Home Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Re: Back to the Drawing Board....

Aaaaaahhhh... You're using a 1000 ohm/25W resistor between the filament CT and ground, along with -130 volts on the grid? If so, in effect you're "double-biasing" the 845. You're running the tube way down into cut-off, like Class C region :-). Remove the 1K resistor and ground the 10VAC center tap. Set the grid voltage to about -110. That should put you at between 60-80mA. Good enough for testing purposes. You really want 10 ohms/2 watts from CT to ground, and measure .8 volts to ground for 80mA.


This post is made possible by the generous support of people like you and our sponsors:
  K&K Audio / Lundahl Transformers   [ K&K Audio / Lundahl Transformers Forum ]


Follow Ups Full Thread
Follow Ups


You can not post to an archived thread.