I suspect this is an RF detector, just picking up signals and amplifying it to see whats going on in the air. I got a mystery device in TTL era version that turned out to be probably used to find the sources of interference, could be something similar.
I think you're probably right, that certainly makes the most sense to me! The flying leads definitely look like they were intended to pick up RF signals in the air, so you may be on to something with it being an interference detector.
My first thought that it was an "operational amplifier." The differential inputs are the two extra leads. BTW: the 11 pin octal socket was/is standard for relays with 3 DT contacts.
I know this is far fetched, but I remember seeing an article about WW II anti-aircraft shells being outfitted with 'proximity fuses'. They were tiny, tube operated, withstood high g forces of being shot out of the anti-aircraft gun and low power. Once fired, they emitted radio signal and if they received a response (tiny echo from being near an airplane) they triggered the explosive. Used in Pacific theater, (they didn't want to risk losing a dud and having Germans reverse engineer them). This probably isn't that, but it brought that to mind, those tiny, rugged tube devices were like a primitive radar unit, didn't have to actually HIT the enemy plane anymore, just get close and the charge exploded sending out shrapnel that hit the enemy plane.
That's actually the second suggestion I've seen so far that it might be a proximity fuse, which is a really cool idea! I'd never thought about WW2 proximity fuses, and they're super cool chunks of technology!
I was going to suggest the same thing I had seen a module out of one that had been encased and some sort of Wax. And they had melted out the wax I don't remember if session is online or what might even been before TH-cam potentially. I just remember seeing it years ago. And also I do know there was a radio direction finder loop antenna. Had with those or barely similar to Windows very tiny tubes as well. But definitely is something radio-frequency for sure!
When I was a kid I saw simulator "tubes" in my dad's "junk box" . He was a missile tech for the navy in the 60's. Never was told where or what they were. I just remember thinking that the mini tubes were cool.
That's cool, I'd never heard of simulator tubes though. There were all sorts of really epic stuff coming out of the military in the 50s and 60s using small submini tubes!
Yeah, that was what drew me to it! Sure it doesn't follow the DIP package, but it's a proper, full on circuit, integrated into a single plug-in base, so it's about as close to a vacuum tube IC as I think we'll see!
that was a super fun video. even though the results are inconclusive i loved hearing about your analysis of this circuit! As for the flying leads, I think they were simply going to a voltage source of some sort, like a power supply, maybe screwed into a terminal, like on a bus bar.
Thank you so much! The flying lead that goes through the two 82 Ohm resistors I'm fairly sure is meant for picking up some kind of signal because it goes directly to the grid of tube R1, so it needs some kind of AC signal on it for R1 to amplify. There's certainly a lot of interesting and weird stuff going on here, I'd love to see what it plugged into one of these days!
An interesting video! A really curious device as well. Might I make some suggestions? In the future, when dealing with vacuum tube circuits, it is standard practice to label the tubes as V1, V2, V3 etc. R is most commonly used as a designator for resistors, such as R1, R2, R3 etc. The "Black Mystery Object" may in fact be either an inductor or capacitor. Years ago, while working in R&D, I had obtained a capacitor that looked like a resistor with the exception that it had a pink base color but the value was still indicated by color bands. When it was checked on a network analyzer it was discovered that while it was indeed the value of capacitance I had ordered, it was EXACTLY the value in inductance that my bosses, bosses, boss needed. Isn't electronics fascinating!!!???!!! If you ever find out what this thing actually was, please post it! Subscribing to your channel by the way!
Thank you so much! And thank you for the advice! Normally, I try to follow regular schematic conventions (V1, V2, V3, etc.), but when I was drawing up the schematic I kept getting confused as to which symbol related to which physical tube. Since there's no good indications on the device itself, I ended up labeling the tubes according to their physical position. So, when looking at the component from the top, with the mica capacitor facing up, L_1 is the left tube, M_1 is the middle tube, and R_1 is the right tube. It's not ideal, but it helped me keep things straight while tracing everything out! The mystery component could definitely be an inductor! My primary reasoning behind thinking it was a capacitor is that quite a few audio circuits use a bypass cap in parallel with a resistor on the cathode, which looked to be pretty close to what's going on here. Having said that, the circuit is pretty squarely beyond my design capabilities, so that was just a bit of a wild guess. You're right though, electronics are absolutely fascinating, and there are some truly brilliant people out there that know just how to use (or misuse) components to get them doing exactly what they want!
Ive built a number of widgets in this sort of spider frame construction. Its a really fun mental exercise. usually single block sections for testing, or just because I can. a little audio oscillator on a 1/4 inch TRS jack, RS232-TTL that fit in a backshell, that kinda thing. but the LM1875 and LM3886 chip amps have been my favourite. not counting the rail caps, got the circuit down to about the size of the TO-220 pack. No need for them to be that small, but it was the challenge. sounded pretty good, and weird to be so tiny (and have so much oomph)
Ice cube relays come in 11-pin bases (as well as octal). They make relay bases that break out the 11 pins to screw terminals - lots of hits for Pfy113a on the usual places
That's really interesting you could find Ice Cube relays in an 11-pin base as well! I'm familiar with them in an octal base, but an 11-pin base makes sense as well given how many different contacts relays can have inside them. That PFY113A would make an excellent break out base for this little tube module!
It's so cool to see something so dense and compact, but after poking around it for a few days, it would be an absolute nightmare to repair! And I'm right there with you, I'm so glad I was able to dig into it, but I'm still going a little nuts not knowing exactly what it is, haha.
Very interesting look. Sometimes I wonder if something like this was just a random experiment by someone like you and me with no deeper context to it. Either way it is always fun to analyze something like this and take educated guesses on what the original person might have thought when building it.
It truly is a very cool piece! Like you, I'm torn between this being someone's personal project or something that was actually produced. On the one hand, it's pretty expertly laid out to achieve the level of compactness it has, but on the other, it's a an absolute nightmare and impossible to perform any maintenance on. Still, it was a ton of fun analyzing the circuit and trying to get a little bit of an idea!
Your comment makes me think that this may have been a circuit in one of the electronic magazines of the day that someone built, maybe in the ham field.
Based on what you describe, this seems likely to be an RF pre-amp for the antenna input of, um, something. Given it was made between the introduction of submini tubes in the mid-1950s and when (most, low power) tube devices went out of production in the 1970s, I'd guess this was intended to amplify antenna input for a higher-end, probably FM receiver (or just possibly a compact television). Higher end, because lower end would have likely had a (cheaper) single pentode RF amp running a higher voltage. Don't forget, smaller was expensive back in the day...
I think you're pretty close to on point with what it might be. I'm afraid we'll never know for sure unless someone recognizes and remembers it's original use, but I like the idea of it being an RF pre-amp!
Since the suppressor is comprised of two deflection plates, this is actually a 'beam tetrode' or 'beam pentode' depending on how you count things. The British would call it a 'kinkless tetrode'.
Yup! It seems the naming convention on this type of design is really all over the board. You can see that for this one, Raytheon just calls it a regular "pentode", but I've seen both beam tetrode and beam pentode, as you mentioned, used many times as well!
@@UsagiElectric Patents and trademarks have something to do with that. IIRC Philco had a patent on the power pentode tube design, and RCA HATED to pay royalties. Since Philco didn't offer them a decent cross licensing agreement, RCA developed the beam power tube (6L6, 6V6) to avoid their patents on radios they sold under the RCA name. (I don't think they had a problem with second sourcing the PP tubes for renewal use, or to makers that paid the royalties on the PP to Philco). So some tube makers didn't use the name 'beam pentode' or 'beam tetrode' to avoid stepping or RCA's trademark. The British had their own term for the beam power tube, which they developed independently from RCA (Kinkless tetrode).
The approach I take when reverse engineering something is I first build a BOM, then use that to make a list of pins. As I determine each set of pins that are connected, I write it out as one line on a separate sheet and cross them off the original list. At the end I should have a few pins left that should be easy to verify whether they are unused. Then it's easy to take the BOM and 'node list' to construct the schematic.
I think the tubes at the right could be arranged on differential amplifier (long tail pair) configuration to obtain the amplified and filtered signal from the input (tube at the left with RC network filter) in phase and in opposite phase (inverted). Then that signal could be amplified by power tubes to drive a center tapped power transformer, or something that needs two signals, the original and the inverted one. It could be a rudimentary operational amplifier with a cathode follower input.
I was thinking about it being an operational amplifier / differential pair, because it's pretty reminiscent of the old K2-W tube OpAmp. I believe though that the cathodes of the two on the right are going straight to ground though, and usually a differential pair has a cathode resistor or cathode current source of some type between the cathode and a negative voltage. Of course, that could all be happening in whatever this thing plugs into, so it's hard to tell.
An op amp and a logic gate back in the day shared some similar characteristics. I'm leaning towards a logic gate. Also not a proximity fuse as one opined, as there is no shock packaging.
In case you never figured out what it was, I suspect it was a way for either a manufacturer or the user to upgrade of modify an existing radio, allowing it to perform in different bands or something like that. I have seen a radio with a tube socket on the back but never guessed what it was for. Now seeing this, I think it makes sense.
You basically said it. The second 2 tubes are an amplifier. The first controls it's gain. So what makes sense? An audio stage for a receiver with AGC. Perhaps a portable, battery-powered radio? I'm not seeing where you got the 1 kHz cutoff for the 1 nf coupling capacitor. That grid according to the spec sheet is meant to be negatively biased. So it should be a very high impedance input to the grid. I'm pretty sure the 1 nf will support the the whole audio range.
Thank you! Interestingly, they use insulating covers on quite a few leads because otherwise it would just be a mess of short circuits, but I imagine that it's still a noisy nightmare, haha. To me this piece sits in a weird spot in history. If I'm not mistaken, sub-miniature tubes didn't really start to become common until the mid- to late-50's, but by that time, building stuff on PCBs was also starting to become a bit more common (like my HP 150A scope). This piece might ultimately be more compact to build it this way, but with the tubes laying flat on a PCB, you could remake the circuit and have it be an incredibly thin board, all while having better properties in the circuit and way easier maintainability. I would love to see what it plugged in to some day, I think it would answer so many questions (or just make hundreds of new questions, haha).
Ooh, that's an interesting idea too! The big green components that I thought were a voltage divider could definitely be something else entirely that sets it up as an oscillator for sure.
Supposedly it was a replacement for one of the Western Electric the 200 series peanut tubes that was no longer available by the 50s. I think for battery powered rural telephone stitching amplifying stations. On doing a little more research if could of been a replacement for an acorn tube
How could a complete electronic circuit with three active devices and a handful of various passives be a replacement for a single, early tube type? For that matter, the 11 lin base is all wrong - this was a later development. I must be misunderstanding you?
@@drlegendre Just re-telling what I was told. Showed the video to one of the old guys at the radio club and that was his initial though. After I made the post he came back and said it was more likely a replacement for a set of two acorn tubes, Supposedly at one time there was an 11 pin acorn plug where you would solder in up to 4 acorns. I looked for it but could not find a reference.
I'm not quite sure I'm following, but the idea of it being a replacement for something else is an interesting line of thinking! Honestly, I'm a little torn between it being a custom made piece by an enthusiast, or an actual production piece, because of how densely it's packed and how utterly un-serviceable it is.
@@UsagiElectric I have see these for sale on-line over the years. Could not find a reference for it in tube-lore or in the operations manual I have. (same as a receiving manual but for op-amp and other not AD/RF valves.) Really just a binder of datasheets.
Could it be that 8.2 K resistor IS the plate resistor, and S7 is the output, not power voltage? And M1 could be a simple cathode follower circuit, completely unrelated to the other two tubes (that's why it would need its own filament power line, since it's a directly heated cathode tube).
You know, I think you're absolutely right! I mean, I didn't trace it out wrong, I just read it wrong, haha. I think you're absolutely on point that the 8.2k resistor is the plate resistor, though! The only thing that makes me think M1 is a part of the circuit is that the cathode level actually affects the level of bias on the grid of R1, so it should have some influence on R1 and L1, though it could be pretty minimal.
@@UsagiElectric Some kind of AGC, maybe? Although it is hard to say, without knowing the characteristics of the tubes. Maybe it's some kind of comparator.
@@demindor An analog comparator is a really interesting idea too! And that actually leads some credence to the two separate flying leads. Perhaps they were meant to read two signals and compare them against each other, amplifying the resulting signal or something.
Oh man, the Loewe 3NF is my unicorn! It truly is a tube integrated circuit. I love that they encapsulated the passives in glass too so when they off-gas it doesn't contaminate the vacuum required for the tubes. What a beautiful piece of engineering!
That could definitely be a likely candidate! It might be designed to pick up and amplify a specific frequency of noise that can be then be used to cancel out that noise in the main radio system or something.
@@UsagiElectric years ago I was on the brink of making my own tubes, and one thing I had in mind: to make an integrated circuit wrapped into one single tube. Still today I'm intrigued by the idea even though I'm aware it's totally worthless scientifically and economically speaking, and very likely I'll never do it.
The Datamath is a great little calculator! The version 3 is an excellent model too because you can just change the batteries as necessary. I had to remove the original NiCD batteries that were in mine and replaced them with a little LiPO and boost board from Adafruit. I use mine almost everyday, I love it as a quick and easy to use calculator!
I was thinking if you had a few of these small tubes could that unit be fixed be replacing the tube with the broken wire but what about mixing up some epoxy with some copper powder in it and use it to join the wire back to where it came off and once it has cured you might be able to power it up.
The CK502AX isn't actually that rare or expensive, and I could get a replacement pretty easily on eBay. And, I did think about trying to repair the broken wire - I might even be able to wick some some solder into the base and get lucky that way. Though the copper powder and epoxy idea is a good idea, I'll keep that in mind for the future! The bigger issue is how to power it up. The tube with the broken wire is also M1 in the schematic, and since it's a cathode follower, the heater has a pretty unique requirement for powering it up. I can't just throw 1.25V into pin 9 of the base, because there's no clear path back to ground. Unfortunately, I just don't know enough about how they were powering up the cathode follower here to feel confident in trying to get it going.
They sell a silver containing paint pen for pcb repair. I used this once to repair a CRT grid pin and it worked. The broken pin is pin 3 which is the filament. There is some current there so this might not work.
You'll get no flames from here, any question or guess is a good guess in my book! In this case though, I don't think these are related to anything vacuum related. I think I see where you're coming from though - encapsulating everything in a vacuum to have a sort of enclosed integrated circuit, and that's actually not all that unreasonable, it's been done before! The Loewe 3NF is an actual integrated circuit within one glass envelope. There are three triodes, two capacitors and four resistors all stuffed inside the vacuum. But, what's interesting is that the passive components are actually encapsulated in glass themselves because if they were in the actual vacuum, they would off-gas and contaminate the vacuum. So, you actually were kind of in thinking in the right direction!
You're definitely right about that! These tubes were originally designed for hearing aids, and if a hearing aid experiences 20,000 G's, something has gone horribly wrong, haha.
Old thread, I know, but here's a fun fact: as recounted in the book “12 Seconds of Silence,” by Jamie Holmes - a history of the development of the proximity fuse by the brilliant Merle Tuve and his team- the fuses DID use specially ruggedized hearing-aid tubes, and they WERE made by Raytheon (with Hytron and Bell Labs also involved.) The book includes a cutaway photo of a fuse, and one of its components (labeled “oscillator-detector amplifier thyratron bundle”) looks a bit like the mystery gizmo in this video, right down to being constructed on a multi-pin socket base.
Oooh, that's an interesting guess! I don't think it might be, but that's only because the military liked to use specialized tubes hardened for military use, and the subminis used here are pretty generic pentodes. But, I like your line of thinking!
Yup, space charge tubes are super cool! They were perfect for 12 volt car radios for obvious reasons, but they also eliminated the need for the noisy and failure prone vibrator (a hard thing to google for), which was used to create a square wave and generate high voltage for the tube plates.
I actually use both dark and light mode depending on the time of day, but whenever I screenshot the Discord, I specifically use light mode to get some comments going, haha. Also, my room has windows on three of the four walls, so light mode actually helps with readability given how much ambient light there is in the room.
Hi. Have you considered that S1 &10 could be connected to S6 & 7 outside the unit ? As S1 & S10 could be both biasing and plate resistor arrangements. If you add the 75k and 8k resistors you get a plate resistor, and if you add the 330k and 8k this makes a biasing when paired with the 160k (mayby/possibly added to the 33k which is connected to the ground).
I had thought about that, and it's a good guess given that the K2-W was built with the similar idea of multiple components through a single base. But, I believe the fundamental thing needed for an OpAmp is a differential amplifier, which I don't quite see here.
Thanks for checking the video out! I use DesignSpark PCB for both drawing my schematics and PCB designs. It's not the best EDA software out there, but it's the one I'm most familiar with.
There are people making their own tubes, they look very complex at first, but I was very surprised that isn't that hard to make them, need some practice with glassblowing and metalworking, but the construction of simple amplifier tube(I guess a pentode? I'm not tube expert!) isn't very complex. Maybe I nice project for this channel in the future, make your own opamp form glass and metal. 😁
Interestingly, I don't do anything electronics related for a living. My primary job (pre-covid) was new vehicle training for overseas markets, though with international travel being a bit more difficult now, I've mostly transitioned over to Japanese to English translation and the occasional online training. I'm not complaining too much though, the extra free time at home has given me the time to work on the TH-cam channel!
Thank you! Those little baby bunnies were actually wild cottontail bunnies that we rescued from our dog. We raised them until they were big enough to be released back into the wild!
They're so adorable aren't they! Those were some baby wild cottontails we rescued from our dog and outside cat. We raised them until they were big enough to be released back into the wild!
If those two big green unknown components are coils it starts to look like a Hartley oscillator. If that gets modulated by a second signal in the next tube, this whole assembly is an AM transmitter?
Oooh, that's a very interesting idea! There's actually a third big green component hiding behind the two that are visible, which is why I thought maybe they were a voltage divider, but I like the idea of the flying lead being a transmitter instead of a receiver! That's a line of thinking I hadn't thought about all and could explain why there's a flying lead on the cathode of the cathode follower. Very cool idea!
@@UsagiElectric I also remembered reading an article online about making an oscillator similar to this and placing it in or near an existing radio receiver. When tuned it would create a beat frequency oscillator that would improve the clarity of voices over shortwave. Those two flying leads may be antennas to create such an interaction. Without context of what this thing came out of, it’s hard to say what it was supposed to do. All I can say is HAM radio people have skills that are akin to alchemy.
@@MadScientistGuitarLab Now that's a suggestion I really like! HAM level stuff is certainly on a level of analog wizardry. Shortwave feels a bit high frequency for this, but I don't know enough about RF stuff to tell for sure. But, I think you're getting on the right track with this idea!
Oooh, interesting idea! Though, I'm not sure how related they may be. Vacuum tubes in general are more closely related to N-Channel FETs, but the CK722 was a PNP transistor, which is a functionality that tubes can't really exhibit. However, both being manufactured by Raytheon, there may be more of a connection there than I can see!
@@UsagiElectric I guess CK was used for active devices such as vacuum tubes so they used it for transistors also. People joke about CK722 because it was the first available transistor for electronic hobbyists. You could probably make a MC14500 with them. How many transistors does it have?There are a few on Ebay for $49. A lot of them don't work by now, they were not sealed very well.
Ahh, you're here. Good. We've got a problem. A big one. The controller chip for our water purification system has given up the ghost. Can't make another one and the process is too complicated for a work around system. Simply put, we're running out of drinking water. No water, no Vault. This is crucial to our survival. And frankly, I... I think you're the only hope we have. You need to go find us another controller chip. We estimate we have four to five months before the Vault runs out of water. We need that chip. We marked your map with the location of another Vault. Not a bad place to start I think. Look, just be safe, OK?
It being an multivibrator design is an interesting guess! I don't quite think it could be though because of the coupling capacitor. Flip Flops usually work on DC signals, but the 1nF coupling cap means it really only cares about AC signals.
@Usagi Electric hi really interesting content man if your interested in reverse engineering NOS military equipment hit me up i bought some kind of radio equipment that uses a green eye indicator it's modular seems to go to a rack of some kind it's at least 1950s can send some pics if interested
Oh yeah, that sounds like a really cool piece of equipment! The green eye indicator is often called a Magic Eye and they were used pretty regularly on old radios as a visual way to let you know how closely tuned to a station you were. If you want, hop on over to the Discord and share some photos of it! discord.gg/p7UsfHD
This voltage divider and AC offset tube circuit sugest it could work in a diferential equation solving tube computer like AKAT-1 en.m.wikipedia.org/wiki/Jacek_Karpi%C5%84ski
Interesting, that was definitely not a direction I was thinking, but it could very well be! More importantly though, I hadn't heard of the AKAT-1 before, and that thing is epic! Aside form the capability, which is amazing too given when it was built, the aesthetic is top class. It would look perfect sitting inside a Mid-Century Modern home designed by Frank Lloyd Wright or something. Thanks for turning me on to that awesome piece of history!
@@UsagiElectric look, in my opinion it is definently not a RF as tubes are not shielded ( but glued together) capacitors grade is not RF grade and module kind of circuitry desighed to be mass produced and easy replaced sugest its rather fits to socket board with hundreds of such elements in arrays, external leads perhaps were used to do " logic programing" by hardwiring them into inputs outputs. Early computers were not always touring machines ( read. Theoretical Pawlak machine) which was predecessors to todays neural network, then opamps were intorduced to replace tube modules in analogue computers, free world newer experience some designs of suc computers becouse neither Karpinski nor Pawlak ( creator or ODRA Polish conputer operating in negative radix insteadd of binary system) get passporrs to leave dammed communistic block... Karpinski ended up running Pig farm ( real swines and hogs) as he said in the interview: "I preffere real Swines then the The government ones." ;)
@@marcsmithsonian9773 I definitely see where you're coming from! With RF, I think it could probably be fine for ULF, VLF or LF up to about 1MHz. At such low frequencies, the importance of shielding and RF grade components isn't quite important. These type of Mica capacitors I see very regularly on old AM tube radios which here in the US runs from about 500kHz up to 1,700kHz (1.7MHz). I'm not quite as familiar with early differential calculators as I am with the later IBM style computer like the 604 or 650, so it's definitely possible that the component was used for some kind of early analog computing application!
@@UsagiElectric You make a good point, despite the fact it could work in LF aplication, still I believe ahield of some sort wpuld be aplied to what I observed in old tube circuitry, I work alot on tume amps as hobby testore old HK, Fishers and RCA and they all use shield in preamp section and tuner , so I figured back then wnginers were quite religious about shielding from interference, I would be suprised if that actualy was RF part. But I am not an autority on that. GOOD LUCK !
I suspect this is an RF detector, just picking up signals and amplifying it to see whats going on in the air.
I got a mystery device in TTL era version that turned out to be probably used to find the sources of interference, could be something similar.
I think you're probably right, that certainly makes the most sense to me!
The flying leads definitely look like they were intended to pick up RF signals in the air, so you may be on to something with it being an interference detector.
My first thought that it was an "operational amplifier." The differential inputs are the two extra leads.
BTW: the 11 pin octal socket was/is standard for relays with 3 DT contacts.
I know this is far fetched, but I remember seeing an article about WW II anti-aircraft shells being outfitted with 'proximity fuses'. They were tiny, tube operated, withstood high g forces of being shot out of the anti-aircraft gun and low power. Once fired, they emitted radio signal and if they received a response (tiny echo from being near an airplane) they triggered the explosive. Used in Pacific theater, (they didn't want to risk losing a dud and having Germans reverse engineer them).
This probably isn't that, but it brought that to mind, those tiny, rugged tube devices were like a primitive radar unit, didn't have to actually HIT the enemy plane anymore, just get close and the charge exploded sending out shrapnel that hit the enemy plane.
@@mikefochtman7164 - You’re correct about the P-fuses. The ones I’ve seen are quite simple. Just one VT device.
Likely WW2 related. Example, Proximity fuses included mini vacuum tube circuits
That's actually the second suggestion I've seen so far that it might be a proximity fuse, which is a really cool idea! I'd never thought about WW2 proximity fuses, and they're super cool chunks of technology!
I suppose that’s also consistent with the relay type base....
I was going to suggest the same thing I had seen a module out of one that had been encased and some sort of Wax.
And they had melted out the wax I don't remember if session is online or what might even been before TH-cam potentially.
I just remember seeing it years ago.
And also I do know there was a radio direction finder loop antenna. Had with those or barely similar to Windows very tiny tubes as well.
But definitely is something radio-frequency for sure!
When I was a kid I saw simulator "tubes" in my dad's "junk box" . He was a missile tech for the navy in the 60's. Never was told where or what they were. I just remember thinking that the mini tubes were cool.
That's cool, I'd never heard of simulator tubes though. There were all sorts of really epic stuff coming out of the military in the 50s and 60s using small submini tubes!
Very interesting tube. Its like integrated circuit IC but with tube.
Yeah, that was what drew me to it! Sure it doesn't follow the DIP package, but it's a proper, full on circuit, integrated into a single plug-in base, so it's about as close to a vacuum tube IC as I think we'll see!
@@UsagiElectric IBM made lots of things like that! There were also integrated tube opamps.
that was a super fun video. even though the results are inconclusive i loved hearing about your analysis of this circuit! As for the flying leads, I think they were simply going to a voltage source of some sort, like a power supply, maybe screwed into a terminal, like on a bus bar.
Thank you so much!
The flying lead that goes through the two 82 Ohm resistors I'm fairly sure is meant for picking up some kind of signal because it goes directly to the grid of tube R1, so it needs some kind of AC signal on it for R1 to amplify.
There's certainly a lot of interesting and weird stuff going on here, I'd love to see what it plugged into one of these days!
An interesting video! A really curious device as well.
Might I make some suggestions? In the future, when dealing with vacuum tube circuits, it is standard practice to label the tubes as V1, V2, V3 etc. R is most commonly used as a designator for resistors, such as R1, R2, R3 etc.
The "Black Mystery Object" may in fact be either an inductor or capacitor. Years ago, while working in R&D, I had obtained a capacitor that looked like a resistor with the exception that it had a pink base color but the value was still indicated by color bands. When it was checked on a network analyzer it was discovered that while it was indeed the value of capacitance I had ordered, it was EXACTLY the value in inductance that my bosses, bosses, boss needed. Isn't electronics fascinating!!!???!!!
If you ever find out what this thing actually was, please post it!
Subscribing to your channel by the way!
Thank you so much!
And thank you for the advice! Normally, I try to follow regular schematic conventions (V1, V2, V3, etc.), but when I was drawing up the schematic I kept getting confused as to which symbol related to which physical tube. Since there's no good indications on the device itself, I ended up labeling the tubes according to their physical position. So, when looking at the component from the top, with the mica capacitor facing up, L_1 is the left tube, M_1 is the middle tube, and R_1 is the right tube. It's not ideal, but it helped me keep things straight while tracing everything out!
The mystery component could definitely be an inductor! My primary reasoning behind thinking it was a capacitor is that quite a few audio circuits use a bypass cap in parallel with a resistor on the cathode, which looked to be pretty close to what's going on here. Having said that, the circuit is pretty squarely beyond my design capabilities, so that was just a bit of a wild guess.
You're right though, electronics are absolutely fascinating, and there are some truly brilliant people out there that know just how to use (or misuse) components to get them doing exactly what they want!
Ive built a number of widgets in this sort of spider frame construction. Its a really fun mental exercise. usually single block sections for testing, or just because I can. a little audio oscillator on a 1/4 inch TRS jack, RS232-TTL that fit in a backshell, that kinda thing. but the LM1875 and LM3886 chip amps have been my favourite. not counting the rail caps, got the circuit down to about the size of the TO-220 pack. No need for them to be that small, but it was the challenge. sounded pretty good, and weird to be so tiny (and have so much oomph)
Ice cube relays come in 11-pin bases (as well as octal). They make relay bases that break out the 11 pins to screw terminals - lots of hits for Pfy113a on the usual places
That's really interesting you could find Ice Cube relays in an 11-pin base as well! I'm familiar with them in an octal base, but an 11-pin base makes sense as well given how many different contacts relays can have inside them. That PFY113A would make an excellent break out base for this little tube module!
What a compact and lovely circuit. Sometimes it's nice not knowing.
(but not this time. ha ha)
It's so cool to see something so dense and compact, but after poking around it for a few days, it would be an absolute nightmare to repair!
And I'm right there with you, I'm so glad I was able to dig into it, but I'm still going a little nuts not knowing exactly what it is, haha.
Very interesting look.
Sometimes I wonder if something like this was just a random experiment by someone like you and me with no deeper context to it.
Either way it is always fun to analyze something like this and take educated guesses on what the original person might have thought when building it.
It truly is a very cool piece!
Like you, I'm torn between this being someone's personal project or something that was actually produced. On the one hand, it's pretty expertly laid out to achieve the level of compactness it has, but on the other, it's a an absolute nightmare and impossible to perform any maintenance on.
Still, it was a ton of fun analyzing the circuit and trying to get a little bit of an idea!
Your comment makes me think that this may have been a circuit in one of the electronic magazines of the day that someone built, maybe in the ham field.
Based on what you describe, this seems likely to be an RF pre-amp for the antenna input of, um, something. Given it was made between the introduction of submini tubes in the mid-1950s and when (most, low power) tube devices went out of production in the 1970s, I'd guess this was intended to amplify antenna input for a higher-end, probably FM receiver (or just possibly a compact television). Higher end, because lower end would have likely had a (cheaper) single pentode RF amp running a higher voltage. Don't forget, smaller was expensive back in the day...
I think you're pretty close to on point with what it might be. I'm afraid we'll never know for sure unless someone recognizes and remembers it's original use, but I like the idea of it being an RF pre-amp!
Since the suppressor is comprised of two deflection plates, this is actually a 'beam tetrode' or 'beam pentode' depending on how you count things. The British would call it a 'kinkless tetrode'.
Yup! It seems the naming convention on this type of design is really all over the board. You can see that for this one, Raytheon just calls it a regular "pentode", but I've seen both beam tetrode and beam pentode, as you mentioned, used many times as well!
@@UsagiElectric Patents and trademarks have something to do with that. IIRC Philco had a patent on the power pentode tube design, and RCA HATED to pay royalties. Since Philco didn't offer them a decent cross licensing agreement, RCA developed the beam power tube (6L6, 6V6) to avoid their patents on radios they sold under the RCA name. (I don't think they had a problem with second sourcing the PP tubes for renewal use, or to makers that paid the royalties on the PP to Philco).
So some tube makers didn't use the name 'beam pentode' or 'beam tetrode' to avoid stepping or RCA's trademark. The British had their own term for the beam power tube, which they developed independently from RCA (Kinkless tetrode).
@@scharkalvin wasn't it *Philips* that had the pentode patent, and not Philco?
@@goodun2974 Possibly. I only remembered that the name began with 'P'.
Nice! It also remembers me of the Lowe 3NF valve, the 1st IC manufactured in"large" quantities
The approach I take when reverse engineering something is I first build a BOM, then use that to make a list of pins. As I determine each set of pins that are connected, I write it out as one line on a separate sheet and cross them off the original list. At the end I should have a few pins left that should be easy to verify whether they are unused. Then it's easy to take the BOM and 'node list' to construct the schematic.
wow....a turboencabulator...nice miniature portable turboencabulator, or something.
Ah, the turbo encabulator, an absolute classic!
I think the tubes at the right could be arranged on differential amplifier (long tail pair) configuration to obtain the amplified and filtered signal from the input (tube at the left with RC network filter) in phase and in opposite phase (inverted).
Then that signal could be amplified by power tubes to drive a center tapped power transformer, or something that needs two signals, the original and the inverted one.
It could be a rudimentary operational amplifier with a cathode follower input.
I was thinking about it being an operational amplifier / differential pair, because it's pretty reminiscent of the old K2-W tube OpAmp. I believe though that the cathodes of the two on the right are going straight to ground though, and usually a differential pair has a cathode resistor or cathode current source of some type between the cathode and a negative voltage. Of course, that could all be happening in whatever this thing plugs into, so it's hard to tell.
An op amp and a logic gate back in the day shared some similar characteristics. I'm leaning towards a logic gate. Also not a proximity fuse as one opined, as there is no shock packaging.
The metal cap and cover is missing from that module. It had a cover and insulated connector on the top.
Oh man, it sounds like you recognize the module! Do you have any information on it or insight as to what it might be?
Imagine a world where transistors were never invented. Only tubes getting smaller and smaller.
In case you never figured out what it was, I suspect it was a way for either a manufacturer or the user to upgrade of modify an existing radio, allowing it to perform in different bands or something like that. I have seen a radio with a tube socket on the back but never guessed what it was for. Now seeing this, I think it makes sense.
Those tubes remind me of the 6314 units for phantom tube microphone I made two years ago.
You basically said it. The second 2 tubes are an amplifier. The first controls it's gain. So what makes sense? An audio stage for a receiver with AGC. Perhaps a portable, battery-powered radio? I'm not seeing where you got the 1 kHz cutoff for the 1 nf coupling capacitor. That grid according to the spec sheet is meant to be negatively biased. So it should be a very high impedance input to the grid. I'm pretty sure the 1 nf will support the the whole audio range.
Nice work! I assume they are limited as to the functions they can fit into one tube due to lack of insulation between parts?
Thank you!
Interestingly, they use insulating covers on quite a few leads because otherwise it would just be a mess of short circuits, but I imagine that it's still a noisy nightmare, haha.
To me this piece sits in a weird spot in history. If I'm not mistaken, sub-miniature tubes didn't really start to become common until the mid- to late-50's, but by that time, building stuff on PCBs was also starting to become a bit more common (like my HP 150A scope). This piece might ultimately be more compact to build it this way, but with the tubes laying flat on a PCB, you could remake the circuit and have it be an incredibly thin board, all while having better properties in the circuit and way easier maintainability.
I would love to see what it plugged in to some day, I think it would answer so many questions (or just make hundreds of new questions, haha).
Esse componente substituia uma valvula para um transistor de germanio PNP na época.
my guess is that the first tube is some kind of gyrator or oscillator, and pins s1 are for a specific external tuning capacitor.
Ooh, that's an interesting idea too!
The big green components that I thought were a voltage divider could definitely be something else entirely that sets it up as an oscillator for sure.
Supposedly it was a replacement for one of the Western Electric the 200 series peanut tubes that was no longer available by the 50s. I think for battery powered rural telephone stitching amplifying stations. On doing a little more research if could of been a replacement for an acorn tube
How could a complete electronic circuit with three active devices and a handful of various passives be a replacement for a single, early tube type?
For that matter, the 11 lin base is all wrong - this was a later development.
I must be misunderstanding you?
@@drlegendre Just re-telling what I was told. Showed the video to one of the old guys at the radio club and that was his initial though. After I made the post he came back and said it was more likely a replacement for a set of two acorn tubes, Supposedly at one time there was an 11 pin acorn plug where you would solder in up to 4 acorns. I looked for it but could not find a reference.
I'm not quite sure I'm following, but the idea of it being a replacement for something else is an interesting line of thinking!
Honestly, I'm a little torn between it being a custom made piece by an enthusiast, or an actual production piece, because of how densely it's packed and how utterly un-serviceable it is.
@@UsagiElectric I have see these for sale on-line over the years. Could not find a reference for it in tube-lore or in the operations manual I have. (same as a receiving manual but for op-amp and other not AD/RF valves.) Really just a binder of datasheets.
Uhm... We should try to come back to this ICs to solve the chip crunch before 2023🤔🤔
Haha, not quite as compact as silicon, but these little submini tubes are awesome!
@@UsagiElectric just details, it doesn't matter the size, but the way you use it!😂😉
is it a module from a backpack military transciever?
That would be awesome and about the right era for it too!
I know nothing about those old transceivers though, so I haven't got a clue, haha.
Could it be that 8.2 K resistor IS the plate resistor, and S7 is the output, not power voltage?
And M1 could be a simple cathode follower circuit, completely unrelated to the other two tubes (that's why it would need its own filament power line, since it's a directly heated cathode tube).
You know, I think you're absolutely right! I mean, I didn't trace it out wrong, I just read it wrong, haha. I think you're absolutely on point that the 8.2k resistor is the plate resistor, though!
The only thing that makes me think M1 is a part of the circuit is that the cathode level actually affects the level of bias on the grid of R1, so it should have some influence on R1 and L1, though it could be pretty minimal.
@@UsagiElectric Some kind of AGC, maybe? Although it is hard to say, without knowing the characteristics of the tubes. Maybe it's some kind of comparator.
@@demindor An analog comparator is a really interesting idea too! And that actually leads some credence to the two separate flying leads. Perhaps they were meant to read two signals and compare them against each other, amplifying the resulting signal or something.
@@UsagiElectric Still, hard to guess without knowing anything about the surrounding circuitry.
I see a video from you - I like.
Thank you so much!
Reminds me of the Loewe 3NF tube, a three tube circuit in one socket
Oh man, the Loewe 3NF is my unicorn! It truly is a tube integrated circuit. I love that they encapsulated the passives in glass too so when they off-gas it doesn't contaminate the vacuum required for the tubes. What a beautiful piece of engineering!
I read about ICs like this, as components in radios. But I don't know who used them or for what exactly.
That could definitely be a likely candidate! It might be designed to pick up and amplify a specific frequency of noise that can be then be used to cancel out that noise in the main radio system or something.
Strange circuit but love the ic concept out of tubes.
It's definitely weird, but it's also definitely cool to see an integrated circuit using tubes!
@@UsagiElectric years ago I was on the brink of making my own tubes, and one thing I had in mind: to make an integrated circuit wrapped into one single tube. Still today I'm intrigued by the idea even though I'm aware it's totally worthless scientifically and economically speaking, and very likely I'll never do it.
lovely bunnies, and great work!!
Thank you!
Those little baby buns are adorable aren't they!
I have a Datamath myself; a version 3 model which I believe was built in Italy. It's just missing its battery cover.
The Datamath is a great little calculator!
The version 3 is an excellent model too because you can just change the batteries as necessary. I had to remove the original NiCD batteries that were in mine and replaced them with a little LiPO and boost board from Adafruit. I use mine almost everyday, I love it as a quick and easy to use calculator!
I was thinking if you had a few of these small tubes could that unit be fixed be replacing the tube with the broken wire but what about mixing up some epoxy with some copper powder in it and use it to join the wire back to where it came off and once it has cured you might be able to power it up.
The CK502AX isn't actually that rare or expensive, and I could get a replacement pretty easily on eBay. And, I did think about trying to repair the broken wire - I might even be able to wick some some solder into the base and get lucky that way. Though the copper powder and epoxy idea is a good idea, I'll keep that in mind for the future!
The bigger issue is how to power it up. The tube with the broken wire is also M1 in the schematic, and since it's a cathode follower, the heater has a pretty unique requirement for powering it up. I can't just throw 1.25V into pin 9 of the base, because there's no clear path back to ground. Unfortunately, I just don't know enough about how they were powering up the cathode follower here to feel confident in trying to get it going.
They sell a silver containing paint pen for pcb repair.
I used this once to repair a CRT grid pin and it worked.
The broken pin is pin 3 which is the filament.
There is some current there so this might not work.
Could those wires sticking up be for a "getter" to maintain a vaccum? Please don't torch me I've an 8th grade education.
You'll get no flames from here, any question or guess is a good guess in my book!
In this case though, I don't think these are related to anything vacuum related. I think I see where you're coming from though - encapsulating everything in a vacuum to have a sort of enclosed integrated circuit, and that's actually not all that unreasonable, it's been done before! The Loewe 3NF is an actual integrated circuit within one glass envelope. There are three triodes, two capacitors and four resistors all stuffed inside the vacuum. But, what's interesting is that the passive components are actually encapsulated in glass themselves because if they were in the actual vacuum, they would off-gas and contaminate the vacuum.
So, you actually were kind of in thinking in the right direction!
That’s a puzzler. It amplifies, but bizarrely. It’s not a VT fuse, those particular tubes were not designed for 20,000 G’s.
You're definitely right about that!
These tubes were originally designed for hearing aids, and if a hearing aid experiences 20,000 G's, something has gone horribly wrong, haha.
Old thread, I know, but here's a fun fact: as recounted in the book “12 Seconds of Silence,” by Jamie Holmes - a history of the development of the proximity fuse by the brilliant Merle Tuve and his team- the fuses DID use specially ruggedized hearing-aid tubes, and they WERE made by Raytheon (with Hytron and Bell Labs also involved.) The book includes a cutaway photo of a fuse, and one of its components (labeled “oscillator-detector amplifier thyratron bundle”) looks a bit like the mystery gizmo in this video, right down to being constructed on a multi-pin socket base.
Could it be part of proximity fuse?
Oooh, that's an interesting guess!
I don't think it might be, but that's only because the military liked to use specialized tubes hardened for military use, and the subminis used here are pretty generic pentodes. But, I like your line of thinking!
You are aware of the 12 volt plate tubes developed and used in the last few years of car radios prior to solid state?
Space Charge tubes. I've built several low power guitar amps out of those. Mostly using the 12U7 and 12K5, but I also built a single tube 12AL8 amp.
Yup, space charge tubes are super cool! They were perfect for 12 volt car radios for obvious reasons, but they also eliminated the need for the noisy and failure prone vibrator (a hard thing to google for), which was used to create a square wave and generate high voltage for the tube plates.
How is variable gain done with pentodes? Could the first tube be to vary the gain?
Nice video, thanks :)
Thanks for checking it out!
15:42 You know that there is a dark mode for Discord? 👀
I did not even know there is a light mode...
He's old, he likes the light lol.
I actually use both dark and light mode depending on the time of day, but whenever I screenshot the Discord, I specifically use light mode to get some comments going, haha.
Also, my room has windows on three of the four walls, so light mode actually helps with readability given how much ambient light there is in the room.
Hi. Have you considered that S1 &10 could be connected to S6 & 7 outside the unit ? As S1 & S10 could be both biasing and plate resistor arrangements. If you add the 75k and 8k resistors you get a plate resistor, and if you add the 330k and 8k this makes a biasing when paired with the 160k (mayby/possibly added to the 33k which is connected to the ground).
Could it be a vacuum tube Operational Amplifier.
I had thought about that, and it's a good guess given that the K2-W was built with the similar idea of multiple components through a single base. But, I believe the fundamental thing needed for an OpAmp is a differential amplifier, which I don't quite see here.
May I ask what software are you using for your schematics? Thank you!
Thanks for checking the video out!
I use DesignSpark PCB for both drawing my schematics and PCB designs. It's not the best EDA software out there, but it's the one I'm most familiar with.
I think it's a radio rf amplifier of some sort
I think you may be on the right track, that would certainly explain the flying leads coming off the top!
There are people making their own tubes, they look very complex at first, but I was very surprised that isn't that hard to make them, need some practice with glassblowing and metalworking, but the construction of simple amplifier tube(I guess a pentode? I'm not tube expert!) isn't very complex. Maybe I nice project for this channel in the future, make your own opamp form glass and metal. 😁
Very cool channel. Subscribed!
Thank you so much!
Get on with it! [Too late, Bailed at 1:42 due to "chuntering-on".]
I love your name. Usagi electric
Thank you!
That was interesting. I have some russian submini tubes that I have been meaning to do something with one day.
This has me wondering, what does usagi do for a living?
Interestingly, I don't do anything electronics related for a living.
My primary job (pre-covid) was new vehicle training for overseas markets, though with international travel being a bit more difficult now, I've mostly transitioned over to Japanese to English translation and the occasional online training. I'm not complaining too much though, the extra free time at home has given me the time to work on the TH-cam channel!
try glasslinger onn youtube he makes old tubes
Glassslinger makes some really excellent stuff, they've got some serious fabrication skills!
The best.
Thank you so much!
sch!sch! All you need is Schematic!!!
If I can see the schematic, I can make a lot more sense of things!
Though in this case, I'm still totally confused as to what it might be, haha.
@@UsagiElectric Many video dont show schematic.
But you showed us the schematic writen in CAD.
thx
all you need is schematic!!!
I'm wondering if it was a microphone pre amp? A lot of the early microphones required a pre amp? Hence the small size.
Old condenser microphone internals, perhaps?
Oooh, now that's an interesting guess! I hadn't thought about high end microphones using some systems like this, but that's possible.
Very informative video Sir....cuteee bunnyyyyy
Thank you!
Those little baby bunnies were actually wild cottontail bunnies that we rescued from our dog. We raised them until they were big enough to be released back into the wild!
@@UsagiElectric nice Sir ....
2:43
"The population density of this little thing is insane..."
😅😅
I wasn't quite sure how to refer to just how incredibly dense it was, haha.
@@UsagiElectric
That was OK...
i'm def here for the bunnies
They're so adorable aren't they!
Those were some baby wild cottontails we rescued from our dog and outside cat. We raised them until they were big enough to be released back into the wild!
If those two big green unknown components are coils it starts to look like a Hartley oscillator. If that gets modulated by a second signal in the next tube, this whole assembly is an AM transmitter?
Oooh, that's a very interesting idea!
There's actually a third big green component hiding behind the two that are visible, which is why I thought maybe they were a voltage divider, but I like the idea of the flying lead being a transmitter instead of a receiver! That's a line of thinking I hadn't thought about all and could explain why there's a flying lead on the cathode of the cathode follower. Very cool idea!
@@UsagiElectric I also remembered reading an article online about making an oscillator similar to this and placing it in or near an existing radio receiver. When tuned it would create a beat frequency oscillator that would improve the clarity of voices over shortwave. Those two flying leads may be antennas to create such an interaction. Without context of what this thing came out of, it’s hard to say what it was supposed to do. All I can say is HAM radio people have skills that are akin to alchemy.
@@MadScientistGuitarLab Now that's a suggestion I really like! HAM level stuff is certainly on a level of analog wizardry. Shortwave feels a bit high frequency for this, but I don't know enough about RF stuff to tell for sure. But, I think you're getting on the right track with this idea!
Maybe this CK502AX tube was replaced by the CK722 transistor.
Oooh, interesting idea!
Though, I'm not sure how related they may be. Vacuum tubes in general are more closely related to N-Channel FETs, but the CK722 was a PNP transistor, which is a functionality that tubes can't really exhibit. However, both being manufactured by Raytheon, there may be more of a connection there than I can see!
@@UsagiElectric I guess CK was used for active devices such as vacuum tubes so they used it for transistors also. People joke about CK722 because it was the first available transistor for electronic hobbyists.
You could probably make a MC14500 with them. How many transistors does it have?There are a few on Ebay for $49. A lot of them don't work by now, they were not sealed very well.
Ahh, you're here. Good. We've got a problem. A big one. The controller chip for our water purification system has given up the ghost. Can't make another one and the process is too complicated for a work around system. Simply put, we're running out of drinking water. No water, no Vault. This is crucial to our survival. And frankly, I... I think you're the only hope we have. You need to go find us another controller chip. We estimate we have four to five months before the Vault runs out of water. We need that chip. We marked your map with the location of another Vault. Not a bad place to start I think. Look, just be safe, OK?
War... War never changes...
Life in the Vault is about to change.
I have around 600 vacuum tubes with me. 😊
Nice, that's a healthy collection!
I had thousands in 1989.
I threw them away, they took up too much space.
I wish I still had them.
i have strange zirconium arc vacuum tube I don't know what it's for never used from navy 1944 destroyer ship i found it in normandie france
VT fuse ?
I don't see anything in there that looks like it could work as a fuse, but that's an interesting idea!
It kind a looks like a vacuum tube scope Probe
Oooh, that's a very interesting guess!
I still have a box of tubes here that I promiced to send you
you still want them or not?
Weather balloon?
Suprb video love from india
Thank you very much, and hello to India!
so its vacuum tube based IC
Yup, that's why I was so interested in this little piece!
It's a flip-flop!
It being an multivibrator design is an interesting guess!
I don't quite think it could be though because of the coupling capacitor. Flip Flops usually work on DC signals, but the 1nF coupling cap means it really only cares about AC signals.
@@UsagiElectric Thank you for you reply Usagi, of course it was just a wild guess!
Have you ever thought about making a wristwatch with nixies?
@Usagi Electric hi really interesting content man if your interested in reverse engineering NOS military equipment hit me up i bought some kind of radio equipment that uses a green eye indicator it's modular seems to go to a rack of some kind it's at least 1950s can send some pics if interested
Oh yeah, that sounds like a really cool piece of equipment! The green eye indicator is often called a Magic Eye and they were used pretty regularly on old radios as a visual way to let you know how closely tuned to a station you were.
If you want, hop on over to the Discord and share some photos of it!
discord.gg/p7UsfHD
ask mr carlson. he might know
If he sees the video, I'd love to hear his thoughts!
This voltage divider and AC offset tube circuit sugest it could work in a diferential equation solving tube computer like AKAT-1 en.m.wikipedia.org/wiki/Jacek_Karpi%C5%84ski
Interesting, that was definitely not a direction I was thinking, but it could very well be!
More importantly though, I hadn't heard of the AKAT-1 before, and that thing is epic! Aside form the capability, which is amazing too given when it was built, the aesthetic is top class. It would look perfect sitting inside a Mid-Century Modern home designed by Frank Lloyd Wright or something.
Thanks for turning me on to that awesome piece of history!
@@UsagiElectric look, in my opinion it is definently not a RF as tubes are not shielded ( but glued together) capacitors grade is not RF grade and module kind of circuitry desighed to be mass produced and easy replaced sugest its rather fits to socket board with hundreds of such elements in arrays, external leads perhaps were used to do " logic programing" by hardwiring them into inputs outputs. Early computers were not always touring machines ( read. Theoretical Pawlak machine) which was predecessors to todays neural network, then opamps were intorduced to replace tube modules in analogue computers, free world newer experience some designs of suc computers becouse neither Karpinski nor Pawlak ( creator or ODRA Polish conputer operating in negative radix insteadd of binary system) get passporrs to leave dammed communistic block... Karpinski ended up running Pig farm ( real swines and hogs) as he said in the interview: "I preffere real Swines then the The government ones." ;)
@@marcsmithsonian9773 I definitely see where you're coming from!
With RF, I think it could probably be fine for ULF, VLF or LF up to about 1MHz. At such low frequencies, the importance of shielding and RF grade components isn't quite important. These type of Mica capacitors I see very regularly on old AM tube radios which here in the US runs from about 500kHz up to 1,700kHz (1.7MHz). I'm not quite as familiar with early differential calculators as I am with the later IBM style computer like the 604 or 650, so it's definitely possible that the component was used for some kind of early analog computing application!
@@UsagiElectric You make a good point, despite the fact it could work in LF aplication, still I believe ahield of some sort wpuld be aplied to what I observed in old tube circuitry, I work alot on tume amps as hobby testore old HK, Fishers and RCA and they all use shield in preamp section and tuner , so I figured back then wnginers were quite religious about shielding from interference, I would be suprised if that actualy was RF part. But I am not an autority on that. GOOD LUCK !