Interesting findings on the internet

mnementh · Post by **mnementh** » Mon Aug 18, 2025 3:25 pm

I found these resources today while trawling for a .pdf manual for my Eico 250 VTVM:

https://www.worldradiohistory.com/Archi ... o-1974.pdf

https://www.kevinchant.com

mnem

kevinchantdotcom.jpg

MED6753 · Post by **MED6753** » Thu Aug 28, 2025 6:30 pm

EICO was a most worthy competitor to Heath. Sadly they went the way of the dodo too.

Edit...EICO also sold audio kits but I don't see them in that catalog. Perhaps it was a separate catalog. I do have an EICO catalog somewhere in my stash along with dozens of Heathkit catalogs.

Zenith · Post by **Zenith** » Fri Aug 29, 2025 9:28 am

I always thought EICO was a lesser manufacturer of TE, not a kit company. We don't see EICO much this side of the pond. Heathkit/Daystrom was well established here and they had a factory in Gloucester. Heathkit turns up regularly at swapmeets here. I have a few units; a VTVM, a distortion meter and an audio wattmeter. There were a few other companies of that sort. Jason and Knight come to mind. Those sort of companies, like electronics shops aimed at hobbyists and hams, were things of a particular era.

tggzzz · Post by **tggzzz** » Wed Sep 03, 2025 11:05 am

We are used to fast transistors switching in ps. Now we have to get used to switching in as, attoseconds, 10^-18s.

Yup, forget GHz, forget THz, this is PHz territory.

...demonstrating a current on/off switching effect on a ~630 attosecond scale (~1.6 petahertz speed)...

https://www.planetanalog.com/attosecond ... switching/

BU508A · Post by **BU508A** » Fri Sep 05, 2025 4:04 pm

How nature really measures space and time

tautech · Post by **tautech** » Sat Sep 06, 2025 1:31 am

The falls and rise of IC and component exports per country since 1980.

tggzzz · Post by **tggzzz** » Mon Sep 08, 2025 9:06 am

At last, some interesting uses for smartphone... physics experiments using the phone sensors. https://phyphox.org/ One example is a chirped sonar. Another is using the accelerometer to see heart rate.

It also shows raw sensor readings, e.g. number of GPS satellites and horizontal/vertical accuracy 6m/19m with 5 satellites, 2m/10m with 20 satellites.

mnementh · Post by **mnementh** » Sat Sep 13, 2025 8:51 pm

Complete robot.jpg

https://archive.org/details/isaac-asimo ... volume-one

2 Giggibachis, 24 hours, All of Asimov's Robot Stories in one audiobook.

mnem
should keep me off the street & out of trouble for a while...

tggzzz · Post by **tggzzz** » Fri Sep 19, 2025 7:55 am

Got an open container of IPA at home? If you see any white crystals in it, gently put it down, run away, and call the bomb squad....

https://www.sciencedirect.com/science/a ... 0924000754
https://www.sciencedirect.com/science/a ... 1225000347
https://pubs.acs.org/doi/10.1021/acs.op ... 12?ref=PDF paywalled, but the abstract is sufficient

You may already have seen that on the HPAK group https://groups.io/g/HP-Agilent-Keysight ... age/153895

mnementh · Post by **mnementh** » Tue Sep 30, 2025 5:22 pm

tggzzz wrote: ↑Fri Sep 19, 2025 7:55 am Got an open container of IPA at home? If you see any white crystals in it, gently put it down, run away, and call the bomb squad....

https://www.sciencedirect.com/science/a ... 0924000754
https://www.sciencedirect.com/science/a ... 1225000347
https://pubs.acs.org/doi/10.1021/acs.op ... 12?ref=PDF paywalled, but the abstract is sufficient

You may already have seen that on the HPAK group https://groups.io/g/HP-Agilent-Keysight ... age/153895

mnem
who you gonna call...?

tggzzz · Post by **tggzzz** » Wed Oct 08, 2025 9:14 am

Mesmerising Game of Life on steroids. https://www.sagejenson.com/36points/

Use control panel dropdown on the top right to choose from 40 examples, and diddle the parameters. I rather like "growing on a sea of sand".

Some patterns take 30s to settle down, and unsurprisingly the starting point can be significant.

Explanations:
https://bleuje.com/physarum-explanation/
https://github.com/Bleuje/interactive-p ... me-ov-file

mnementh · Post by **mnementh** » Sat Oct 11, 2025 12:54 am

https://benjaminheine.blogspot.com/2014 ... scene.html

mnem
*drawn*

tggzzz · Post by **tggzzz** » Sun Oct 12, 2025 11:48 am

From the "About Bloody Time Too" department...
https://www.theguardian.com/world/2025/ ... the-movies
Move over, Alan Turing: meet the working-class hero of Bletchley Park you didn’t see in the movies

EC8010 · Post by **EC8010** » Sun Oct 12, 2025 9:42 pm

Oh yes. Tommy Flowers was the Dollis Hill Post Office engineer who made Colossus. So he made Turing's ideas practical. And Welchman worked out where to apply Turing's ideas. Don't tell me; you're keeping an eye out for a Colossus... They're quite big and probably rather power-hungry judging by the number of valves. Still, it would make your recent VNA acquisition look small.

tggzzz · Post by **tggzzz** » Sun Oct 12, 2025 9:52 pm

I will tolerate one tube/valve in a piece of test equipment. 1500? Not a chance!

EC8010 · Post by **EC8010** » Mon Oct 13, 2025 8:16 am

A quick calculation says that if they were all 6J5 (which were in Colossus), that would be 2.8kW of heater power. Cosy.

bd139 · Post by **bd139** » Tue Oct 14, 2025 9:51 am

I've been in the room when it was running at TNMOC. It sure feels like 2.8kw!

EC8010 · Post by **EC8010** » Tue Oct 14, 2025 3:43 pm

I keep meaning to visit TNMOC. Talking of museum pieces, my Windoze XP machine was getting difficult about booting. A friend suggested that dodgy RAM was likely. I unplugged one of the 1Gb cards, started looking in the BIOS, pressed "ESC" too many times and it booted. And again on three successive days. So it could be that RAM card or it could be the socket. I bought two 2Gb cards and fitted them and job's a good 'un. It's a nice quick machine (2.4GHz, quad core, SSD, racing pegs) and is my workhorse. Much nicer than this horrible thing.

Cubdriver · Post by **Cubdriver** » Tue Oct 14, 2025 3:45 pm

tggzzz wrote: ↑Sun Oct 12, 2025 9:52 pm I will tolerate one tube/valve in a piece of test equipment. 1500? Not a chance!

My limit thus far has been something over 70 with the HP 524 series counters. It's almost time to break one out and start wowrking on it again - it's getting colder in these parts...

-Pat

tggzzz · Post by **tggzzz** » Tue Oct 14, 2025 4:09 pm

EC8010 wrote: ↑Tue Oct 14, 2025 3:43 pm I keep meaning to visit TNMOC.

I traditionally visit it after DDARC in Luton. Highly recommended: where else can you discuss schematics with the helpers :0

Talking of museum pieces, my Windoze XP machine was getting difficult about booting. A friend suggested that dodgy RAM was likely. I unplugged one of the 1Gb cards, started looking in the BIOS, pressed "ESC" too many times and it booted. And again on three successive days. So it could be that RAM card or it could be the socket. I bought two 2Gb cards and fitted them and job's a good 'un. It's a nice quick machine (2.4GHz, quad core, SSD, racing pegs) and is my workhorse. Much nicer than this horrible thing.

I arrange my Xfce window manager to act like WinXP. I hate hidden Start Menu items that move around. And just don't mention "modern" hintless touch screen fondleslab GUIs.

EC8010 · Post by **EC8010** » Tue Oct 14, 2025 6:06 pm

Now that's a real piece of electronics; even the cat's impressed. All those valves and bevel gears too!

Real computers admit they are computers and don't pretend to be 'phones. They have mice, standardised keyboards, and their screens are not touched because we don't tolerate fingerprints on the anti-flare coating. Moreover, they do real computing things; big engineering spreadsheets, SPICE, technical drawing, running experiments over GPIB. They do not play Doom.

tautech · Post by **tautech** » Mon Oct 20, 2025 9:46 am

An interesting history of electronics downunder, 27 mins
Australia's Forgotten Electronics Giant
https://www.youtube.com/watch?v=RbzgfBLrscg

Zenith · Post by **Zenith** » Mon Oct 20, 2025 2:17 pm

EC8010 wrote: ↑Sun Oct 12, 2025 9:42 pm Oh yes. Tommy Flowers was the Dollis Hill Post Office engineer who made Colossus. So he made Turing's ideas practical. And Welchman worked out where to apply Turing's ideas. Don't tell me; you're keeping an eye out for a Colossus... They're quite big and probably rather power-hungry judging by the number of valves. Still, it would make your recent VNA acquisition look small.

Tommy Flowers had considerable experience of using valves in Post Office equipment. It was assumed that relays would be used for Colussus because valves were too unreliable. Flowers said that valves were reliable if they were never turned off. Relays weren't fast enough. So it was.

After the war the whole Colossus project was above Top Secret, so much so that the machines and most of the documentation was destroyed. Flowers received no recognition for his contribution. He proposed a design for a project using a large number of valves and was told that valves were too unreliable to consider. He couldn't tell them why he knew that wasn't so.

I asked about leaving the Colossus switched on permanently when I visited TNMoC, last time. The guide said the original Colossus was indeed never powered off, but they couldn't afford to do that. They powered it up over a few minutes using a variac and that avoided most of the problems. It needed about 10 valves a year replaced, which isn't bad. I thought it must be some variac they were using. Looking round there was indeed a huge variac, specially made for them and presented by the Claude Lyons company.

I visit once a year after the Dunstable Downs radio rally. The rally is one of the best and Bletchley Park is more or less on the way home. I suppose I could say that it's museum I've seen and it can be crossed off the list, but I think it needs supporting.

Zenith · Post by **Zenith** » Mon Oct 20, 2025 2:24 pm

tautech wrote: ↑Mon Oct 20, 2025 9:46 am An interesting history of electronics downunder, 27 mins
Australia's Forgotten Electronics Giant
https://www.youtube.com/watch?v=RbzgfBLrscg

Australia had a very strong shortwave radio market because for lot of communities SW was the normal means of communication. "Flying Doctor to Walambula base".

My impression has been that they had a relatively small, but excellent, electronics industry. AWA was a big player but there were a few others. A few AWA products were rebadged by others.

tggzzz · Post by **tggzzz** » Tue Oct 21, 2025 8:18 pm

Small and light electrons tunnelling through barriers is ... old and boring.

So how about hydrogen atoms tunnelling through barriers?
https://pubs.acs.org/doi/10.1021/acscentsci.5c00943
and an easier exposition at
https://www.science.org/content/blog-post/tunnel-away

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