Claim: Stuart Ballantine attended Drexel Institute from 1917-1920 and worked as a radio expert at the Philadelphia Naval Shipyard, then he discovered the "antenna effect" in such systems and invented the capacity compensator for its control; later in 1920-1921 he undertook graduate studies in mathematical physics at Harvard University.
Evidence: From 1917-1920 Ballantine attended Drexel Institute and worked as a radio expert at the Philadelphia Naval Shipyard, where he led design of the Navy coil-type radio compasses. He discovered the "antenna effect" in such systems and invented the capacity compensator for its control. In 1920-1921 he undertook graduate studies in mathematical physics at Harvard University, then spent a year at the Radio Frequency Laboratories in Boonton, New Jersey, where he worked on radio receivers and made inventions for stabilization of radio-frequency amplifiers via a Wheatstone bridge, linear detection at high signal levels, and automatic volume control.