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!
Andrew Heller for getting multiple characters from one tube, you could use a deflection yoke like a CRT TV. A pair of coils on either side of the tube which create magnetic fields, deflecting the electron beam inside the tube. Deflect the beam to the left and display a “1” for a moment, deflect to the right and display “2” for a moment, and repeat back and forth, hundreds of times per second and due to persistence of vision, the tube will appear to display the number “12.”
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.
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).
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
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.
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.
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, 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!!
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.
So was I thinking. You could instead of a 12 hour day make a 9 houreish day or 0-9 houreish day to fit in the digits. Also, why not use some of the parts of the kit?
Yeah, that's a good idea, i just made my own IN-12 / IN-17 Nixie Tube Clock, now waiting for nuts and crews so i can make my bow where he goes in. Love the old look of the Nixie Tubes. www.pvelectronics.co.uk/index.php?main_page=product_info&products_id=39
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.
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
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.
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 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!
@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. :)
Agreed Fran! Get boxed stuff out and enjoy it! Plus also the clock is a demo piece, it's not running all the time, and it can under-power the tube to preserve it, so the new NIMO in there will probably stay good-as-new indefinitely.
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.
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.
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
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?
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.
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!
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.
That, or adding a small spring that pushes the contact onto the tube with just minimal force. Would take the mechanical stress off the tube and its seals...
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.
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.
You had to put it near-contact, not an inch away. Now I am not convinced yet. Also, is your geiger counter sensitive enough for the low keV energy being emitted?
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.
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.
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".
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.
I wouldn't expect xrays from 1750 volts, but it is possible. Years ago xrays were a concern with color TVs and CRT monitors, since the HV could be around 25-35 kv. Looking at a schematic of an old color TV set some sections were indicated for "xray protection" but not sure how that is accomplished...frequency or current limiting? CRTs were impregnated with lead particles to help block any xrays. One of my deceased uncles refused to buy a color TV years ago for this reason. He was content with a B&W TV (one gun is better than three he reasoned).
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!
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.
Wow, I didn't know there was a version before Neil. I'll have to look for that. great info. I saw Split Enz open for Tom Petty in the 1981 in NJ and they were awesome. Thanks again for your videos.
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 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.
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.
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.
X-ray emission not really a problem, until you are upto the 15KV range. 10x the anode voltage for these Nimo tubes. Get the datasheet for a color TV regulator tube, such as a 6BK4: frank.pocnet.net/sheets/137/6/6BK4.pdf
If the tube with the dim 0 and 5 had been displaying those digits most of the time then there should be some evidence of burn marks in the phosphor like the original tube.
With 2000V and 100 um of glass, what comes out is in the order of 10^-6 and if you stay below the Si edge, say at 1600 V, nothing measurable comes out. Besides, Geiger is not the nost efficient for X-rays, and its window also stops most of the soft ones. You can check this here: henke.lbl.gov/optical_constants/filter2.html
you could, in order to remove the cathode poisoning, but you have to be really careful because if you go too hight, you will boil all of the thermionic compounds from the cathode and turn it into a piece of wire!
It was my (admittedly limited) understanding that the old TV rejuvenators merely bucked the filament voltage up to compensate for weakened cathode emission near end of tube life. Poisoning is, as I understand it, due to a different cause and can be 'fixed' by increasing cathode-anode current rather than merely upping the cathode voltage. Or is there more than one fix for the poisoning issue?
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!
Fran Blanche 7 other foods that are radioactive potatoes, carrots, beer, low sodium salt, red meat, lima beans and Brazil nuts.
Fran, you can get multiple digits on one tube using external deflection electromagnets and multiplexing.
I wonder if the “old” tube would benefit from being degaussed.
If you have three of them I would love to see you make a 3-digit digital clock with it
Andrew Heller for getting multiple characters from one tube, you could use a deflection yoke like a CRT TV. A pair of coils on either side of the tube which create magnetic fields, deflecting the electron beam inside the tube. Deflect the beam to the left and display a “1” for a moment, deflect to the right and display “2” for a moment, and repeat back and forth, hundreds of times per second and due to persistence of vision, the tube will appear to display the number “12.”
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!
Waiter, two Nimo Splits, please!
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
Now you just need ]ONE MORE[ to make a whole 4-digit clock display! This was great, Fran. Thanks so much!
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).
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
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.
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.
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!
The world's largest collection of NIMO tubes. Nicely presented!
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, 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!!
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.
So was I thinking. You could instead of a 12 hour day make a 9 houreish day or 0-9 houreish day to fit in the digits.
Also, why not use some of the parts of the kit?
Excellent video =D I would go with the old tubes - keep the nice new one for a rainy day!
Yeah, that's a good idea, i just made my own IN-12 / IN-17 Nixie Tube Clock, now waiting for nuts and crews so i can make my bow where he goes in.
Love the old look of the Nixie Tubes.
www.pvelectronics.co.uk/index.php?main_page=product_info&products_id=39
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 you are the female version of Mr. Wizzard in electronics. Thank you for all that you do.
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
@19:00 You did it girl, you did it!! Thank You!!
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.
Wow - thanks for your work!
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.
Throughly enjoyed this , Fran!
Exotic, dangerous, eerie & green. I like it!
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 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!
@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. :)
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
A new in box nimo is of no use... So it's in the clock - not NIB anymore!
Agreed Fran! Get boxed stuff out and enjoy it!
Plus also the clock is a demo piece, it's not running all the time, and it can under-power the tube to preserve it, so the new NIMO in there will probably stay good-as-new indefinitely.
Yes....
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.
Test the geiger counter against the HV rectifier tube in a valve scope.
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.
Use all three tubes for a three-digit clock -- hrs & min with a simple "1" indicator of some sort for the tens position.
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
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!
I'd use them all.. very cool tubes..
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?
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.
Next video - Finding Nimo. ;-)
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.
Split Enz Mental Notes LP on the shelf, very nice
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!
Thanks for the Geiger counter experiment, Fran !
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.
That, or adding a small spring that pushes the contact onto the tube with just minimal force. Would take the mechanical stress off the tube and its seals...
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 love the quirks of those tubes, it gives them character. :)
Lovely tubes. A question: What is the High Voltage PS model number and where did you source it?
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.
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.
You had to put it near-contact, not an inch away. Now I am not convinced yet. Also, is your geiger counter sensitive enough for the low keV energy being emitted?
I'm just glad these didn't become mainstream. With 7-segments you can't have much of font problems...
That is surprising to see such a variation in dimensions.
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.
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.
Wonderful, enjoyable, informative video! Thank you.
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.
Just discovered your channel today. Very nice and instructive. And nice attittude also!
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".
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.
I wouldn't expect xrays from 1750 volts, but it is possible. Years ago xrays were a concern with color TVs and CRT monitors, since the HV could be around 25-35 kv. Looking at a schematic of an old color TV set some sections were indicated for "xray protection" but not sure how that is accomplished...frequency or current limiting? CRTs were impregnated with lead particles to help block any xrays. One of my deceased uncles refused to buy a color TV years ago for this reason. He was content with a B&W TV (one gun is better than three he reasoned).
All these display vacuum tubes look cooler than LED's.
10 of these are now posted on Ebay with power supply and more.
Fran I must ask, do you, like me, lust after an Aston Martin Lagonda with the CRT dashboard?
Buick had a crt touch screen in the mid/late 1980’s. it was used for engine, climate, and i believe radio control
It looks like an evaluation kit, designed for engineers considering using them to try them out, which explains the single-digit bezel.
Haha! I was hoping you'd put some bananas in there but didn't think it would happen. Great video!
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!
Split Enz rock. Thanks Fran. I love your videos. Cheers from NZ.
The ENZ - the sound track of the my teenage years in NZ!! Neil Finn now playing for Fleetwood Mac!! Awesome Video Fran. - Cheers Roy.
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.
Phil Judd era / pre-Neil... favorite Enz album
Wow, I didn't know there was a version before Neil. I'll have to look for that. great info. I saw Split Enz open for Tom Petty in the 1981 in NJ and they were awesome. Thanks again for your videos.
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.
My guess it is for a selector display.
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.
The IEE has a trademark R on lower R corner on 1 marked NIMO so was most likely the newer of the 2.
on a hunt for old tubes? can i call it “Finding Nimo”
Could you please share circuit of the sound box for that Geiger counter?
Simple 9v powered LM386 to drive 8 ohm mini speaker.
thank you
What was the lifespan of such tubes? I guess very long.
Have you considered making a "history of display technology " clock where each digit is a different technology: NIMO, Nixie, LED, etc?
There are LED's in the 10's of seconds digit runner in the circuit board, so this kinda is that.
Could the heat from expansion of the tube be a problem in the tape holder i.e. cracking?
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.
Very kwel! Thank you for sharing!
Fascinating.
Do you have any idea how much these would have cost back in the day?
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....
You would need 15 kV or more to get X-rays...
If your Geiger counter starts going crazy, RUN!, because it means giant mutated ants are just over the ridge.
Fran - Smoke detector for the Geiger demo ;)
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.
X-ray emission not really a problem, until you are upto the 15KV range. 10x the anode voltage for these Nimo tubes. Get the datasheet for a color TV regulator tube, such as a 6BK4:
frank.pocnet.net/sheets/137/6/6BK4.pdf
You need to get more of these (somehow) and make at least a hour+min clock.
If the tube with the dim 0 and 5 had been displaying those digits most of the time then there should be some evidence of burn marks in the phosphor like the original tube.
I remember from school that you require over 25KV on the anode to produce X rays.
"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. 🤓
With 2000V and 100 um of glass, what comes out is in the order of 10^-6 and if you stay below the Si edge, say at 1600 V, nothing measurable comes out. Besides, Geiger is not the nost efficient for X-rays, and its window also stops most of the soft ones. You can check this here: henke.lbl.gov/optical_constants/filter2.html
Fran you are the coolest😎😎😎😎😎
the p31 may be the phosphor they use
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 :)
Voltage is far too low for X rays. Even CRT's at 25kV was to low to measure against background radiation we had to test them back in the 80's.
I have a set of those files. They are indispensable. Took me a while to get the correct spelling on that!
Can you use a tube rejuvenator like they used to on televisions to fix the old tube?
you could, in order to remove the cathode poisoning, but you have to be really careful because if you go too hight, you will boil all of the thermionic compounds from the cathode and turn it into a piece of wire!
It was my (admittedly limited) understanding that the old TV rejuvenators merely bucked the filament voltage up to compensate for weakened cathode emission near end of tube life. Poisoning is, as I understand it, due to a different cause and can be 'fixed' by increasing cathode-anode current rather than merely upping the cathode voltage. Or is there more than one fix for the poisoning issue?
no, you are correct sir, I was being overly simplistic in my explanation.
Awesome fran
Three tubes? time for a desk clock build now that would be cool...