I found magic eye tube in my closet. It was removed from sold old radio. This tubes were used in old radio units to indicate fine tuning of radio station. In old tape recorders such tubes indicated recording level. I decided to put this lamp into my tube audio amplifier to look it “cooler”.
Here is the result.
This image is borrowed image from the internet. Here you can see the beam wider.
I used schematics looking something like in the left part of the image. But this circuit works like oscilloscope and it is not very nice. Better result maybe will be achieved using right side circuit. The detect and capacitor will filter out the high frequency signal, leaving only the bass. Just select the 0.1 capacitor according you needed indication speed.
The tube is old soviet Russian 6Ð•1ÐŸ or western tube EM80.
Any way you might make an avi of the magic eye tube in action please?
I have a small problem I am trying to solve…. I want to use the EM80 as an audio input indicator, but as you might guess I’m not building this around a high voltage application (though I can if I must). Currently, I am using a lower voltage (up to 50VDC) hybred design and am stuck in the mud. I came in to electronics in the descrete comp. / digital era and have extensive knowledge in recent topology; but again, as you can see not in valve techs. Can you point me in the right direction schematic wise….? I appreciate you help. Best Regards, Greg