frantone
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Magic Eye Tubes
🕑 Added 2019-01-01 18:58:53 +0000 UTCIn this short excerpt from the 4th part of my nostalgia Heathkit IT-12 build I briefly explain the structure and function of the magic eye display tube. Enjoy!
Comments
TomArnd
The engineering and architecture of those vacuum tubes is really beautiful!
Whoops! Hit the wrong button. Anyway, I was telling my 39 year old son about magic eye tubes and how much I have loved them since I was a kid. He didn't know what I was talking about. So I got online and showed him a bunch of variations. He was amazed. No I gotta build a spectrum display of some sort with the things to go with my tube amp. What I would like best is a bar type that just grows in length vertically, one bar per tube. But I have not yet seen any that do this.
Val Packett
I keep reading this as HealthKit and wondering how Apple's recent framework relates to this :D
Greetings Fran,
God 420
these are cool tubes
The DM70 is a rather unusual example of such, being a very small directly heated example. It has a display rather like an exclamation mark, the idea being that you adjust the recording level so the line just falls short of touching the dot for max undistorted level.
Gee Bee
Thanks for the description, Fran! I remember these tubes from big old-fashioned radios in "furniture" consoles, but never knew how they worked.
Not just any eye-opener. A magic eye-opener. :-)
John N Nelson
Watching this has brought back memories from the 1960's. My first radio was a Silvertone shortwave radio. It had a magic-eye tube to tube for signal strength. I was given the radio by a neighbor but had to learn enough to replace the dried electrolytic capacitor to eliminate the hum. It was a good learning experience. learned that the IF transformers carried 300+ voltages of B+ voltage "the hard way" (screwdriver flew across the room). Thank Fran.
It's interesting to find someone else who was way way into magic eye tubes in their youth. I thought they were just the neatest thing ever. Dangerous as all get out, though, with their high voltage plate. I'm lucky to have survived my experiments.
An eye-opener :) Never realized the little cap was just aesthetic
