PRR said:By letting it cook a week I was able to getter some of the gas, but bias was still non-zero and erratic. People talk of gassy tubes, but in 40+ years experience, I never saw a "slightly gassy" tube, only complete failures (dead TV or amp) caused by a gassy tube.
I am testing a new PP 300B and I have one tube showing an intermittent blue light as shown in the attached picture.
Does this mean it is a bad tube or any gas/vacuum leakage?
Thanks for your help
Intermitent blue glow is bad for me.
Do you have large and intermitent noise?