Bell and Howell Model 34 Oscilloscope

I have started to repair this scope. I can put a signal to the vertical input and see a sign wave on the CRT. I see this only if the sync control is turned all the way clockwise. When I start to turn the sync to the left I loose the waveform at about three o'clock . I have the schematic and the sync control comes off the plates of the 12BH7.
All the other controls seem to work fine. When I loose the waveform I get a vertical line?????

Hi, Wonder where you got a schematic for the 34. I have the scope but I thought that it was patterned ater a Heathkit but don't know which one. Can you help me find a manual/schematic? Thanks, Marvin

mmoss111 wrote:Hi, Wonder where you got a schematic for the 34.  I have the scope but I thought that it was patterned ater a Heathkit but don't know which one.  Can you help me find a manual/schematic?  Thanks, Marvin

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