Note
Radio, Feb 1940, p. 3.
Lafayette catalog number 82, p. 115.
Lafayette catalog number 87 (New York), p. 57.
Concord catalog 4-46 (1946), p. 107.
The Hallicrafters SX-25 "Super Defiant" is a classic piece of shortwave radio history, an imposing and quality communications receiver that cemented Hallicrafters' reputation as a premier manufacturer of "the radio man's radio." Introduced in 1940, the SX-25 was a significant step up from its predecessor, the SX-24 "Defiant." While the SX-24 was a solid performer, the SX-25 was built with 12 tubes (compared to the SX-24's nine) and featured a push-pull audio output stage, providing a richness and fidelity of sound that was a hallmark of its design.
The SX-25 was an all-wave receiver, covering a broad frequency range from 540 kHz to 42 MHz across four bands. This made it a versatile instrument for both general broadcast listening and amateur radio use. A separate bandspread feature allowed for precise tuning of the amateur radio bands (80, 40, 20, and 10 meters), a crucial capability for the serious ham operator.
Weighing in at over 50 pounds, the SX-25 was built to last, with a hinged top cover for easy access to its intricate internal components.
Beyond its technical specifications, the SX-25 was a marvel of design for its time. The distinctive Art Deco styling of the front panel, with its large, analog dials and S-meter, made it an attractive centerpiece in any radio shack. Features like a crystal filter for improved selectivity, BFO and ANL made it a top-tier performer.
Basic specifications
Single conversion superheterodyne circuit with BFO, AVC, ANL, S-meter, RF gain, mute, standby, two position tone control, and a calibrated bandspread for 80, 40, 20, and 10 meters.
Requires external speaker, 500/5000 Ω.
Coverage: 540 kHz to 42 MHz
IF: 455 kHz
ANL
BFO
AVC
S-meter
Crystal filter
Variable Selectivity
Calibrated Bandspread
Audio output: 8 watts, 500/5000 Ω
Power: 120 VAC, 120 watts
Tubes: (1) 80, (2) 6F6, (1) 6J5, (1) 6H6, (2) 6SQ7, (4) 6SK7, (1) 6K8
References
Brief description, Radio News, Jun 1940, p. 21.
