First time I've seen anything like this.
 

I've been retesting boxes of old tubes and attempting rejuvenation on some of them. A couple of nights ago, this happened:

https://live.staticflickr.com/65535/...d63bfd79_z.jpg

For the safety of my equipment, I should have just cut the power and left it alone. But I couldn't resist repeating it to get a quick video:

https://flic.kr/p/2hcncrU

I won't give you any more information. The photo and video are unaltered. Who can guess what's happening?

82 or 83 mercury vapor full wave rectifier? :scratch2:

jr

Ditto. Those dark splotches around the bottom of the glass envelope look like condensed mercury.

Jr. tech got it.
 

Its an 83, basically an 80 with mercury vapor. I have an AK radio that uses two of them.

Y'all win. I lose. I bought this in March 2013 as an 80 and first tested it 25 January 2014. It tested 'good' and I put it away. BUT...I put a sticker on it that says "World Tube/Used/Mar 20013/No ID on Tube." It didn't light up then like it did in the photo and video. I got the 83 data sheets and retested the tube. Heathkit TT1 settings are virtually the same for the 80 and 83. I can see some constant blue now, but after multiple tests, I only got one blue flash for a second. I took some new photos and will take some more when it's dark.

Well, it DESERVES to go out in a Blaze of Glory.... You have any way to put power to it, put it atop a fencepost & shoot it w/a 22 ? If you could do THAT after dark, it MIGHT put out a Real Show for ya....Yeah, I know... I'm SICK....

So if it's got mercury, is it supposed to do that? Or is that just a result of the testing procedure? Cuz I believe mercury arc rectifiers do that normally, but idk what this tube does.

What "Normal" Looks Like
 

No, it's not supposed to look like the video. I Suppose that's a result of keeping it on the shelf for 6 years--maybe bits of mercury sticking to the glass or the filament burning off some elemental mercury. After the video was taken the tube returned to normal. Normal looks like this:

https://live.staticflickr.com/65535/...764a9f4e4d.jpg

This photo was taken in the tube tester. If I switch to the other plate, the blue switches to the opposite side.

So after some “warm up” time has more mercury vaporized?

jr

That's pretty....If that is interchangeable with an 80 it might be cool to install it in a set where you can see it in operation.

An 83 can glow blue during normal operation but generally just down inside the plate structure.

83 draws 3A filament while an 80 is 2A. Also 83 has a lower voltage drop across the plates and generates more electrical noise. So it's not a drop in replacement but can sub for an 80 in some cases.

Take a look at the light show produced by six 866s and a couple of smaller mercury vapor tubes in this 1 kW audio amp.

https://m.youtube.com/watch?v=G7qMVYf85sM

jr

ybmti!

The filaments on those output tubes draw 14A each.

One big use for the 83 is in the Hickok TV-7, 600/600A, 6000/6000A, and similar tube testers. The 866 was used in a great many broadcast and Ham transmitters, as well as in big audio amplifiers for indoor and drive-in theatres. I think that I still have some downstairs.