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Getter on the side...
Edits: 06/13/21Follow Ups:
Morgan Jones in "baking valves" and Robert Tomer in "getting the most out of vacuum tubes" mention to bake valves when they are slightly gassy. Morgan Jones mentions something like 10 hours at 120C and Tomer at 200C for an hour IIRC. But do not try this with valves that have a bakelite socket as bakelite does not take to kindly to it. (Octal valves are out).
If a tube has been stored for a long time and has not been used then there are always some polutants leached out of the metals or from the glass.
If a tube is gassy and you put the full B+ on it after many years of non-use then depending on the circuit you run a decent risk of arcing and destroying the tube.
There are reports than some larger power tubes can take up to 200 hours before they start to "sing" at their rated voltages / plate dissipation.
Which brings me to another pet peeve: more output transformers experience an early demise in fixed bias amplifiers than in cathode bias amplifiers. (not to mention fixed bias has less linearity than cathode bias).
Study the early materials and old masters rather than jumping on the current fad of believing everything published on the web (that has not experienced a critical review by colleagues which was mandatory in the past before you were allowed to publish).
AM
None of it is applicable to the concern at hand. Tungsram simply manufactured the tubes this way - that's how they look when everything is fine.
You have a Tungsram EL84, made in Hungary. If you search for photos of that tube, you will note that they all have that metallic deposit around the dual plate holes. That is a completely normal characteristic of those fine tubes.
FWIW - I much prefer Tungsram EL84 to genuine vintage Mullard or other Philips EL84, with exceptions for '50s rX_ types from Sittard or Austria. They exhibit superb detail, with extended frequency range.
They are labeled Haltron and came in Haltron boxes. But Haltron bought tubes all over the place apparently.
nt
I don't think use moves getter around like that. Now the dark spots opposite the round hole in a Mullard EL84 plate are quite something else.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
...with getter flashing on the sides and top. The flashing looks slightly used but it's very hard to tell how much without testing it to find out how strong it is, which is what really matters.
Bas, what tube type?
other side
.
Not sure you should jump to that conclusion.
What leads you to think that it's used?
Because it looks like used tubes...but except where one sees black spots...it looks like getter material. And in my amp it sound flat.
I got the tubes from someone who's father passed away. It was in new boxes. So I think someone put in new tubes. And put the old tubes in the new boxes...and kept them.
Just reaching here but I have found that some old stock tubes I have put in service sound as you say perhaps because they are somewhat gassy yet. I had some Russian 6P3S-EV that took a bit of cooking until the getter did it's job and cleared any remaining gas. Once done they worked just fine in an ST70 as outputs.
It sucks to get old. It really sucks to get old and bitter.
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