  A problem of diffraction of a symmetrical transverse magnetic mode $
\text{TM}_{0l} $ by an open-ended cylindrical waveguide corrugated inside is
considered. A depth and a period of corrugations are supposed to be much less
than the wavelength and the waveguide radius. Therefore a corrugated waveguide
wall can be described in terms of equivalent boundary conditions, i.e. a
corresponding impedance boundary condition can be applied. Both vacuum case and
the case of uniform dielectric filling of the waveguide is considered. The
diffraction problem is solved using the modified tayloring technique in Jones
formulation. Solution of the Wiener-Hopf-Fock equation of the problem is used
to obtain an infinite linear system for reflection coefficients, the latter can
be solved numerically using the reduction technique.
