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peter_scott · 16th Sep 2019, 9:04 am

Thanks for those suggestions Andy. You are quite right about R63 mine reads 45 ohms instead of the 38 ohms intended and I did parallel it up to give 35 ohms but didn't see any change in the frame ripple. I also tried messing with C60 and it definitely makes a very significant reduction in the HT ripple at the frame timebase. The thing I can't understand is that I don't see any significant change in the frame ripple regardless of whether the HT ripple is reduced or not! Perhaps that does point to heater "crosstalk" even with grounded cathodes.

I have a lot of ECL80s and lots are duds that I should discard but I'll try again for a good swap. I haven't tried swapping the PZ30 but I will do.

Thanks,

Peter

16th Sep 2019, 9:04 am	#37
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,274	Re: Yet Another Bush TV22 Thanks for those suggestions Andy. You are quite right about R63 mine reads 45 ohms instead of the 38 ohms intended and I did parallel it up to give 35 ohms but didn't see any change in the frame ripple. I also tried messing with C60 and it definitely makes a very significant reduction in the HT ripple at the frame timebase. The thing I can't understand is that I don't see any significant change in the frame ripple regardless of whether the HT ripple is reduced or not! Perhaps that does point to heater "crosstalk" even with grounded cathodes. I have a lot of ECL80s and lots are duds that I should discard but I'll try again for a good swap. I haven't tried swapping the PZ30 but I will do. Thanks, Peter __________________ http://www.nostalgiatech.co.uk https://www.youtube.com/c/PeterScott/videos