A Sink Radio
The Story of the Singing Sink
By Newcomb Weisenberger

Spontaneous Reception can happen when intense Radio Frequency radiation strikes ordinary things in an unordinary way. An amplitude modulated (AM) carrier needs only simple rectification to produce an audio signal. The audio frequency needs a transducer to modulate the air in order to be heard. If the radio frequency is strong enough the air itself will speak.

When powered, transmitters and transmission lines will feed an arc to any piece of metal placed near, but not touching them. This miniature lightning strike ionizes the air producing a roaring sound for as long as the arc is maintained. As the transmitter is modulated, the arc sound will follow with enough fidelity for speech recognition and with power to fill a room. This self-powered "receiver" has no parts and only one circuit. And that circuit is "open"!

Years ago we all were familiar with certain minerals-galena crystals were popular-that conduc-ted current in one direction much more efficiently than in the reverse direction. Dissimilar metals in contact, or loose, corroded, connec-tions can act as rectifiers too. (The current flowing from the rough surface to the polished one is noticeably stronger than in the reverse direction.)

When of the proper length for the frequency, the conductors themselves act like tuned "resonant" circuits. Many stories have been told of unexpected receivers being found in odd places. Dental work can produce radio sounds, but I have never heard it happen. When new telephones were being installed at Buena Park, California, each had a small capacitor in place to block the sounds of KFl. The radio signal had been loud enough to annoy the subscribers.

I worked for Earl E. May when he operated 1000-watt regional station KMA at Shenandoah, Iowa. The transmitter building was located in a low open field north of town. This site was for a good ground. The highway was elevated about six feet as was the transmitter building. The basement garage was at ground level. The transmitter and its equipment filled the first floor. A second floor provided a small apartment. Chief Engineer, Ray Schroeder, wife and child lived up there. l was on transmitter watch one morning when Ray came downstairs wanting to show me something. He led me up the narrow stairs and into his little kitchen, stopping by the sink. "Yes, you know!"

KMA program was projecting out of the hot water faucet and bouncing back out of the sink! If the faucet was closed enough to stop the water but no further, you could control the volume by carefully adjusting the handle. The faucet was rectifying the RF signal. It sounded about like a horn speaker. The sink's shape had replaced the exponential horn!