| morfeas |
This is how it looks when you let some air in.
:xeye: |
|
|
| Frank Berry |
WOW!
What kind of tube? That's spectacular! |
|
|
| morfeas |
ECC81
Can't imagine how it would look with a big one. |
|
|
| Layberinthius |
It looks beauutiful!!! How did you get the air out increcementally?
Was there a hairline crack to begin with eh?
:bigeyes:
If only they sold em like this and they operated in normal parameters :) |
|
|
| redwine1118 |
HI,
Just like the emission color for a mercury vapour rectifier (RCA 83)
Red:D |
|
|
| Sch3mat1c |
Hehe, I've had a gassy 12AT7. A special thing about this type on my tube tester is I can arrange the voltages so I get electron emission through the holes in the plates and get some blue spots on the glass.. well this thing not only had blue spots but purple trails showing every electron moving! :bigeyes: :D
Tim |
|
|
| morfeas |
I did bend the pins just a little to get better contact in a loose socket. I think with heating up the pin-glass seal broke letting just a zip of air inside. No cracks on the glass.
Still have the tube around and the getter looks fine.
Have done this (bending the pins) many times with other brands and had no problem.
The most spectacular was the arcs inside. Amazing view. |
|
|
| Sch3mat1c |
If there was any crack whatsoever it would continue to leak. And tubes tend not to be self-healing when it comes to vacuum, so that's odd..
Tim |
|
|
| fdegrove |
Hi,
| quote: | | This is how it looks when you let some air in. |
That's not air but a polluted cathode surface that somehow releases it's ions all of a sudden.
If it were a leak it would have killed the tube within a split second.
Either way it's quite unique...:D
Cheers,;) |
|
|
| Layberinthius |
Looks like something out of Star Trek or inside a star :D
That blue glow gets me thinkin...
Stop me Frank!!! :P
Has anyone seen a supply of Blue Neon 'power-switch' indicator lamps? or a 'tuning-indicator' Blue version?
I'm sure if there were they'd sell like hot-cakes, maybe someone with influence can whisper in Svetlana/Sylvania's ear about making a few volume level indicators with blue glow? :D |
|
|
| richwalters |
Hi there...It's the CVC bit on the bottle that's bothering me......You did wiggle a pin to get the effect ??? I get most of my tubes from that source.......aah
rich |
|
|
| fdegrove |
Hi,
| quote: | | I get most of my tubes from that source.......aah |
Don't worry too much, Rich....
Chelmer's been a good source for many, many years.
Cheers,;) |
|
|
| richwalters |
Hi Frank....... yes I know them well....... thanks for assurance. My old working veins of Marconi Chelmsford (UK) coming out of here.....
My recent failure is a JJ KT88 which came off stage with a duff heater only after 10 hrs smooth service......no apparent reason why it failed, no H/C shorts or shock especially when it's used in same circuit amongst others.
I've often wondered about that little blue running glow inside between the electrodes in good tubes....esp when the B+ is boosted up. Presumably exhaustion isn't a perfect process but I also had one that had an EL34 with a pink glow.....what gas creates this ?..... sounds like metal outgassing....
rich |
|
|
| fdegrove |
Hi,
| quote: | | no apparent reason why it failed, no H/C shorts or shock especially when it's used in same circuit amongst others |
I suppose I don't need to suggest it but have you checked for a cold solder joint on one of the heater pins?
| quote: | | what gas creates this ?..... sounds like metal outgassing.... |
I'm not sure what exactly the gas is but it is outgassing for sure...
You hardly ever saw that on NOS tubes from reputed manufacturers'...Except when B+ was really pushed up high.
Nowadays most people seem to think this is quite "normal".
Me thinks the machinery/pumps is showing its age.
It normally won't do any damage, it just makes for a reduced lifecycle as the getter is going to be exhausted sooner.
Cheers,;) |
|
|
| stormy |
hi, hehe looks lovely.
I expect to see some blue emmision in the valves on my amp.
should look the same amount on all output valves in PP if
thay are matched ok.
of course Im not a audiophile, I dont suppose you would drive your amps the same as musicians do.
regards stormy. |
|
|
| richwalters |
<I suppose I don't need to suggest it but have you checked for a cold solder joint on one of the heater pins?>
(quote not workin here)
Yup....Frank ...thanks for suggest.....this pin check is one on my list....generally this area is pretty reliable and I generally check this with a low heat soldering iron.....not a good idea of overheating those fragile copper glass bonds.......No doubt I'm expecting a replacement for whom............um, yes, CVC......
rich |
|
|
| cogsncogs |
| quote: | | I've often wondered about that little blue running glow inside between the electrodes in good tubes....esp when the B+ is boosted up. Presumably exhaustion isn't a perfect process but I also had one that had an EL34 with a pink glow.....what gas creates this ?..... sounds like metal outgassing.... |
Dark blue on the inside glass (like an 8 or a hour glass) in an EL34 I consider a good sign. Also with some dark blue inside, fixed not moving (floating). Sometimes you can see the intensiity change along with the music. Cool to look at.
Pink or purple, very bad! Usally a sign of a gassy tube or vaccum leak. Had some cheap EL34's go orange on me (thermal runaway) and after that a pink glow floating around inside. Seen that in gassy/bad horzontal output tubes.
Once sneezed on 4 hot EL34's. Pink/purple flashes, zzzaappp-hmmmmm! Very bad day!:bawling:
I'm trying to remember exactly what ionized gas('s) causes the pink glow :scratch: , oh well. I read about it once in a very old RCA television tech manual.
Cheers
Wayne |
|
|
| Layberinthius |
| If I remember correctly pink glow is oxygen? Similar to Aurora Borealis? |
|
|
| Sch3mat1c |
That's what I recall.
And nitrogen is...blue? Argon purple?
Tim |
|
|
| Layberinthius |
| Yes, nitrogen is blue afaik :) |
|
|
| Magura |
| quote: | Originally posted by Sch3mat1c
That's what I recall.
And nitrogen is...blue? Argon purple?
Tim |
Yes, argon is purple....i see that when using a TIG welder for aluminium.
Magura:) |
|
|
| jamesjung21 |
well, the blue color is caused by oxygen.
That's why the sky is blue.
- I love chemistry... :cool: - |
|
|
| Sch3mat1c |
...Raleigh scattering...
(Dust in the atmosphere scatters light. Blue is scattered more than red, hence, we see a blue sky. The reds and greens pass on through.)
;)
However...liquid oxygen happens to be blue. But that's because of loose electrons or something. (See also: liquid ammonia with sodium or potassium metal (as I recall) dissolved in it.) It's also paramagnetic - a thin, extremely cold liquid is attracted to magnets! :D
Tim |
|
|
|
