Quote:
Originally Posted by Zsuttle
Someone just check this and my logic. Assuming that the screen on the 6BQ6 doesn't provide any voltage, the resistor (R15) faces the whole 340v of the B++. Given this, we can determine the "should be" resistance of R15 based off of the given voltage drop from the Sams voltage chart. If I did my math correctly, the resistance should be about 8K ohms. Why isn't it 8K ohms then?
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I don't see how you can calculate a "should be" resistance value without knowing the nominal average screen grid current.
The average screen grid current can vary with the peak current and the length of time that it draws current, which I would think is a function of the drive control. So, I would look at the drive control value and also the adjustment procedure in SAMS. I would expect the DC screen voltage measurement varies with the drive adjustment (check if it's so?).