Spectra Physics 125

[MrNIFty923]

I am looking for any documentation for the big and old Spectra Physics 125 and or a 250 model exciter. Recently acquired a SP 164 argon and thought a good sized HeNe would be a good compliment for holo work. The exciter has one swelled up cap but all the tubes check out fine and the rest of the circuit boards look fine. I know the laser is old but I would really like to get it working again. There is another SP 125a that has been sitting in my office as a bench for a few years with a broken tube and it's always been a nagging desire to see one of these monsters producing a beam. I was kind of hoping that I could fine a replacement tube for one of these, but I don't think that is gonna happen.

[icecruncher]

My understanding is that these behemoths are soft seal and problematic on older ones because of it. (At least from what I remember on Sam's Laser FAQs) Usually, if they have been just sitting for a lengthy period of time, you won't have any success in getting them to run, if they are run regularly they are fine.

But, there are people much more knowledgeable on these than me that should comment.

[mixedgas]

My understanding is that these behemoths are soft seal and problematic on older ones because of it. (At least from what I remember on Sam's Laser FAQs) Usually, if they have been just sitting for a lengthy period of time, you won't have any success in getting them to run, if they are run regularly they are fine.

But, there are people much more knowledgeable on these than me that should comment.

Not all is lost. There are a few out there with hard seals and rebuilt tubes. If you have an actual business use, new tubes are available and two companies have rebuilt them for years (commercially) with great results. Still, your playing the lottery and odds are low.

Steve

[Eidetic]

I have one that's still operational with what appears to be an original tube from the late '60s. Still gives 65mW with a good mode. Vacuum tube version of the model 250 power supply too. The fan sticks occasionally. I have the manual too. What do you need from it?

[mixedgas]

He's looking for a capacitor. I Quote:

"One of the caps is swelled up on the exciter. The cap is a Plastic Capacitor Inc. (Lk 10-105), if anyone knows where to find a replacement one that would be great."

So we need to know the rated capacitance and rated voltage of that one cap for a start.

Here is the Plastic Capacitors, Inc Web site:

http://www.plasticcapacitors.com/

Here is the LK series, but type 10 is discontinued.

http://www.plasticcapacitors.com/typelk.php

Looking at the numbers, 10 seems to be the voltage range, and it looks like they make higher voltage models now. A higher voltage rating is better in a replacement, anyways.

So which will be quicker, MrNifty emailing PC to find out what it is, or Eidetic looking at the schematic?


Steve

[MrNIFty923]

Which companies could do the tube refurb? I'm guessing it would be pretty expensive though, right? The use is for hologram making for the company I work for.

[MrNIFty923]

I would love to have a copy of any of the manuals for the power supply and the laser head.

[MrNIFty923]

The capacitor is rated voltage is 1000 volts. It's either a 1 or .1 mfd I acidentally deleted the specs off my phone trying to copy it. I think it is 1 mfd though.

[mixedgas]

"Which companies could do the tube refurb? I'm guessing it would be pretty expensive though, right? The use is for hologram making for the company I work for."

Evergreen Laser and Cambridge Laser Labs for starters... Cambridge has the legal rights to the SP glass tube design and makes the best hard sealed Brewster windows, as they do a huge amount of tubes per year. Cost depends on what is actually being done....

Do you have the etalon option for single mode lasing?

I'll see if I still have the PDF of the manual. That is like 4 laptops ago. I do have the hard copy for sure.

Steve

[MrNIFty923]

One of the laser heads I have has the optical cavity extension to attach extra optics. I don't have the etalon, but I would like to get that as well.