Caramel Magic Eye
Some years ago I built several radios featuring a special tube called the EM83 Magic Eye from Russia using a schematic from Jara Krysatech in Czechia. These were just super sets and a lot of fun to operate. Those tubes, however, have vanished from the face of the planet. I found a couple on Ebay that look like they had been dragged behind horses for a few days and passed on them. Finally I located a guy in Germany that had a couple of new ones which I snapped up and this next radio is the result.
The cabinet is round so that attention is focused on that glorious tube in the center. It has a curly maple cowling and the top panel is curly maple as well. The sides are of quilted maple bent very carefully for the circlular shape. I tried to tint lacquer in a Butterscotch shade but came up with this Caramel instead. Still it is very attractive after it and the rest was finished with several coats of clear nitro cellulose lacquer. The tuning knob is solid brass buffed and polished to a brilliant shine.
The cabinet is only 5 ½” in diameter and 1 ½” deep which was a problem when it came time to stuff all the components inside. A dual secondary transformer was required for the filament voltage of 6.3 vac and the plate voltage of 125 vac. This transformer’s filament supply is actually 12.6 volts so 2 watt resistors were needed to trim that down. A 1n4001 with a 100uf 250 volt capacitor was used to get smooth dc current for the plate. And those transformers and capacitors that size are BIG for such a small space. So the coil was wound with 180/46 Litz wire on a toroid to 241uh and a 365pf variable capacitor completed the tank circuit. I was surprised that the toroid coil would provide such great selectivity and sensitive tuning. It tunes signals like a knife!
But those two bright green beacons command the set with the right one indicating modulation (voice, music, noise) while the one on the left does signal strength. I live so far from civilization that very little signal strength exists here but there is one Spanish station that makes it move some. I put this on YouTube for those interested in watching….not a bad little tune either.
All that is needed is a wire antenna, a ground source, headphones and 115vac to enjoy this very special item. I hesitate to part with it because when these tubes are gone that’s it!