During WWII the Germans had crystals that glowed at resonance. Some place I have about a dozen of them on different frequencies. These were mainly used for calibration purposes, much like in our ARC-5 transmitters that utilized a crystal and a magic eye tube. About 55 years ago I had an old German radio guy tell me about crystals that glowed. I thought he was crazy. Turns out he was right. 73 - Mike
Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -----Original Message----- From: time-nuts <[email protected]> On Behalf Of ed breya Sent: Saturday, March 6, 2021 5:42 PM To: [email protected] Subject: Re: [time-nuts] Old Crystal. Haha - interesting pictures. It looks like they really do glow, but I doubt it's from anything the crystal element is doing - it and the mount structure may just serve as the electrodes for a gas discharge lamp. If the envelope is filled with some relatively "inert" gas or mixture, instead of vacuum, then you have a discharge lamp. Using say, dry nitrogen or krypton (common fillers, I think), you may get the bluish color at some conditions. If you excite it with high enough AC voltage at limited current, it will strike and run. I doubt that the crystal would be mechanically damaged unless you could somehow apply the excitation at "exactly" the resonant frequency, but I'd think it would become no good as a normal crystal anymore, since various things could deposit onto or depart from the surface, affecting the resonance and Q. If the voltage is high enough that it arcs over and ruins the connections, that's another story. The voltage will at least be limited by the gas. If the current is allowed to get too high, then the whole thing will be shot. Ed _______________________________________________ time-nuts mailing list -- <mailto:[email protected]> [email protected] To unsubscribe, go to <http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
