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Old 23rd Jun 2021, 6:35 pm   #11
ChristianFletcher
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Join Date: Dec 2003
Location: South Yorkshire, UK.
Posts: 900
Default Re: Murphy Type V350

I have been doing work on the Murphy and as can be seen in the picture the frame is severely collapsed. I have changed out a few of the very sad looking capacitor and the electrolytic in the linearity control. My question is could the frame collapse be a mechanical issue or perhaps a faulty frame coil.

Looking at the scope waveform these are all slightly low but I wouldn’t have thought that would produce such a distorted frame. Adjusting the frame height and linearity do increase the frame height vertical but the bottom line where the frame is collapsed into doesn’t move at all it’s stuck halfway up the screen and doesn’t respond to adjustment.

What’s the most logical way to diagnose the frame collapse. I am think I should really be looking at the final drive to the frame coils to see if the magnitude is correct. Some of the scope pictures look very linear and not like capacitor charging curves

Thanks Chris

Picture 3 Anode V7
Picture 4 Grid V10
Picture 5 Anode V10
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Last edited by ChristianFletcher; 23rd Jun 2021 at 6:44 pm.
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