Panrock wrote:PS. PT mag long lost. I have decided to provide you with a complete timebase and s/separator schematic showing the actual current setup and with all component values marked ...
Steve Anderson wrote:As for the herringbone pattern, try breaking the junction of C61 and R34, bring up the brightness to a mid-grey and see if said pattern has gone.
Steve Anderson wrote:Now I have not heard of a CRT going 'active' before, but it is a glorified triode so perhaps it is possible. Keeping C61 disconnected, try a 100nF cap to ground (400V) from the junction of R58/59/61/62. If that does nothing similar caps from the wipers of VR7 & VR8 to ground.
Steve Anderson wrote:Next, if the above does nothing, with C61 still disconnected, temporarily place a 100nF between 1 & 2 of the CRT (grid/cathode).
Steve Anderson wrote:If only I were in Sedgeberrow now, between the two of us I'm sure we could have this fixed in time for a celebratory Sunday pub-lunch! The attached looks ideal and local!
Steve Anderson wrote:Hi Steve, I didn't study your revised version that well, I was in a bit of a rush that day.
Steve Anderson wrote:Now I see what you've altered around the vertical sync separator/integrater. But I think there's an error in the revision. I can't see how V14 gets its anode volts unless via the screen circuit. It may well be correct but it's not a configuration I have seen before. But I'm no expert on valve/tube sync separators.
Steve Anderson wrote:If you feel in the mood do try another CRT. Do you have any spare SP61's? Or you could swap a few around...and see if there's any change.
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