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alnwlsn 48 minutes ago [-]
I have a couple of these. Of the ones in a working device, they are in capacitor ("condenser") checkers. You rotate a dial until the eye tube goes from closed to open, then read off the capacitance on the dial.
I don't remember the exact design off hand, but I seem to remember that about all that's inside one of these is the eye tube, a rectifier tube, and a handful of resistors and capacitors. Can also test leakage and shorts. They really knew how to get a bunch of things done with about 10 components back then.
alt227 3 hours ago [-]
I was hoping this would be some new fangled way of viewing magic eye images mapped onto the inside of a tube through something like polar coordinates and viewed like a kaleidoscope. I was disappointed.
VorpalWay 3 hours ago [-]
I think the vaccum tube that it turns out to be is even cooler.
EvanAnderson 2 hours ago [-]
When I was about 12 or 13 I recovered an old reel-to-reel recorder from the trash that had a magic eye tube on it (acting as a recording level meter). The mechanism was broken so it couldn't play or record tapes, but the magic eye worked. I'd never seen anything like it. I'd play with the thing in a dark room and enjoyed the eerie green glow from the magic eye and the warm yellowish glow from the tubes inside coming thru the vents. I saved the magic eye tube and still have it in a box somewhere.
monocasa 2 hours ago [-]
They're real fun.
I'm building a vacuum tube computer and want to use some somewhere, even though everything I've come up with is very shoehorned in. Best I've come up with is showing progress in the reset sequence.
Although right now the clock circuit isn't well defined (I've got a micro controller running the clock and front panel like signals while prototyping), so maybe a pll lock indicator.
irdc 3 hours ago [-]
I remember playing with my father's collection of tape recorders when I was young and one of them had such a "cat's eye". Maybe that's where my love for glowing phosphors started.
andai 2 hours ago [-]
Old electronics had so much sovl.
joemi 2 hours ago [-]
Might be dating myself by not being up to date on the latest slang or abbreviations, but what is "sovl"?
nemomarx 1 hours ago [-]
soul but using the roman v, I think. I've seen it before with cvlt that way
rbanffy 1 hours ago [-]
I wish we could manufacture these things again. Preserving the ability to build obsolete machines is important.
JackFr 58 minutes ago [-]
It's cool, no doubt, but why precisely is it important? I find the engineering that went into late steam locomotives fascinating and much more complex and scientifically designed than the casual observer notices. But building one would be very expensive and serve no other purpose than to delight some nerds (which is a fine result but unlikely to be worth the price.)
m463 3 hours ago [-]
I remember as a kid some device had one of these, but I can't for the life of me remember what it was.
ErroneousBosh 2 hours ago [-]
It is likely to have either been the recording level indicator on an old valve reel-to-reel tape recorder, or the tuning indicator on an old valve FM radio.
Animats 2 hours ago [-]
The whole point of the Magic Eye tube was that it was cheaper than an analog meter. So it was the consumer-grade replacement for one. On pro gear, you'd find a meter movement and pointer, which is harder to make than a vacuum tube.
In "The Day the Earth Stood Still" (1951, not the remake), when the visitor goes into his flying saucer and powers up a communicator to report to HQ, there are two huge Magic Eye tube like devices. So back then it was a cliche for "radio". Start at 55 minutes.
I don't remember the exact design off hand, but I seem to remember that about all that's inside one of these is the eye tube, a rectifier tube, and a handful of resistors and capacitors. Can also test leakage and shorts. They really knew how to get a bunch of things done with about 10 components back then.
I'm building a vacuum tube computer and want to use some somewhere, even though everything I've come up with is very shoehorned in. Best I've come up with is showing progress in the reset sequence.
Although right now the clock circuit isn't well defined (I've got a micro controller running the clock and front panel like signals while prototyping), so maybe a pll lock indicator.
In "The Day the Earth Stood Still" (1951, not the remake), when the visitor goes into his flying saucer and powers up a communicator to report to HQ, there are two huge Magic Eye tube like devices. So back then it was a cliche for "radio". Start at 55 minutes.
[1] https://archive.org/details/day-the-earth-stood-still-1951
I suspect it must have been a radio. I remember it said something about eye, but was always dark.
The Magic-Eye Tuning Indicator, W G Morley, The Radio Constructor, March & April, 1969:
https://www.r-type.org/articles/art-137.htm