electronics like its 1922 - Page 1
Forum section: electronics / general

author: strawberry
author_rank: Super Contributor
timestamp: October 24, 2022, 08:19:14 pm
content: it would be more fun with hand made resistors and capacitorssounding lightbulbs

author: AndyBeez
author_rank: Frequent Contributor
timestamp: October 24, 2022, 08:29:37 pm
content: Cool. [ except for the H.T. ]Back then, our EE ancestors built their circuits onrealbreadboards.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2022, 08:55:23 pm
content: I especially admire the mica capacitors and the "body-end-dot" rod resistors, but those alligator clips are anachronistic.

author: Gyro
author_rank: Super Contributor
timestamp: October 24, 2022, 09:01:15 pm
content: It's the first time I've seen tube construction like that, that hasn't involved a glass lathe.

author: TimFox
author_rank: Super Contributor
timestamp: October 24, 2022, 09:07:12 pm
content: Quote from: AndyBeez on October 24, 2022, 08:29:37 pmNote the brads holding the brass squares to the wood breadboard, forming useful terminals.

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 26, 2022, 12:24:16 am
content: Quote from: TimFox on October 24, 2022, 08:55:23 pmAlligator clips were available in the 1920's:https://worldradiohistory.com/Archive-Catalogs/Allied-Catalogs/Allied-Catalog-1929.pdfPage 46. Just 7c a dozen.

author: jonovid
author_rank: Super Contributor
timestamp: October 26, 2022, 01:07:57 am
content: awesome stuff jdflyback, way to go!

author: TimFox
author_rank: Super Contributor
timestamp: October 26, 2022, 03:39:07 am
content: Quote from: bsfeechannel on October 26, 2022, 12:24:16 amThe clips on page 46 of the 1929 Allied catalog are notalligatorclips, certainly not like the ones illustrated in the post that are on modern cheap test leads.

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 26, 2022, 04:16:24 pm
content: Quote from: TimFox on October 26, 2022, 03:39:07 amTry this one.https://worldradiohistory.com/Archive-Catalogs/Lafayette-Catalogs/Lafayette-1932-Spring-Summer.pdfNot only they resemble the alligator clips we have today, but they also are called alligator clips.So, they are period correct.

author: TimFox
author_rank: Super Contributor
timestamp: October 26, 2022, 04:36:45 pm
content: Since we’re nit-picking, the Lafayette catalog is from 1932…

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 27, 2022, 02:29:20 am
content: 1916

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2022, 02:43:42 am
content: The 1916 ad shows two kinds of clips, but neither is an "alligator clip".

author: Cyberdragon
author_rank: Super Contributor
timestamp: October 27, 2022, 03:46:18 am
content: The crocodile clip or alligator clip was invented in 1908 by Ralph Mueller.https://pecm.co.uk/mueller-electric-inventors-of-the-crocodile-clip/?utm_source=rss&utm_medium=rss&utm_campaign=mueller-electric-inventors-of-the-crocodile-clip

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2022, 02:28:19 pm
content: In careful usage, the "alligator clip" has upper and lower jaws that meet, while in the "crocodile clip" the upper jaws go inside the lower jaws.My original "anachronism" comment referred to the modern cheap alligator-clip test leads in the photo that are ubiquitous now.

author: coppice
author_rank: Super Contributor
timestamp: October 27, 2022, 02:34:54 pm
content: Quote from: Gyro on October 24, 2022, 09:01:15 pmWhen I was at UCL they got some of Fleming's original experimental thermionic diodes out of storage, and used modern parts to make a simple radio from one of them. It was some anniversary event. Those valves looked like they have been produced by an expert glass blower.

author: strawberry
author_rank: Super Contributor
timestamp: October 27, 2022, 04:56:30 pm
content: 1920 1.10$ adjusted to inflation 2022 ~18$thicker metal for jaws not to slip when grabbing on some thinner wire..

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2022, 05:29:03 pm
content: Quote from: coppice on October 27, 2022, 02:34:54 pmI'm curious about the original Fleming valves: were they constructed by adding an anode to a pre-existing commercial incandescent lamp?

author: coppice
author_rank: Super Contributor
timestamp: October 27, 2022, 05:46:04 pm
content: Quote from: TimFox on October 27, 2022, 05:29:03 pmWell, I was there in the early 70s, and all the staff who made those things had moved on....If you look at the pictures athttps://en.wikipedia.org/wiki/Fleming_valveI think they work historically from left o right. Its quite possible the right hand picture is the one I saw being fired up. I remember it had a tubular anode like that one, The construction wasn't much different from early incandescent lamps. A nipple at the top seemed to be the point of evacuation, like early incandescent lamps, or most valves up to the end of their reign in the late 60s/early 70s. However, I don't think they modified an incandescent lamp. They made a custom envelope from scratch in a similar style. The bulbous shape was probably just the result of it being blown by hand.

author: TimFox
author_rank: Super Contributor
timestamp: October 27, 2022, 08:49:01 pm
content: Interesting detail from your source: Fleming called his device an "oscillation valve", which confused me until I realized his meaning that it "valved" oscillations, not that it was an "oscillating valve".Careful language usage!

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 28, 2022, 01:56:28 am
content: Quote from: TimFox on October 27, 2022, 02:28:19 pmAt the company where the alligator clip was invented, they think otherwise:QuoteAnd they were ubiquitous then. Mueller alone produced 85,000 alligator clips per day way back in 1922.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2022, 03:32:50 am
content: I maintain that the distinction between an "alligator clip" and a "crocodile clip" is useful, and there is no point in using both terms to describe the "alligator clip" in the lower part of that picture.Sometimes, you will find a crocodile clip to be more appropriate for your application, and if they both have the same name how do you specify the desired clip?That's why I used the term "in careful usage".I notice that Mueller Electric (who make high-quality crocodile and alligator clips) refer to their BU-85 as a "crocodile clip", where the jaws nest, which agrees with my point here.https://www.muellerelectric.com/product_files/449/DS-BU-85.pdfThey also refer to their BU-60 as an "alligator clip".https://www.muellerelectric.com/product_files/325/DS-BU-60C.pdf

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 28, 2022, 08:10:54 pm
content: Quote from: TimFox on October 28, 2022, 03:32:50 amTaken from the last picture I posted above.In the US, we have one type of clip that is referred to as a crocodile clip --which is a type of center-spring ALLIGATOR CLIP.So, crocodiles are also alligators when it comes to clips. In other parts of the world, alligator clips receive other suggestive names (besides the equivalent of crocodile) like lizard clips, pike jaws, jacaré (a type of South American alligator) clips, and so on and so forth.The name is irrelevant. The thing is that the alligator/crocodile/pike/jacaré/lizard clips/jaws of the kind shown in the video were available since the beginning of the rise of electronics in the early 1900s.If we're looking for a real anachronism in the OP's video, it is the music at the end: it should be ragtime. Not pop.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2022, 08:34:01 pm
content: True crocodiles and alligators have different shaped jaws, but neither have the exact shape of what I insist on calling a "crocodile" clip where the upper jaw goes inside the lower jaw.https://www.everythingreptiles.com/alligator-vs-crocodile/Note that alligators have a U-shaped snout, while crocodiles have a more pointed triangular snout.I recommend the nomenclature used in the two Mueller data sheets I posted, since the two clips are different and it represents careful usage to call them something different.Again, the "anachronism" I mentioned was not the clips themselves but that they were modern cheap Radio-shack-type clip leads.

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 28, 2022, 09:19:27 pm
content: RadioShack was founded in 1921.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2022, 09:25:52 pm
content: Did they use thin PVC insulation on their clip leads back then?

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 28, 2022, 10:17:09 pm
content: You can bet your bottom dollar that insulators for alligator clips were available way back when, since they were intended right from the start to be used with test leads.But then it is not the alligator clip or it having an insulation that was anachronistic. Perhaps it was the "thin PVC". In that case, the video is full of anachronisms: the modern vacuum pump, the modern gas torch, the battery operated drill, the HD digital camera he used to film it, to name a few.

author: TimFox
author_rank: Super Contributor
timestamp: October 28, 2022, 10:57:54 pm
content: I had some quite old crocodile clips on the test leads for a pre-war Simpson 260 meter.The rubber insulation used on the clips and the wires had hardened with age and cracked off.

author: james_s
author_rank: Super Contributor
timestamp: October 28, 2022, 11:52:15 pm
content: That's pretty impressive. Functional vacuum tubes without the use of a diffusion or turbo pump and not even a getter, I wouldn't have thought they would work at all, much less well enough to be sealed off.

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2022, 04:09:08 am
content: Lee de Forest believed that a hard vacuum would not work in a tube: he thought that some gas was required for electron flow.

author: coppice
author_rank: Super Contributor
timestamp: October 29, 2022, 03:31:47 pm
content: Quote from: TimFox on October 28, 2022, 10:57:54 pmWhile big chunky crocodile clips used to have a rubber covering, most clips used two chunks of something rigid, like bakelite, on the two sides of the clip.

author: jonpaul
author_rank: Super Contributor
timestamp: October 29, 2022, 04:00:13 pm
content: My 2018 IEEE Spectrum reconstruction with 2050 Thyratrons of the 1942 first ADC.used many (but not all) vintage parts.Was in IEEE Spectrum February 2019 issue.Jon

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2022, 04:14:49 pm
content: My favorite vintage part there is the hermetically sealed paper capacitor ("2.0 mfd/400 V"), and I appreciate transparency in construction!When I used "MCAs" (multi-channel analyzers, which analyzed pulse height and displayed the pulses in a histogram) back in the 1970s, I researched the literature and found a model from sometime around 1950 that was built like a pinball machine: the pulse height drove a solenoid that launched ball bearings onto a tilted surface, and the different impulse values resulted in the balls landing in different bins.The 2050 and 2051 glass-octal thyratrons (2051/VT-109 used in your reconstruction) were commonly used in jukebox mechanisms pre-war.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 29, 2022, 04:55:14 pm
content: Quote from: james_s on October 28, 2022, 11:52:15 pmAfter a good bake out by heating the whole system to > 200 C there is very little outgasing. A sealed glass system than does no longer needs contineous pumping. Ideally one would seal off the glass while it is still relatively hot. The tubes in the video do use a getter (the titanium wire on top of the actual tube), though there is not very much of the getter evaporated to the glass wall. If need the getter could be heated even more. Evaporating some titanium is pretty effective in pumping down in the high / UHV vaccuum range, as long as one keeps helium and neon out. Modern 2 stage rotary pumps are not that bad and can be a start for the titanium to work.

author: jonpaul
author_rank: Super Contributor
timestamp: October 29, 2022, 05:36:39 pm
content: Tim many thanks:The large plastic caps in lower photo are for the preamp B+ 3 stage RC/HV Zener filter/regulator.When they fire, Thyratrons induce noise pulses on the B+ which the 100k gain Preamp (2X 6SN7) pickup, causing motorboating.See the "debugging..unexpected interactions" part of the IEEE Spectrum articles.Jon

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2022, 06:37:21 pm
content: In the lower right-hand corner of the preamp schematic, should the 470 k resistor be to the right of the 100 nF capacitor, to make a voltage doubler?

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2022, 09:12:00 pm
content: jonpaul:I just finished reading a newly-published history of the "rise of American intelligence" from WW I through WW II to the beginning of the Cold War: Nicholas Reynolds, "Need to Know", Mariner 2022.Unfortunately for my interests, the technology is mentioned only in historical context, with brief mentions of "business machinery" supplied by IBM and AT&T for cryptology.The voice scrambler is not even in the index, but pp 245-246 describe a typical bureaucratic fight (in Washington) when the visiting Alan Turing, there to describe Enigma to US Army and Navy Intelligence, wanted to see the prototype scrambler.The book mentions that the scrambler development was a joint project between the Army and Navy, done at Bell Laboratories.I'm going to look through the bibliography for recent works that discuss the technology of that era in more detail (aside from Enigma, which has been discussed in great detail).

author: jonpaul
author_rank: Super Contributor
timestamp: October 29, 2022, 09:43:27 pm
content: Tim, the 470 k is in the correct placement as a decay time constant.Yes it is a voltage doubler in the lower rightSearch for SIGSALY in NSA, NCM, IEEE SPECTRUM, cryptomuseum.orgThe Cryptologic theory and design of SIGSALY was at BTL, Claude Shannon, Nyquist, Blackman....Turing visited BTL well after the first SIGSALY deployment, to evaluate for use by the UK.He confirmed Shannon's unbreakable voice scrambling system.As UK wanted it's own scrambler, Turing designed Delilah, but it was unworkable and only a prototype was made, post war.to bust another myth, first crack of Enigma keys was not by Turing but three Polish mathématiques at University of Poznan, 1932.Cryptographically Yours,Jon

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2022, 02:01:57 pm
content: The book I just read concentrated on American intelligence agencies, but did describe the origins of the Enigma decryption in Poland when discussing the co-operation between US and UK cryptology.(A detail from that book: much of the American equipment built from the Enigma information supplied by UK was built by National Cash Register: lots of mechanical wheels and stuff.)One achievement of the US before entering the war was the US Navy's breaking of the "Purple" code used by Japanese diplomats.Although the US had no useful agents on the ground in the Nazi government, they had something better: the Japanese ambassador to Berlin was perhaps more Nazi than the Germans, spoke perfect German, and was a close confidant of Hitler.The US read his dispatches back to Tokyo, including after he inspected the upcoming battlefield in Normandy.Meanwhile, the Soviet Union had Sorge in Tokyo, but didn't share much of his intelligence with the US.

author: bsfeechannel
author_rank: Super Contributor
timestamp: October 30, 2022, 04:36:12 pm
content: Quote from: TimFox on October 28, 2022, 10:57:54 pmSo, it would be quite improbable to get an intact insulation produced in the 1920s. But, if by anachronistic you mean not produced in the 1920, so are the tubes, produced well into the 21st century.

author: TimFox
author_rank: Super Contributor
timestamp: October 30, 2022, 05:32:00 pm
content: Avoiding "anachronism" in this context does not imply that all objects and props must be made in the original century.Note the use of accurate replicas of harpsichords and krummhorns in authentic performances of 16th-century music.A true anachronism is the mention of clock chimes in Shakespeare'sJulius Caesar.

author: coppice
author_rank: Super Contributor
timestamp: October 30, 2022, 06:06:40 pm
content: Quote from: TimFox on October 30, 2022, 05:32:00 pmWhat is anachronistic about that? In Roman times they used various tools to measure time, and had someone chime a bell each hour. Just as computer used to be a human job title, clock isn't a lot different.

author: Infraviolet
author_rank: Super Contributor
timestamp: October 30, 2022, 11:26:41 pm
content: Ofcourse, whenever we mention that Turing was not alone in breaking Enigma, we also need to mention Tommy Flowers and Bill Tutte who actually built the Colossus computer, not to forget the later working in breaking the Lorentz Engima upgrade. The museum at Bletchley is worth a look for those in the area.

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2022, 03:08:45 am
content: Quote from: coppice on October 30, 2022, 06:06:40 pmSeehttps://myshakespeare.com/julius-caesar/act-2-scene-1-popup-note-index-item-the-clock

author: coppice
author_rank: Super Contributor
timestamp: November 01, 2022, 08:52:18 pm
content: Quote from: TimFox on October 31, 2022, 03:08:45 amSo both myshakespeare.com AND you need to read more history.

author: TimFox
author_rank: Super Contributor
timestamp: November 01, 2022, 09:29:23 pm
content: There are many anachronisms in Shakespeare, includingJulius Caesar.https://anachronisticnook.weebly.com/anachronisms-in-julius-caesar.htmlBut that is not the only reason why we honor him.Also:https://en.wikipedia.org/wiki/Clock_chimeandhttps://www.scientificamerican.com/article/a-chronicle-of-timekeeping-2006-02/Trust me, I have read much history: classical, medieval, modern, etc.I was careful during my formal education to avoid history classes, so when I started to read history after graduation I did not find it boring.\The actual text in question:Julius Caesar, Act 2, Scene 1:TREBONIUSThere is no fear in him. Let him not die,For he will live and laugh at this hereafter.[Clock strikes.]BRUTUSPeace, count the clock.CASSIUSThe clock hath stricken three.TREBONIUS’Tis time to part.

author: coppice
author_rank: Super Contributor
timestamp: November 01, 2022, 10:25:18 pm
content: Quote from: TimFox on November 01, 2022, 09:29:23 pmYou are sounding like young engineers who say things like "a radar couldn't have included a Fourier transform before DSP was practical", because they've only learned digital ways to achieve that functionality.

author: TimFox
author_rank: Super Contributor
timestamp: November 01, 2022, 11:34:30 pm
content: No. I have read the text, seen the play several times, and am familiar with ancient/classical timekeeping machinery.The text reads "hath stricken three": that means that "the clock has struck three", not merely that it is 3 AM.An example to cite, not my uneducated opinion:https://scholarworks.uni.edu/cgi/viewcontent.cgi?article=1074&context=csbsresearchconfI also know that Fourier transforms are spelled with only one F.When I was in grad school, the Cooley-Tukey algorithm for the faster computation of the discrete Fourier transform was still new, but my colleagues were implementing it on Data General Nova minicomputers.Other colleagues were doing two-dimensional Fourier transforms with a laser and optical bench.https://www.ams.org/journals/mcom/1965-19-090/S0025-5718-1965-0178586-1/S0025-5718-1965-0178586-1.pdf

author: coppice
author_rank: Super Contributor
timestamp: November 02, 2022, 12:48:46 am
content: Quote from: TimFox on November 01, 2022, 11:34:30 pmWell, it was new to Cooley and Tukey.

author: TimFox
author_rank: Super Contributor
timestamp: November 02, 2022, 03:26:28 am
content: By the early 1970s, it was no longer new for Cooley and Tukey.

author: coppice
author_rank: Super Contributor
timestamp: November 02, 2022, 11:12:48 am
content: Quote from: TimFox on November 02, 2022, 03:26:28 amHave you been in meetings where you say something key, and it gets no response. Then an hour later someone says the same thing thing and everyone reacts appropriately. By that time the rest of the room has caught up enough to respond as they ought to have done the first time, but they 100% utterly forget the same thing had been raised earlier. Cooley-Tukey is a classic example of that happening on a longer term. What amazes me about many examples of this effect is what were the original inventors thinking about when they figured the thing out the first time? They were often so far from having any practical use of their idea that its amazing they ever pondered the issue.