Hallicrafters T-67 HV corona ring

[dcl0]

Hi guys,

I swapped the damper with another NOS tube I had - unfortunately it made no difference. Turning B1 (horizontal drive) crowds the image to the right (as it should) but does nothing with the bright vertical line. Turning B4 (horizontal linearity) does nothing when it is turned (neither does B3, the width).

I poked around with a scope looking first at the control grid of the horizontal output tube V19. Not the best saw-tooth pattern with bumps at the beginning. The pp voltage there is actually 111 volts (I had the wrong probe setting on that one).


Next I looked at pin 2 of the horizontal oscillator V18B which feeds the control grid of V19.


However pin 5 of the horizontal oscillator V18A was difficult to get the scope to trigger on. Ultimately with tweaking of the contrast control I got a stable trace. This section feeds the horizontal linearity and width controls.


Finally looking at the control grid of V18A (pin 4) which collects signal from one side of the horizontal sync discriminator V17 (6AL5). This seems weak with a peak height of only 306 mV. Sams or Riders don't give sample scope images for this set. Do these images seem reasonable?????


As I was rechecking around the horizontal sweep section I noticed something funny. The components wired to pins 2 and 7 on the Horizontal sync discriminator V17 (6AL5) are swapped from what is pictured in the SAMS. However the wiring as found is consistent with what is pictured in Riders. Does this matter? or should K1 be paired with P1 and K2 with P2 for correct function of the tube?