Indeed, the HQ-1XX lines are confusing and HQ's prior to the 160 are also reported to have outstanding AM sound.
The HQ-160 was the High End of their General Coverage receivers from 1958-60. At the same time the HQ-145 was also available. (1959-61). And Just to further confuse the issue, the HQ-145A ran from 1966-1969. Based on my read of the specs and difference of the HQ receivers I have tried that came after the HQ-160. The 160 was probably that last one to deliver (out of the box) a pleasing "fat" sound on AM. The HQ's following the 160 seemed to be focused on Communications Quality sound. This may have been a concession to SSB performance. I have noted that the HQ-180A's command a very high price in that "E" auction place and I will admit I have not heard one, however if the audio on the HQ-180A is anything like my HQ-170A, the 160 was indeed the last of Hammerlund's great AM receivers. (the 170a is Ham Band only and the 180A is General Coverage) The source of production dates used was Fred Osterman's "SW Receivers Past & Present" 2nd edition. Steve W1TAV
