Unexpected treasure find - Page 1
Forum section: electronics / general

author: TerraHertz
author_rank: Super Contributor
timestamp: March 16, 2016, 04:12:37 pm
content: This post could have been in "what did you score today" except it's mostly not test gear.A friend of mine is selling his house and moving overseas. It was his parent's house, but his father died, mum moved back to Poland, and so my friend feels it's time to go somewhere else. Only problem was, he'd left it till the last few days to clear out the house before sale contract settlement. I'd missed seeing his "come and take anything you want" announcement on a forum we use, and so with only 3 days till his house handover I got a phone call on Saturday evening. "Hey, there's some stuff here you might like."Ha ha... I'd had a very strenuous day on Thursday - long hike with a 30Kg backpack full of stone-working tools, then a day using them in the heat. On Friday could barely move. Saturday was still tottering around in pain.On Sunday, hard work most of the day, right through the night and into Monday morning, with one other friend helping our friend clear his house. Then more on Monday afternoon. He has a disability due to recent major injury, the task had just overwhelmed him and it definitely wasn't going to happen otherwise.Anyway... his dad was a materials scientist working for CSIRO. He had a lot of tools. Unfortunately in his declining years they'd become very disorganized, and then finally were stored in an under-house space, so suffered a bit from damp. Still... I got two car loads of mixed stuff. Mostly hand tools, some electronics, books, kitchenware, and assorted 'science debris.'By now I've sorted through most of it at my place, surface-rust removed all the good tools, and merged the tools into my workshop.Nothing in the way of modern test gear unfortunately. Too much to detail, but a few useful/interesting things stand out. Plus one totally unexpected great treasure.* An antique miniature oscilloscope. A Philips GM5655. It's valve. The power connector is electric kettle style, and the mating plug with woven-cloth mains cord came with it. The round CRT has no graticule. I haven't yet researched this or hunted a manual. Not even tried powering it up. Still to decide whether to keep it as a museum piece, or sell it. I have too many projects.* A nice big Variac.* Piece of vacuum system, with two linear motion feedthroughs and verniers. (Useful for parts for my vacuum system.)* A 'thing'. I know what this is, have tested it and it works. The matchbox is covering the spoiler. Who else recognizes it?I had an identical one years ago, but wasn't aware it should only be used in short duty cycles and so the internal coil overheated and shorted. Oops. I also have a more modern functional equivalent, but the very old ones just look cool.Oh and yes, I have noticed the mains plug with reversed A & N wires. Not that it matters with this, given the _other_ exposed contact.* Old style 'copper lump' soldering iron. Extra interesting due to the copper being not one piece, but several layers brazed and rivetted together.* A mound of hand and power tools.While sorting stuff at his place into piles to take home, send to Vinnies, or send to the dump, I'd found a box with a few lab gas bottles. I'd assumed they were empty, and didn't put on my glasses to read the labels then. Put in my pile to take home since I'm looking for such bottles for my vacuum system project.Sorting boxes out at home I finally got down to that one. And.... discover I now have an apparently full, never opened bottle of 99.95%+ pure Helium-3. According to the label it contains 2 liters, I presume meaning 2L at STP. My friend says this was probably something his dad saved from being tossed out back in the 1990s at CSIRO. Back then He3 wasn't incredibly expensive. It is now.http://www.lunarpedia.org/index.php?title=HeliumQuoteThe other bottles are Nitrogen-15 and Oxygen-18, also of high isotopic purity.Well, they are neat gas bottles but I certainly need the money more. So, they will be sold.Next question: What are they actually worth, and how to sell them?

author: HAL-42b
author_rank: Frequent Contributor
timestamp: March 16, 2016, 04:27:28 pm
content: I'm most impressed by the vacuum feedtrough.We want teardown!

author: Kjelt
author_rank: Super Contributor
timestamp: March 16, 2016, 05:09:45 pm
content: Check out the date on the gas bottles, if they are over date they are worth 0 to professionals.The handtools: check for antique ones with brand name such as Stanley, they are highly collectible and can be worth quite some money.

author: Artlav
author_rank: Frequent Contributor
timestamp: March 16, 2016, 05:39:24 pm
content: Quote from: Kjelt on March 16, 2016, 05:09:45 pmHuh?Since when He-3 have an expiration date?Or is it about the seals on the bottles themselves?

author: SeanB
author_rank: Super Contributor
timestamp: March 16, 2016, 06:02:07 pm
content: Matchbox is covering the Varian name, it is a vacuum leak detector, or high voltage miniature tesla coil.The issue with the gas cylinders is that if they are past test date they need to be pressure tested and recertified, as they are vessels under pressure, and above a certain volume (3l IIRC) they either have to be a single use non refillable vessel, or need a pressure test to 1.6 rated pressure every few years. I have a whole series of these certificates for air compressor tanks, not too cheap, but good so you can have a professional team inspect and check wall thickness and internal condition, along with testing safety valves and checking the pressure gauge is still reading correctly.

author: Kjelt
author_rank: Super Contributor
timestamp: March 16, 2016, 09:55:13 pm
content: As SeanB explains it is about the condition of the bottles themselves.As far as I know they have a limited guaranteed lifetime after which they are taken out of commission.on top of that before they are refilled they are inspected and tested since wrong conditions might have corroded the bottle and affected its integrity.

author: TerraHertz
author_rank: Super Contributor
timestamp: March 16, 2016, 11:58:38 pm
content: About the lifetime of the cylinders - you're all thinking 'welding gas' or other high pressure use.And if these _were_ under high pressure use that would be true, and for that purpose the He-3 cylinder for example is stamped "DOT-3E1800 M9001 5-92 E4 304L"Which would be a certification listing for pressure contents of 304 liters, manufactured May 1992.And I SO WISH it contained 304 liters of He-3!But He-3 is an extremely rare gas, and for such use the standard practice is to not go much above atmospheric pressure. High pressure storage would incur too great a risk of sudden loss of major amounts, ie very costly goofs. So it's stored in small cylinders at quite low pressure.It would always be used in systems where the gas is used in tiny, tiny quantities, fed by pulse-leak valves into high vacuum apparatus. Even the feed lines would be micro-capillary, pumped to high vacuum and baked out at high temperature before opening the valve from the cylinder, to avoid contamination of the precious high-purity gas.This cylinder is labeled to contain just two liters. Pressure will be something well below 10 atm. The cylinder is stainless, it's a lab-bottle intended for long term single use, and there's no issue of date expiry at all.With any non-rare gas I could just crack the valve open a bit to see if the cylinder is under pressure. Not this one. Even a very brief outlet to air would be losing significant fraction of the total contents. Also if it had been in-service there's no guarantee the pressure is still above one standard atmosphere. In typical applications it would be used until totally evacuated - as good a vacuum as the destination apparatus.Even removing the sealed end-cap on the outlet side of the valve would be a stupid and pointless contamination risk, so I haven't and never will be. I don't (as yet) have the equipment set up to properly deal with something like this, so the rule is 'don't fiddle'. I'm just going to trust the tear-off status label. It has portions to tear off as the cylinder goes through a use cycle. The "FULL" tab is still attached, so it's a fair assumption that it really is full.It's a pity I daren't take the end-cap off. Since the cylinder has its weight written in felt pen: 684.4g. The present weight is around 725g and I'm pretty sure that is not all He-3. More likely the end-cap, tag and attachment wire.Here are pics of a related item in that haul. It's a rare-gas container, of glass. Oxygen-18 in this case. As supplied the glass bulb containing the gas is completely sealed. The closeup shows the little glass nipple and movable weighted capsule that is struck against the nipple to break it open. All done under vacuum.This one has been opened but the conical valve above it is greased and in OFF position. There's no way to determine status of contents without a vacuum system and mass spectrometer. So for now this is a piece for my museum.

author: TerraHertz
author_rank: Super Contributor
timestamp: March 17, 2016, 12:31:17 am
content: Quote from: SeanB on March 16, 2016, 06:02:07 pmIt is a vacuum leak detector, but by Edwards of England. Maybe manufactured before Varian existed. I don't know when, but hope to find out.Basically, it's a small Tesla coil, for hand use. The slider control changes spring tension on contacts, that are pulled open by field in the coil. The HV (many KV) terminal is that 'antenna' thing sticking out the end.It's used to find gas leaks in vacuum system glassware. The apparatus is pumped down to a reasonable vacuum, and that wand is moved around against the glass near suspected leak points. It forms a visible corona discharge across the surface of the glass, and if there's any path through the glass to the easily ionized low pressure gas inside, the corona arcs find it. The visual result is very obvious. Looks cool. (And playing with it for too long because it's so fun, is how I broke my earlier one.)Accidentally arcing it to the body probably wouldn't be fatal, since the HV is very high frequency and would mostly stay on the surface. But I expect it would hurt a lot and I've fortunately never experienced it.At some point I'll try to do a teardown. Also of that vacuum vernier feedthrough. Lots to do at the moment.

author: HAL-42b
author_rank: Frequent Contributor
timestamp: March 17, 2016, 12:38:54 am
content: Quote from: TerraHertz on March 16, 2016, 11:58:38 pmMore likely this refers to304L Stainless Steel. (L stands for Low Carbon)

author: TerraHertz
author_rank: Super Contributor
timestamp: March 17, 2016, 01:04:42 am
content: Quote from: HAL-42b on March 17, 2016, 12:38:54 amHmm, thanks, probably you are right. Usually cylinders do have a rated gas volume (at STP) stamped on them, but it looks like these were custom made by/for Cambridge Isotope Laboratories. In which case they'd always be for low pressure use, and the inertness of the cylinder would be more important than the high pressure limit.

author: vindoline
author_rank: Unknown
timestamp: March 17, 2016, 05:13:53 am
content: As long as the cylinders are in good shape (and they look new) the contents will be fine. The He-3 will be very interesting to people looking to make DIY neutron detectors. That is basically the fusor crowd. Check out the forums athttp://www.fusor.netI'm sure someone will be happy to take it off your hands. Off the top of my head, I don't know any hobbiest uses for N-15 or O-18, but they are also very expensive and valuable.

author: TerraHertz
author_rank: Super Contributor
timestamp: March 17, 2016, 08:27:37 am
content: Quote from: vindoline on March 17, 2016, 05:13:53 amI rather suspect DIY fusor enthusiasts won't be able to afford market price. Usually I give unwanted stuff away or sell for very little, but this is one item I want to sell for as close to market value as possible.www.fusor.netinsists on registration with real names. Which is unacceptable to me, so after I found out my registration was in violation of the rules I de-registered.I have some ideas for finding a buyer. But still busy dealing with the rest of the recent 'stuff-alanch'. Need to clear off workspaces so current projects can continue.Of course if someone finds this thread while googling "Helium-3 for sale", then feel free to contact me. But it will be at near market value. Once I find out what that is.

author: tggzzz
author_rank: Super Contributor
timestamp: March 17, 2016, 09:49:19 am
content: Quote from: TerraHertz on March 17, 2016, 08:27:37 amGiven the unverified contents, that's a nice chicken-and-egg conundrum!Traditionally for high value items which could be adulterated (i.e. Au), people used touchstones before completing a purchase. It might be necessary to agree a price contingent on mutually agreed testing. No, I have no idea what testing could be done!Is there any chance the container was a "joke" left on a shelf to confuse/amuse visitors to the lab?

author: TerraHertz
author_rank: Super Contributor
timestamp: March 17, 2016, 12:40:20 pm
content: Quote from: tggzzz on March 17, 2016, 09:49:19 amYes, it is. I think it's lucky there are several cylinders, of other rare isotope gases. Hopefully a deal can be done for all of them, with one cylinder acting as 'touchstone'.QuoteSo far as I know, it requires a high vacuum system with precision gas feed, and mass spectrometer.But anyone who needs such gases would likely have those anyway.QuoteNope. They weren't 'on a shelf in a lab'. They were buried in the personal effects of an ex-CSIRO materials scientist. Along with several other cool high-purity element samples, a whole lot of ion-implantation samples (anyone want some chunks of gallium arsenide? How about some pure Beryllium foil - yes I know it's extremely toxic. It's well contained), a whole bunch of semiconductor charged particle detectors, etc...He'd been retired for years, then died of some motor neurone wasting disorder. And yeah, I'm bearing in mind that might possibly have been related to materials he handled. So am being very cautious with all potential toxics. Or it might have been something supposedly 'harmless' - like the nearly empty bottle of White Spirits I found in his laundry. That stuff is used as a household and industrial cleaner, but from my own experience it's a nasty cumulative neurotoxin via repeated skin contact.Anyway, I'm told he saved them from being tossed out, while he was working for CSIRO back in the 90s. I have some of his business cards, and his name is written on one of the oxygen cylinders as the purchase addressee. It's entirely plausible, especially given some of the insane corporate/government wastefulness I've seen during my life.I'm hoping my friend (who is the heir to all this stuff) will have time to give me a written transfer of ownership, before he goes overseas. I've told him about the cylinders, he knew about them, intended them for me, and even after learning the potential value is cool with me having them. Might be something to do with the house selling for above 2 million.I keep finding more neat things among it. How about this UV-444B Photodiode, by EG&G? So huge!(Anyone have the data? I find plenty of web references to it, but no datasheet so far.)

author: Kjelt
author_rank: Super Contributor
timestamp: March 17, 2016, 03:33:19 pm
content: Ok so these are different gas cylinders , good, He3 is around $2000/litre i see when I google the stuff and is in high demand.So how do you know:1) If it is really He3 in there or the previous owner used an empty cylinder to store something else? For instance I used a balloon gas cylinder as an extra capacity for my pressure air system.2) How much is in there?3) If the quality is still 100%?So if I were you I would contact a manufacturer of that stuff if he is interested/willing to buy it from you, in that company probably the only people exist that can answer the three questions and use the stuff anyway.

author: SeanB
author_rank: Super Contributor
timestamp: March 17, 2016, 06:21:32 pm
content: Can I put up a hand for one of the GaAs chunks, would be nice to see if I can make a LED out of it, or at least get it to emit light just by using random probing with a stainless steel needle.

author: Shadetreeprops
author_rank: Regular Contributor
timestamp: March 18, 2016, 12:18:11 am
content: i have not found anything good in weeks, i am starting to get withdawles from not finding sweet stuff.but on a good note, a guy that overseas bunker cleans out has become a buddy to me. so i asked if he runs across certain things to set them where i can get them, and take them home.i thought he would say, i cant do that man..but i got, a handshake and a no problem, ill keep and eye out for good electronics throwouts for you man...YIPPIE!

author: TerraHertz
author_rank: Super Contributor
timestamp: March 18, 2016, 01:58:50 am
content: Quote from: Shadetreeprops on March 18, 2016, 12:18:11 amIntriguing... Good luck! Hope the shipping bugs don't bite, and don't get stuck with safely disposing of any unwanted warheads.Here's another amusing find amongst the pile. A very old soldering iron, engraved "AAEC".Australian Atomic Energy Commission. Ha ha, that nice old variac also has an AAEC engraving. After cleaning, it's in excellent condition and works fine. I'm very happy.I wonder if tips are still available for this old iron? It works, but needs a new tip.@SeanB, there are lots. Some appear to be clean wafers and fragments of wafers, others are small wafer pieces that have been implanted with unknown stuff. Very poor documentation, but it seems like they were experimenting with making doped GaAs for charged particle detectors. I think these chunks are probably not useful for anything other than conversation pieces. If you like I'll send you a few pieces, PM me your address. When I find out the postage cost I'll let you know. Will customs declare as something like "semiconductor material samples, 2nd hand, value $1, gift" unless you have a better idea.I'll take some pics when I move that box again. Btw, you are aware it's probably highly toxic, right?Allow me a week or two, I really have to deal with all this stuff, clear my work space and get a few other things done asap. Remind me if I seem to have forgotten.

author: lowimpedance
author_rank: Super Contributor
timestamp: March 18, 2016, 02:10:04 am
content: Quote from: TerraHertz on March 18, 2016, 01:58:50 amThat is the older (much older!) version of the SCOPE iron. Parts are still available.And indeed they are great irons and will pump out some serious heat, but be mindful of the duty cycle though, and that the carbon element inside the barrel also may need replacing.see here:http://www.wiltronics.com.au/catalogue/509/power/test-equipment-tools/tools/soldering-irons/scope-soldering-irons-spares-and-parts/Also from memory WES in Ashfield used to keep spares too.