I Built A DIY Vacuum Tube Diode 

Thanks for the info, I was never able to find that anywhere else, perhaps what happened before I received it was that a tapered NPT fitting had been jammed into it and that's why it's difficult. To be clear, I'm not proposing to use vacuum grease on this or any other part of the system. Apiezon Wax W is a solid, semi-permanent vacuum sealing wax.

btw, I stumbled onto your video about the turbo repair some time ago and I really enjoyed it!

@@SignalDitch I wouldn't put anything other than a solid plug with an oring in that port, it's way too close to the rotor for comfort. Thanks for watching :)

Thanks! I'm not sure how it would do... If I had to guess, I'd say it would work quite well, but I can do some testing for you if you'd like. I'm sure I can dig up some small copper discs or washers for testing. It seems to have decent power, and if none of the included coils were right for your application, you may be able to bend your own that would work. I'll play with it and let you know.

@@SignalDitch If you could, I'd be really interested to see how it behaves! My understanding with these things is that they are generally low frequency (e.g. 50kHz), and work best with magnetic workpieces - i.e. rusty iron bolts ;-) For anything non-magnetic, you're relying on skin losses alone, so usually they operate much higher (e.g. 500kHz-1MHz) to get sufficient heating.

I'm actually working on an update to that project right now! The chuck design that I talked about in the last video isn't going to work out, but I think I've come up with something much simpler and better performing. If you want to see how it's going, I just published some pics and renders on the Patreon: www.patreon.com/posts/76897248 And thanks for the kind words, I'm hoping the content only gets better as the projects get more finished!

I'll put it on the list!

We'll get there!

I think industrially the getters are flashed while on the vacuum manifold. The reason I sealed mine off before flashing is because I wasn't confident in the current configuration of the vacuum system, and I knew that there was a lot of getter material so I was hoping it would act as a sublimation pump to further lower the pressure in the tube.

My understanding is production radio/tv tubes were roughed down, sealed off, and the getter flash did all the work achieving the final hard vacuum. jdflyback used this method and saw success, IIRC Simplifier also made some tubes this way with a Ti anode, they just red plated the tube until it performed well. I think this sort of multi stage high vacuum setup is more for proper development work, testing things on the pump. One thought I've had for a low budget tube lab is sealing on a disposable Ti sublimation pump if a smaller induction heated Ti halo getter isn't enough to go from whatever rough vacuum a cheap two stage AC service pump can hit.

It's good to hear from another hobbyist! I definitely got lucky with this tube, I expect to make quite a few more before I get another sealed device, haha. My understanding about the Edwards EXT255H is that there were two different models made, a 24V and an 80V, with the 24V being the newer of the two. Supposedly, Edwards were somewhat aware of how confusing this was and made sure that the connectors are incompatible, so you can't connect an 80V controller to a 24V pump or vice-versa. Unfortunately, the controller is named after the motor drive power (80W) which means that, confusingly, the EXDC80 comes in both 80V and 24V flavors. I was lucky enough to get my 24V pump with the controller included and I found a thread on the Fusor.net forums that (somewhat) elucidated the wiring. The good news is: If you indeed have the 24V pump and controller then you only need to supply 24VDC! I'm running my turbo off of a Meanwell EDR-120-24 which is a relatively inexpensive DIN-rail 24V5A power supply and it seems plenty sufficient for the job. There are a handful of wires that come off of the controller and you connect 24V and GND between two of them, one of them is an active-low start switch, one is an analog output that gives the proportional pump speed in tenths of a volt (0-10VDC where 7.5VDC represents 75% speed) and then there's an output that goes high when the pump is running >80% speed (intended to switch a relay for process control stuff) If you need it, I can find the wiring diagram that I worked off of, I think I ended up marking up a page out of the controller datasheet with info from the fusor forum post.

@@SignalDitch Okay that answers my questions! Definitely glad I asked before hooking it up to my 80V power supply... The controller my EXT255H came with has 24V printed on its back label, which is what made me second guess the 80V thing. I'll have to get a power supply for it but that's not a big issue. Honestly I'll probably order the one you mentioned as I'm rather a fan of Meanwell power supplies. My controller has the (standard?) DB 15 connector on it. From the manual I found, I should be able to get it wired up correctly; however I wouldn't say no to seeing your wiring diagram as confirmation given these pumps are decently expensive. Thank you for replying and thank you for the wealth of information! It really helps progress this niche field when we work together!

Yes! I finally posted another video and more are coming soon

I am very interested in both of those projects! I have a lot of reference material stashed away about SEMs and cyclotrons!

Just kidding. I imagine you imagine there is some political or antihero worship shit going on when in reality that is just my loser dad.

@@l_shaun_bunds_l Are you David? I appreciate the support! But you've credited me with a lot of intention here. Would you believe I actually don't know your last name because you don't use it on your Patreon profile?

Wait, you've given me a hint now, can I guess? Is it Kaczynski?