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ionization gauges and vibration
I am putting things together piece by piece, and I'm noticing that the point where I've temporarily installed my ionization gauge tube has quite a bit of vibration from the roughing pump. Am I correct in assuming that this would be bad for the tube? Thanks, -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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bolts/nuts for conflat flanges?
3
Hi folks. Is there a standard, or at least a favorite, for the bolt/nut sets for conflat flanges? Thanks, -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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vacuum chamber advice
10
Hello learned colleagues, I'm hoping to pick your brains for a little advice. I am trying to put together a small vacuum system for basic experimentation/exploration/education with plasmas of various sorts. I have a line on a small molecular drag pump with some accessories, and am now looking for a suitable chamber. I just found this on eBay: https://www.ebay.com/itm/334429705034 With its various flanges and such, it looks to be flexible enough for my very basic needs. I would, of course, try to talk the seller down a bit. However, I am a neophyte when it comes to chambers, fittings, etc. I know just enough to get into trouble. I see what appears to be at least one conflat fitting, etc. What I'm looking for here is a basic "yes, that'll do" or "no, don't buy this". Like "you'll never find something to fit that flange", etc type of real-world advice. I'd like to plumb some pumps into it, put in a couple of electrical feed-throughs, that sort of thing. Opinions? Thanks, -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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ionization gauge fittings
9
Ok, more dumb questions. :) I have a new ionization gauge tube here that I would like to use, if possible, in the system I am constructing. Its connection is a metal tube around 1" in diameter. I see many on the market like this, and many with just glass. How are these generally connected to systems, is there a type of fitting that somehow attaches to that metal tube? Thanks, -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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There's also a bucket with the other bolts, some serious steel bars, other fasteners and odds and ends, and the 1/2" thick steel top door plate that used to slide to the side to access the rotor and such. The electronics mount to inside the front doors at the bottom. The Welch 1402 slides on some rails at the bottom. Like I said, it's... dirty... from sitting outside in the NM sun for the last 7 or 8 years.
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more chamber stuff
Or perhaps: https://www.ebay.com/itm/234484099785 That one seems a bit simpler. I see 8" conflat blanks and gaskets aren't absurdly expensive. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Hey folks, this list sure has been quiet lately. I'm restoring an Amray 1200 bench-top SEM, and my attention has turned to the vacuum system. The instrument has been down to air and stored in a garage for 20+ years. I have some experience with vacuum, but not much. With all of the valves closed, pumping with a rotary pump against about half a meter of the internal plumbing, I can get down to about 20 millitorr repeatably, if the TC gauge is to be believed. It took about a day to reach that point, but now I can get there from atmospheric pressure in a minute or so. I presume that was adsorbed water. Now I'm opening the roughing valve and trying to pump down the column and chamber. This significantly increases the volume of the system that's being pumped, so I'm expecting days of getting rid of the water. But, leaving it running overnight last night, it didn't budge from ~220 millitorr. I assume there's a leak. Hunting around with my cheap-but-functional ultrasonic leak detector, I've found that there's a big ugly wax seal at the top of the column where the filament and HV leads enter the electron gun assembly. See attached photo. (if this mailing list is set up to allow such attachments) There's a significant leak right there, which changes as I massage that gloopy waxy stuff around. I think that wax may have deteriorated with age. It's pliable, but it doesn't seem to adhere very well to anything, including the wires it's supposed to create a seal around. Does anyone know what this stuff is, where I can get more (that I can afford), or in general have any other thoughts or advice about this? This is a stately instrument that's in really good shape, all things considered, and I'd love to get it running again. Thanks, -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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TIF 9100V Vacuum Pump Problem
7
As a retired electronic engineer, I have had at least a casual interest in both high-vacuum and mechanically-pumped vacuum techniques. Recently I ran into a vacuum problem with my TIF 9100V vacuum pump while pumping down the air-conditioning system of a Volvo. Rather than the fault being in the pump, it seems to be a leak between the isolation valve and vacuum port of the system, as when the vacuum port is capped and the isolation valve closed, the six vacuum led indicators rather quickly go out (the vacuum gauge is connected between the valve and port). As this pumping system is mechanically complex to disassemble, I thought it wise to ask an appropriate interest group if members have encountered, diagnosed, and solved this problem. But searching groups.io, I could not locate any professional HVAC groups. Thus I was led to your vacuum group. I hope this is not off-topic for this group Regards, Bruce Hunter Mill Valley, CA
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silvering (was Re: [VacuumX] Anybody still alive?
5
I tried an experiment with spray silvering vs aluminizing. The two methods seem to produce equivalent results, but you have to clean the mirror more carefully with the silvering method. Writeup is here, starting on page 2. http://capitalastronomers.org/SD_year/2021/StarDust_2021_06.pdf Guy Brandenburg Washington, DC
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Anybody still alive?
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Just bought a Varian V-70 aaaaaand controller from Ebay. Wish me luck.
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vacuum regulator
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I am a tech in instrumentation maybe you can help me i use vacuum for made some coupole Mirror by put some vacuum inther a schett of milar but I know how to built a pressure regulator like steam analog regulator but fot vacuum ana;laog regulator difficle can yhou help jack 47 71 quebec city
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Vacuum projects
I seem to have been inducted into the new Vacuum-X group. My projects in the high vacuum area have been intermittent over the last few years, but it still draws my attention if an interesting project comes to mind. There's a forum I've contributed to some time back that may be of some interest to the members here if you haven't visited there yet. The link is https://diyvacuumtubes.com/ It's somewhat dormant right now, but a lot of this old technology may resurface after they drop "The Big One"!
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Moving to group.io
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Hi All, Just a quick missive from your absentee group owner. I'm in the process of getting things going to transfer this group and the ATM_Free group over to Group.io, however I would really appreciate some help with the costs involved. Sadly going forwards a few donations here and there towards the US$220/year hosting fees would be greatly appreciated. The 开云体育 portal has the option to enable donations towards group costs so the funds would be handled at arms length. Getting the ball rolling on the transfer of these two groups is going to stretch my finances, so feel free to message me at VacuumX-owner@... for details on how you can help out. Best regards, and clear skies. Thomas Janstrom.
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Moving the group to Groups.IO
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Hi All, Just a quick missive from your absentee group owner. I'm in the process of getting things going to transfer this group and the ATM_Free group over to Group.io, however I would really appreciate some help with the costs involved. Sadly going forwards a few donations here and there towards the US$220/year hosting fees would be greatly appreciated. The 开云体育 portal has the option to enable donations towards group costs so the funds would be handled at arms length. Getting the ball rolling on the transfer of these two groups is going to stretch my finances, so feel free to message me at VacuumX-owner@... for details on how you can help out. Best Regards, Thomas Janstrom
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ADMIN: Yahoo Groups shutdown
15
I'm sure everyone here is aware of the impending Yahoo Groups shutdown. Just a moment ago I received the 1,000th email on that subject in the past 48 hours. This conversation is playing out everywhere but I've seen no mention of it here. Is the group owner present? We have to move, and now. I can help if needed, but either way, this has to happen. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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(No subject)
5
Hi, I am new to the group. Has anyone build a setup to CVD to aluminumnize a mirror?
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Varian 860 cold cathode controller
I have a dead varian 860 cold cathode controller for a vacuum gauge. It got shorted out inside and I’m not sure I can fix it (replacing one burned out resistor didn’t suffice) and I’m not sure of my ability to track down and fix anything else that blew out also. Anybody have a good one they’d like to sell? The 860A would probably work, too. Guy in cold & cloudy DC
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Past Its Hay-Day?
10
I think im going to move to PA!!! But alas its a long way from New Zealand. I myself am a lurker, and not messaged within this group before, im collecting pieces to build myself a telescope sputtering chamber, so i joined to get tips and to learn from some rather experienced individuals. Im almost there, all i need is a diffusion pump and either a 14" bell jar or a tig welded stainless chamber, but getting hold of pressure vessel heads here in NZ is nigh impossible as with almost everything i am interested in...so its custom spun heads or a bell jar, both qiute expensive. I am so enviouse of the surplus shops and brick'a'brack junk shops you have in the USA, i tottaly would jump in my truck and travel interstate to pick up an old chamber or bell jar, the adventure of driving tot new places and to pick up some "science gold" at the end of that rainbow is intoxicating. nerd-vana!!
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getting started, etc (was Re: Past Its Hay-Day?)
Same here, and now I'm just waiting for a bored mentor type of guy who's stuck in a small house to start showing up at my lab to get things going with vacuum. I'm an electronics guy working as a consultant in the embedded systems world. I have a background in instrumentation, some working knowledge of lasers and physics stuff, and a strong interest in vacuum systems. I have some vacuum hardware, and a lot of lab space (which seems to be what most people lack, which is why I mentioned "stuck in a small house" above) in a pair of commercial buildings that I own. I'm based just outside of Pittsburgh. Is anyone here nearby and up for hacking? I've got some hardware (and am willing to amass more), space, power, and interest...just need someone to work with who will take the lead on getting some vacuum goodness going. Oh, and there's also that nice electron microscope over on the other side of my lab. I had it running great many years ago, but it has been open to air since then. Gotta get that running. Anyone? -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Past Its Hay-Day?
10
Such a pity. This group has been tailing off since 2011. Such a wealth of insight too! Think a Yahoo re-org had something to do with it.
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