The large 'ball bearing mount' to 'V' receptacle was at that time patented, but by a rather small company I believe, and ALL the laser companies employed it on mirror mounts, optical mounts, as well as the 'pre-set' laser rail mount configurations... and they did not pay any royalties, unless they were a 'mount' vendor.
13:30 That yellow residue is a typical color for Tungsten trioxide which is chicken yellow and that makes me think that the wire actually is tungsten and thus this very thick to be able to withstand the oxidation from the air, but why they would use tungsten that would oxidize instead or fex ni-cr wire or such I have no idea but I guess they had their reasons.
Shame those lenses had deteriorated so much - it would have been nice to see it operate. Thanks for the teardown - I have seen this model used, but never seen inside one!
You said at 4:45 that periscope mirror is "changing length without changing the angle". How that can possibly be? Periscope is mounted on a pivot and it obviously rotates, at 16:20 ? I might be wrong, but I only see that periscope is rotating, no translation.
+HitAndMissLab The periscope does rotate, but the angle of the light beam is unaffected due to the optical setup where the light goes through the periscope, off a mirror then back through the periscope.
+tesla500 Ohh, lightpath returns on itself. I was wandering where the interference came from ;-). Obviously it interferes with itself. Yeah, at first I didn't understand how path lengthens with periscope. Than I though about it and it became obvious. Never thought of that principle.
tesla500 well are you interested in any old tube radios? thats the first thing that comes to mind. i just scored like 5 random old radios from a guy who was going to throw them away. but yeah i'll send you an email.
Yeah, the NaCl, and potential 'dust' is the reason for the internal shields. What you call the 'laser power supply' is actually a 'high voltage' step-up transformer (in the industry called a 'brick.' Different lasers, different flash lamps, different plasma configurations require different bricks.' NO laser operates without the back ( fixed in this case) and front mirror (semi-reflective, adjustable as you pointed out) are to be in absolute PROPER alignment... slight errors can produce very poor output, as well as possible 'hot spots' that can burn opitics.So perhaps the 'laser' is shot, but in these circumstances a good one' would fail too IMHO. The rather 'low frequency' flashing indicates that a bad brick ratio could be the culprit, as well as laser (front mirror) alignment issues. This IS an infrared laser, so knowing the 'spec' of it's output may even indicate that seeing it visibly is very very unlikely. On the other hand, the gases in these laser tubes are KNOWN to deteriorate with time, even when on the shelf. When new, they 'change' over the first month quite a bit, flatten-off, and deteriorate slowly. In fact, the gas balance selected is not for initial optimal output, but for allowing the 'burn-in' period to be shorter.
I think it's because NaCl is the only material that also passes visible light, so the visible reference laser can pass through. I can conceive of having separate optics for the laser though, so there should be a way around it.
tesla500 I've seen ZnSe optics that are transparent, but as they were yellow they probably attenuated the red light from the laser too much and this thing probably predates yellow lasers.
randacnam7321 I have some ZnSe optical windows and I just tried shining a red diode laser through one and there is very little attenuation. However, one big difference between NaCl and ZnSe is the index of refraction. NaCl is only about 1.5 but ZnSe is 2.5. Maybe this has something to do with it, since the need for optical anti-reflection coatings would be less with NaCl, and those coatings typically have a much more limited bandwidth than the material itself will transmit.
They didn't have the cheap ZnSe back in the 80s (or the cheap CO2 lasers.) Today you can buy non-melting ZnSe or CaF2 replacements for NaCl windows for Perkin Elmer FTIR.
The choice of 'Power One' power supplies from mid-80's to 90's was because they were cheap; they were cheap because THEY were Apple's choice, and Power One could economically beat all their competitors. One short cut they maintained? No final test! The 'customers' did the testing... as that was the economical choice; and nothing 'custom.' They WOULD tell you what modification for you to make to them... for instance, when/if you noticed perhaps that the EMI wouldn't pass spec. (Note too, when reconfiguring, leaving an output 'open' can eliminate output on another rail; that is, load of one rail is necessary for output on another. )
I am in the process of changing the Source coil, my question is how is that coil attached under the firebrick foam? Does it just pull out and push another in or does bottom of coil wraped around a screw? We are taking our chances doing it ourselves to save thousands shipping and fixing it. If you can still remember how it attaches that would be great, this video has been a big help up to this point, thanks in advance
Can someone give me some information about the mechanism of moving mirror. As you say they are using a swinging periscope , can you throw some light on it.
Beckman instruments came up with moving mirror to control the launch of D2 flash lamp energy into a grating. If you study the design of a Selsyn (synchro) motor you will understand the principle of the this control. Interestingly, that portion of the Beckman design (now FAR out of patent) was incredibly robust, and precise; and lent itself to scanning spectrophotometry. Self alignment took place at start-up, using the 'natural' peaks to be found in in the D2 spectrum. The electronic design of this device would be similar.
Very cool to see the insides of an FTIR spectrometer. Nice teardown!
You know what would be really cool? To see a new video from you, Ben ._.
I was half expecting to see the cat come along and start licking those NaCl windows...
The large 'ball bearing mount' to 'V' receptacle was at that time patented, but by a rather small company I believe, and ALL the laser companies employed it on mirror mounts, optical mounts, as well as the 'pre-set' laser rail mount configurations... and they did not pay any royalties, unless they were a 'mount' vendor.
13:30 That yellow residue is a typical color for Tungsten trioxide which is chicken yellow and that makes me think that the wire actually is tungsten and thus this very thick to be able to withstand the oxidation from the air, but why they would use tungsten that would oxidize instead or fex ni-cr wire or such I have no idea but I guess they had their reasons.
Those mirrors might be good for a mini-schliren photo setup. Cool teardown.
at 8:27 it feels like reviving an ancient computer control console in fallout. somehow that feels so good..
Shame those lenses had deteriorated so much - it would have been nice to see it operate.
Thanks for the teardown - I have seen this model used, but never seen inside one!
Very interesting video as always - thanks for sharing :)
You said at 4:45 that periscope mirror is "changing length without changing the angle". How that can possibly be? Periscope is mounted on a pivot and it obviously rotates, at 16:20 ? I might be wrong, but I only see that periscope is rotating, no translation.
+HitAndMissLab The periscope does rotate, but the angle of the light beam is unaffected due to the optical setup where the light goes through the periscope, off a mirror then back through the periscope.
+tesla500 Ohh, lightpath returns on itself. I was wandering where the interference came from ;-). Obviously it interferes with itself.
Yeah, at first I didn't understand how path lengthens with periscope. Than I though about it and it became obvious. Never thought of that principle.
why was the laser causing so much interferiance with your microphone ?
Couldn't hear a single word you said while you had the dead laser fired up, it caused a LOT of popping interference in your microphone!
could i trade you for the laser tube?
Sure, let me know what you have, tesla500@hotmail.com
tesla500 well are you interested in any old tube radios? thats the first thing that comes to mind. i just scored like 5 random old radios from a guy who was going to throw them away. but yeah i'll send you an email.
Think about all the engineering gone into that. Awesome!
I interviewed there 1984, when they were designing: w/cutting-edge 68000 processor!
Where do you get all this cool stuff?
Do you think it is possible to use a similar equipment to identify the element composition of a metal surface?
So, if you put those lenses in a glass of water, would they break down into solution?
Yep.
Wow had no idea simple table salt was being used to make expensive specialized infrared optics.
Nice stuff you don't see every day :)
Yeah, the NaCl, and potential 'dust' is the reason for the internal shields. What you call the 'laser power supply' is actually a 'high voltage' step-up transformer (in the industry called a 'brick.' Different lasers, different flash lamps, different plasma configurations require different bricks.' NO laser operates without the back ( fixed in this case) and front mirror (semi-reflective, adjustable as you pointed out) are to be in absolute PROPER alignment... slight errors can produce very poor output, as well as possible 'hot spots' that can burn opitics.So perhaps the 'laser' is shot, but in these circumstances a good one' would fail too IMHO. The rather 'low frequency' flashing indicates that a bad brick ratio could be the culprit, as well as laser (front mirror) alignment issues. This IS an infrared laser, so knowing the 'spec' of it's output may even indicate that seeing it visibly is very very unlikely. On the other hand, the gases in these laser tubes are KNOWN to deteriorate with time, even when on the shelf. When new, they 'change' over the first month quite a bit, flatten-off, and deteriorate slowly. In fact, the gas balance selected is not for initial optimal output, but for allowing the 'burn-in' period to be shorter.
There any reason to use NaCl optics vs. ZnSe or Ge (besides relative material cost)?
I think it's because NaCl is the only material that also passes visible light, so the visible reference laser can pass through. I can conceive of having separate optics for the laser though, so there should be a way around it.
tesla500
I've seen ZnSe optics that are transparent, but as they were yellow they probably attenuated the red light from the laser too much and this thing probably predates yellow lasers.
randacnam7321
I have some ZnSe optical windows and I just tried shining a red diode laser through one and there is very little attenuation. However, one big difference between NaCl and ZnSe is the index of refraction. NaCl is only about 1.5 but ZnSe is 2.5. Maybe this has something to do with it, since the need for optical anti-reflection coatings would be less with NaCl, and those coatings typically have a much more limited bandwidth than the material itself will transmit.
They didn't have the cheap ZnSe back in the 80s (or the cheap CO2 lasers.) Today you can buy non-melting ZnSe or CaF2 replacements for NaCl windows for Perkin Elmer FTIR.
The choice of 'Power One' power supplies from mid-80's to 90's was because they were cheap; they were cheap because THEY were Apple's choice, and Power One could economically beat all their competitors. One short cut they maintained? No final test! The 'customers' did the testing... as that was the economical choice; and nothing 'custom.' They WOULD tell you what modification for you to make to them... for instance, when/if you noticed perhaps that the EMI wouldn't pass spec. (Note too, when reconfiguring, leaving an output 'open' can eliminate output on another rail; that is, load of one rail is necessary for output on another. )
I wonder what the price tag on that was when it was new?
If you have to ask, you couldn't afford it ;)
superdau On the contrary, I'm sure the price tag will be re-reassuringly expensive. ;-)
I am in the process of changing the Source coil, my question is how is that coil attached under the firebrick foam? Does it just pull out and push another in or does bottom of coil wraped around a screw? We are taking our chances doing it ourselves to save thousands shipping and fixing it. If you can still remember how it attaches that would be great, this video has been a big help up to this point, thanks in advance
Usually must disassemble. It's held in a 2-piece metal block with tightened screws. But not hard to DIY, we replace those all the time here at UW.
Amazing chanel!!!!
Muito bom
very interesting!
Can someone give me some information about the mechanism of moving mirror. As you say they are using a swinging periscope , can you throw some light on it.
Beckman instruments came up with moving mirror to control the launch of D2 flash lamp energy into a grating. If you study the design of a Selsyn (synchro) motor you will understand the principle of the this control. Interestingly, that portion of the Beckman design (now FAR out of patent) was incredibly robust, and precise; and lent itself to scanning spectrophotometry. Self alignment took place at start-up, using the 'natural' peaks to be found in in the D2 spectrum. The electronic design of this device would be similar.
Polish the windows... All you need is a rag and a little spit ;)
F