JDSU 2214-30SLQTA Argon laser testing and PSU Tweak

[daryldee]

Hi LASERS!

It's just since I was a child that I would own an argon laser...
I was fascinated by a '90s pseudo sci-fi movie where there was one in a lab, lasing and reflecting all around the room, with this beautiful azure color.
So, many years later, I bought one piece at a time and I managed to assemble it.

But now, I need help among you savvy, since I couldn't find (or interpret) any info on SAM's laser FAQs to help me on making it work correctly.
Let me jump straight to the problem with some details:

The model: as per post thread title - JDSU 2214-30SLQTA.
The PSU: JDSU 2110U-MLS.
The cooling system: Original duct pipe; so, present.
The problem: LOW output power, almost none, not a real change between Light/Current mode switching.
Suspected PSU incompatibility.

Help me please, maybe I should modify the 2110U-MLS PSU : ).
More details will follow with some pictures, a video, and measurements below.

24 ~ 54 VDC: DC+
-115 ~ 138 VDC: Cathode/Filament (F1/F2)
14.6 VDC: +15 VDC
-14.9 VDC: -15 VDC

14.0 VDC: Start+
0.0 VDC: Start-

Descriptions under each media:

This is the working behaviour of the laser.
You can hear the clicks of the PSW, everything looks normal as described in the SAM's FAQs.
The Yellow channel in the oscilloscope is the DC measure of the POWER output, the Blue is the LIGHT output.
When I switch between the two modes, the power rises because the pots are set one to 5k and the other to 100 Ohms; I see no noticeable difference if I invert the pot's settings.



The general picture.
Note the starter circuit box is open, I did it to see if I could measure something.



The laser head, removed from a KLA Tencor optical inspector.



My control panel. The umbilical cable connectors where open for a general check.
No difference if reassembled.



This is the scope measurements in low power, all the pots at minimum.
Yellow is POWER, blue is LIGHT.



This is the maximum I can get.



For the sake of reporting.

Well, that's it for the moment.
I hope I will get help from you soon!
I am anxious to make this beast work : ).

Thanks and have a nice day,
Dario.

 

[Anthony P]

I do not have an answer for you. I own two similar lasers and I can tell you that the output on yours looks "jacked up". At that range, you should see a tiny dot on your card about 1-2mm diameter. I wonder if your tube is not lasing and you are just seeing the glow of the argon.

 

[lasingfox]

looks like the mirrors could be misaligned. on the jdsu heads, they are glued and hard to access while power on but maybe you could jam piece of plastic through one of the vent holes to nudge the mounts and maybe get a tiny bit of 488nm? they come with these little collars usually for adjusting but again, hard to access while powered up and pretty dangerous, haha. Do you have a small HeNe to check the alignment maybe?

 

[Anthony P]

What is the current to the tube? Even on standby or low power you should have around 4 amps. At full power maybe 8amps.

 

[diachi]

What is the current to the tube? Even on standby or low power you should have around 4 amps. At full power maybe 8amps.

Looks like they've tried 4A and full current (~10A), going by the scope screenshots.

Definitely not lasing, probably misaligned, or it has a saggy cathode which is interfering with the cavity.

 

[Mosc007]

My working Argon had a miss-aligned front mirror. I had to make up a bracket that fitted over the front end of the tube and had 3 screws into it from the metal frame. By adjusting the screws I was able to slightly bend the front mirror mount and align the mirror. That got it working well. The bracket has to be nylon though. High voltage on the front of the tube. I think I posted a pic on here but it was a few years ago now.

 

[lasingfox]

My working Argon had a miss-aligned front mirror. I had to make up a bracket that fitted over the front end of the tube and had 3 screws into it from the metal frame. By adjusting the screws I was able to slightly bend the front mirror mount and align the mirror. That got it working well. The bracket has to be nylon though. High voltage on the front of the tube. I think I posted a pic on here but it was a few years ago now.

some of the jdsu tubes have metal collars for just that.

 

[daryldee]

[...] the output on yours looks "jacked up". [...] I wonder if your tube is not lasing and you are just seeing the glow of the argon.

Could it be? Do you think it's the filament glow through the argon?

looks like the mirrors could be misaligned. on the jdsu heads, they are glued and hard to access while power on but maybe you could jam piece of plastic through one of the vent holes to nudge the mounts and maybe get a tiny bit of 488nm? they come with these little collars usually for adjusting but again, hard to access while powered up and pretty dangerous, haha. Do you have a small HeNe to check the alignment maybe?

Yes I have it! How should I use it to do the check?
I will try it this weekend.

What is the current to the tube? Even on standby or low power you should have around 4 amps. At full power maybe 8amps.

Looks like they've tried 4A and full current (~10A), going by the scope screenshots.

Definitely not lasing, probably misaligned, or it has a saggy cathode which is interfering with the cavity.

To do a proper measurement I should use the multimeter, and remove some cabling (Filament has 4, 2 yellow and 2 blue per side).
In reply to Diachi, I don't know if the range is correct, the manual reports that every PSU/TUBE could report a different power and light output measurement.
If I recall well, the correct measurement for this tube SHOULD be between "0" and 4v at 10A.

[...] High voltage on the front of the tube. I think I posted a pic on here but it was a few years ago now.

How high? I measure a DC output to the tube of around 24 ~ 54 VDC: DC+
Am I measuring the wrong output?

some of the jdsu tubes have metal collars for just that.

Very interesting. I hope I have something similar.

Thanks to everybody!
Very good insights, I will post updates soon

 

[diachi]

Could it be? Do you think it's the filament glow through the argon?

No, that's not the filament glow. The tube has clearly lit, that's the glow from the argon itself. Filament glow is orange and not nearly as bright.

To do a proper measurement I should use the multimeter, and remove some cabling (Filament has 4, 2 yellow and 2 blue per side).
In reply to Diachi, I don't know if the range is correct, the manual reports that every PSU/TUBE could report a different power and light output measurement.
If I recall well, the correct measurement for this tube SHOULD be between "0" and 4v at 10A.

Why do you want to remove cabling...? Filament is required to run properly.

Light measurement isn't always accurate/calibrated, current measurement should be though. Scale is 100mV/1A so your 400mV reading is the expected 4A idle current and the ~1V reading is the expected 10A maximum.

How high? I measure a DC output to the tube of around 24 ~ 54 VDC: DC+
Am I measuring the wrong output?

These tubes should be somewhere around 104V at the designed tube current of 8A if memory serves me right.

How are you measuring the tube voltage...?

Answers/further questions in red.

 

[hakzaw1]

Wish I knew more...
Mine would only 'idle' until I got a JDSL interface.. there is a way to jump the pins in the DB25 But I do not know which ones you should jump or if you will get more than idle.
also afaik you should pull the air thru NOT blow it into the laser. My ML (square type w/fans on top) makes 5 lines.. 6 lines if you push more.
It makes wonderful Lumia.. and heats up a cold room a little.

 

[diachi]

Wish I knew more...
Mine would only 'idle' until I got a JDSL interface.. there is a way to jump the pins in the DB25 But I do not know which ones you should jump or if you will get more than idle.
also afaik you should pull the air thru NOT blow it into the laser. My ML (square type w/fans on top) makes 5 lines.. 6 lines if you push more.
It makes wonderful Lumia.. and heats up a cold room a little.

Sam's FAQ has the pinout and schematics for a controller, as does the manual for the PSU. Can't remember off the top of my head what pins are needed but can be set up to be adjustable current with a pot easily.

And yes, air should be pulled through not blown in.

 

[hakzaw1]

here is the same remote interface I got on eekbay for my ML Argon-




I got a different one first --it has no LCD Screen where the mW shows- and cheaper. I wish I knew more about some of the options-- looked for an 'owners manual'.

JDS Uniphase 2500 Laser Remote Interface | eBay

JDS Uniphase. Laser Remote Interface. Model: 2500.

www.ebay.com

(that even I can understand) so what I DO know I learned from trial and error. I can make it idle and run- duh that is a no brainer BUT I would like to know more.. looked at Dr.Sam and did not find much--maybe I need to check there again. When I have it in 'run' and 'on' in the right setting I see the mW and it goes from IDLE to very bright-more than 100mW--I think I when I press Current (Mode) and Current (displaly) the Amps show. and can be adjusted.
When I press Light I see the mW-and bottom left there is a switch INTERLOCK Local on or REMOTE- remote- but I am not sure which I use and when- the db 25 (?female) on the front there is a jumpwire going from the top right pin to the top left pin. The other JDSU 2500 came with no jump and I have only used that one-- I have another cheaper version- no LCD Screen- I think that one is 2550 (?) not sure where it is ATM. I need to know what I am doing instead of pressing 'buttons' to see what I am doing-- an Owners Manual for Dummies.. not even sure why the is another db 25 on the front- the one on the back (male) is attached to the PS.


Since I have two of these I only have used the one w/o the jump wire.. any link or help understand all this MUCH better would be great..
MYB if you jumpwired the same pins on your PS you might get more than Idle-- I never tried.
I am not 100% that what is have put here is correct.
This would be the perfect time to run all my argons
No propane in the big tank- have not used the heater in the attic for 9 years- this weekend plus Mon and Tue we will have the coldest winter in 10 years- monday night down to 6 degrees- some snow maybe in north Houston.. I am close to the gulf and were we get slightly warmer temps most of the time..I hope we do not lose power--I am only using small electric space heaters in two rooms.. right now it is 46 in my living room- I can escape to my neighbors if needed.
sorry for going so off-topic ( sign of cabin fever)
hope everybody is OK - watch out for the black ice-IT killed 6 in DFW Thursday ...1 mile long wreck 100 cars and trucks--(daytime) guess it could have been worse (at night for sure)... praying for the families.

 

[Mosc007]

How high? I measure a DC output to the tube of around 24 ~ 54 VDC: DC+
Am I measuring the wrong output?

The tube votage once ignited should be around 110-150 VDC depending on gas pressure.

Be carefull when measuring though. The Ignitor voltage is around 15k so can easily blow your DMM up.

 

[LSRFAQ]

JDSU tubes are not glued. The hard seal glass frit, when fired, has the appearance of grey epoxy,. Trust me, JDSU argons use sealing glass frit. Its fused on with an induction heater in a vacuum , from a frit preform made of partially fused frit powder. See attached...

Steve