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Old 10-16-2013, 02:14 PM
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TinCanAlley TinCanAlley is offline
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Quote:
Originally Posted by DaveWM View Post
per Zenith 40-180=-140 overall bias

Per yours 33-190=-157 overall bias

extra -17 v neg bias does not seem like it should be too much, but I don't now that for sure.

the 40 or 33v on G1 is a simple voltage divider of a 390k and 75k resistor connected to the 250v source. if the 390k has drifted up that would reduce the G1 bias.

the 190 is a result of the bias and the load on the output transistors. for that I would look at those resistors on the service setup and maybe the 18k collector load resistors on the output transistors (they go to the 250v source).
I have new 18K and 1.8K resistors for the setup. I got them in case I needed to change them. I tried to test them, but they both come up as 1.6K. I'm sure it's because they share a connection. I'll have to life them and test.
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