WSUI a century ago

WSUI transmitter in 1923

"Our first [voice and music] broadcast transmitter [c. 1919] incorporated two experimental vacuum tubes sent to me by a friend and Iowa graduate who is employed by a large electrical firm which was then just starting experimental work with vacuum tubes. They required 500 volts direct current which, in those days, was hard to come by. We drove four direct current motors as generators. With all the attendant difficulties, we did get our 500 volts until the transfer circuits in the Physics Building broke down. ... [T]he microphone after 5 minutes' use used to become too hot to touch so we switched to a second microphone to allow the first to cool off. The quality must have been terrible but those who listened with earphones and cat-whisker detectors thought it was excellent." — Carl Menzer, "Fifty Years of Broadcasting"—The Transit, vol. LXXIII No. 2, November, 1968, p. 21