Hammarlund, an American manufacturer, launched the first commercially sold superhet in 1931 and was a well-known manufacturer of amateur and commercial shortwave receivers until the end of the 1960s.

Like other American manufacturers, the Hammarlund company was initially founded to produce components necessary for radio (self) construction. It was not until 1931 that the first complete radio set, the „Comet“, was sold; this and its successor „Comet Pro“ were the first commercially available superheterodyne receivers.

The ultimate shortwave receiver was introduced in 1936 as the „Comet Super Pro“. This receiver, known as the Super Pro for short, was gradually developed from the prototype SP 10 and the regular model SP-110, and the SP-600, the final model in the series, was produced in numerous variants until 1972. The characteristic front with the main and band spread tuning dial visible in two cut-outs was only slightly redesigned over the years.

In the mid-price segment, a second receiver series was added, which began in 1938 with the HQ-120 or HQ-120X (with quartz filter) and saw also further development over the decades into the HQ-140, HQ-160 and HQ-180, which was for sale until 1973. The front panel of this receiver series is also unmistakable with its two dial windows, the S-meter in between and the optional station clock.

After a less than successful attempt to gain a foothold in the solid state sector with the transistorised amateur radio receiver HQ-215, receiver production was discontinued at the beginning of the 1970s and the company was sold several times, including to the Cardwell Group.

• Hammarlund Mfg. Co. on the website of www.radiomuseum.org