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Still trying to figure out the focus issue on the right side. I tried rotating the focalizer 180 degs but that had no effect. I thought that if it was at fault that the problem would switch to the left side.
I scoped all the voltages including the HV. They're stable. Only the HV shows any structure and I don't believe it's enough to cause the problem.
All the photos have a vertical scale sensitivity of about 60V/div. It was AC coupled using a 20KVDC, max pulse 40KV scope probe.
In the first photo you see the pips correspond to the horizontal retrace. The rest of the variation is due to the video signal. The second photo has the time base set to view the vertical sweep period and the fuzz is the horizontal retrace pips. In the last photo I turned the brightness down and all you see are the horizontal pips.
I think the horizontal pips are capacitively coupled from the windings on the yoke to the aquadaq, which is capacitively coupled to the dag on the inside connected to the HV. The horizontal windings are closest to the neck of the CRT.
The HV was about 11KV during this test. The variation appears to be about 50 volts PP. I doubt that 50 volts would affect the focus much.
The resistor in series with the HV supply is about 470K. So, 50 volts means about 100 micro-amps, which is probably reasonable with the brightness set high.
I looked at the old test pattern photos I took with the 10MP4 and I see that it has the same problem, just to a lesser degree. I'm starting to think that the problem is with the yoke.
I'm going to ring test the yoke and perhaps swap the horizontal leads to see if the focus issue moves to the other side of the screen or stays put.
John
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