Sparton 16A211 Width Problem

[Steve McVoy]

OK, my turn with a 15 inch color set issue. I've been trying to find a width problem with this set with no luck. It lacks about an inch on each side. Width and Hor. Linearity work properly. I've checked all the tubes (by substitution) and all caps are new.

I have the proper waveforms and p-p voltages at W17 and W18 (see the schematic). Power supply busses are within 5 volts. On the 6BG6s, screen voltage is right, but the cathode voltage is 12 vs 18 on the schematic. Grid voltage is -25, but I noticed that setting of the hor. drive changes it from about -15 to -30. I can just barely get 20 kv on the CRT with the HV control full up. Boost is 550 vs 620 on the schematic. Damper plate voltage is right.

I have checked all the resistors and capacitors in the H. out, flyback and damper areas. I've even changed the yoke. Like all 15 inch sets, the major components are RCA.

This thing is driving me crazy. Anyone have any ideas?

Schematic is here (better to download the pdf so you can zoom in):

http://www.earlytelevision.org/image...ton_16a211.pdf