Sony ST-JX3
A stereo FM/AM tuner from Sony featuring precise tuning technology and visual signal indicators.
Overview
The Sony ST-JX3 is an AM/FM stereo tuner manufactured by Sony. It was priced at ¥32,000 around 1981 and designed for high-fidelity radio reception. The unit measures 430 mm in width, 55 mm in height, and 340 mm in depth, weighing 3.4 kg. It features advanced tuning technologies aimed at improving signal clarity and stability.
Specifications
| Original price | ¥32,000 (around 1981) |
| External dimensions | Width 430x Height 55x Depth 340 mm |
| Weight | 3.4kg |
| Practical sensitivity | 1.8 μV (IHF), 10.3 dBf (new IHF) |
| Stereo distortion factor | 0.12% |
| Effective selectivity | 80dB |
| Spurious interference ratio | 75dB |
| Separation | 50dB |
| Power consumption | 8W |
Design
The Sony ST-JX3 employs an Acute Servo Lock method to lock onto the optimal tuning point within a narrow range, ensuring stable reception. It features SENS switches and CAL TONE circuits to enhance real sensitivity on both FM and AM bands for clearer weak-signal reception. The FM IF stage includes a uniphase filter, while the AM section supports high-fidelity reception through increased bandwidth. A litmus dial pointer changes from red to green when tuned, accompanied by a 3-point LED signal indicator. Additional features include a low-pass filter and a beat cut filter.
Market
The Sony ST-JX3 appears in current listings on eBay and Mercari. Service manuals are available for purchase through various online sources, including vintageaudiostore.com and eBay.
eBay Listings
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