Hammarlund Manufacturing Co.Inc. were first established in 1910. After WWII their range of HF, VHF and UHF receivers were beginning to take shape into a recognisable product range. The twin dial layout, with an S-meter sitting between them, of the HQ129 and Super-Pro of 1946 were to be echoed in later models such as the HQ170, made in 1959, shown here.
The SP600JX "Military Model" of 1952 with the same twin dial arrangement but with the S-meter an the left was clearly from the same stable, providing as before, and as the later HQ170 and 180, the 6-metre band.
The HQ170 is a triple conversion receiver made specifically for amateur band use. Because it uses valves which take time to warm up it includes a clock which can be set to turn on the receiver 30 minutes before it was needed in order to let the frequency stabilize.