Home Tube DIY Asylum

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

RE: enough current to bias 2 x kt150 tubes

Ok, so the .5A 6.3vac filament trans should be perfectly fine for the job?
I still don't understand why it worked in my shop for over an hour with solid cathode current on the output tubes of 75ma and the bias voltage was rock steady as well at -52vdc measured at the last dropping resistor. I took out the "test tubes" which were a mismatched duo of a GE 6550A and a Russian kt88. Plugged in the kt90s and after about a 5 minutes the current started to steadily climb while bias voltage steadily lowered. I turned it off, put in the old testing tubes and this time they could not hold bias worth a darn.


This post is made possible by the generous support of people like you and our sponsors:
  Kimber Kable  


Follow Ups Full Thread
Follow Ups

FAQ

Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.