The invention provides an improvement in the means for supporting a
container of effusive material located on the terminal end of an
antenna-type positioning member for use in a cathode ray tube. The
supporting structure is comprised of a rotatable member accommodated on
axle means affixed to the positioning member at a region rearward from the
forward edge of the material container. An augmentive fender-like
protective component is associated with the rotatable member to shield
that member from effusive material and to prevent any accumulated electric
charge thereon from interfering with the scanning of the electron beam in
the tube.