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sexton_mallard · 19th May 2018, 11:31 pm

Tonight I got my scope out and connected to the on the grid/pin 2 of the PL81, attached is a pic of the waveform. The scan coils are disconnected and a vertical line is displayed on the screen as before. Twiddling the horizontal hold shortens and lengthens the waveform as expected as the line frequency goes up and down. I calibrated the scope lead beforehand and have it set to x10. Again, I have -45 volts on the grid/pin 2 of the PL81. The heater glow of the U26 is barely visible, my gut feeling the EHT being generated is weak and the extra loading of the scan coils damps what little EHT is getting generated. Should I be getting more of a sawtooth waveform?

19th May 2018, 11:31 pm	#66
sexton_mallard Heptode Join Date: Sep 2013 Location: Ellesmere, Shropshire, UK & Co. Cork, Ireland. Posts: 501	Re: Kolster Brandes RV 10 (Crown) Tonight I got my scope out and connected to the on the grid/pin 2 of the PL81, attached is a pic of the waveform. The scan coils are disconnected and a vertical line is displayed on the screen as before. Twiddling the horizontal hold shortens and lengthens the waveform as expected as the line frequency goes up and down. I calibrated the scope lead beforehand and have it set to x10. Again, I have -45 volts on the grid/pin 2 of the PL81. The heater glow of the U26 is barely visible, my gut feeling the EHT being generated is weak and the extra loading of the scan coils damps what little EHT is getting generated. Should I be getting more of a sawtooth waveform? Attached Thumbnails __________________ Dom Less snakes...more ladders! Last edited by sexton_mallard; 19th May 2018 at 11:34 pm. Reason: clarified wording