toc(i,j)=toc(i,j)-tov(kk,ibj)
+        endif
+      enddo
+    enddo
+  enddo
+
+! send messages from check nodes to variable nodes
+  do i=1,M
+    tanhtoc(1:7,i)=tanh(-toc(1:7,i)/2)
+  enddo
+
+  do j=1,N
+    do i=1,ncw
+      ichk=Mn(i,j)  ! Mn(:,j) are the checks that include bit j
+      Tmn=product(tanhtoc(1:nrw(ichk),ichk),mask=Nm(1:nrw(ichk),ichk).ne.j)
+      call platanh(-Tmn,y)
+!      y=atanh(-Tmn)
+      tov(i,j)=2*y
+    enddo
+  enddo
+
+enddo
+niterations=-1
+return
+end subroutine bpdecode120
diff --git a/lib/fsk4hf/encode120.f90 b/lib/fsk4hf/encode120.f90
new file mode 100644
index 000000000..577bbe860
--- /dev/null
+++ b/lib/fsk4hf/encode120.f90
@@ -0,0 +1,116 @@
+subroutine encode120(message,codeword)
+! Encode an 60-bit message and return a 120-bit codeword. 
+! The generator matrix has dimensions (60,60). 
+! The code is a (120,60) regular ldpc code with column weight 3.
+! The code was generated using the PEG algorithm.
+! After creating the codeword, the columns are re-ordered according to 
+! "colorder" to make the codeword compatible with the parity-check matrix 
+!
+character*15 g(60)
+integer*1 codeword(120)
+integer colorder(120)
+integer*1 gen(60,60)
+integer*1 itmp(120)
+integer*1 message(60)
+integer*1 pchecks(60)
+logical first
+data first/.true./
+data g/            &
+ "65541ad98feab6e",&
+ "27249940a5895a3",&
+ "c80eac7506bf794",&
+ "aa50393e3e18d3f",&
+ "28527e87d47dced",&
+ "5da0dcaf8db048c",&
+ "d6509a43ca9b01a",&
+ "9a7dadd9c94f1d4",&
+ "bb673d3ba07cf29",&
+ "65e190f2fbed447",&
+ "bc2062a4e520969",&
+ "9e357f3feed059b",&
+ "aa6b59212036a57",&
+ "f78a326722d6565",&
+ "416754bc34c6405",&
+ "f77000b3f04ff67",&
+ "d48fbd7d48c5ab9",&
+ "031ffb5db3a70cb",&
+ "125964e358c4df5",&
+ "bd02c32a5a241ea",&
+ "4c15ecdd8561abd",&
+ "7f0f1b352c7413e",&
+ "26edb94dfd0ae79",&
+ "ca1ba1ee0f8fb24",&
+ "49878a58cb4544c",&
+ "3dbcd0ff821b203",&
+ "c1f4440160d5345",&
+ "b5ea9dc7a5a70ab",&
+ "cebcf7d94976be4",&
+ "0968265f5977c88",&
+ "c5a36937faa78c3",&
+ "f0d4fef11e01c10",&
+ "e35fc0c779bebfe",&
+ "cf49c3eb41a31d5",&
+ "3f0b19352c7013e",&
+ "0e15eccd8521abd",&
+ "dda8dcaf9d3048c",&
+ "fee31438fba59ed",&
+ "ad74a27e939189c",&
+ "736ac01b439106e",&
+ "ab5d2729b29bfa1",&
+ "edf11fb02e5a426",&
+ "5f38be1c93ecc83",&
+ "1e4b3b8dc516b3e",&
+ "84443d8bee614c6",&
+ "d854d9f355ceac4",&
+ "a476b5ece51f0ea",&
+ "831c2b36c4c2f68",&
+ "f485c97a91615ae",&
+ "e9376d828ade9ba",&
+ "cac586f089d3185",&
+ "b8f8c67613dafe2",&
+ "1a3142b401b315d",&
+ "87dbedc43265d2e",&
+ "bb64ec6e652e7da",&
+ "e71bfd4c95dfd38",&
+ "31209af07ad4f75",&
+ "cff1a8ccc5f4978",&
+ "742eded1e1dfefd",&
+ "1cd7154a904dac4"/
+
+data colorder/     &
+  0,1,2,21,3,4,5,6,7,8,20,10,9,11,12,23,13,28,14,31, &
+  15,16,22,26,17,30,18,29,25,32,41,34,19,33,27,36,38,43,42,24, &
+  37,39,45,40,35,44,47,46,50,51,53,48,52,56,54,57,55,49,58,61, &
+  60,59,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79, &
+  80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99, &
+  100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119/
+
+save first,gen
+
+if( first ) then ! fill the generator matrix
+  gen=0
+  do i=1,60
+    do j=1,15
+      read(g(i)(j:j),"(Z1)") istr
+        do jj=1, 4 
+          icol=(j-1)*4+jj
+          if( btest(istr,4-jj) ) gen(i,icol)=1
+        enddo
+    enddo
+  enddo
+first=.false.
+endif
+
+do i=1, 60
+  nsum=0
+  do j=1, 60 
+    nsum=nsum+message(j)*gen(i,j)
+  enddo
+  pchecks(i)=mod(nsum,2)
+enddo
+itmp(1:60)=pchecks
+itmp(61:120)=message(1:60)
+codeword(colorder+1)=itmp(1:120)
+
+return
+end subroutine encode120
diff --git a/lib/fsk4hf/ldpcsim120.f90 b/lib/fsk4hf/ldpcsim120.f90
new file mode 100644
index 000000000..ba684f88b
--- /dev/null
+++ b/lib/fsk4hf/ldpcsim120.f90
@@ -0,0 +1,219 @@
+program ldpcsim120
+! End to end test of the (120,60)/crc10 encoder and decoder.
+use crc
+use packjt
+
+parameter(NRECENT=10)
+character*12 recent_calls(NRECENT)
+character*22 msg,msgsent,msgreceived
+character*8 arg
+integer*1, allocatable ::  codeword(:), decoded(:), message(:)
+integer*1, target:: i1Msg8BitBytes(9)
+integer*1, target:: i1Dec8BitBytes(9)
+integer*1 msgbits(60)
+integer*1 apmask(120)
+integer*2 checksum
+integer colorder(120)
+integer nerrtot(120),nerrdec(120),nmpcbad(60)
+logical checksumok,fsk,bpsk
+real*8, allocatable ::  rxdata(:)
+real, allocatable :: llr(:)
+
+data colorder/   &
+  0,1,2,21,3,4,5,6,7,8,20,10,9,11,12,23,13,28,14,31, &
+  15,16,22,26,17,30,18,29,25,32,41,34,19,33,27,36,38,43,42,24, &
+  37,39,45,40,35,44,47,46,50,51,53,48,52,56,54,57,55,49,58,61, &
+  60,59,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79, &
+  80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99, &
+  100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119/
+
+do i=1,NRECENT
+  recent_calls(i)='            '
+enddo
+nerrtot=0
+nerrdec=0
+nmpcbad=0  ! Used to collect the number of errors in the message+crc part of the codeword
+
+nargs=iargc()
+if(nargs.ne.3) then
+   print*,'Usage: ldpcsim  niter  #trials  s '
+   print*,'eg:    ldpcsim    10   1000    0.75'
+   return
+endif
+call getarg(1,arg)
+read(arg,*) max_iterations 
+call getarg(2,arg)
+read(arg,*) ntrials 
+call getarg(3,arg)
+read(arg,*) s
+
+fsk=.false.
+bpsk=.true.
+
+! don't count crc bits as data bits
+N=120
+K=60
+! scale Eb/No for a (120,50) code
+rate=real(50)/real(N)
+
+write(*,*) "rate: ",rate
+write(*,*) "niter= ",max_iterations," s= ",s
+
+allocate ( codeword(N), decoded(K), message(K) )
+allocate ( rxdata(N), llr(N) )
+
+! The message should be packed into the first 7 bytes
+  i1Msg8BitBytes(1:6)=85
+  i1Msg8BitBytes(7)=64
+! The CRC will be put into the last 2 bytes
+  i1Msg8BitBytes(8:9)=0
+  checksum = crc10 (c_loc (i1Msg8BitBytes), 9)
+! For reference, the next 3 lines show how to check the CRC
+  i1Msg8BitBytes(8)=checksum/256
+  i1Msg8BitBytes(9)=iand (checksum,255)
+  checksumok = crc10_check(c_loc (i1Msg8BitBytes), 9)
+  if( checksumok ) write(*,*) 'Good checksum'
+write(*,*) i1Msg8BitBytes(1:9)
+
+  mbit=0
+  do i=1, 7 
+    i1=i1Msg8BitBytes(i)
+    do ibit=1,8
+      mbit=mbit+1
+      msgbits(mbit)=iand(1,ishft(i1,ibit-8))
+    enddo
+  enddo
+  i1=i1Msg8BitBytes(8) ! First 2 bits of crc10 are LSB of this byte
+  do ibit=1,2
+    msgbits(50+ibit)=iand(1,ishft(i1,ibit-2))
+  enddo
+  i1=i1Msg8BitBytes(9) ! Now shift in last 8 bits of the CRC
+  do ibit=1,8
+    msgbits(52+ibit)=iand(1,ishft(i1,ibit-8))
+  enddo
+
+  write(*,*) 'message'
+  write(*,'(9(8i1,1x))') msgbits
+
+  call encode120(msgbits,codeword)
+  call init_random_seed()
+  call sgran()
+
+  write(*,*) 'codeword' 
+  write(*,'(15(8i1,1x))') codeword
+
+write(*,*) "Es/N0  SNR2500   ngood  nundetected nbadcrc   sigma"
+do idb = -10, 24 
+  db=idb/2.0-1.0
+!  sigma=1/sqrt( 2*rate*(10**(db/10.0)) )  ! to make db represent Eb/No
+  sigma=1/sqrt( 2*(10**(db/10.0)) )        ! db represents Es/No
+  ngood=0
+  nue=0
+  nbadcrc=0
+  nberr=0
+  do itrial=1, ntrials
+! Create a realization of a noisy received word
+    do i=1,N
+      if( bpsk ) then
+        rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran()
+      elseif( fsk ) then
+        if( codeword(i) .eq. 1 ) then
+          r1=(1.0 + sigma*gran())**2 + (sigma*gran())**2
+          r2=(sigma*gran())**2 + (sigma*gran())**2
+        elseif( codeword(i) .eq. 0 ) then
+          r2=(1.0 + sigma*gran())**2 + (sigma*gran())**2
+          r1=(sigma*gran())**2 + (sigma*gran())**2
+        endif 
+        rxdata(i)=0.35*(sqrt(r1)-sqrt(r2))
+!        rxdata(i)=0.35*(exp(r1)-exp(r2))
+!        rxdata(i)=0.12*(log(r1)-log(r2))
+      endif
+    enddo
+    nerr=0
+    do i=1,N
+      if( rxdata(i)*(2*codeword(i)-1.0) .lt. 0 ) nerr=nerr+1
+    enddo
+    nerrtot(nerr)=nerrtot(nerr)+1
+    nberr=nberr+nerr
+
+! Correct signal normalization is important for this decoder.
+!    rxav=sum(rxdata)/N
+!    rx2av=sum(rxdata*rxdata)/N
+!    rxsig=sqrt(rx2av-rxav*rxav)
+!    rxdata=rxdata/rxsig
+! To match the metric to the channel, s should be set to the noise standard deviation. 
+! For now, set s to the value that optimizes decode probability near threshold. 
+! The s parameter can be tuned to trade a few tenth's dB of threshold for an order of
+! magnitude in UER 
+    if( s .lt. 0 ) then
+      ss=sigma
+    else 
+      ss=s
+    endif
+
+    llr=2.0*rxdata/(ss*ss)
+    apmask=0
+
+! max_iterations is max number of belief propagation iterations
+    call bpdecode120(llr, apmask, max_iterations, decoded, niterations)
+
+
+! If the decoder finds a valid codeword, niterations will be .ge. 0.
+    if( niterations .ge. 0 ) then
+! Check the CRC
+      do ibyte=1,6
+        itmp=0
+        do ibit=1,8
+          itmp=ishft(itmp,1)+iand(1,decoded((ibyte-1)*8+ibit))
+        enddo
+        i1Dec8BitBytes(ibyte)=itmp
+      enddo
+      i1Dec8BitBytes(7)=decoded(49)*128+decoded(50)*64
+! Need to pack the received crc into bytes 8 and 9 for crc10_check
+      i1Dec8BitBytes(8)=decoded(51)*2+decoded(52)
+      i1Dec8BitBytes(9)=decoded(53)*128+decoded(54)*64+decoded(55)*32+decoded(56)*16
+      i1Dec8BitBytes(9)=i1Dec8BitBytes(9)+decoded(57)*8+decoded(58)*4+decoded(59)*2+decoded(60)*1
+      ncrcflag=0
+      if( crc10_check( c_loc( i1Dec8BitBytes ), 9 ) ) ncrcflag=1
+
+      if( ncrcflag .ne. 1 ) then
+        nbadcrc=nbadcrc+1
+      endif
+      nueflag=0
+
+      nerrmpc=0
+      do i=1,K   ! find number of errors in message+crc part of codeword
+        if( msgbits(i) .ne. decoded(i) ) then
+          nueflag=1
+          nerrmpc=nerrmpc+1 
+        endif
+      enddo
+      nmpcbad(nerrmpc)=nmpcbad(nerrmpc)+1  ! This histogram should inform our selection of CRC poly
+      if( ncrcflag .eq. 1 .and. nueflag .eq. 0 ) then
+        ngood=ngood+1
+        nerrdec(nerr)=nerrdec(nerr)+1
+      else if( ncrcflag .eq. 1 .and. nueflag .eq. 1 ) then
+        nue=nue+1;
+      endif
+    endif
+  enddo
+  snr2500=db+10*log10(0.4166/2500.0)
+  pberr=real(nberr)/(real(ntrials*N))
+  write(*,"(f4.1,4x,f5.1,1x,i8,1x,i8,1x,i8,8x,f5.2,8x,e10.3)") db,snr2500,ngood,nue,nbadcrc,ss,pberr
+
+enddo
+
+open(unit=23,file='nerrhisto.dat',status='unknown')
+do i=1,120
+  write(23,'(i4,2x,i10,i10,f10.2)') i,nerrdec(i),nerrtot(i),real(nerrdec(i))/real(nerrtot(i)+1e-10)
+enddo
+close(23)
+open(unit=25,file='nmpcbad.dat',status='unknown')
+do i=1,60
+  write(25,'(i4,2x,i10)') i,nmpcbad(i)
+enddo
+close(25)
+
+
+
+end program ldpcsim120
diff --git a/lib/fsk4hf/ldpcsim168.f90 b/lib/fsk4hf/ldpcsim168.f90
index 8d0219a41..ca1bee1e4 100644
--- a/lib/fsk4hf/ldpcsim168.f90
+++ b/lib/fsk4hf/ldpcsim168.f90
@@ -14,7 +14,7 @@ integer*1 apmask(168)
 integer*2 checksum
 integer*4 i4Msg6BitWords(13)
 integer colorder(168)
-integer nerrtot(168),nerrdec(168)
+integer nerrtot(168),nerrdec(168),nmpcbad(84)
 logical checksumok,fsk,bpsk
 real*8, allocatable ::  rxdata(:)
 real, allocatable :: llr(:)
@@ -33,6 +33,7 @@ do i=1,NRECENT
 enddo
 nerrtot=0
 nerrdec=0
+nmpcbad=0  ! Used to collect the number of errors in the message+crc part of the codeword
 
 nargs=iargc()
 if(nargs.ne.3) then
@@ -47,8 +48,8 @@ read(arg,*) ntrials
 call getarg(3,arg)
 read(arg,*) s
 
-fsk=.true.
-bpsk=.false.
+fsk=.false.
+bpsk=.true.
 
 ! don't count crc bits as data bits
 N=168
@@ -62,7 +63,8 @@ write(*,*) "niter= ",max_iterations," s= ",s
 allocate ( codeword(N), decoded(K), message(K) )
 allocate ( rxdata(N), llr(N) )
 
-  msg="K1JT K9AN EN50"
+!  msg="K1JT K9AN EN50"
+  msg="G4WJS K9AN EN50"
   call packmsg(msg,i4Msg6BitWords,itype)  !Pack into 12 6-bit bytes
   call unpackmsg(i4Msg6BitWords,msgsent)  !Unpack to get msgsent
   write(*,*) "message sent ",msgsent
@@ -180,22 +182,19 @@ do idb = -10, 24
 ! If the decoder finds a valid codeword, niterations will be .ge. 0.
     if( niterations .ge. 0 ) then
       call extractmessage168(decoded,msgreceived,ncrcflag,recent_calls,nrecent)
-      if( ncrcflag .eq. 1 ) then
-        ncrcflag=1
-      else 
-        ncrcflag=0
-      endif
       if( ncrcflag .ne. 1 ) then
         nbadcrc=nbadcrc+1
       endif
       nueflag=0
 
-! Check the message plus crc against what was sent.
-      do i=1,K
+      nerrmpc=0
+      do i=1,K   ! find number of errors in message+crc part of codeword
         if( msgbits(i) .ne. decoded(i) ) then
           nueflag=1
+          nerrmpc=nerrmpc+1 
         endif
       enddo
+      nmpcbad(nerrmpc)=nmpcbad(nerrmpc)+1
       if( ncrcflag .eq. 1 .and. nueflag .eq. 0 ) then
         ngood=ngood+1
         nerrdec(nerr)=nerrdec(nerr)+1
@@ -211,9 +210,16 @@ do idb = -10, 24
 enddo
 
 open(unit=23,file='nerrhisto.dat',status='unknown')
-do i=1,128
+do i=1,168
   write(23,'(i4,2x,i10,i10,f10.2)') i,nerrdec(i),nerrtot(i),real(nerrdec(i))/real(nerrtot(i)+1e-10)
 enddo
 close(23)
+open(unit=25,file='nmpcbad.dat',status='unknown')
+do i=1,84
+  write(25,'(i4,2x,i10)') i,nmpcbad(i)
+enddo
+close(25)
+
+
 
 end program ldpcsim168