GE Talaria projector light valve

Extreme teardown of a GE Talaria projector colour light valve.
Update video : • GE Talaria follow-up
GE Talaria documents : www.one-electro...
My talk on the Eidophor : • Eidophor: 1950's Steam...
History of the Eidophor book : electricstuff.c...
Advertisment for Eidophor : • Eidophor commercial

[@whatdoyouwantfromlif]

Used to maintain one of these in the BBC "Breakfast Time" studio in the early 1980s. It back-projected animated graphics onto a 5 foot screen for the weather man (Francis Wilson) to stand in front of and wave his arms around, which was quite a tall order at the time. For use in-shot it had to be bright enough to compete with the studio lighting, and we all know the television camera is very unforgiving of colour impurity or shading etc. The diffraction gratings created on the oil film required a very stable video input. If the input was disturbed or switched to a non-synchronous source, a wave of uneven oil would pass across the scanned area, taking about 20 minutes to clear. This looked like a series of bubbles or bright clouds sweeping diagonally across the screen and was very noticeable. On the weather map graphic it looked uncannily like a weather front approaching from the north Atlantic! The getter thing hanging out of the bottom was called the IHSP (Internal Hydrogen Sorption Pump), and it was the main thing that determined the lifespan of the light valve. When the titanium filament went open-circuit you were running on borrowed time because the vacuum would be slowly contaminated by gases from the oil. Then it was time to get out the cheque book and order a new light valve (£17,000 UK at 1980s prices). The other thing that could kill the light valve was explosion of the xenon bulb. This was a several-hundred watt high pressure lamp mounted in a reflector behind the light valve itself. If you tried to operate this lamp beyond its recommended service life the pressure could build up dangerously, until it failed. Bits of broken bulb and lens could then be thrown forward into the delicate input dichroics causing all sorts of damage. There was an hours meter on the projector but I don't recall any automatic shutdown when the bulb hours had been exceeded. Thank you for reminding me of this amazing device and showing its internal details. Even at the time it seemed unbelievable that the concept could work at all, let alone with reasonable consistency and reliability. The routine alignment procedure was long-winded and not at all intuitive, and had to be followed to the letter by a specially trained engineer. Any slip could result in rainbow colours and shading over large areas of the picture, and the only solution was to go back and start again. Casual adjustment was very much discouraged, to the extent that we engineers had to fit a padlock and chain to deter unauthorised fiddling!

[@mikeselectricstuff]

Thanks- one of the things I love about these kinds of teardowns is getting info from people that used them!

[@mikeselectricstuff]

Pity about the pump filament being the limiting factor - they could easily have put a few more spare filaments in there!

[@SeanBZA]

@@mikeselectricstuff Yes that CRT base certainly had enough spare pins, though probably the designers figured out that when the getter filament was dead the drive filament would probably be well past it's best anyway, so a rebuild to replace the one will of course also involve replacing the other.

[@AppliedScience]

Most interesting teardown I've seen in a long time. Thanks for making the video. I'd love to hear the conversation between the engineers and business people regarding the cost/benefit analysis for that projector.

[@rkan2]

Mike seriously needs to send the oil for you to analyze!

[@jguy584]

Ben, this is exactly the kind of crazy thing you would figure out how to DIY...

[@aronbjr]

I integrated six of these (into one image) for Whitney Houston’s “I’m Your Baby Tonight Tour”, with pneumatic shutters (these have a low contrast ratio), and X Y alignment mirrors along with a huge mount for the six projectors. They take a while to warm up, cool down, and are difficult to tour with!

[@KallePihlajasaari]

Props to you. Tell some more stories or they will be lost for all time when you forget/slip the mortal coil. At least here in youtube comments they will survive for eternity.

[@IanScottJohnston]

From an old Ebay Ad for one of these:- "The Talaria was a $100,000 projector, used most commonly in closed-circuit TV. …The Pope owned two, Hugh Hefner owned about a dozen and they were all over the Pentagon and in flight simulation. Microsoft co-founder Paul Allen had one, Steve Jobs had one, and we rented them to all the big rock groups for concerts, including eight for the Rolling Stones for their Steel Wheels tour"

[@douro20]

The one which cost $100,000 used three light valves, one for each of the primary colours, and a 10kW xenon short-arc lamp.

[@electronash]

From the wiki... "The single lens color projector (PJ5000 line) use dichroic filters to separate the white light of the xenon bulb in two channels, Green and Magenta. RGB color separation and processing is obtained using vertical wobbulation of the electron beam on the oil film to modulate the green channel and sawtooth modulation is added to the horizontal sweep to separate and modulate Red and Blue channels. The optical system used in the Talaria line is a Schlieren optic like an Eidophor, but the color extraction is much more complex."

[@electronash]

It almost sounds like that tiny variation in the beam pattern causes a change in the direction of the reflected light. And that slight direction change of the beam gets amplified by the whole Schlieren optics thing, because it only needs a very tiny amount of change. Maybe that can separate the red and blue from the magenta light using a chromatic abberation effect? No idea. lol (and Green gets activated like a "monochrome" version of the tube, where the light gets deflected a tiny bit in the vertical direction?)

[@electronash]

And then of course I see Mike uploaded a follow-up vid, nine hours ago. lol

[@Spirit532]

The lump on the side is certainly a vacuum pump - not entirely sure which kind, but by the looks of it, it's probably either an evaporable getter, or a titanium sublimation pump. The rings are heatsinks, to recondense the vapors(and either activate them, or capture the gas if it's a tisub). The beads are an oil filter - the pump can pump gases, but if it meets oil, there will just be lots of carbon decomposition. The oil is likely a silicone high vacuum oil with special light-valve-y electrostatic-y additives. Looks almost identical some diffusion pump silicone oils - goop at low temp, liquid at high temp, and low vapor pressure(for high vacuum operation). The ceramic electron gun is most likely because they were _very_ disposable - and while rebuilding the rest of the tube wasn't necessary, the gun likely failed quite often due to the extreme operating conditions(imagine how much power you'd need in this beam!). Ceramic vacuum assemblies are very easy to put into mass production - metal to ceramic brazing is fast and cheap, and ceramics can be prefabricated, along with the metal(likely kovar) rings.

[@Mikkel324]

Nice analysis! The oil consistency reminds me a bit of Santovac 5, which is a polyphenyl ether diffusion pump fluid. DC705 silicone oil is pretty viscous as well, but less so than Santovac. I've seen recommendations against using silicone fluids in vacuum systems with electron optics, due to the formation of insulating silica coatings on electrodes upon decomposition.

[@Spirit532]

@@Mikkel324 That is a valid concern! I wonder what they're doing to avoid that. Perhaps that meshy filter thing is less for filtering the oil, and more for separating the dead oil from the still good bulk?

[@KallePihlajasaari]

The light output came from an external light source, the e-beam was only needed to scan the oil film which amplified the signal massively.

[@whitcwa]

Very nice! I had one of these at my work around 1982. It took 20-30 minutes to get a decent image after startup because the disk turned so slowly. You could see the image slowly become more complete as the disk turned. I remember scouring the service manual for how they made color in a single light valve. I recall that the electron beam deflection was modulated at two frequencies around 100MHz, I believe, for the color signals. The modulation created diffraction gratings in the oil. US patent 3437746 seem to cover it.

[@mikeselectricstuff]

The Eidophor used velocity modulation, I think because altering beam current would change the depth of the charge within the oil - may have been something similar, though the tails on the cathode connection on the electron gun don't look like they're designed for 100MHz!

[@Spirit532]

@@mikeselectricstuff Are you sure the tails are not also for transport? It looks like they clip on very roughly, and maybe there was a special cap that went on in the projector.

[@KallePihlajasaari]

@@Spirit532 The main light source shone past the electron gun so it had to be robust and small as possible. Another comment above suggested the modulation was added to the x and y deflection signals, wiggles in X would generate patterns at one grating frequency and wiggles in the Y scan would generate patterns at the other grating frequency. I think the tiny X-Y deflection plates would have added those wiggles and the big X-Y plates would have provided the raster scanning.

[@tombombadil1989]

mike, you have the coolest teardowns on youtube. everytime i see a new upload i know im going to learn something new

[@sanches2]

Couldn't have said it better myself! He showcases amazing things :)

[@xjet]

Thanks for another fascinating tear-down and explanation Mike.

[@richardgabrielson9046]

Some of the stuff online dates the Talaria to the early 1980's. I worked at a GE location from 1972-1980 which had at least one GE light valve projector in service during that time for rear projection of "outside" view for aircraft cockpit simulators. I suppose it might have been a development prototype. This was 5-10 years before the commercial introduction of Talaria in 1983. None of my colleagues called it "Talaria" at the time, just "light valve." I'm pretty sure the one used in the project I worked on for a time had more than 10k hours on it before I left.

[@blackrockcity]

I can confirm that I found documentation of exactly this setup online related to a Boeing flight simulator... possibly for military training.

[@kevvywevvywoo]

The talaria replaced the eidophor in NASA's mission control in the early 80's and was replaced again in 1990 by Hughes LCD units, there's a paper on it on the NASA archive

[@bskull3232]

The "heater" thing you've mentioned is probably a combination of hit wire to break down larger molecules and ion pump to absorb smaller molecules.

[@otherunicorn]

Indeed. Looks like a getter stack.

[@justcallmeavi3255]

The device that is seen on the outside is a "sublimation vacuum pump", for removing the impurities from the vacuum itself, not the oil, fascinating technology that is still used today, think modern day air filters, similar system of using a very pure gaseous metalloid to attract gaseous impurities to itself, they don't last long however, so 1000 work hours is a bit too long for a system like that, we'd estimate 600 hours before it dips below its peak, over 800 hours and its probably working at less than half efficiency, its also a "off the shelf" unit, probably to keep costs down, usually with custom equipment they commission their own "filters" to be built specific for purpose, in which case we would recommend two "torus", "flat plate" or "disc" units, it would use far less power overall and would make the unit more streamlined, something tells us that costs were tight when it came to this!

[@smenor]

Are those beads molecule sieves then ?

[@randacnam7321]

The 2 separate pumps may be to account for that; one for the first 500hr and the other for the second 500hr of the tube's life.

[@lezbriddon]

in a world of embedded processors and leds, this is area51 technology

[@maxtorque2277]

I simply can't imagine the man hours, grey hairs and fainancial resource required to turn this thing from a concept that worked on a bench to a (reasonably) robust commercial product!! (and the EOL setup, calibration and test required to get working units out the door of the facility that made them)

[@ElectraFlarefire]

I like the demo at the end of the oil towards the end, makes it much easier to visualize how this might work.

[@bwheatonmv]

Nice breakdown. A friend on Facebook who also used to operate them posted your video. You got everything pretty right as far as I remember. So - color. Did you notice the correlation between the dichroics and the schlieren gratings? That’s because green is created - deformed in order to pass through the paired gratings - by horizontal modulation - a wave applied to the plates and red/blue by vertical modulation. The hard part (apart from dealing with the oil and temperature) of operating was tuning the front optical schlieren to block all the light from the lamp 2 hence all the thumbscrews on the front optics. Making a ‘darkfield’ we called it. Then the split green and magenta waves were applied to plates and that caused deflections in the oil that allowed either green or magenta light to pass through. The extra wrinkle was that video is a horizontally scanned signal, so a black video frame would actually produce a bright green frame. So - an extra cancellation wave was applied horizontally to make your ‘electronic darkfield’. That was a bit of an art form - it was never really perfect. I seems to remember a few adjustments to that. There was also some horrible ‘flatfield’ adjustments to compensate for the natural differences in deflection across the oil surface, to get a sort of flat color field. That also never really worked and was very temperature dependent! Side fact - the talaria op was also first at work to turn on the oil heater for an hour in the mornings!

[@ceecrb1]

My dad always tells the story of one of these projectors holding up the start of a corporate show in London, that it was the day he learned the best and quickest thing to do when there's a problem at was just leave the specialist tech alone to do his job.

[@kevtris]

yeah I think that side thing is a fancy getter assembly to keep the vacuum clean. The oil breaking down might cause contamination, or maybe it can off gas over time. those discs look like a large version of a regular tube getter, and there's a bunch of them stacked up.

[@Minimelkav]

You have NO idea how long I have been waiting for a video on light valves :) VERY cool

[@hightechstuff2]

Just when I thought I seen it all.... Super impressed with this video. Though the destructive teardown made me sad for such a work of art. It was done in the name if SCIENCE! Thanks Mike!

[@Basement-Science]

Those beads on top of the "electron gun" are definitely a vacuum rated descicant, it will take out water vapor and maybe some other small molecules.

[@djtransnazgrz]

Thing under may be an ion pump or something similar. They are used in closed systems that need consistent pumping to maintain a high vacuum.

[@zeitgeist909]

Love this channel. He does the most interesting teardowns on youtube.

[@1710000huh]

I'm glad to see you still making these sweet videos, Mike. Thanks a lot!

[@SeanBZA]

Think that was designed to service, just take the unit, place in a jig, and bake in an oven at 250C to get the vacuum epoxy above glass transition, and it would fall apart. Likely first break the gas seal, which is easy to do with a hot wire and thermal stress, though likely GE did have the whole assembly in a vacuum when doing this, so as to allow them to not contaminate the oil, or have it catch fire when they allowed it to come back to room temperature. Got to be some real special oil, to not evaporate any amount in a high vacuum., and still act like an oil.

[@rkan2]

kzbin.info/www/bejne/hpuuq3aIoMhqe9k&lc=Ugw6pO06_lVZCZnqAZp4AaABAg gives nice insight :P Supposedly they lost the way to manufacture the oil in the early 90s.

[@christopherthumm4348]

That electron tube with white pellets at the end looks like a gas filter I have . I'm absolutely fascinating with this kind of stuff , I have war time vacuum tube circuits and hi kv radar magnetrons that I love to geek out over

[@mikeh4840]

I think its an ion pump. Its purpose is to degas the tube, continually. Regular tubes have a passive getter. This is an active getter device.

[@Bin216]

Presumably the electron gun is in ceramic because of the external heating from the lamp it is in front of, coupled with the relative isolation from any form of heat sync, and the filament working temperature, I would imagine it was easier to package it in a housing which withstand the heat. Also being opaque would eliminate a light path around the electron gun avoiding the filters at the back of the tube.

[@sharplessguy]

I am/was certified by GE to repair and operate Talaria.

[@craigcampbell7638]

Really!!! I would love to know what the most common failure was on these devices. (Besides end of life for the valve) when i started in the av field 20 ones years ago we were still hanging Barco and Sony 3 gun crt projectors. But the company owners and senior managers always talked about light valves in that way people do when they are commiserating how far the industry has come in thier lifetime.

[@tookitogo]

So tell us more, please!!! And if you have technical docs, service manuals, etc, please share them!!

[@markgardiner6124]

Me too - spent a week at GE's PDPO learning how to set one up - we had one of the first Talaria PJ5055 in the UK, after Samuelson and Anna Valley, who were the importers.

[@T2D.SteveArcs]

I like the "Hot wire getter strip" assembly .. great video Mike 😎👍👍

[@andrewsweet43]

The weird electro gun thing that you thought was a vaccum gauge reminds me of a diffusion vaccum pump of some sort...

[@tamaskovacs9335]

Why did You destroy it? I now restore two of these projectors using this tube...... Maybe need a spare one

[@memejeff]

11:35

[@Arnthorg]

do you repull the vacuum on the tubes? I imagine there's quite a bit of air that got into the tubes through the glue bond over the decades.

[@MVVblog]

And at the end, everything come together again :D Very interesting piece of equipment. Now I must know how it works.

[@beamer.electronics]

A brilliant dissection of alien technology. All the best, Beamer.

[@tookitogo]

Is it a coincidence that your channel name, Beamer, is the common word for “video projector” in German, Dutch, and a few other languages?

[@beamer.electronics]

@@tookitogo Thank you for your question and Sub. I'm aware of the coincidence, but if you look at my logo, you'll see a fishing boat - a Brixham Beamer, I live in Devon, UK, and I enjoy those local boats. Alas though when anybody KZbin searches for me, they have to scroll through millions of projector and BMW sites :) All the best, Beamer.

[@tookitogo]

@@beamer.electronics Oh? I don’t see the boat anywhere. The avatar is your face, and the channel background is electronics parts. (I’m on the iPad app, not sure if anything else shows up in a browser.) But that’s lovely, I’m jealous of people who live near the sea! (Switzerland is just a little bit landlocked, and lakes just aren’t the same!) I’ll check out your videos soon, many of them looked interesting, hence the sub. :) Cheers!

[@WolfmanDude]

Wow these things actually exist?!? I had the concept in my head, but always assumed it was a strange dream. I cant belive it really works/exists!

[@simoninkin9090]

this is insane man! are you a programmer by any chance? have you seen Category Theory?

[@AntonBabiy]

Never heard of this technology, thanks for the real interesting teardown!

[@MikeCornelius_drelectro]

I used to work with these in the 90's and have always been fascinated with how they work, until today none of the available documentation really helped clear it up. Than you so much for sacrificing this one, everything now makes sense. However, as you say, the colour mixing is still a bit mysterious, but having seen it I feel as though I could solve that challenge if I was charged with designing the thing, whereas the oil valve thing totally bakes my noodle.

[@yuribochkarev4477]

Потрясающая технология, спасибо за очередное интересное видео

[@drelephanttube]

I absolutely love the crazy tech you look at on your channel. Thanks!

[@cnxunuo]

Those pellet looks like molecular sieve, the gauge like object could be a getter pump

[@SeanBZA]

Yes looks like a getter assembly and vacuum gauge all in one, heat up the filament to measure the vacuum, and then toast the getter disks to get a higher vacuum and remove the oil vapours.

[@landspide]

I suspect the colour comes from the 3 coated glass plates (green on inside) and how it interacts with the pattern on the grating... Maybe controlling the height of the oil interruption mixes the colour?

[@jtveg]

A truly fascinating and unique device. Thanks for sharing such a detailed and insightful teardown.

[@craigadam]

How does somebody imagine and design this?

[@blackrockcity]

They say that some people at MIT are 1000x smarter than other people at MIT...

[@BrendaEM]

Dichronic filters. Could the crt parts be some kind of getter? It reminds me if a oil delay guitar effect that used oil to store audio. Cool teardown.

[@tremorist]

My induction stove makes patterns in the cooking oil.

[@Phoen1x883]

Is the bit after 25:49 just leftovers from editing? Can probably trim it in the YT editor rather than reupload it if so.

[@alancordwell9759]

What do you think the oil is composed of?

[@Spirit532]

It's almost certainly a silicone oil, potentially fluorinated, and with lots of magical additives. It looks nearly identical to some Dow Corning products for oil diffusion high vacuum pumps - and it makes sense, since this would have to maintain high vacuum with a liquid inside.

[@alancordwell9759]

@@Spirit532 thanks - interesting!

[@simonstergaard]

King of obscure teardowns !

[@AlecKristi]

Wow! That's some amazing tech... Back from the days when we used physics to get things done )))

[@ThePoolboy789]

at 22:40 wouldn't that encoder still spin even if the inner disk was stuck since its mounted to the motor? or do you think the magnetic coupling is strong enough to stall the motor?

[@JamesReedy]

Agreed looks like an ionization vacuum gauge, pretty fancy built in diagnostics. Ohh watched more, is it some kinda getter?

[@PixelmechanicYYZ]

Rule #1 of operating a Talaria... don't ever ever ever ever ever tip it on its side...!!!!

[@2smoker64]

The electron gun look alike appears to be be a getter stack..

[@dcallan812]

Thats a great teardown, such an interesting bit f kit.

[@pradolover]

Is that oil similar to engine fan clutch silicone oil?

[@procrastinator1842]

It looks a lot like pdms to me which is used in viscous applications.

[@kakd1870]

Hmm, i was wondering how the schmoo was handled for transportation the last time I saw a pic of this with no description.

[@ephjaymusic]

That tech is absolutely mental! Love it!

[@MyProjectBoxChannel]

Is this the technology used in the NASA control room big screen, during the moon landing?

[@AHaensel]

@@aphenioxPDWtechnology I think only the TV video was Eidophor, weren't the maps this elaborate shadow play of metal stencils?

[@GlutenEruption]

@@AHaensel all 3 of you are actually correct: kzbin.info/www/bejne/hGPZZZ5-lLWmhJo - a completely custom eidophor was definitely used for the B&W TV, but according to the nasa documents, we know that was definitely replaced with a color GE Telaria some time between when they shifted to color camera on Apollo 12 (so late 69-70) through the upgrades in the mid 1980s. They possibly used an eidiphor with a color wheel early on for color TV before they switched to the Telaria. And the map and other displays used a combination of 5 1KW slide projectors using metal coated glass slides with a pre-etched icon or map combined with a blank slide that used a diamond stylus to cut the telemetry line directly into the plate. All controlled by ibm system 360 mainframes in the Apollo era.

[@brynyard]

Wow, didn't know disturbances in the force could be used to make images :)

[@BryceAWD]

Thank you. This is a technology I didn't know existed.

[@AintBigAintClever]

Interesting (to me) to see what looks like flat-flex on the temperature sensor at 7:31. How long's that stuff been about?

[@tookitogo]

Probably the 1960s.

[@scotttay420]

I still have manuals for this, the TLV and the MP for VGA. remember VGA?

[@alienonearthgmail]

The electron gun looking thing is most likely a heated getter pump.

[@jakesteed9622]

I have two of them

[@KallePihlajasaari]

Are they still working, you could host retro re-run evenings and charge nerds lots of money. 🙂

[@rot_studios]

What a piece of tech haha, this thing is quite something

[@poprawa]

This technology is a real madness

[@poprawa]

My bad. Digital, solid state stuff is mind blowing madness when proposed to replace that

[@randomelectronicsanddispla1765]

The only think I can think the strange assembly might be is an absorption vacuum pump/ getter on steroid.

[@proluxelectronics7419]

It's more complicated than RF gear...

[@msylvain59]

Damn x-ray tubes and photomultipliers tubes look like they are just annoying junk now 🤓 The first projector I seen in action in my life was a huge ceiling mounted 3-CRT Barco, somewhere in the mid 90's, I never saw one of those running sadly.

[@heinrichhein2605]

The assembly is a vaccum pump

[@waldovanderwesthuizen4557]

Sputter pump... Maybe... Would not be surprised if the wire on the inside was titanium...

[@waldovanderwesthuizen4557]

Got the name wrong. The real name is "titanium sublimation pump"...

[@heinrichhein2605]

@@waldovanderwesthuizen4557 From what i know, it is not just a sublimation Pump, you see also from the construction it is quite a different concept

[@heinrichhein2605]

i have to take a better look at it but it resembles more a Non-evaporable getter if you look at the disks, but then the pressure seams a bit high for that

[@robertw1871]

@@heinrichhein2605 I agree, it’s unusual and must have something to due with controlling something other than straightforward vacuum, my guess is it’s to deal with something breaking down in the oil over time not just typical air impurities. Possibly breaking down from the huge photon source of the arc lamp and extreme UV radiation.

[@connerlabs]

Liked before even watching 😀

[@scaleop4]

never seen anything like this before..nice vid.

[@m3sca1]

amazing contraption

[@realcygnus]

Quite a nifty Gizmo !

[@christopherleubner6633]

The white stuff is torr seal epoxy resin. The oil inside is probably perchlororo biphenyl. You can wet a piece of tissue and burn it. If it burns with a green smokey fire that is it.

[@blackrockcity]

Googling perchlororo biphenyl turns up nothing. Can you say more about it?

[@blackrockcity]

@@tonycollins7062I’m skeptical because PCBs were banned before the Telaria.

[@kylerhaged3476]

Very cool teardown!

[@robot797]

are you sure its oil and not glycerin? I have a few projection tv's that use that as a lens

[@tookitogo]

Yes, it’s oil. Every description of schlieren-optics projectors say it’s oil.

[@KallePihlajasaari]

Glycerine would boil in a vacuum. It is a selected oil that is selected to work at a temperature that is higher than you would get from the projection lamp alone so that it can be heated to a stable temp which then dictates the viscosity profile.

[@peepopalaber]

thats super interesting tech.

[@paulvandergroen9569]

Try a patent search Mike.

[@DanFrederiksen]

Never heard of it

[@EdTannenbaum]

I remember hearing from a service person that they used WHALE OIL because of its properties.

[@bobweiss8682]

Unlikely because it would need to have a consistent composition and very low vapor pressure to preserve the vacuum. And whale oil doesn't gel up like that at room temperature. Most likely some kind of silicone, with additives to control dielectric constant and conductivity.

[@Desmaad]

@@bobweiss8682 I thought it maybe an ionic liquid since they're quite viscous and don't evaporate.

[@b19drums70]

Whale Oil Beef Hooked

[@danbrit9848]

Most expensive microwave plate assembly I've ever seen...lol

[@simoninkin9090]

what is going on? 2 days ago I learn about Homotopy Theory, Topological Defects and Nematic Colloids and now you are showing me this?

[@SpinStar1956]

Gee, I’m soooo happy you’ve decided to repair it, and show us it actually working! 🤣😂🤣

[@markhodgson2348]

Wow amazing Mike

[@martinjones9318]

Vacuum Optics in Tucson Arizona provided a refurb service where they would break the neck of the vessel using tungsten wire and replace the oil. The process to remake the vessel was a closely guarded.

[@silverXnoise]

Did engineers of this era sit around daring one another to invent the wackiest possible gadgets? Bonus points if you can get organizations and government to shell out large fortunes for ‘em.

[@MrTridac]

If you think about it, a DLP device is also a pretty wacky idea. Imagine the first guy thinking "What if I had one mirror for each pixel? A million mirrors. Seems reasonable."

[@DrTune]

Given there was a lucrative demand to project large format video, and so few ways to achieve it - practical or impractical.. These old things seems so bizarre and clunky but the new stuff is even more bizarre it's just invisible to the eye.

[@silverXnoise]

@@DrTune You are probably right. LCD is certainly on par with the oily mechanisms on display here. “Growing” silicon wafers is also a rather bonkers notion.

[@boriss.861]

Another good video Mike cheers. Andy of PhotonicInduction your take on this? or a GE Talaria designer engineer.. Mini Fresnel screen for focusing?

[@Engineer_Stepanov]

Wow.

[@WobblycogsUk]

What a fascinating device, we don't know how easy we've got it now! Might be a crazy idea but two colour projection made me think 3D. Did you say it was military equipment? Maybe they were using it to view stereoscopic surveillance images.

[@tookitogo]

The surveillance imagery would have been shot on film in those days.

[@Stainless316L]

Nice Raygun

[@TheBackyardChemist]

16:00 Given the age of this thing, I would be somewhat worried about the possibility that the resin is asbestos-filled for whatever reason.

[@esepecesito]

For sure he had a respirator.

[@andrewschannel3635]

Thanks for sharing this, Disappointed that you couldn’t find a way of powering up the electron gun when it was together. Also would have preferred a 720p video with some subtitles.

[@mikeselectricstuff]

Google auto-caption is surprisingly good. Sometimes KZbin takes a while to render the 720p version.

[@Phoen1x883]

720p is up now if you want to see a bit more detail.

[@StormBurnX]

it already is a 720p video though...?

[@andrewschannel3635]

@@StormBurnX it is now, but wasn’t available at the time, I didn’t realise that there was a delay while the higher resolution was being rendered.

[@MRooodddvvv]

Don't turn it on - take it apart !

[@0xbenedikt]

150k GBP, that's expensive!

[@StubbyPhillips]

Sweet!

[@HBees79]

.... and I thought those white tubes were for water cooling.... ⛲🌧️📽️

[@eliotmansfield]

probably more impressed with your misdescribed ebay search term

[@ovalwingnut]

A projector? Oh my Darwin! "jaw on floor"... Clearly, CLEARLY this is AAT (Advanced Alien Technology) and I beg of you to destroy it immediately and never speak of this again. The danger is real. Seriously :O) ..and thank you!

[@addlinda1]

We have an OLD GE projector we’re trying to price for an Estate sale in Latham, NY this coming Saturday, 8/19/2023. It has no model#, no name on the casing, no identifiers. (Correction: it has a General Electric metal tag attached to the back,Model: BY Type: 1, volts: 115, CY: 60, AMP: 4.0 Made in Milwaukee Wisconsin U.S.A. ) The family said it was an old GE projector. It looks about this size, but it’s encased in plain grey metal case. Can anyone help? I’ll try to get more pictures. Anyone interested in buying it contact me.

[@Vladimir-hq1ne]

That is what they tried to use for filming nuclear tests. Alas, gamma was too much for providing the measures. Edit - not tubes but receptors. Basically, inversed. As dichroic filters very thin discs of lantanides were used...

[@fvckyoutubescensorshipandt2718]

Strange. You think once green and blue leds were invented they would have just made the movie screen a giant 100kW led TV instead of still using ancient film with a light shined on it.

[@tookitogo]

This technology predates blue LEDs by nearly half a century. And projection-brightness LEDs took another 25 years to become a reality. Direct-view LED isn’t even mature enough for cinema use _today._ What on earth makes you think it’d be workable in the 1960s-70s?!? Video technology back then sucked. Video (i.e. direct electronic moving image recording) didn’t even _begin_ to catch up to film until about 20 years ago, and was hellaciously expensive and fickle. Even just a few years ago, top-quality movies and TV (like Breaking Bad) was shot on film, not digital, because it had that bit of extra quality. Only in the past 10 years has digital gained a decisive quality lead over film.

[@KallePihlajasaari]

@@tookitogo I am very disappointed about the amount of compression artefacts that are allowed on regular consumer video, TV, cellphone and the like, It is almost as if 4k pixels is essential but shape distortion is fine when looking at some detail that moves at a different speed to the background.

[@tookitogo]

@@KallePihlajasaari For sure! We may have more pixels, but we aren’t getting as much more image detail. On the one hand, I do understand that the sheer amounts of data involved necessitate aggressive compression. But it is often taken too far. :/