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Re: Drake L4-B no Grid Current.


 

Ok, so after buying new tubes and ruling, it is not the tubes that was exspenseve.
I poked around the bias and discovered that I had no bias voltage. Tracing back the bias to the soft start board. I do not have any voltage on the yellow wire from the filament transformer. I believe I have 2.5 volts on the filament leads and 12 volts on the blue wire out of the filament transformer. I am running the amp on 240v.? I have 120v on all terminals when the amp is off at the terminal strip, and with the amp on, I get 120v on the outside strips and nothing in the middle two. Is that right because it's jumped for 240v? I was thinking about trying it set up for 120v and see what that did. Also, I had to buy past the soft start relay because the timer transistor went again, which was disappointing. It would be greatly appreciated if anyone has any recommendations to help debug.

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