A Precision Deflection Yoke

A deflection yoke for an image-orthicon was built entirely from printed circuits and operated in a television camera. With the exception of resistance (which for the printed circuit model was much higher) the parameters of a conventional wire-wound yoke were quite readily reproduced, including inductances per coil of as much as 16 millihenries. The use of wider conductors, improved drafting techniques and allowances for undercutting will reduce the resistance to an acceptable value. Furthermore, reasonable care in etching should provide good yield from the printed material, correlation between calculated and measured values, and close tolerances on electrical characteristics. While the experimental work reported here was rather limited in scope, experience with printed coils in other sections of RCA indicate that tolerances of better than 1 per cent inductance and 10 per cent resistance can be realized.