Collins 75A-4
$$$$·
| Frequency | RX: 160–10 m (amateur bands) |
| Power | Receiver only |
| Modes | AM, CW, USB, LSB |
| Weight | 20.4 kg (45 lb) |
| Connector | SO-239 |
| Year | 1955 |
| mic | Collins 4-pin (S-Line) or varies by model |
| antenna | SO-239 |
A 455 kHz mechanical filter, passband tuning, a Q-multiplier notch, and a proper product detector for SSB. The 75A-4 was widely regarded as the receiver to beat through the late 1950s.
Receiver only; needs a separate transmitter. Heavy and large. The mechanical filters are irreplaceable if damaged. Alignment requires test equipment. Expensive when new, still expensive used.
A landmark amateur receiver. A properly aligned 75A-4 receiving clean SSB still sounds excellent. Paired with the KWS-1 transmitter, it formed the top amateur station of the late 1950s.
The Collins 75A-4 is widely regarded as the finest amateur communications receiver of its era, the last and best of the legendary 75A series, introduced in 1955. It is a receive-only tabletop set covering the amateur bands from 160 through 10 meters using a 22-tube, mostly double-conversion superheterodyne design (single conversion on 160 meters), and it brought Collins Mechanical Filters to the amateur receiver for selectivity that was simply in a class of its own.
Those mechanical filters, combined with excellent image rejection and Collins' renowned stability, made the 75A-4 the receiver of choice for serious operators, and its product detector made it genuinely capable on the newly popular single sideband as well as AM and CW. Paired with the KWS-1 transmitter it formed the famous 'Gold Dust Twins.' A clean 75A-4 remains one of the crown jewels of vintage amateur radio.
It is a discontinued classic. See the matched KWS-1 transmitter and the earlier 75A-1.