vacuum tubes?

[user 69385]

Those old 6L6 tubes will probably work in guitar amps and might bring a pretty penny.

The 6L6's are also used in old EEG and EKG machines I believe

 

[sonnie son]

Hi Compscrapper,

Do you have any with the numbers:
6L6GC
12AX7
EL84

I have a B & K Precision tube tester to check them with. If you're interested in selling any of these I'd be interested. Please let me know.
Thanks

Yes I do have

 

[Ag and Au]

I have a rich history with vacuum tubes, specifically klystrons and traveling wave tubes (TWTs).

If they are copper tubes (and not glass tubes) they will have some precious metals/alloys inside that were used as braze material during its construction. This braze material will alloy again with the copper when heated in the furnace. My thoughts are the copper will have more value than the PMs (plus the effort to recover them).

Also, many of these tubes have used Beryllium oxide (BeO) as a ceramic (to hold the vacuum in, but still let the signal pass through),
a deleterious compound that you don't want to mess with.

Who made the tubes that you are referring to?

 

[adam mizer]

Yes I do have

Older 6L6 and 12ax7 and maybe 12at7 that pass tube tests and audio noise test will sell for more.
Sometimes coke bottle style sell for big bucks.
Mullard also a good name. Sylvania RCA ECG JAN and maybe more names.
Jan military related ones also in demand.
May have different numbers on the based on STR numbers, you need cross references.
Usually up to1980's and earlier stuff, don't know if 1990's were okay, just kept getting worse over the years.