electronics like its 1922

[bsfeechannel]

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.

[TimFox]

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.

[james_s]

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.

[TimFox]

Lee de Forest believed that a hard vacuum would not work in a tube:  he thought that some gas was required for electron flow.

[coppice]

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.

While 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.

[jonpaul]

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

[TimFox]

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.

[Kleinstein]

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.

After 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.

[jonpaul]

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

[TimFox]

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?

[TimFox]

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).

[jonpaul]

Tim, the 470 k is in the correct placement as a decay time constant.

Yes it is a voltage doubler in the lower right

Search for SIGSALY in NSA, NCM, IEEE SPECTRUM, cryptomuseum.org

The 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

[TimFox]

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.

[bsfeechannel]

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.

So, 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.   

[TimFox]

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's Julius Caesar.

[coppice]

A true anachronism is the mention of clock chimes in Shakespeare's Julius Caesar.

What 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.

[Infraviolet]

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.

[TimFox]

A true anachronism is the mention of clock chimes in Shakespeare's Julius Caesar.

What 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.

See  https://myshakespeare.com/julius-caesar/act-2-scene-1-popup-note-index-item-the-clock

[coppice]

A true anachronism is the mention of clock chimes in Shakespeare's Julius Caesar.

What 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.

See  https://myshakespeare.com/julius-caesar/act-2-scene-1-popup-note-index-item-the-clock

So both myshakespeare.com AND you need to read more history.

[TimFox]

There are many anachronisms in Shakespeare, including Julius Caesar.
https://anachronisticnook.weebly.com/anachronisms-in-julius-caesar.html
But that is not the only reason why we honor him.
Also:  https://en.wikipedia.org/wiki/Clock_chime   and   https://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:

TREBONIUS
There is no fear in him. Let him not die,
For he will live and laugh at this hereafter.

[Clock strikes.]

BRUTUS
Peace, count the clock.

CASSIUS
The clock hath stricken three.

TREBONIUS
’Tis time to part.

[coppice]

There are many anachronisms in Shakespeare, including Julius Caesar.
https://anachronisticnook.weebly.com/anachronisms-in-julius-caesar.html
But that is not the only reason why we honor him.
Also:  https://en.wikipedia.org/wiki/Clock_chime   and   https://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:

TREBONIUS
There is no fear in him. Let him not die,
For he will live and laugh at this hereafter.

[Clock strikes.]

BRUTUS
Peace, count the clock.

CASSIUS
The clock hath stricken three.

TREBONIUS
’Tis time to part.

You 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.

[TimFox]

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=csbsresearchconf
I 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

[coppice]

When I was in grad school, the Cooley-Tukey algorithm for the faster computation of the discrete Fourier transform was still new.

Well, it was new to Cooley and Tukey.

[TimFox]

By the early 1970s, it was no longer new for Cooley and Tukey.

[coppice]

By the early 1970s, it was no longer new for Cooley and Tukey.

Have 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.