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Old 03-08-2020, 06:23 PM
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Yamamaya42 Yamamaya42 is offline
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Join Date: Nov 2018
Location: Round Rock TX
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Quote:
Originally Posted by Kevin Kuehn View Post
Well now that I looked it does appear both Sams and Riders voltage references are from chassis ground. I do think the b- dropper string is easier to understand looking at the Sams schematic. B+ center tap is connected through the focus coil and 3 series resistors to ground. Because all b+ current passes through those components it creates a negative voltage across it's path to ground. The closer you get to ground, the less negative the voltage becomes. Hope that makes sense?

right now, all voltages are wrong, which is not surprising, since my tube sockets and pins are very dirty, i need to clean, many would not even light up heaters w/o removing and replacing.

the point that shows 300v on the Riders is at 378v with the variac at 70% and the point that says -100v shows -30v.

the big resistor in the voltage bleeder is getting very warm, burned my finger.
I'm gonna see what happens after i clean the tubes, I'm hoping that after they are clean and the load is more stable, the voltage will be more stable, otherwise, i will have to track down why it is not normal :/
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