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-   -   GE 211 "flash" question (http://www.diyaudio.com/forums/tubes-valves/229234-ge-211-flash-question.html)

Shadowboxer 3rd February 2013 02:25 AM

GE 211 "flash" question
 
I have a pair of GE 211 / VT-4-C tubes, which I picked up at a ham event years ago.

They look great, but I am a little unsure of the condition. They do not appear to have been "flashed" yet; i.e., there is no silver deposit on the inside of the glass. The little pod of barium (?) is still intact inside the tube. You can see it in the photo below. Also, there is slight discoloration on the glass above the "getter" pod; it is more noticeable on this tube (second photo) than the other.

http://shadowboxer.smugmug.com/Music...GE211_01-L.jpg

http://shadowboxer.smugmug.com/Music...GE211_02-L.jpg


Do these conditions generally indicate anything about the tube's useability or condition? Thanks!

HollowState 3rd February 2013 04:27 AM

Quote:

Originally Posted by Shadowboxer (Post 3353690)
Do these conditions generally indicate anything about the tube's useability or condition? Thanks!

Yes, they sure do. The second picture shows the getter has been consumed and is most likely very gassy and unusable. It's vacuum may have been compromised. The other one is difficult to say whether it's totally gone to air or just never flashed. But never having been flashed is extremely rare. You should at least have them hypot tested for gas before use. Or you could just light the filaments (10v) and see if they glow correctly. By this I mean, see if the filament color and intensity looks proper (bright and yellowish). If very gassy, or if they have air the filament will be dim or may even smoke. And with HV applied, they may show a bluish glow if gassy.

Shadowboxer 3rd February 2013 02:04 PM

I'll try 10v on the filaments and see what happens. Thank you for the quick reply!

tubelab.com 7th February 2013 05:59 PM

1 Attachment(s)
I got this 211 from a hamfest for $5. The reason for the price is obvious. The glow is present with or without filament power, apply a few hundred volts to the plate and GLOW!!!!!

oldies 8th February 2013 07:37 AM

Quote:

Originally Posted by tubelab.com (Post 3360045)
I got this 211 from a hamfest for $5. The reason for the price is obvious. The glow is present with or without filament power, apply a few hundred volts to the plate and GLOW!!!!!

you mean 211 with a dead filament will shine with 100-200Volts?

wicked1 8th February 2013 02:47 PM

If it has some gas inside.

bear 8th February 2013 08:26 PM

Nice display tubelab!

People will pay extra for that! :D

tcqanh 29th October 2013 01:13 AM

Quote:

Originally Posted by Shadowboxer (Post 3354169)
I'll try 10v on the filaments and see what happens. Thank you for the quick reply!

Hi,

How are your tubes now ? Can they work ?

Regards,


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