Need more info on this Hellium Cadmium laser

I found this laser and PSU on ebay and I was wondering if anyone knows more about these.  The laser head looks like a good deal.  The PSU=not such a good deal.
http://cgi.ebay.com/P50614-Liconix-...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
http://cgi.ebay.com/Liconix-4000PS-...96144146QQcmdZViewItemQQptZLH_DefaultDomain_0

Surely someone knows about these...

Daguin and Gooey should jump in on this one :

man I hate auctions like that - chopped cables and no way to determine the working condition

They are gorgeous lasers, but usually break in transit as they are ultra fragile. The head looks like it's in good shape, replacing the cables might be a bit of a pain but with only 500 hours on it, it *should* work. Keyword is: should.

Getting a working HeCd laser from ebay is even more of a gamble than getting a working argon from ebay.

Here is mine in action, although my head is a bit bigger and has two discharge cathodes whereas the one in the auction will only have one.

MarioMaster said:

man I hate auctions like that - chopped cables and no way to determine the working condition  

Click to expand...

I know.  I've been wanting a nice argon or other gas laser for a while now and all of the ones on ebay have some kind of catch that stops me from buying it.  It's always one of the following.
A-The laser works and has all the needed parts, but it's way too expensive.
B-The laser works and has all needed parts, but it takes something stupid like three phase electricity.
C-The laser has all the needed parts and looks good, but it comes "as is" and untested with no warranty.  Basically if it comes to your door and doesn't turn on then you have a $500 paperweight.
D-Laser is missing power supply.  A laser without the matching PSU is good how?  Also they can't test it without the supply.
E-Argon laser that has been left on a shelf for years unused=dead plasma tube=$500 paperweight.

GooeyGus said:

They are gorgeous lasers, but usually break in transit as they are ultra fragile. The head looks like it's in good shape, replacing the cables might be a bit of a pain but with only 500 hours on it, it *should* work. Keyword is: should.

Getting a working HeCd laser from ebay is even more of a gamble than getting a working argon from ebay.

Here is mine in action, although my head is a bit bigger and has two discharge cathodes whereas the one in the auction will only have one.

Click to expand...

Do HeCd lasers need to be used every other month like argons do? If not the head might be worth it if you can get it for $75.

Yes they do, they are even more finicky than argon lasers (by far!)

Coherent said:

[quote author=MarioMaster link=1234425031/0#3 date=1234560193]man I hate auctions like that - chopped cables and no way to determine the working condition  

Click to expand...

I know.  I've been wanting a nice argon or other gas laser for a while now and all of the ones on ebay have some kind of catch that stops me from buying it.  It's always one of the following.
A-The laser works and has all the needed parts, but it's way too expensive.
B-The laser works and has all needed parts, but it takes something stupid like three phase electricity.
C-The laser has all the needed parts and looks good, but it comes "as is" and untested with no warranty.  Basically if it comes to your door and doesn't turn on then you have a $500 paperweight.
D-Laser is missing power supply.  A laser without the matching PSU is good how?  Also they can't test it without the supply.
E-Argon laser that has been left on a shelf for years unused=dead plasma tube=$500 paperweight.

[/quote]


You just have to be patient - I have three argon lasers (and sold my first one, so if I had that I would now have 4) I purchased on Ebay, and only one was "not so good".   All these over about a 3 year period.  

I don't know about HeCd lasers, but if you're hunting for a decent argon, some words of advice:

Look for sellers that have some experience/knowledge in dealing with lasers and electronics.
Look for sellers that have excellent feedback and will stand by their sales.
Look for listings that guarantee no "DOA" and have a return/refund policy.  If they offer this then they have to honor it, or at least you'd have a very good chance of getting your money back if something is wrong.

IMO I'd avoid general electronics dealers (and any other listings) that state the item is untested and "as is" that don't deal almost exclusively in lasers.  If someone has an argon for sale and you look at their other stuff and they are a baseball card dealer then that's a red flag...unless you want to take a huge chance.

Avoid listings where the seller has no clue about lasers in general; if they spell the word "lazer" that's a huge flag there!

Three out of four isn't bad - you can find good, complete working units on Ebay if you're careful.

Speaking of HeCd lasers - a few days ago a complete (apparently) working unit was sold for about $275.00.  It was sold as-is but they did have a beam shot of sorts - the laser was putting out a blue dot on the wall in the photo.  I was watching that one but I'm kind of tapped out money-wise after buying that 514nm argon a couple weeks ago.

I got mine as a fully working system for $99 (+$150 for shipping) but it was sold "as-is, untested". It's all about taking chances.

How funny. I just recently tried to get the HeCd in our lab (same model, Liconix working.  It was working, then wasn't used for ~yr, now it is dead.  The He pressure slowly builds up and if it is too high, it will not lase.  These lasers are very finicky.  We found that they are really difficult and expensive to fix.  So, we have a large paper weight, probably similar to the one on ebay.

Sam's has a FAQ, but you've probably already seen that.
http://www.kellerstudio.de/repairfaq/sam/laserhec.htm

K

By the way, you have to wonder about the last part of this line "cadmium is considered to be a toxic heavy metal, even the vapor is not fun and tastes terrible. "

kristopher said:

How funny. I just recently tried to get the HeCd in our lab (same model, Liconix working.  [highlight]It was working, then wasn't used for ~yr, now it is dead. [/highlight] The He pressure slowly builds up and if it is too high, it will not lase.  These lasers are very finicky.  We found that they are really difficult and expensive to fix.  So, we have a large paper weight, probably similar to the one on ebay.

Click to expand...

From Sam's FAQ

[highlight]It is suggested to run these HeCd lasers for 24 hours for every month of storage.[/highlight] The reason is the the Helium will diffuse from its high pressure reservoir into the tube, resulting in a high He pressure/tube voltage. I have had to run some tube for months to bring the He pressure down far enough to allow lasing. You can't just raise the Cd partial pressure to get these things to lase. Keep monitoring the tube voltage day after day and you will see a drop from the depletion of excess He.

Have you tried the dry ice trick to get it to start?

Peace,
dave

Dave,

The laser belonged to someone else, a professor that retired. Otherwise we would have been using it . Why not, right?

Dry ice trick? What about a liquid nitrogen trick? That should work the same way, right? Just lower the pressure enough to get it lasing.

K

kristopher said:

Dave,
The laser belonged to someone else, a professor that retired.  Otherwise we would have been using it .  Why not, right?
Dry ice trick?  [highlight]What about a liquid nitrogen trick?[/highlight]  That should work the same way, right?  Just lower the pressure enough to get it lasing.
K

Click to expand...

LOL! That might work a bit too quick for the temperature to stabilize external to internal

I hear it can make a nice banana hammer though

Peace,
dave

kristopher said:

Dave,

The laser belonged to someone else, a professor that retired.  Otherwise we would have been using it .  Why not, right?

Dry ice trick?  What about a liquid nitrogen trick?  That should work the same way, right?  Just lower the pressure enough to get it lasing.

K

Click to expand...

Unplug the helium heater and just let it run. Assuming you can get it to start up and maintain plasma discharge, after a while it will lase again, if it's only a He pressure problem. It might need to run for a loooong time though. Like a week or so. Maybe more. If it wont start at all, use an oudin/tesla coil (handheld model BD-10A is the weapon of choice!) and zap the tube, that should get your discharge to maintain.

Also, and I'm sure you know this but it never hurts to mention, these lasers dont lase right away like most others do. They take about 5-10minutes before they start producing laser light. It could be 325nm as well... hold up a sheet of paper a few feet away and see if you get any florescence.

Thanks Gooey Gus. I'll try your suggestions. The laser head only has 110 hours, so it shouldn't be depleted of Cd (Don't they last ~1000hrs?).

I have checked the HV from the power supply and it looks fine, too. Since this is the power supply that it was working with before, I don't think that is the issue.

We have a telsa coil that should do the trick, too.

Kristopher