RadioBanter - View Single Post

June 19th 06, 02:26 AM posted to rec.audio.tubes,rec.radio.amateur.homebrew

wrote:
flipper wrote:
I've got a 6EM7 that does the same thing and it's visual appearance is
perfect as well so I doubt it's your circuit.

Come to think of it I had some nearly-new (back when I was a kid!)
6146B's go into grid-and-plate-current-runaway-at-idle like this 807

I have seen it with many NOS power tubes in this power class. Doesn't
seem to be a problem with bright filament types but maybe it can be.
Fix is to throw out the offending tube.

If you can't get NOS tubes at Surplus hut prices, my advice is to buy
NEW tubes. From someone you can get a refund from.