      SUBROUTINE TA_TO_TB(TA, TB)

	IMPLICIT NONE

	REAL(4) AVV(4),AHV(4),AOV(4),AHH(4),AVH(4),AOH(4)

	INTEGER(4) ISTART,IFREQ
	REAL(4) TA(7),TB(7)
      REAL(4) DELTA(4),CHI(2,4),XFAC,TCOS

C     DATA INITIALIZATION

      DATA ISTART/1/
      DATA DELTA/0.03199,0.02685,0.01434,0.01186/
      DATA CHI/.00379,.00525,.00983,0.0,.02136,.02664,.01387,.01967/

C     BEGIN EXECUTION

      IF(ISTART.EQ.1) THEN
      ISTART=0
      DO IFREQ=1,4
      IF(IFREQ.EQ.2) CYCLE
	TCOS=2.7
	IF(IFREQ.EQ.4) TCOS=3.2
      XFAC=(1.-CHI(1,IFREQ)*CHI(2,IFREQ))*(1.-DELTA(IFREQ))
      AVV(IFREQ)=(1.+CHI(1,IFREQ))/XFAC
      AHV(IFREQ)=-CHI(1,IFREQ)*(1.+CHI(2,IFREQ))/XFAC
      AOV(IFREQ)=(1.-AVV(IFREQ)-AHV(IFREQ))*TCOS
      AHH(IFREQ)=(1.+CHI(2,IFREQ))/XFAC
      AVH(IFREQ)=-CHI(2,IFREQ)*(1.+CHI(1,IFREQ))/XFAC
      AOH(IFREQ)=(1.-AHH(IFREQ)-AVH(IFREQ))*TCOS
	ENDDO
      ENDIF


      TB(1)=AVV(1)*TA(1) + AHV(1)*TA(2) + AOV(1)
      TB(2)=AHH(1)*TA(2) + AVH(1)*TA(1) + AOH(1)

      TB(3)=1.01993*TA(3) + 1.994

      TB(4)=AVV(3)*TA(4) + AHV(3)*TA(5) + AOV(3)
      TB(5)=AHH(3)*TA(5) + AVH(3)*TA(4) + AOH(3)

      TB(6)=AVV(4)*TA(6) + AHV(4)*TA(7) + AOV(4)
      TB(7)=AHH(4)*TA(7) + AVH(4)*TA(6) + AOH(4)

      RETURN 
	END
