I failed to notice how much larger the digits are on the "new" nimo tube compared with my original burned one. Honestly, that formerly new-in-box tube looks amazing in the clock!

Trivia: If anyone's wondering what the "P31" at the end of the tube part number means, it refers to the type of phosphor used. P31 is the most common green type used in instruments like oscilloscopes. BONUS! - All the phosphor types: en.wikipedia.org/wiki/Phosphor#Standard_phosphor_types

I love that, instead of a handheld Geiger counter, Fran uses a good and hefty vintage model which has been customized. Bonus points for the custom part's matching style of a metallic case and retro looking speaker grill.

It's good to know that it's safer to eat a nimo tube at dessert than bananas. Thanks Fran!

Hello, this was a pretty good factory build tubes. They work after 40-50 years with almost no damage. At this time, it's almost impossible to get electronic stuff who works so long or who works after so many years. Thank you for uploading. cu Toni

Working next to these tubes is MUCH safer than waking up next to an alarm clock with those glowing "hands". That was amazing how the counter reacted to those clock hands!! (This is in another video of Fran).

Now you just need ]ONE MORE[ to make a whole 4-digit clock display! This was great, Fran. Thanks so much!

Hey, you're in my daddy's territory, now! He had a dedicated screwdriver set up for exactly that purpose, making sure the voltage is discharged safely. I may still have it somewhere, in fact! 🤔 Really cool to watch, I've gotta say - brings back some memories!

Fran you are the female version of Mr. Wizzard in electronics. Thank you for all that you do.

oh maaaan when you turned that nimo tube around.... and it filled up the whole frame, I would use that as a desktop wallpaper! So gorgeous!

Called it. When Fran was explaining the operating principle of the tube, it sounded like although the tube was energized to 1700 volts, the voltage differential between the anodes and the cathodes was mere fractions of a volt meaning it wouldn't have been anywhere near the electron energies needed to produce x-rays. It is possible though to improperly energize even a normal vacuum tube in such a way that it produces a small amount of x-rays but Fran knows what she's doing, as did IEE.

Fran, I was an equipment engineer for 10 years at the Dosimeter Corporation of America until it was purchased by a British firm and shipped overseas. The company was a merger of the Bendix Aviation Instruments Division and the Landsverk Electrometer Corporation. These companies have roots in the 1940’s and were responsible for the design and manufacture of Geiger counters, area alarm monitors, stray radiation detectors for the Nuclear Medicine Departments of hospitals, and (most importantly) direct-reading personnel dosimeters for nuclear power companies, atomic powered ships, and other military use. MOST of the manufacturing equipment still used 1940’s to 1950’s technology to build the instruments that are still state-of-the-art. We had production lines of differential voltage testers with Nixie tubes, and stock of NOS tubes for the rare replacement. We had huge water-cooled Lepel Induction Welders that ran continuously for years on vintage Thyratron tubes. We had glass fiber drawing machines that melted E-glass beads in a platinum crucible and drew them to a uniform 8 micron(!) diameter to make the indicating fiber in a direct reading dosimeter - after it was sputtered with platinum to make it conductive in a Balzer High Vacuum Sputtering machine. My point? I was fortunate enough to spend my early career learning about, maintaining, and (where possible) improving the technology. The equipment of this age was designed and built so well, that even though it appears primitive in comparison to “modern” equipment, it was accurate, repeatable, reliable, and being electro-mechanical, easy to troubleshoot and repair. I love watching you use some of the equipment that I began my career using. Thank you for keeping the knowledge of these things alive.

X-rays shouldn't be a problem, unless applied topically. 😸you tubes today look like fine jewels, I am so glad that you are archiving and creating good data for these items. After you have moved on to the next higher dimension there will be "The FranLab Memorial Museum", a wonderful tribute to you. Luv ya, Bill Ackley. SA TX

Fran, your devotion to and time spent modifying your socket assembly for the two new tubes seems a fitting tribute to the time and devotion of the engineers who originally designed the tubes back in 1059-67.

First that Ive ever heard(or seen) about NIMO tubes. They would seem to be somewhat better than Nixis; easier to read "wider" font. Wider angle of viewability. I suspect that IEE box was one of those "engineering design/demo kits". Remember the old Motorola HEP kits? One of the most unusual numerica displays I knew of were the "Numitron" displays. They looked just regular seven segment LEDs, but each segment was an incadesint filament.

Excellent video =D I would go with the old tubes - keep the nice new one for a rainy day!

Fran, it probably does emit soft x-rays as all electron tubes do but if your power supply is 1.7kv then 1.7KeV x-rays won't penetrate the glass of the tube. Most tube manufacturers eventually incorporated lead in the glass to block but who knows which one. That thing is really cool, thanks for sharing!!

The world's largest collection of NIMO tubes. Nicely presented!

Fran, you should be working for NASA. What with all your experience and knowledge you would be a big asset for them. Love your videos!

Awesome. I'd love to find one for my collection. It would also be very interesting to get hands on a dead one to dissect it.

Wow - thanks for your work!

i remember when i was 11-12 yrs old, 1980/81, was the first time i saw these and the Nixie tubes. I was so amazed with all they could stuff inside them with great precision. I really like the different style the numbers on ther other tubes you received. Maybe the size of the diameter has to do with the years they were made. Also, bananas can suck up radiation from the environment and soil. Ive heard ones growing where we've dropped radioactive bombs are very toxic!

I love the quirks of those tubes, it gives them character. :)

Exotic, dangerous, eerie & green. I like it!

Throughly enjoyed this , Fran!

Very interesting, thanks for the videos regarding the Nino tubes and U Pa. old lab. Ton of neat stuff, too bad some took a walk.

Wonderful, enjoyable, informative video! Thank you.

I'd make a clock with 3 digits and use them all. Also I think the 0 and 5 might have been in a machine or instrument where that particular digit in changed in 1/2 increments e.g. 12.5, 13.0, 13.5 etc.

Next video - Finding Nimo. ;-)

Just discovered your channel today. Very nice and instructive. And nice attittude also!

Nice geiger! I absolutely love my Lionel Electronic Labs (yes, *that* Lionel!) CDV-700 Model 6b (circa 1964) with a genuine CDV-705 speaker unit. The crazy thing is: My geiger was maintained in someone's inventory until at least 2009 as it had a calibration that claimed to be valid until Nov 2010!

Haha! I was hoping you'd put some bananas in there but didn't think it would happen. Great video!

Split Enz rock. Thanks Fran. I love your videos. Cheers from NZ.

Split Enz Mental Notes LP on the shelf, very nice

@19:00 You did it girl, you did it!! Thank You!!

It would be interesting to measure an old 01-A triode valve, common in ancient radio's from the 20's and 30's. The fully gettered ones have a thoriated tungsten heater to help with emission, and being an alpha emitter, a geiger counter would possibly show some leakage. PS, great video again Fran. Cheers.

I'm just glad these didn't become mainstream. With 7-segments you can't have much of font problems...

the differences in those tubes is probably why they were in "kits" handed out as samples - they were manufacturing defects that didn't pass QA. They were functional, just had "cosmetic" issues.

I'd use them all.. very cool tubes..

Thanks for the Geiger counter experiment, Fran !

The golden anode contact is likely beryllium copper, which is known for maintaining its springiness without weakening. It's a common quality spring & contact material.

Fascinating!

You aren't going to get any hard X rays until starting at 25 KV or higher. 3 to 25 KV just positive rays. I wouldn't concern about that.

I was taught to discharge TV tubes with 2 flat-head screwdrivers crossed over. One on the conductive back coating, then the other under the boot. I did it rarely, so it was a bit scary! 35 kV! The tube itself acted as a capacitor, but i guess it makes sense to be sure with other tubes

It looks like an evaluation kit, designed for engineers considering using them to try them out, which explains the single-digit bezel.

All these display vacuum tubes look cooler than LED's.

I would say the NIMO marked tube is later as I noticed a (R) bottom right of the IEE logo. Which would suggest they the Left tube is either pre production or early run before they named them.

As I understood it, the only tubes that ever produced significant amount of xrays were rectifier tubes and overdrawn voltage regulator tubes. Good to know.

Very kwel! Thank you for sharing!

Interesting video as usual. Also like the "Split Enz" album on the shelf. With Neil Finn replacing Lindsey Buckingham in Fleetwood Mac it seems very timely.

Awesome fran

That's awesome Fran. Great find! Can't believe you managed to get ahold of new-in-box NIMO tubes.

Fascinating.

Have you ever seen a 132 x 24 full ASCII display terminal using this very technology? I have, at the newly opened SF Misconduct Center. 1st Comdex if my memory serves me right.

I'd either leave the old one, the first one you've had in, for nostalgia and memories, or I'd find a way to use all three :)

Few thoughts i had while watching: Silicone tape seems like it could help you quite a bit with getting the different tubes to fit without lots of prep in between tubes. It's kinda pricey, but if it saves you an hour or so it might be worthwhile. As for what it is exactly, it's a type of silicone rubber that is only meant to stick to it's self, but, it seems to be reasonably good at sticking to clean glassware. It could provide a protective grip on a vacuum tube without requiring a bunch of filing to remove the gripping pads. The biggest issue might be heat build up around the silicone tape, since it's not a very efficient heat conductor, but it is an excellent electrical insulator, so there's no issue there. The off center numbers might have been intentional to prevent image burn in on the tube. With regards to the burn in "Zero" image on the NIMO tube in the clock: What if you took an LED that was the same color as the phosphor in the NIMO, and you shined the light onto the NIMO tube such that the burned in image wasn't illuminated. The idea being that this would add wear to the phosphor in a negative pattern to what's already worn into the tube. The main issue with this idea would be the required light intensity, and whether that intensity could be reasonably done without damaging the tube. You might need a laser diode instead of a simple light emitting diode. This probably would shorten the life of the NIMO Tube, but you have 2 replacements capable of being used so maybe that's something that might be interesting to try. With regards to the dim 1 and 5, that seems like an out-gassing issue. Especially since they appear bright and fade to a lesser intensity. That could be caused by several things. Perhaps a small amount of the Getter, which was usually barium back in the day, evaporated and deposited somewhere inconvenient. In the presence of oxygen, both tungsten and molybdenum, which are both used extensively in vacuum tubes, form poly-atomic ions. As far as weird outputs from vacuum tubes, I'm generally more concerned with microwaves than X-rays. People get paranoid when they hear "Thorium-doped Tungsten electrode".

That is surprising to see such a variation in dimensions.

Use all three tubes for a three-digit clock -- hrs & min with a simple "1" indicator of some sort for the tens position.

@25:00 - yeah, possibly a dithered least significant digit. Ooh Fran! One more tube and you could do an automotive tach - another first and another the only one in the world! LM2917 -> ICL7135 -> 7441. :)

Test the geiger counter against the HV rectifier tube in a valve scope.

on a hunt for old tubes? can i call it “Finding Nimo”

The headband on those 'phones looks like it was made out of a large hose clamp. Funky. My old rad meter has a similar setup with an external audio amp though. It can run 'phones, or you hang the amp box on the side from the speaker jack and it clicks away.

i would put the one with the zero burned in because i would like to preserver the new one. As you said new ones are very rare

I think that "old" tube has sustained a shock, and the different stencil grids have moved around. you can see the 6 has moved up, letting electrons under it. That, or manufacturers defect.

not sure if these tubes have a heated cathode, but try it with the heater Off instead if it has one. I read somewhere that some of the old Diode tubes gave off x-rays when the heater filament wasn`t on and old TV sets, but were fine when the cathode was hot. :-D

Lovely tubes. A question: What is the High Voltage PS model number and where did you source it?

Fran - Smoke detector for the Geiger demo ;)

Trick taught me by "old-school" maintenance techs when inserting camera tubes like chalnicon, saticon or plumbicon etc into their plastic supporting scanning coil frame-holder was to apply some HUMAN OIL to its glass outer body....! A quick wipe either side of yuh nose and then a wipe with your same finger onto ONLY the body TRULY made a difference. The thing would just slide in and you'd never ended up with a jam up!

If you did have to go back to the old tube with the burned in 0, would it help to put a filter of some kind in front of it, a lighting gel or the like. Same sort of thing they used to use on old LED displays to hide the packages and just let the digits shine through? Would look like good if you could mount one in a circular frame, set it front of the display on a 3D mounted pillar, like some kind of optics experiment.

BRAVO !!

This just takes me back to a few years ago, my great uncle was very into the field of electronics, and I was just getting into the field of electronics, he passed away 2 years ago, and his wife invited me and my grandpa to go and look at all his stuff and we could have whatever we wanted, my grandpa is a mechanical engineer while my great uncle was an electrical engineer, so they did work on some projects together, my grandpa did the mechanical stuff and my great uncle did the electrical stuff, when we went down to his basement to see what we could find, we found all kinds of tubes, my great uncle was still using some tubes up until he died, in the 40s during WW2 he built a TV for the family out of parts he found and bought. He had everything to do with tubes though, he had a tube tester, vacuum tube analog volt meters, all sorts of stuff, I should have grabbed more. My grandpa has some stuff old electronics stuff, but nowhere near the amount he had. But my grandpa did have a lot to do with electrical advances in the 60s 70s and 80s he worked for HP and made all sorts of stuff for them, he would mill circuit boards, and his biggest project was when he made the parts for the first ultrasound machine developed by HP.

Hey Fran, If you need a good way to pad for tubes and provide a little tolerance, Check out Funky Foam. You can find it at any craft store and its super great adhesive neoprene foam. If you waller out the socket and put some funky foam in there, it should allow for tube variance with little issue.

Could the heat from expansion of the tube be a problem in the tape holder i.e. cracking?

Amazing

I see your a fan off Split Enz! Howdie from Australia

"I've got my Geiger counter here..." Of course she's got a Geiger counter...why wouldn't she have one? lol This is why I love Franlab. 🤓

So, now you have three tubes. You could make a clock... That would be cool. Also, you could do a video just on the geiger counter. That thing is cool. It conjures up images of 1950's - 60's nuclear scientists, test explosions in Nevada, a secret fallout bunker somewhere etc. Now I want one. In fact, I looked for this and couldn't find one. All they had was the later (at least they looked later) yellow ones. Any chance of you selling it? It probably costs more than I can afford but wow it sure is cool.

The IEE has a trademark R on lower R corner on 1 marked NIMO so was most likely the newer of the 2.

If your Geiger counter starts going crazy, RUN!, because it means giant mutated ants are just over the ridge.

Awesome Cool Video ( You Rock )

Fran you are the coolest😎😎😎😎😎

Pretty Amazing Technology For The Day... Considering The Wheel Was Invented Only A Year Earlier... 😄 Just Kidd'n... 😉

Love it! :D

10 of these are now posted on Ebay with power supply and more.

You need to get more of these (somehow) and make at least a hour+min clock.

I

That one jerk just had to hit the thumbs down. Great vid as always Fran :)

I'm a little late to the party, so I'm confuse about the X-ray thing. I guess the electrons get accelerated between cathode and anode and electrons and positrons would make for good beta radiation source, if they could penetrate the glass, but I doubt they have enough kinetic energy. As far as the X-rays are concerned, according to wiki you need much higher potential difference of at least 30 kV and a target anode made of special material to even have a chance of creating X-rays. And even then, the energy efficiency of conversion is at 1% at best. Still, a very interesting assembly and experiment.

I remember from school that you require over 25KV on the anode to produce X rays.

Would a strong laser shot at the face of the nimo be able to feather or blurr the burnt in zero? I'm just throwing out ideas.

You are a genius. Didn't I say that already? :-)

Have you considered making a "history of display technology " clock where each digit is a different technology: NIMO, Nixie, LED, etc?

i seriously want to physically meet and have a coffee/tea with you Fran lol.

It would be TOO cool if by some sort of electronic wizardry these could be used in the power section of an old tube amp....

Three tubes? time for a desk clock build now that would be cool...

That audio box needs a proper stomp switch, a funky paint job, and a name like "Clickfuzz" or something. :)

Hey Fran. Noticed the registered trademark on the right tube ( 4:27 ) ? Does that say something on the use of the 'NIMO' name perhaps

I would imagine that just like CRT monitors, that if driven improperly (i.e to much voltage) that you may get a trace or two of x-rays. X-rays are formed in vacuum due to regular photons being accelerated to a very high velocity as they do not impact other molecules or photons very frequently. Be careful with any type of vacuum tube, as improper use can cause small or large amounts of x-rays. You never really know unless you have some form of equipment to detect them.

I'm not an expert on these tubes (obviously) but the 0 and 5 on the "old" tube look a bit similar to what I have seen in CRT color TV's that got bumped. In the case of the TV's the mask got bent or displaced. Could it be that this tube was dropped and the (possibly hot?) mask got damaged?

Thanks, Fran for making your Nimo fixture work with the new tubes. Knew you wouldn’t let us down!(darn auto correct.) never typed Nimo before.