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Spectra Physics 155 HeNe

diachi

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My "new" (to me at least...) HeNe showed up today! It's a Spectra Physics 155 manufactured in 1983. The output spec is 0.95mW at 632.8nm, but after 33 and a bit years I'd say it's probably not making that anymore, although it does still lase! :D


Picture time...

Came in a nice big box filled with bubble wrap, good job to the seller there! Leatherman for scale.
dcnks2w.jpg


YxMLRcG.jpg



Nice round dot:
OHrgcwx.jpg


And the best part, the rather nice looking glass tube! :p

The camera picks it up the glow as being much more yellow/orange than it is, it actually looks fairly healthy to the naked eye, closer to the sort of pinkish orange glow a HeNe should have.
1FbdMCV.jpg



Cathode "end". The cathode is the metal piece in the larger glass tube.
I2OWF0l.jpg



Anode. The anode on the 155 is half way down the tube, SP157s and 159s actually use almost the same tube, but with the anode further down. This increases the length of the discharge/gain medium and results in a fairly big jump in power (up to ~5mW output).
MNmENHp.jpg



Looking down the tube.
yQk58ae.jpg



Unfortunately it does seem to have some power supply issues, it'll only start intermittently (or sometimes not at all). Will need to troubleshoot that, it may be a combination of failing driver and an old tube or it could just be the driver - thankfully they are very simple so repairs shouldn't be too difficult. :D

Hope everyone enjoyed the pictures/thread! :) Hopefully I'll have some more goodies to share with everyone over the next month or so, stay tuned. ;)
 
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Is it weird that I might've been paying more attention to that leatherman? :p That gas laser is really neat, never seen one like that before. Where did you pick it up from, eBay I'm guessing?
 

diachi

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Is it weird that I might've been paying more attention to that leatherman? :p That gas laser is really neat, never seen one like that before. Where did you pick it up from, eBay I'm guessing?

Haha, not at all, they are nice tools!

Yeah, these old tubes were much more interesting looking. It did come from eBay, can't remember the price, but it was a pretty good deal, I'll need to check later.
:)
 

CurtisOliver

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Lovely HeNe Diachi. That dot is lovely and round. Other than the power supply issues you have mentioned, it looks in very good shape. Nice find and enjoy. :beer:
 
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Nice HeNe diachi...
Is that the Laser you needed the PS for ??

Jerry
 

BowtieGuy

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Great pics of your new HeNe, diachi, thanks for sharing!
I hope you get your power supply problems sorted out.
:kewlpics:
 

diachi

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Lovely HeNe Diachi. That dot is lovely and round. Other than the power supply issues you have mentioned, it looks in very good shape. Nice find and enjoy. :beer:

Not bad for 33 years old and $20 (before shipping)! :D

Nice HeNe diachi...
Is that the Laser you needed the PS for ??

Jerry

Nope, that was for the 6mW Melles Griot HeNe from Lazerman121, that one has the "normal" tube design where it's a glass tube with the bore running through the middle. Going to post pictures of that once I build a housing for it. :)

Great pics of your new HeNe, diachi, thanks for sharing!
I hope you get your power supply problems sorted out.
:kewlpics:

Thanks :)! Lazerman121 has a damaged PSU for one of these that he said he'll send me. Hopefully I can transplant some parts from that and get mine up and running properly! I'm blaming the HV caps on the multiplier at the moment.
 

CurtisOliver

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I do my own occasional browse to see what is out there. Much of the good deals frustratingly are over the pond.
I managed to get an old HeNe for around £20 from a UK seller a while back. He wasn't too happy as he made a mistake on the listing cost. :p
 
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Lovely old tube, diachi. Sorry to hear it has issues, but with its age, not a total surprise. Thank you for sharing the photos.
 
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Been spending a lot of time on eBay lately! :p

There's been a whole bunch of these for sale recently, I linked several in the eBay thread.


Congrats on the side-arm. Hope you get something working to stabilize the HENE driver for it.

I've seen tons of the them over the years. I like the side-arm HeNe tubes, just have a very cool look to them. (And more shaped glass in the tube is always neat.

I'm always tempted to get one when I see the prices. Only thing that has stopped me is the output on these is very low (I think they are all less than a mw. (http://web.mit.edu/8.13/8.13d/manuals/spectra-physics-155-155a-155c-he-ne-lasers.pdf) But a second side-arm would be cool to have.

I know these were very common in school experiments for a while and for anyone else looking you can usually pick one up on the cheap.

And having an embedded power supply makes them a good deal for the money.

Power supplies can be pricey on their own!
 
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Thanks, Icecruncher. It is nice to see the manual for these old HeNe lasers again. Even though it is not polarized (random polarization), the c/2L= 550 MHz, which ain't bad at all.
 

diachi

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Congrats on the side-arm. Hope you get something working to stabilize the HENE driver for it.

I've seen tons of the them over the years. I like the side-arm HeNe tubes, just have a very cool look to them. (And more shaped glass in the tube is always neat.

I'm always tempted to get one when I see the prices. Only thing that has stopped me is the output on these is very low (I think they are all less than a mw. (http://web.mit.edu/8.13/8.13d/manuals/spectra-physics-155-155a-155c-he-ne-lasers.pdf) But a second side-arm would be cool to have.

I know these were very common in school experiments for a while and for anyone else looking you can usually pick one up on the cheap.

And having an embedded power supply makes them a good deal for the money.

Power supplies can be pricey on their own!


Thanks! Me too, luckily the supplies in these are very simple.

These older gas lasers are nicest for just that reason, they've gotr all that nice glass work!

Can be found for very low prices, but you're correct, output power is tiny, at least on the 155. The 157 and 159 are spec'd at 3mW and 5mW respectively, while the 155 is 0.4-0.76mW when running at spec, which it's unlikely any of them are anymore.
 
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Nice find! The tube is probably low on Helium. I have one too, one of the oldest ones ever made. (a 156 with the older grey case instead of a tan one, from the early 70s) I rarely starts and is low in power. they're all soft seal, so they're in varying states of decay. Many have a bad seal job and go completely dead, but some have a good enough seal job that they don't leak atmosphere, but instead the helium leaks out due to how small it is. Helium is so light it can diffuse through the seal and glass, though very very slowly so over years of sitting the tube is left with no/not enough buffer gas left in it. the later 155s like yours have a slightly better driver. Mine is even simpler electrically. It runs on a modern supply fine though, but at a lower power than it is supposed to due to the lower pressure. I soak tubes in helium from time to time, but it takes forever and is expensive to re-pump/soak them so its usually not worth it for tiny tubes like these. Re-fills are pricy as hell in particular. Tubes that are still good like this one it sometimes can be revived back up to spec if you're patient and persistent and know how to do it though. Overshooting it however will put you in an even worse spot so care has to be taken. I did it to a bunch of long 124s a while back. some have come out better than others. so I have some of the only working 124s on the planet. I've only ever seen a few that work. Almost all of them are dead as can be at this point. I do see 155s and 120s that still work rarely though. I've got 3 model 120s now-2 tan ones and an older 70s one. :D Ancient old tubes from a time long past...

I should update this thread....but here's more on the model 120:
http://laserpointerforums.com/f43/l...y-quest-find-pic-heavy-91321.html#post1327104
 
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Wow, a 124 that works :)

I'd love to see one (or better- own one) of those.

I'm always leery about the big soft seal tubes. Once in a while I see a 124 pop up on ebay. But they are NEVER working obviously :(

So - still on topic :)

How often do you need to fire a soft seal to keep it healthy? Assuming there is no real leak and it is healthy to start with?



Nice find! The tube is probably low on Helium. I have one too, one of the oldest ones ever made. (a 156 with the older grey case instead of a tan one, from the early 70s) I rarely starts and is low in power. they're all soft seal, so they're in varying states of decay. Many have a bad seal job and go completely dead, but some have a good enough seal job that they don't leak atmosphere, but instead the helium leaks out due to how small it is. Helium is so light it can diffuse through the seal and glass, though very very slowly so over years of sitting the tube is left with no/not enough buffer gas left in it. the later 155s like yours have a slightly better driver. Mine is even simpler electrically. It runs on a modern supply fine though, but at a lower power than it is supposed to due to the lower pressure. I soak tubes in helium from time to time, but it takes forever and is expensive to re-pump/soak them so its usually not worth it for tiny tubes like these. Re-fills are pricy as hell in particular. Tubes that are still good like this one it sometimes can be revived back up to spec if you're patient and persistent and know how to do it though. Overshooting it however will put you in an even worse spot so care has to be taken. I did it to a bunch of long 124s a while back. some have come out better than others. so I have some of the only working 124s on the planet. I've only ever seen a few that work. Almost all of them are dead as can be at this point. I do see 155s and 120s that still work rarely though. I've got 3 model 120s now-2 tan ones and an older 70s one. :D Ancient old tubes from a time long past...

I should update this thread....but here's more on the model 120:
http://laserpointerforums.com/f43/l...y-quest-find-pic-heavy-91321.html#post1327104
 




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