Magic Eye Tubes - my new love in life

[fdesalvo]

I am going to build am amp around these.  Maybe some other, more decorative device instead.

I'm also going ot get a handful of these subminiatures, which I am also in love with.

For those of you that don't know about these:
"The 'magic eye' valve for tuning radio receivers was invented in 1932 by Allen B. DuMont (who spent most of the 1930s improving the lifetime of cathode ray tubes, and ultimately formed the DuMont Television Network).  It is a miniature cathode ray tube, usually with a built-in triode signal amplifier. It usually glows bright green, (occasionally yellow in some very old types, e.g., EM4) and the glowing ends grow to meet in the middle as the voltage on a control grid increases. It is used in a circuit that drives the grid with a voltage that changes with signal strength; as the tuning knob is turned, the gap in the eye becomes narrowest when a station is tuned in correctly.  The RCA 6E5 of 1935 was the first commercial tube.."
-Wiki

[youtube]YgnX7hbf75s[/youtube]

 

[Verne Bunsen]

I've got magic eye tubes in my hi-fi power amps and I built a magic eye vu meter from a Mr. Nixie kit for my dad, they definitely set a high bar for cool factor.

 

[fdesalvo]

Man, a Nixie kit is high on my list of things to do. 

 

[fdesalvo]

I still don't trust the Germans!

 

[BigSteve22]

I still don't trust the Germans!

Hey! I resemble that!  :icon_jokercolor:

Those are some cool tubes! When I saw the title of this thread, I was thinking about those pictures that turn 3D when you cross your eyes, but these are just as interesting, and actually have a purpose!

 

[fdesalvo]

I still don't trust the Germans!

Hey! I resemble that!  :icon_jokercolor:

Those are some cool tubes! When I saw the title of this thread, I was thinking about those pictures that turn 3D when you cross your eyes, but these are just as interesting, and actually have a purpose!

I keed! I keed!

I really love old tech. 

 

[fdesalvo]

Gah!  Derailed by a tube lamp sidequest!  This gives me a way to enjoy microphonic/bad tubes.  Updates soon, I hope.

 

[Logrinn]

I still don't trust the Germans!

Come now, I'm sure it's just a language thing:

[youtube]https://youtu.be/yR0lWICH3rY[/youtube]

 

[Cagey]

Another fun tube is the "Decatron", which was was used primarily for counting.

Company I worked for about 100 years ago used them in "cycle counters" to check the accuracy of timers calibrated in cycles based on line frequency. The timers were used to switch circuits in units of 1/60 of a second. This picture shows how they were usually mounted...

How cool would it be to have all your amp's control settings displayed that way? :laughing7:

 

[amigarobbo]

I had a couple in a old 50s tuners, they were great!

Mind you this would give me nightmares

 

[Axkoa]

Another fun tube is the "Decatron", which was was used primarily for counting.

How cool would it be to have all your amp's control settings displayed that way? :laughing7:

I would say it would be easier just to have LED's... :icon_biggrin:

 

[Cagey]

Of course. But, back then, there were no such things as LEDs. Today, LEDs have matured way past being cool and well into pedestrian.

I wouldn't seriously consider uing Decatrons for anything other than a "steampunk" sort of thing. The control circuitry for them wasn't terribly complex, but it certainly wasn't anything intuitive. We used to hate to work on them.

 

[Axkoa]

I sort of wish I was born a while before I was actually born, hell, my birth date is only around 6 months from the year 2000...

I just wish I would've been able to grow up with a lot of the analog stuff, everything is just digital now. It just seemed easier to get into the analog side of things than to get into digital stuff and programming. You can't really try out stuff using PCB's and coding...

 

[Cagey]

I can tell you firsthand that from an engineering standpoint, the digital stuff is a LOT easier to deal with. Design, experimentation, use, repair, cost, functionality - no matter how you look at it, digital wins hands down. Where digital sometimes gets difficult doesn't have to do with being digital, it has to do with devices having myriad capabilities that are tough to get your arms around coupled with a poorly conceived user interface. Anyone who's ever had to deal with some of the older rack-based SFX can tell you how it puts murder in their hearts aimed at whoever designed the stuff. hell, for years 97% of the VCRs in the world were blinking 12:00 because even programming the clock was a special kind of hell.

 

[Axkoa]

Fair enough  :laughing7:

 

[ByteFrenzy]

Setting the channels on VCR's was the worst. And my whole family expected me to handle that because I 'do something with computers'.

 

[mayfly]

You can't really try out stuff using PCB's and coding...

Not sure that I agree with that.  There's currently a renascence of electronics going on based on tiny embedded systems like Arduino etc.  Those things are pretty simple to get running and breadboard on, and as long as you're not running an OS on them or something will be pretty reliable.

Something like that when I was young had to be built up using 74LS parts. 

 

[ByteFrenzy]

I spent some time a while ago fooling around with an FPGA... you could actually draw your schematic in its IDE, with discrete components, transistors, even 74series IC's, compile the thing and push it into the FPGA, wire up the external connections, and it would behave as if you'd actually built it on a piece of breadboard. Obviously it doesn't have the mojo of tubes but it seemed like a pretty handy way of throwing something together. Especially considering that you can change bits of your design without having to break out the soldering iron each time.

 

[Logrinn]

Setting the channels on VCR's was the worst. And my whole family expected me to handle that because I 'do something with computers'.

[youtube]https://youtu.be/qQGgaI-BcI4[/youtube]

 

[ByteFrenzy]

Yeah, that's a pretty good approximation.