The first commercial superheterodyne radio receiver, the RCA AR-812 brought out March 4, 1924 priced at $286. It used 6 triodes: a mixer, local oscillator, two IF and two audio amplifier stages, with an IF of 45 kHz. Used with the loop antenna and horn speaker shown. Exhibit in the National Electronics Museum, 1745 West Nursery Road, Linthicum, Maryland, USA. All items in this museum are unclassified. The museum permitted photography without restriction.