SUBROUTINE H_4d(ZTRA3,STRA3,dl_v) 7,1

      IMPLICIT NONE

      include 'champ.cdk' 
      include 'chobs.cdk'

      COMPLEX ZTRA3(IKTX,IKTY,52),STRA3(IKTX,IKTY,52)
      COMPLEX Z(IKTX,IKTY),S(IKTX,IKTY)
      REAL dl_v(2*N*N*(NSTOP+2)),dl_u(2*N*N)
      REAL U(N,N),W(N,N)
      INTEGER KX,KY,KW
      REAL JX
      INTEGER IR,NOBS

      NOBS = 0
      DO NT = 1,NSTOP+2
        DO KX=1,IKTX
        DO KY=1,IKTY
           Z(KX,KY) = ZTRA3(KX,KY,NT)
           S(KX,KY) = (0.,0.)
        END DO
        END DO

        CALL H(Z,S,dl_u,NT)

        DO IR = 1,2*N*N
           NOBS = NOBS +1
           dl_v(NOBS) = dl_u(IR)
        END DO
      END DO

      RETURN
      END