General > General Technical Chat
electronics like its 1922
strawberry:
1920 1.10$ adjusted to inflation 2022 ~18$
thicker metal for jaws not to slip when grabbing on some thinner wire..
TimFox:
--- Quote from: coppice on October 27, 2022, 02:34:54 pm ---
--- Quote from: Gyro on October 24, 2022, 09:01:15 pm ---It's the first time I've seen tube construction like that, that hasn't involved a glass lathe.
--- End quote ---
When 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.
--- End quote ---
I'm curious about the original Fleming valves: were they constructed by adding an anode to a pre-existing commercial incandescent lamp?
coppice:
--- Quote from: TimFox on October 27, 2022, 05:29:03 pm ---
--- Quote from: coppice on October 27, 2022, 02:34:54 pm ---
--- Quote from: Gyro on October 24, 2022, 09:01:15 pm ---It's the first time I've seen tube construction like that, that hasn't involved a glass lathe.
--- End quote ---
When 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.
--- End quote ---
I'm curious about the original Fleming valves: were they constructed by adding an anode to a pre-existing commercial incandescent lamp?
--- End quote ---
Well, I was there in the early 70s, and all the staff who made those things had moved on....
If you look at the pictures at https://en.wikipedia.org/wiki/Fleming_valve I 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.
TimFox:
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!
bsfeechannel:
--- Quote from: TimFox on October 27, 2022, 02:28:19 pm ---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.
--- End quote ---
At the company where the alligator clip was invented, they think otherwise:
--- Quote ---My original "anachronism" comment referred to the modern cheap alligator-clip test leads in the photo that are ubiquitous now.
--- End quote ---
And they were ubiquitous then. Mueller alone produced 85,000 alligator clips per day way back in 1922.
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