Abstract: A television display system comprises a kinescope, deflection yoke and magnetic field influencing apparatus. The field influencing apparatus comprises a pair of magnetically permeable members disposed on either side of the yoke. One end of each member is positioned within the external field of the toroidally-wound vertical deflection coil. The other end of each member is divided into an upper and lower field-forming arm. The upper arms of each member are disposed adjacent each other such that a gap is formed between them in the vicinity of the entrance end of the yoke. The lower arms are similarly disposed. The gaps are vertically aligned with the longitudinal axis of the kinescope. The width of the gaps is less than the spacing between the outer electron beams in the vicinity of the entrance end of the yoke. Flux from the external field is channeled into each permeable member to the ends of the field-forming arms. A field is produced between the upper arms of each member and the lower arms of each member.