Trouble firing up my new HeNe tube

Did you put a ballast resistor in series with the
Anode of the Tube like in the Pic in Post #2.....:thinking:

Jerry

Well, looks like the tube that I got is dead as well. Just saw a couple of blue sparks in the microwave :eg: and no joy when I hooked it up to the PS.

Scared to touch this thing now. :crackup:

*ZAP*

lol holy crap! Power supply got me.

about the oudin - tesla coil. this is used to just test the gas integrity of a sealed tube? or for something else? i have one - well a plasma globe - which will make an unpowered (by the ps) tube light up without lasing.

daguin said:

Oudin Coil w/Safety Switch

Peace,
dave

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Thanks for the link. I missed it since we both posted at the same time earlier. If I decide to get more untested tubes I may contact le quack and get one of his boards to test with.

lasersbee said:

Did you put a ballast resistor in series with the
Anode of the Tube like in the Pic in Post #2.....:thinking:

Jerry

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There's a 77k ballast resistor built into the positive lead going to the mounts I got from Sam. You can barely see it in my avatar pic.

Ghostchrome said:

*ZAP*

lol holy crap! Power supply got me.

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Welcome to the world of gas lasers. One reason all my lasers connect to their PSUs via alden style connectors is so I can disconnect them and short the pins to discharge the built up charge on the tube. That's one way I could tell the PSU was working when trying that tube. I could see and hear the spark when I shorted the pins.

Ghostchrome said:

*ZAP*

lol holy crap! Power supply got me.

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Now I told you in the other thread about that:na:

It's more of a surprise than pain but it will get your attention


Sorry about your guys tubes

Did anyone get good tubes from that link? I bought one, and I am afraid that I got a bad one too. -.-

LtKernelPanic said:

Welcome to the world of gas lasers. One reason all my lasers connect to their PSUs via alden style connectors is so I can disconnect them and short the pins to discharge the built up charge on the tube. That's one way I could tell the PSU was working when trying that tube. I could see and hear the spark when I shorted the pins.

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hmm I'll definately have to look into that.

n2stuff said:

Now I told you in the other thread about that:na:

It's more of a surprise than pain but it will get your attention


Sorry about your guys tubes

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Yeah, I guess I didn't leave it sit long enough.

Wolfman29 said:

Did anyone get good tubes from that link? I bought one, and I am afraid that I got a bad one too. -.-

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Yep, that's where I got mine.

cheech226 said:

about the oudin - tesla coil. this is used to just test the gas integrity of a sealed tube? or for something else? i have one - well a plasma globe - which will make an unpowered (by the ps) tube light up without lasing.

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The coil will cause the gas in the tube to glow if its still present.

So I just got mine in the mail and it's really neat. Never had a gas laser before. No PSU yet though. I do have a HV flyback run on a ZVS though.

The question is, how can I check if my tube has degassed? I turned my flyback on and drew an arc and put the tube within 3-4 inches of the arc (so it wouldn't arc to the tube itself) and I didn't get any glow. Does that mean that it is dead? :\

Also - does it matter what the current/frequency/voltage is of the HV HF source that I put the tube near?

EDIT: Alright, so I read on Sam's Laser FAQ that I would be able to test it out by hooking it up even to an HV AC source (like my flyback transformer) if I put enough resistance to limit current. I think I may have killed my tube though, because when I was measuring current, I didn't realize I was measuring DC current until I had already tested it. Under that same test layout that I tested the tube with, I was measuring 70mA D: I don't know what happens when you overcurrent a HeNe tube, but I assume it dies =p I saw no plasma or anything. I eventually reduced the current to about 7-10mA (a BUNCH more resistors), I tried it again, but no plasma or nothing

Should I still try to stick it in a microwave?

I'd try the micro. I only let it go 5 seconds. I'd be shocked if yours worked. I feel bad for posting that link now but it's a known risk when buying untested, used gas lasers.

^^ meh, don't feel bad. It was worth a shot, and would have been hella cool if they worked.

There's always next time.

I don't think 70mA for a short time with no observable glow would have destroyed your HeNe tube, they're pretty robust in that regard. That being said you should have seen a glow with even a few picoamps of high frequency HV near the tube.. it is probably dead and not by your fault.

This is looking more and more like some one unloaded a bunch of dead tubes on eBay!

Sigurthr said:

This is looking more and more like some one unloaded a bunch of dead tubes on eBay!

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Yeah...

Anyone leave him feedback yet? :eg:

I think he mentioned that he wasn't sure if they worked or not (which is complete BS, but whatevs)

Yeah, I made the mistake of purchasing another -.-

Ghostchrome said:

Yeah...

Anyone leave him feedback yet? :eg:

I think he mentioned that he wasn't sure if they worked or not (which is complete BS, but whatevs)

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I did. I left positive because I couldn't in good faith leave negative for something that was advertised as as-is untested. I did note the tube was EOL aka dead. Oh well I'm going to keep it around to use as a demo tube so don't have to keep handling one of my good tubes to show people.

On a related note I got my PSU in the mail today. I'm going to try it with the little 6" tube that I got from Sam. I may have to take wannaburn up on his offer if the tubes he has are similar to the dead one for visible plasma.