Hallicrafters SX-100
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| Frequency | RX: 0.538–1.58 MHz (BC) + 1.72–34 MHz (3 SW bands) |
| Power | Receiver only |
| Modes | AM, CW, SSB |
| Weight | 15.6 kg (34.4 lb) |
| Connector | 300 Ω antenna terminals (+ optional SO-239 coax) |
| Year | 1955 |
| antenna | 300 Ω terminals (mounting holes provided for an optional SO-239 coax) |
The definitive Hallicrafters general coverage SSB receiver. Selectable sideband reception lets you choose USB or LSB to reject interference; you can listen to AM on either sideband, eliminating QRM on one side. The notch filter and 100 kHz crystal calibrator are upgrades over the SX-96 it replaced. Gear-driven tuning with flywheels is buttery smooth, the metal cable bandspread drive will never need replacement. Crystal filter with 4-position selectivity. Double conversion with the 50 kHz LC filter system provides excellent selectivity. 14 tubes. The SX-100 is the most popular Hallicrafters SSB-era receiver.
34.5 lbs. External speaker required. Single-ended 6K6 audio output, adequate but not hi-fi (the push-pull audio of the SX-28/42/62 is better for music). General coverage only, no VHF. The 50 kHz IF alignment is more critical than 455 kHz receivers, misalignment significantly degrades selectivity. Two Mark variants with different 2nd IF frequencies complicates parts interchange.
Hallicrafters' most successful premium receiver. The SX-100 took the SX-96's pioneering selectable sideband architecture and added the notch filter and crystal calibrator that made it a practical daily-use SSB receiver. The gear-driven tuning is a mechanical pleasure. Widely used and well-documented, one of the best-supported vintage receivers for restoration. No serious Hallicrafters collection is complete without one.
The Hallicrafters SX-100 is a premium communications receiver from 1955, a 14-tube set built for serious selectivity and stability on the amateur and shortwave bands. It covers the broadcast band from 538 to 1580 kHz plus three shortwave bands spanning 1720 kHz to 34 MHz, and its standout engineering feature is a crystal-controlled second conversion to a low 50-kilohertz IF, which gives it excellent stability and the sharp, stable selectivity needed for crowded-band work and single sideband.
Reviewed in QST in December 1955, the SX-100 was regarded as one of the best receivers in its class, with a crystal filter, a notch filter, selectable-sideband reception, and a 100-kilohertz crystal calibrator that set Hallicrafters' upper-tier sets apart from its consumer models. Its gear-driven main and bandspread tuning is famously smooth, and its combination of stability, selectivity, and clean audio made it a favorite of operators moving into the SSB era.
It needs an external speaker, and its antenna connects to 300-ohm screw terminals, with mounting holes provided for adding an SO-239 coax connector. It remains a highly regarded vintage receiver and a discontinued classic. See the ham-band SX-101 and the iconic SX-28.