The Black Boxes
The Collins A-Line appeared as a new generation of amateur products following World War II. Introduced with the 75A-1 receiver and 30K-1 transmitter, the A-Line reigned for over a decade, ending with the 75A-4 receiver and KWS-1 transmitter, which ushered in the Single Sideband era.
The A-Line existed during the age of AM (and CW) operation. Interestingly, the first A-Line transmitter (the 30K-1) was a floor-standing model, as was the last, the mighty KW-1, a 1000 watt 600-pound brute six feet tall.
The S-Line replaced the A-Line in the late ’50’s.
Art Collins rather liked this picture and used it to produce a QSL card. Equipment from left to right: 32V-3 Transmitter, 312A-1 speaker with station control elements added, 75A-3 receiver, and KW-1 transmitter behind Art. These were the last AM amateur products produced by Collins Radio before entering the single sideband era.