Sony ST JX4 (1981–1982)
A digital synthesizer tuner from Sony's early 1980s lineup. Stereo FM/AM reception, locked to a quartz reference.
Overview
The Sony ST JX4 is an AM/FM stereo tuner built from 1981 to 1982. It uses digital tuning with a quartz lock synthesizer system, so the frequency stays put. It has stereo left/right audio outputs for a hi-fi setup. It covers the standard FM (87.5-108 MHz) and AM (530-1610 kHz) bands. Units turn up in a silver finish, often with the original box, the styrofoam inserts, and the user manual.
Specifications
| FM tuning range | 87.5-108MHz |
| AM tuning range | 530-1610kHz |
| Sensitivity | 1.9uV (FM), 200uV (MW) |
| Supported Modes | AM, FM |
| Features | Digital |
| Audio Outputs | Stereo L/R |
| Color | Silver |
Design
The ST JX4 tunes with a quartz lock synthesizer system. That gives precise, stable frequency selection on both FM and AM.
Market
The tuner originally retailed for $845.75, going by an original receipt. Collectors sell it on eBay and Facebook Marketplace, and some units come with service manuals, original boxes, and accessories. Owners report units in excellent working condition, with fully functional controls and low-noise performance.
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