How to Make a Sealed Cathode Ray Tube at Home
Вставка
- Опубліковано 11 вер 2024
- In this video I show how to make a sealed hot cathode Cathode Ray Tube (CRT). This is in contrast to the multiple other videos on UA-cam that show cold cathode didactic CRTS that operate continuously pumped. This tube is self contained with its vacuum maintained with a titanium getter.
Electronics engineer of 47 years Now 72 finished as an Aerospace Engineer, now retired
WOW What you did was AMAZING!! I started as a Black and white TV repairman while in collage. Most young people today have no idea what giants shoulders they are standing on!. You Have shown a wide range of knowledge and talents. from Metallurgy to induction heating and way beyond! You Actually know What a CRT is and everything needed to make one. I watched because I wanted to know how to Smooth over the end of a glass Tube as I want to make a high Q glass Variable capacitor. You made it look so easy, I going to have a go of it. Thanks for Who You Are!!
Dude he's an Android I just know it. Why doesn't he show his face? His fingers don't burn and they don't conduct the high voltage from the uninsulated spot welder he just squeezes bare handed. Oh did I mention he builds vacuum tubes in his shed!! Absolutely a time traveling android visiting the 21st century as part of his Android future college anthropology technical studies doctorate. I just know it! 😉
Lol yeah @@Xsiondu
It's crazy the niche you fill on UA-cam of diy vaccume based electronics and how fucking good of a job you do filling that niche. I hope more peaple come across this channel because I know for sure that more peaple are interested in this type of content.
Thank you! I have thought about this as well. With so many creators on youtube I think it is cool to make videos few others are.
JD, You are the "Mad Scientist"! I just LOVE your videos, great and pure explanations and your commentary is superb! You are the original De Genius!!!
Thank you so much Gary!!!
I know it's a year after the fact but instead of "Mad Scientist" I was thinking more of "Amish tech support".
I can't express how much I love this video
Thank you so much!
like the use of titanium for the getter.
Thank you. All the credit goes to Simplifier. simplifier.neocities.org/. I first found out about it on his website.
He was the one who made me realize you could build tubes without the extensive equipment that glasslinger has.
@@jdflyback good work, and thanks for the URL
The waveform at the end was truly amazing considering the fact that the electron gun is so simple compared to the commercial oscilloscope CRTs.
In the course of making my own "thermionic vacuum devices", i have found out two things that may be of interest to you:
1. The electrostatic deflection of electrons may also be done externally. This can be achieved by placing a piece of copper tape on the tube and applying a voltage to it, just like you would if the "plate" was inside the tube.
2. This one i can't say for sure, since it's only been a month or so, but i managed to create a diode tube with a glass-to-metal seal made entirely out of nickel wire, so no tungsten in between.
The catch is that i used 5 minute epoxy at the flare side of the stem and let the tube sit for a day before vacuuming it out. The tube still holds a vacuum, but that whether or not it will stay this way remains to be seen.
Since then i have made 5 or so different kinds of tubes that all use the same type of seal, and all of them still hold a fairly good vacuum, although the filament in one of them has burnt out. The only disadvantage that i have found for this type of seal is that it can't handle extreme temperatures (over 100°C at the stem), but the advantages should be clear.
Thank you! That is exciting! I have not tried epoxy before but that is an option. I would have thought that the epoxy itself would be permeable to gas but the fact that your tubes still have a vacuum probably rules that out. The temperature is an issue though, since I heat my tubes while pumping to try and remove fingerprints and other contaminants on the internal parts. If a higher temperature epoxy could be found this could be a good option.
I've had no issues with the epoxy seals when heating the tube to outgas it. However i am usually quite careful and never let the flame rest near the seal for too long. This of course reduces the effect of the outgassing as i can't heat the glass too much, but it seems to drive out the moisture and other contaminants adequately.
I was also surprised that the epoxy didn't let air through it. The first time i tried this, i was trying to salvage a tube with a cracked seal and figured that i could at least get it to hold a vacuum for a while if i put epoxy in it, but the solution turned to work well in semi-long term too.
It's however worth noting that the epoxy can't be used for fixing large cracks in the walls of the tube. I don't know why this is, but it could be that the large surface area increases the chance of there being leaks. The other (and the more likely) possibility is that the epoxy leaks a tiny amount of air and the larger the leak area, the faster the intake of air, so i wouldn't recommend this type of seal as a long term solution, but it's certainly useful for making prototypes.
@@jdflyback jb weld is said to be good for vacuum use
@@manitoba-op4jx No, it remarkably hasn't!
The vacuum is more or less as good as when it was first sealed off and even the filament still works.
Amazing - every Physics undergrad should watch this course before they start - so they appreciate tow things
a) the amazing craft and engineering that went into supporting the great phsyics discoveries
b) the amazing tech they have at their fingertips now to be able to do the experiments they do.
Well done!
I did a very similar thing, when I was about 13.
But by pulling apart a triode valve (tube?), adding phosphor from a lamp, adding a magnesium getter, resealing it, evacuating it, then igniting the getter.
Alas, I could not acquire a dot, but got a satisfying white glow that varied when I waved a magnet near it.
That was good enough for me at that age, with no help whatsoever.
How did you do that at 13 ? Like how was it financed ?
That is unbelievable. Have you thought about using a small Erlenmeyer flask for the end of the CRT? It would already have a good shape to it for the screen and I believe they are made of Pyrex.
This was my first thought when I started watching the video. Now I want to try it myself! I hope he does it, though. I bet he'd be way more successful than me.
applied science did this in his diffusion pump video but the issue is that the neck is not long enough (and thus the deflection coils are less effective), however that should be easily fixed by adding on another length of tube
Pyrex is more difficult to work with. Incompatible with the glass he is using.
Whoops, he is using Pyrex.
yeah borosilicate glass is the standard nowadays (i didnt say pyrex because its a brand not a type of glass and theres that whole pyrex cookware fiasco)
hugely underrated. is is insane to see that you can diy such devices
Dude: The s**t you're doing is amazing, and the only reason you're not getting a million+ views is because it's over most folks' heads. (Possibly including me, but I like to pretend I can keep up.) I'm just really happy to watch something like this.Thanks for what you do, and I hope the thanks you get from me (and a couple thousand other nerds) makes it worth your while.
You may get even better output with a flat bottomed flask , also heat the tube in a soft flame when you're evacuating it on the pump, it helps drive trapped air out of components, impressive work 😊
I only just found your TUBE vids, i can't stop watching them every one better than the previous, i started building tube radios at the age of 9 i just love tubes and it is nice to see that the interest is still there in younger generations. My compliments mate
That's an amazing result you've got there! I've attempted CRTs a few times myself, but getting good results with amateur gear is quite difficult. I've gotten a beam that I could deflect with magnets, but there was no aperture to make a usable dot, just a wash of illumination. I've messed around with titanium as a getter (also saw that from Simplifier :D ) and the potential of using it for a resistive filament style getter, just haven't added it to a CRT yet.
Also glad to see you're using Pyrex. When I got into glassworking, the easiest source for glass was FMS Neon as I'm about 1.5 hour drive away from them. As such, I have a good 50lbs of soft glass, and boy is it finicky! It has a really nice advantage in the fact that I can just seal titanium wire right through it, but annealing is very critical. On top of that, you don't often get second chances to fix things as reheating soft glass almost always goes wrong, even if you're extremely gentle.
Struggle aside, this beautiful tube of yours has rekindled my interest in making another CRT attempt! Keep up the awesome work!
Thank you! I am glad to see other people interested in glass work, not nearly enough are. Pyrex really is hard to beat in terms of the ability to reheat. I never get something right the first time and the ability to heat and move something or fix a crack is invaluable for the amateur. I started out with soft glass too but never could make anything more complicated than a glow tube. If you attempt please make a video! I would love to see another persons setup.
@@jdflyback Yeah it really is an art that needs more appreciation. I feel more people might get into it if they actually knew more about it. Where do you source your pyrex? And how expensive is it? I paid around $4 per pound for my soft glass. I actually never did more than take pictures of progress as I made my devices, but have been interested in attempting to record the process. I think this is the incentive I needed to give that a shot!
I got most of my glass at a university surplus store for scrap price but I have heard good things about mountain glass. www.mountainglass.com/all/boro-clear/pyrex/standard
I am not completely aware of what is a good price for glass but they might be on the expensive side for genuine pyrex. I would think the cheaper knock off could work (under the brands section) as long as the thermal characteristics are the same.
@@jdflyback thanks for the link! I'll have to see how their prices compare with some of the listings I've been seeing on ebay. Next I'll have to see if I can find some thicker tungsten or maybe kovar for the seals.
Sounds good! Let me know if you find any deals on tungsten wire, I have been sourcing it from a seller called prommark on ebay.
www.ebay.com/sch/prommark/m.html?_nkw=&_armrs=1&_ipg=&_from=
I dont know what to say, im really impressed! I recently saw dr stone and in it they made a primitive crt monitor and suddenly i wanted to know how it could be made at home. This video explained the process really well and i wish to replicate this myself. Thank you.
Dr. Senku in real world :D
Lmao XD
Well done, my compliments! That is the real thing!
Thank you so much Ko! I have been a fan for a while! I love your construction style of brass nails on wood.
I love this! you demystify one of the weirdest vintage electrical devices and show how it can be made with simple components.
What is most amazing for me is determination that makes You to push project to this stage using primitive tools. Im after electronic school bu i will not even start with that small set of equipment. Very impresive!!
I love your "first principles" lab setup! as exemplified by the wine cork used as a compression spring on your welder. So glad the Algo brought your channel my way
This cool project was an amazing amount of work, so I hate to be an armchair CRT maker... but since you might be interested I thought that I would point out that you might be able to make tighter, more intense beams by housing the filament inside a Pierce geometry and then making the Anode aperture a bit wider.
Dr stone science holds up
Absolutely 😏☕
Wow! That is just incredible - blowing glass and ending up with those mesmerizing patterns.
Holy cow, bro. In the 80 crt was still old but the mainstay. Now, the shits called straight up stone age!! Made me laugh, and remember the old days growing up. I'm watching and sharing with a friend who has made his own radios before.
Not sure what's more impressive... The project or all the home-made tools!
People like you (and maybe even me) be would be handy if a zombie apocalypse happens!
Thank you so much Clem!
Berotak senku 🧐
Very nice work! You might be able to focus the beam into a smaller spot if you wind a solenoid coil around the neck of the tube, between the anode and the screen.
Great video!
Alex
I FOUND DR.SENKU 😁
😂 sasuga
That’s very impressive, well done.
Thank you!
What you manage to do with the tools you have is more than amazing. Very well done.
Great video it's great to see that tubes have not lost their fascination 👍
Thank you very much, beautiful content.
The amount of warm memories of my Father that you have evoked in me with this video is enormous. Thanks again.
This information will be most useful for continuing my own experiments with electron beams. Thank you!
I've been using Faraday Wax to seal my leads next to the glass, instead of tungsten, though I've heard gallium works quite well too. At the same time however, I've been using a cold cathode electron gun, so gallium or Faraday Wax would probably melt from heating a hot cathode. I might just be a scrub though. I've been trying to make my apparatus modular so I can use it to experiment with different components.
Your glass working tips are very helpful as well. I can't believe I forgot I could use a power drill to turn the tube for flaring! I feel like an idiot now for trying to do it by hand.
I can also see now a lot of the mistakes I made when trying to blow my own bulb; didn't know I was supposed to pinch it off, and I probably didn't get it hot enough. I just bought some zinc sulfide powder online for my screen, because I was too scared to touch anything potentially toxic (not that I haven't broken a few florescent bulbs for science before).
Is there a trick to making the glass T-junctions though or do you just have to get them super hot? Because I kept messing them up and eventually gave up and tried to build my tubes using different methods.
Using the HV line is a clever way to check for leaks; I never would have thought of that.
Got any other tips, tricks, or recommendations for a fellow enthusiast?
fantastic, totally worth 1:15 worth of video, that's really solid documentation. Scarily cavalier about lab safety though.
I'm just going to dump a few links on you here, on the off chance you might not have come across some of them.
diy glasscutting sandblaster: ua-cam.com/video/u-AZR1BJERk/v-deo.html
glass diffusion pump and cathode ray tube demo: ua-cam.com/video/SrNVLCHrJtY/v-deo.html
diy scanning electron microscope: ua-cam.com/video/ZIJ1jI1xDhY/v-deo.html
the other good use for tubes: ua-cam.com/users/Nakazotovideos
that nixie tube maker guy: ua-cam.com/video/wxL4ElboiuA/v-deo.html
I didn't see you use a graphite block or pad of damp newspaper when you were doing your glasswork, ever tried either?
Pero que maravilloso canal acabo de encontrarme !!! Este conocimiento es sumamente valioso ! Tenía años buscando algo como esto!
Cool video. I have trouble understanding the workings of a monochrome crt I've been working on. You built a complete working one out of parts. Very impressive. All of your glass work on this project makes me wonder how hard it would be to cut open an old crt with screen burn and recoat it. Great job.
Not a good idea. A commercial CRT (basically any vacuum tube) will have a high activity Getter that is activated during production and after pump and seal. The cathode is also coated and activated after seal and Getter flash.
Once the tube is cut atmospheric gas (air/oxygen) will destroy both the Getter and cathode. CRTs that are remanufactured for screen damage will also get a new gun installed, and after pump and seal go through the Getter flash and cathode activation. Same for CRTs that are re-gunned due to weak emission (dim screens) This is worth doing for TV Color tubes as the screen and shadow mask can be salvaged and represent a lot of "value" (costly production effort)
I worked for a volume CRT builder for a number of years. My dream job at the time, and a great education.
Get my vote for ‘Zombie Apocalypse Survivor’ 😊 !!!
Great video, and really resourceful with your materials and tooling…
This is absolutely fantastic. I forgot to breathe watching this.
Mate, this is stunning. 🎉
My camera was 32 line up i made it multi system using Steve Anderons digital to analog ramp generator since we are dealing with audio bandwidths of a pc which i was using to play back i could really only go up to 64 line ,never tried yet to hook it up to my multisystem NBTV monitors should not be as limited as a pcs sound cards bandwidth . On Troys camera they are all 625 line but very good construction diaries on how to make them and problems worth a look for sure ...mine are all NBTV at the moment i have make also mechanical camera with PMT and a flying spot version over the years .
Thank you - this is wonderful and inspiring :-)
Thank you!
AGAIN, an utterly amazing thermionic device made from scratch.
FANTASTIC.........!
May I ask why you didn't show the "simple" process of boiling off the water to leave the dried phosphor on the face of the tube?
My guess is because it took a while.
@@stargazer7644 Maybe, but that could have just been stated in the video, but I don't want that to be a criticism of a truly fantastic video!!
Congratulations!
It is an excellent project, full of art and science.
I love your wooden housing instruments
This is just wonderful!
A thought on the filament glare: How about exploiting the light vs electrons in magnetic fields effect to "shadow" the screen from the light emitted by the filament?
This means aligning the pinhole and filament in such a way that you have to bend the electrons path to make them hit the screen. The photons go straight and will miss the screen.
For a time in the domestic television industry there were "bent guns" in CRTs. The purpose was to make an "ion-trap" to stop the ions emitted by the cathode from poisoning the center of the screen phosphor. The electron beam was redirected to the center of the gun by an external magnet, the heavier ions were less deflected and harmlessly struct the wall anode.
Amazing result!
Thank you! It has been a long time coming. I would like to add deflection plates someday.
@@jdflyback Remember deflection plates or focusing magnets don't need a vacuum, you can just add them to this CRT.
IT'S ALIVE.
I enjoyed watching that, who needs Netflix.
I also like the fact you have made your own tools and equipment.
Awesome build, no matter what anyone says - its still awesome
I bow before a true master
So many disciplines
MAD SKILLS
Even the tools and other devices are DIY. Remarkable!
Well done ! Would be super to see a video signal going into it , even a still picture would be fantastic .
Thank you so much for taking the time to film, edit and post this masterpiece. There are no words that can describe my appreciation for you👑
Though it does somewhat resemble an electric crack-pipe, 100% an amazing accomplishment, well done!
Nicely constructed!
Great project very cool. It took a lot of hard work to get this done, Thanks for taking us along.
You are really amazing dude
Hi there! I was wondering if you had a circuit diagram or schematic or something for how you power the CRT? I know there's a high voltage transformer involved, but something like that would be really interesting to see!! Amazing results by the way! :P
Thanks! I have a 0- 5V supply connected to the filament, a 0- -100V supply connected to the grid and a 0-30kV supply connected to the anode. All supplies are grounded to one side of the filament. the 0-30kV supply is built using an ac flyback transformer with a tripler. I try to keep the voltage on the tube less than 10kV to keep the xray generation down. I keep a geiger counter nearby when running it. I will try to make a clear schematic in a future video when I try to make a video monitor with it.
Super!!! You genius!!!
Thank you!
Parents walk in while your drying the phosphor material. I swear I'm not smoking crack I'm making a CRT! 🤣 Nice work on building it, I wouldn't have thought it to be possible at home.
Why didn't you put that phosphor on the elements for efficient thermonic electron generation ?
USE A NEEDLE OR PIN. REALLY GREAT VIDEO! SPOT ON!
I love your videos I'm interested in radioactivity you inspired me to make my UA-cam Chanel
That's great work! Excellent!
this is incredibly impressive and educational, subbed
That is really amazing. You are a CB very smart young man with a bright future. 😊
You blow me away.
Nice saw wave, or toroidal wave.
Unbelivable. Respect, man!
i found senkuu in real world😮😊
😂
Yeah, just that I thought when I saw the thumbnail
Wow just wow! That is some skill! Great video!
Very good projects, very few people have this technique of glass, impessive, electronics tubes. Great. How about a suggestion using this glass technique, a prototype of a co2 tube laser...!!! Congratulations
I want to say "you're legandary engineer" ..If there is an empty chair next to you, I would like to come and watch .
Nice. Some suggestions. You probably no this. Do you have glass blowing glasses. They make it much better to work with glass. They absorb the Na line (the yellow color).
Excellent video
IDK if its been brought up in other videos but.......bruh, please tell me you're wearing IR protection........ Like, lampwork is fun and all, but you gotta protect your peeprs.
This looks amazing! I would totally try this (if I knew what I was doing and how to protect myself from x-rays 🤣)!!!
Very inspirational!
фигура лиссажу!!!прикольная!!!
wow its amazing its like littel oscilloscope. so you can see who the tor of the light is going up and than down, so its making a hz like 2 or 5 hz i think, but its rally looking interesting you are really can see electricity ! its wonderful !
Very simple comment to a great video, Brilliant! :)
Thank you for sharing this amazing video.
Very cool project. Well done.
Impressive work!
Thank you!
I THINK HE IS SENKU!
All that you do is absolutely awesome ! :D
I also have a FB page i hoped would have more construction posts but most people were more interested in early television information i do have a bit of my work up there
Very good Selfmade Tube👍😎💖
Thank, really good demonstration, never seen before keep it showing such unique unseen things thank you again S S Haider ATL incharge.
Please show some video on spot welding machine & succession pump level in bars or psi etc.
Nice job 🎉
Very nice. I really like your videos. Very informative. I was wondering if you HAVE TO use water to gather the phosphorus from the lamp? Or could you use a different solvent that evaporates quicker and completely? Such as
Acetone, Trichlor, Alcohol etc...
Any pure solvent should work fine. The powder won't dissolve it any common solvent, we just want to make a slurry. Water works just fine. I did not show the process due to the suggestive nature. The phosphor and water mix is slowly rotated over the flame until it evaporates. This usually takes a few tries to get a good coating. It is possible if the liquid evaporated too quick the screen would be blotchy. During pumping the tube is heated to 900 degrees and any water vapor is driven out.
Absolutely amazing!!!
Wow, impressive.
Absolute incredible!
Thank you!
To what vacuum did you evacuate the tube?
I think my pump can get down to around 10 microns. The rest of the work is done by a titanium getter which I think can get it below 1 micron. It is not great. I am working on a better vacuum system.
Thank you for your video. So impressive!
I have a question. Could you try to show us how a radiological meter is reacting?
just for being sure that it's not created some rays?
Great video! I'm planning on making one of these
It is the coolest thanks for sharing all this knowledge , it looks like a crack pipe 🤣🤣
No it doesn't u never seen a crack pipe
Can you build the deflection yoke
I could make a deflection yoke, but I had good enough luck using relay coils for the deflection. I explain it here: 1:07:23
@@jdflyback thanks for the reply I'm trying to build my own but I'm not to sure on how to add a green Phosphor to the crt screen
I mix the phosphor with water to make a slurry and then if the end of the tube is flat you can let it evaporate. If the end is round you have to rotate the tube over a gentle flame to evaporate it slowly while keeping a uniform layer. 30:17
@@jdflyback now all you have to do is hook up a computer to it :-)
Excelente trabalho.
Where did you get that torch? I've been trying to make my own cathode ray tube using propane and a plumbers torch and I can only get about one in five seals to work. EVERYTHING is perfect but I just can't get the glassblowing right, and with this torch you seem to be able to reliably seal glass every time.
I would greatly appreciate it if you could point me to where I could get one of those torches. Thanks
Sorry I missed your comment! The torch is a bernzomatic ts839 which was from a garage sale. It is really not optimal. I have recently switched to using an oxygen gas torch. Any air gas torch has just barely enough heat to make a seal in pyrex. The key to getting away with it seems to be putting a very thin oxide coating on the tungsten. While making the seal the glass partially dissolves the oxide layer to make a bond to the tungsten with the color of the seal indicating the oxide thickness. (silver-gold = thin, orange-brown = thicker, black = too thick). If the torch is not hot enough or the oxide is too thick the oxide layer will not be reduced to the proper thickness. I am currently using a national 3A blowpipe with a modified N-1 tip using an oxygen concentrator and propane. It is meant as an air gas torch but works with oxygen just fine if you have the right tips (or make your own). 1/5 seals is not bad to be honest at best half of mine are good. I cheat when I make these videos and cut out a lot of the failed stuff because of how long they already are. If you are able to get any seal to look good on an air gas torch it will be a no brainer if you can get an oxygen concentrator.
Back in the day, we wet the surface of tungsten with glass in advance of making a tungsten thru glass seal. Then, when making the seal, you are sealing glass to glass.
how many volts do you express at the anode? from how many volts does it start to emit X-rays?
Im from Brazil
Hello. The tube is run with about 6000v on the anode. Usually xrays do not start until 20000v.
@@jdflyback WOW 20000V!!
tanck you brow