I had a conversation with a tube "expert" last night...

[ThermionicScott]

My favorite permutation is: "Equine quadrupeds may be coaxed to the reference of specific gravity, but may not be compelled to imbibe thereof."


Anyways, those Sovtek 5881/6L6WGC/6P3S-E/whatever are insanely tough. I had one that was starting to exhibit symptoms of gas (losing grid bias, redplating if the pair was biased too hot), so I threw it in the microwave for a few seconds to reflash the getter and now it works perfectly again. Who knows when it will finally die...

[Leo_Gnardo]

5881 - I had one that was starting to exhibit symptoms of gas (losing grid bias, redplating if the pair was biased too hot), so I threw it in the microwave for a few seconds to reflash the getter and now it works perfectly again. Who knows when it will finally die...

You must have an insanely tough microwave. I like that technique, very impressed!

[ThermionicScott]

You must have an insanely tough microwave. I like that technique, very impressed!

I got the idea here on m-e-f a few years ago! The consensus was that it was worth a shot, but just as likely (or more) to kill the tube completely.

[Leo_Gnardo]

I got the idea here on m-e-f a few years ago! The consensus was that it was worth a shot, but just as likely (or more) to kill the tube completely.

No foolin'... I thought it would more likely kill the microwave. Just for fun what's the recipe, how long do you cook the tube, guess it's at 100% power.

[ThermionicScott]

No foolin'... I thought it would more likely kill the microwave. Just for fun what's the recipe, how long do you cook the tube, guess it's at 100% power.

Yeah, here's the link: http://music-electronics-forum.com/t12645/

I guess it's not long enough to potentially damage the microwave.

[Leo_Gnardo]

Yeah, here's the link: http://music-electronics-forum.com/t12645/

I guess it's not long enough to potentially damage the microwave.

Veddy interesting, thanx for the link. Consider it the final hail mary pass for a gasser. Now I'll have to ask around, perhaps a generous customer might have a used/good micro; some folks put a new one in the kitchen every couple years. Living in prehistoric conditions as I do, never have owned one. This would be a good excuse.

[tedmich]

The Russians stayed with tubes several decades longer than the west after all. When Soviet pilot Viktor Belenko defected in a MiG-25 to the United States via Japan in 1976 the Pentagon analysts were amazed that is was chocked full of tubes...

https://www.youtube.com/watch?v=PY9noRJ5y2Y
Methinks Mesa hired these designers....
But some people think 1950s US made guitars were magical as well, which is fine if you find their ridiculous cost inconsequential.

[Leo_Gnardo]

The Russians stayed with tubes several decades longer than the west after all. When Soviet pilot Viktor Belenko defected in a MiG-25 to the United States via Japan in 1976 the Pentagon analysts were amazed that is was chocked full of tubes...

Tube gear much more likely to survive an EMP hit from atomic weapons - if they were used then "obsolete" aircraft like MIG-25 would own the skies while our computer-laden and dependent aircraft would drop like so many stones out of the skies. Yes I know there's been a "hardening" effort for silicon & other sc's vs EMP, hell there were labs at my college devoted to hardening research, but could we depend on that to work when tubes just breeze thru as if nothing happened? While the CIA projected laughter about Soviet obsolescence to the media, I knew that was theater to make the public feel better about USA's vaunted superiority thru technology. Einstein "after WWIII war will be fought with sticks and stones." So who's got the better stick, the better stone.

[Enzo]

That assumes that all the high tech functions of modern electronics could be done by vacuum tubes. Try designing a phased array radar system with tubes, or a GPS course tracking computer.

[loudthud]

Some high tech fighter jets can't fly without computers at the controls or at the least keeping the pilot from trying to do something that will result in a crash. But I sometimes wonder if the danger of an EMP event is exaggerated. When they were testing nukes near Las Vegas close enough to feel the ground shake did any electronics fail on the strip?

[Leo_Gnardo]

When they were testing nukes near Las Vegas close enough to feel the ground shake did any electronics fail on the strip?

Underground tests up there on Frenchman's Flat, no EMP. 1.6 kT test @ Yucca, EMP off the scale, and that's a relatively small weapon. One Russian test set a city generator on fire.

Some Pacific tests turned the lights & phone off in Hawaii. One report, on the "Starfish Prime" test, not so much Hawaii damage, but others did too and are less well reported.

Above ground nuclear testing was done when electric & phone systems were simpler, tube operated for the most part, and more robust, iow few or no transistors. Also not much in the way of satellite communications which would also suffer.

[gui_tarzan]

I have a pair of early 60's TungSol brown bottom 5881s with triple getters out of an organ. They're short, squatty tubes and I hope they're in good shape but I haven't tried them in an amp yet.

[Leo_Gnardo]

I have a pair of early 60's TungSol brown bottom 5881s with triple getters out of an organ. They're short, squatty tubes and I hope they're in good shape but I haven't tried them in an amp yet.

I hope they're in good shape for you, won't need any microwave or EMP treatment. The "real" TungSol 5881's the tubes a lot of people are lookin' for. Standard issue in legendary '59 5F6A Tweed Bassman & other great old Fenders.

[Enzo]

LT is right, some of our high performance jets are inherently unstable, and can only fly with the help of the onboard computer.

yes, EMP is a real threat, but they can harden equipment against it.

[The Dude]

Ever microwave a CD? It's like a little miniature lightning storm.