The Hammarlund Super Pro was an American made high-frequency receiver used during World War II. “The SP-600 Super Pro covered the frequency range of 540 kHz to 54 MHz.”

In 1936 the first of the Super Pro series were manufactured.

According to a November 1940 QST Magazine ad, “The fact that ‘Super-Pro’ receivers are used extensively by the U.S. Signal Corps and many other governmental departments, speaks for itself.”