2018-04-25 17:24:58 +00:00
										 
									 
								 
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								program jt49sim
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								! Generate simulated data for testing JT4 and JT9
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								  use wavhdr
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								  use packjt
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								  use jt4
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								  parameter (NMAX=60*12000)              ! = 648,000
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								  parameter (NFFT=10*65536,NH=NFFT/2)
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								  type(hdr) h                            !Header for .wav file
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								  integer*2 iwave(NMAX)                  !Generated waveform
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								  integer*4 itone(206)                     !Channel symbols (values 0-8)
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								  real*4 xnoise(NMAX)                    !Generated random noise
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								  real*4 dat(NMAX)                       !Generated real data
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								  complex cdat(NMAX)                     !Generated complex waveform
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								  complex cspread(0:NFFT-1)              !Complex amplitude for Rayleigh fading
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								  complex z
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								  real*8 f0,dt,twopi,phi,dphi,baud,fsample,freq,dnsps
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								  character message*22,fname*11,csubmode*2,arg*12
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								  character msgsent*22
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								  nargs=iargc()
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								  if(nargs.ne. 7) then
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								     print *, 'Usage:   jt49sim        "msg"     nA-nE Nsigs fDop DT Nfiles SNR'
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								     print *, 'Example  jt49sim "K1ABC W9XYZ EN37" 4G   10   0.2 0.0   1     0'
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								     print *, 'Example  jt49sim "K1ABC W9XYZ EN37" 9A    1   0.0 0.0   1    -20'
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											2018-04-29 15:06:57 +00:00
										 
									 
								 
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								     print *, 'Use msg=@nnnn to generate a tone at nnnn Hz:'
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								     print *, 'Example  jt49sim "@1500"            9A    1  10.0 0.0   1    -20'
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											2018-04-25 17:24:58 +00:00
										 
									 
								 
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								     go to 999
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								  endif
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								  call getarg(1,message)
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								  call fmtmsg(message, iz)
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								  call getarg(2,csubmode)
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								  imode=ichar(csubmode(1:1)) - ichar('0')
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								  nsubmode=ichar(csubmode(2:2)) - ichar('A')
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								  if(imode.ne.4 .and. imode.ne.9) go to 999
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								  if(nsubmode.lt.0 .or. nsubmode.gt.7) go to 999
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								  call getarg(3,arg)
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								  read(arg,*) nsigs
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								  call getarg(4,arg)
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								  read(arg,*) fspread
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								  call getarg(5,arg)
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								  read(arg,*) xdt
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								  call getarg(6,arg)
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								  read(arg,*) nfiles
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								  call getarg(7,arg)
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								  read(arg,*) snrdb
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								  rms=100.
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								  fsample=12000.d0                   !Sample rate (Hz)
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								  dt=1.d0/fsample                    !Sample interval (s)
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								  twopi=8.d0*atan(1.d0)
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								  npts=60*12000                      !Total samples in .wav file
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								  h=default_header(12000,npts)
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								  dfsig=2000.0/nsigs                 !Freq spacing between sigs in file (Hz)
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								  ichk=0
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								  if(imode.eq.4) then
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								     nsym=206                           !Number of channel symbols (JT4)
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								     dnsps=12000.d0/4.375d0
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								     baud=12000.d0/dnsps                !Keying rate = 1.7361111111
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								  else if(imode.eq.9) then
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								     nsym=85                            !Number of channel symbols (JT9)
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								     dnsps=6912.d0                      !Samples per symbol
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								     baud=12000.d0/dnsps                !Keying rate = 1.736...
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								  endif
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								  write(*,1000) 
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								1000 format('File  Sig    Freq  Mode   S/N   DT   Dop    Message'/60('-'))
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								  do ifile=1,nfiles                  !Loop over requested number of files
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								     write(fname,1002) ifile         !Output filename
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								1002 format('000000_',i4.4)
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								     open(10,file=fname//'.wav',access='stream',status='unknown')
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								     xnoise=0.
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								     cdat=0.
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								     if(snrdb.lt.90) then
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								        do i=1,npts
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								           xnoise(i)=gran()          !Generate gaussian noise
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								        enddo
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								     endif
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								     do isig=1,nsigs                 !Generate requested number of sigs
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								        if(mod(nsigs,2).eq.0) f0=1500.0 + dfsig*(isig-0.5-nsigs/2)
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								        if(mod(nsigs,2).eq.1) f0=1500.0 + dfsig*(isig-(nsigs+1)/2)
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								        if(nsigs.eq.1) f0=1000.0
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								        xsnr=snrdb
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								        if(snrdb.eq.0.0) xsnr=-20 - isig
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								        if(imode.eq.4) call gen4(message,ichk,msgsent,itone,itype)
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								        if(imode.eq.9) call gen9(message,ichk,msgsent,itone,itype)
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								        bandwidth_ratio=2500.0/6000.0
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								        sig=sqrt(2*bandwidth_ratio)*10.0**(0.05*xsnr)
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								        if(xsnr.gt.90.0) sig=1.0
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								        write(*,1020) ifile,isig,f0,csubmode,xsnr,xdt,fspread,message
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								1020    format(i4,i4,f10.3,2x,a2,2x,f5.1,f6.2,f6.1,1x,a22)
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								        phi=0.d0
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								        dphi=0.d0
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								        k=(xdt+1.0)*12000                   !Start audio at t = xdt + 1.0 s
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								        isym0=-99
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								        do i=1,npts                         !Add this signal into cdat()
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								           isym=i/dnsps + 1
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								           if(isym.gt.nsym) exit
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								           if(isym.ne.isym0) then
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								              if(message(1:1).eq.'@') then
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								                 read(message(2:),*) freq
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								              else 
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								                 if(imode.eq.4) freq=f0 + itone(isym)*baud*nch(1+nsubmode) !JT4
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								                 if(imode.eq.9) freq=f0 + itone(isym)*baud*(2**nsubmode)   !JT9
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								              endif
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								              dphi=twopi*freq*dt
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								              isym0=isym
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								           endif
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								           phi=phi + dphi
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								           if(phi.gt.twopi) phi=phi-twopi
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								           xphi=phi
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								           z=cmplx(cos(xphi),sin(xphi))
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								           k=k+1
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								           if(k.ge.1) cdat(k)=cdat(k) + sig*z
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								        enddo
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								     enddo
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								     if(fspread.ne.0) then                  !Apply specified Doppler spread
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								        df=12000.0/nfft
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								        twopi=8*atan(1.0)
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								        cspread(0)=1.0
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								        cspread(NH)=0.
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								        b=6.0                                     !Lorenzian 3/28 onward
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								        do i=1,NH
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								           f=i*df
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								           x=b*f/fspread
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								           z=0.
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								           a=0.
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								           if(x.lt.3.0) then                          !Cutoff beyond x=3
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								              a=sqrt(1.111/(1.0+x*x)-0.1)             !Lorentzian
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								              call random_number(r1)
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								              phi1=twopi*r1
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								              z=a*cmplx(cos(phi1),sin(phi1))
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								           endif
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								           cspread(i)=z
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								           z=0.
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								           if(x.lt.50.0) then
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								              call random_number(r2)
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								              phi2=twopi*r2
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								              z=a*cmplx(cos(phi2),sin(phi2))
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								           endif
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								           cspread(NFFT-i)=z
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								        enddo
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								        do i=0,NFFT-1
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								           f=i*df
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								           if(i.gt.NH) f=(i-nfft)*df
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								           s=real(cspread(i))**2 + aimag(cspread(i))**2
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								!          write(13,3000) i,f,s,cspread(i)
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								!3000      format(i5,f10.3,3f12.6)
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								        enddo
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								!        s=real(cspread(0))**2 + aimag(cspread(0))**2
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								!        write(13,3000) 1024,0.0,s,cspread(0)
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								        call four2a(cspread,NFFT,1,1,1)             !Transform to time domain
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								        sum=0.
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								        do i=0,NFFT-1
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								           p=real(cspread(i))**2 + aimag(cspread(i))**2
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								           sum=sum+p
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								        enddo
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								        avep=sum/NFFT
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								        fac=sqrt(1.0/avep)
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								        cspread=fac*cspread                   !Normalize to constant avg power
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								        cdat(1:NFFT)=cspread*cdat(1:NFFT)     !Apply Rayleigh fading
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								!        do i=0,NFFT-1
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								!           p=real(cspread(i))**2 + aimag(cspread(i))**2
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								!           write(14,3010) i,p,cspread(i)
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								!3010       format(i8,3f12.6)
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								!        enddo
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								     endif
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								     dat=aimag(cdat) + xnoise                 !Add the generated noise
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								     fac=32767.0/nsigs
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								     if(snrdb.ge.90.0) iwave(1:npts)=nint(fac*dat(1:npts))
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								     if(snrdb.lt.90.0) iwave(1:npts)=nint(rms*dat(1:npts))
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								     write(10) h,iwave(1:npts)                !Save the .wav file
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								     close(10)
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								  enddo
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								999 end program jt49sim
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