Argon Ticking

hwang21 said:

I have no other head to test the PSU, the uniphase is clearly incompatible.

How do you see if the cathode is heated up? I have never realigned a gas laser before

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If you can find another LPF member that has a 60X near to you, you can test by meeting up. I imagine you're eager to see the laser work. but it may take some patience testing and identifying where the problem may be.

Troubleshooting something that is new to us is often a real challenge. I think MM said even if it isn't aligned, it will still fire up and glow plasma. Use of the Oudin coil may mean the cathode ignighter is a non-issue, right now.

It may be time to take a peek inside the PSU and post some pics and try and see why the key isn't functioning. I wonder how much it's been monkeyed with inside.

Have you researched this PSU in Sam's Repair FAQ to see if there is some jumpering needed to make it work? If the previous owner could have gotten this to work, he would have, because he can get more money for it. So be prepared for the problem to be not easy to find. But you'll sure become an expert in the process. :yh:

First off (although it won't really make you feel any better) welcome to the "fun" world of used gas lasers

I'm a bit confused.
Do you have two lasers now?

Is the rear portion of the laser remaining "glowing" while the PSU continues to click?

Peace,
dave

Yeah I have to do a bunch of research to figure this out. I don't really know of anyone around here who has a 60X or omni...

I have two argons, one is a uniphase with matching PSU that is working brilliantly, and one is an ALC 60X with omni chrome 155p PSU. This one is the one I'm having trouble with. The first photo shows how the laser is without any help on my part: the side with the three glass valves visible (also the HR end, is that the cathode?) is glowing, the other side (which has the exhaust/sealed off tube, anode?) is not glowing, not even when the laser ticks. It will only glow when I put the tesla to the heat sink on that side, if I put the tesla on the HR side the glass does not glow. The HR end continues to glow between ticks

hwang21 said:

It will only glow when I put the tesla to the heat sink on that side, if I put the tesla on the HR side the glass does not glow.

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The fact it glows with the Oudin coil is a good sign there is (presumably) Ionizable argon inside. But you've still not ruled out a PSU problem. If you've not already, consider giving the Argon Power supply pages at Sam's Repair FAQ a read.

Well they say you learn something new every day. Found out what the extra wires are for. Didn't even know they existed. From the pics posted, it almost looks like it's lighting between the cathode and the "catenode". If that's even possible it makes me wonder if it's just a high pressure problem. I would try disconnecting these wires and try to start the tube with the HV coil, once started let it run a while around 7 amps to bring the pressure down, then reconnect the catenode wires.

Here's the link about the catenode on the FAQ: Sam's Laser FAQ - Argon/Krypton Ion Lasers

Could still be an issue with the cathode not warming up, have you verified the cathode is lit up?

Hmm, good observation, DJZ. That kinda makes the information this is a newer low hour tube more suspect. It may very well be the original circa 1980 tube he's got there.

I have said that I run the cathode for a while
before turning on anode power. This allows the
cathode to get up to a temp of emissivity like many
gas filled radio tubes.
I read long ago that the "half baked" process worked
for some lasers IF the PS was working. That's all.
Good luck --- HM

Yeah I will need to look into the PSU.

The FAQ says I don't really need the system in place other than to help keep dust away from the Brewster windows and such; unless I'm misreading, doesn't that mean I can just snip those wires? I'll see if I can disconnect them, would I need to disconnect both wires of just the HR side (that's the cathode side right?) or what?

How do I verify that the cathode is lit up?

Could a replacement tube be hooked up to the wires? Is there any way to tell if this is a replacement tube or the original?

And I don't think I'll be sending my tube into an oven until I've exhausted some of the possibilities above, but I'll definitely keep that in mind later on if needed, thanks

Hello, I'm gonna try and give you all some tips from my experiences with resurrecting/learning how to build a PSU to power air cooled argons.

First a question for Hemlock Mike, where on the tube would you advise hitting with the oudin coil's spark?

I used to weld plastics and we used Oudin coils to test our welds out, I would point the tip along one side of the weld and hold my other hand over the opposite side and run it along the bead, you would want to do this fairly quickly as the spark wanting to go thru would eventually go thru just like how that will happen on a glass plasma globe over time....!
I have tried my oudin coil on some hard to start tubes and really did not have any luck

I'm thinking another option to an oudin coil would be to use some tin foil taped over an "old school" CRT television's screen, with a wire attached to it.
I don't think them little plasma globes are gonna have enough juice to do what you're trying to do here. Another option might be one of them barbeque grill peizo starters, I'd do a direct connect with one of those somehow.. OR how about trying to use a disposable camera's photoflash cap's juice - or - its trigger coil output.. OR, try a Model-T Ford coil out, I was disappointed that they are not worth much money when I was thinking of selling one
Vintage Ford Model T A Magneto Ignition Coil Wood Buzz Box Dovetailed Logo | eBay

Be creative!@

I'd be worried about zapping the Op Amp'd light feedback board while doing this, if it has one. I know I had removed it when messing around like this, of course this all depends on what method you are going to try also.

The Filament (5-4-3-2-1, Ignition):
On some tubes you can see it and the lovely glow of plasma around it while the tube is running or starting, others you simply cant see it and to get an idea of how hot it is running you would want to peer down the bore or try to see it within the head.
I found that tubes that had a higher cathode voltage (over 2.8VAC) would become harder to startup.
I had built a power supply that I used for my testing/rejuvenation/running/etc, I had tapped into it and used various methods to adjust the filament voltage or turn the filament on and off.
I liked it when the filament was orange with no yellow. On a problem tube I could coax it to ignite sometimes by strategically flicking the filament ON while turning up the anode voltage - or just having it at the right voltage (number of rotations on the ten turn pot, I was not actually reading a voltage) and flicking the switch to ON. While watching what was happening as it striked I could get a feel for what was happening and could vary the Cathode being switched on - or the drive voltage and sort of have some control.

The Filament (-BLASTOFF!-):
OK, She's running now! There may be a beam, there may not be and if so it's a whole 'nother problem What's important at this point is what that plasma around the filament looks like.
What I would like to see is a nice purple-ish glow, I'm guessing at around 445nm.. with NO little "sparklies" happening. Remember when I said I liked an orange glow on it before ignition is hit? Well, on "problem tubes" if we are into the yellow zone then what might start happening as we increase the drive voltage is these little bright spots would flash along the cathode, more often towards the 2 ends actually, and when things are even worst you would see flare-ups, like quick bursts of fire - OR - sustaining flame-like points.. RIGHT NOW if you see that happening TURN DOWN THE JUICE!! let her idle, let her breath for a long time.. then turn it up again slowly.. after doing this a few times you eventually/usually can attain stability.

It was said in the earlier replies that the person(s?) would start off by running the cathode only, heating up the tube, or point at hand was whether to leave it sit and tick.. my feelings on that are "half and half", On problem tubes I'd sometimes let it sit-n-tick, sometimes for hours
Sometimes I'd have the fan running, sometimes not. I'd usually set it up so if it ignited the beam would hit where I am watching.. by my computer monitor, the tv set etc
If I had the fan running I could use that to my advantage and hear the fan drop RPM's slightly as the current demand increased when ignition was attained (That house I was in at the time had real BAD wiring!) I'd recommend turning the filament voltage down a bit lower if it is to sit-n-tick for a long time, cuz again, I feel it would create problems in startup.

If all seems "GO" and there is still no beam exiting then what I would do first before starting out with a mirror alignment session would be to check out the beam's pathway to see if the filament might be blocking it, on an NECGLG3030 the filament is supposed to be centered around the beam and I had one tube with a sagging filament, I was able to (after crossing my fingers) smack it against the wooden doorframe in the correct direction and in doing so was able to make the filament bend back into place - allowing the beam to pass through it. That tube put out great power, success!

And I found the remote connector pinout for the omni PSU on SAMs laser FAQ, but that one has the normal 37 pin layout, whereas mine has horizontal bars at the top and bottom, I think there are around 19 pins and the two bars. Either way though, it looks like this PSU has been pretty deeply fiddled with to not need any jumpers nor key switch to power on the laser :thinking:

That stuff I last posted I had started typing on probably page two of this thread and I became sidetracked.
Mike Hemlock brought up the method of baking in tubes, I had never tried that, my friend Dan Lauritsen (RIP) had used that method a lot and reported success, I have no recall of how long or what temp but he had cooked it in the kitchens oven. The object is to activate the Getter inside the tube, it is coated with Barium and it will soak up impurities, looking at your pictures I see no getters in sight, all is pretty much sealed under metals and I think I have one of them heads myself, it has sat for many years.

Another trick you might want to try that I had used was to take a neon sign transformer that is driven thru a variac to adjust its ouput, obtain a HV rectifier and disconnect that tube, run HV DC thru it in reverse.. get it glowing nicely and let it run for hours.

I'm looking at a circuit diagram of the 60x supply and I do see this (new to me!) cathenode connection..

Can you see ANY orange/yellowish glow down the bore of the tube at all at any point of the countdown sequence??

try removing one of the filament leads and see if it draws a spark when you rub it back onto its filament terminal.

This bit with half the tube igniting has me wondering!
I'm thinking the filament is sagging and blocking the beampath, see if you can cleanly see light thru the bore or try shining a pointer thru it.

Edit: added alc60x schematics edit2: "soak up impurities"

hwang21 said:

No way to clean the capillary? What if I just left the argon to tick for a few hours?

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Oh yeah looking down the HR mirror the entire tube glows a yellow-orange when the PSU is going but before the PSU gives the "tick" (after the tick there is a 10 second delay and then power is supplied to the tube, the PSU fan comes on right after the tick). During the Argon ticking, the tube still glows the same color but each tick emits a bright pinkish-purple blue flash through the tube, see below

I have removed the two wires in question (catenodes), I'm getting bigger flashes now when the Argon ticks (I'm looking down the aperture), enough to be a purple-pinkish blue flash that's pretty bright. I still don't see any laser output/flashes; perhaps one quick weak flash when I was using the tesla but too fast to see clearly and I haven't seen anything except maybe that one time. But now it seems the output side of the tube glows faintly roughly every 2 out of 3 times the Argon ticks, but now I don't see any glow at all on the HR side :thinking:

I haven't been able to dig into the PSU yet, I have a feeling that the PSU is ok but it's just a hunch

that flash is the spark jumping, trying to ignite the gas


edit: I think

Well I had a flash before I disconnected the catenode wires too, it's just that now it's quite a bit brighter. I think the flash looking blue ish might actually be the 488nm or something, just like hundredths of microwatts or something lol. I didn't keep my eye there long enough to make sure

The purple flash is the Argon ionizing for a split second more than likely. I have an Argon bulb that glows a nice purple color when it's on.

So then the stimulated emission process should be intiating/happening during that split second... does that mean it's just wayyyy high tube pressure? I was getting the purple flashes without the tesla. Should I let it tick with the tesla? There's no cooling though with the cover off...