SONY ST-5055A
¥ 29,800 (released in 1973)
Commentary
An FM/AM tuner that is strong in strong electric fields and capable of receiving weak radio waves.
The front-end uses a newly developed junction FET for its high-frequency amplifier circuit, and incorporates a local oscillator circuit and FET mixer circuit to improve its strong electric field characteristics.
The IF section employs a newly developed two element one package solid-state filter and a symmetrical diode limiter, as well as a high-precision Hi-Fi IC designed to prevent misalignment.
In addition, the FM discriminator uses a non-adjustable solid-state discriminator, enabling stable demodulation.
The MPX stereo separation circuit employs a high-integration IC and a non-adjustable coil unit exclusively for IC.
Since it is a sealed unit without adjustment, it is less affected by heat and moisture, and characteristic degradation due to aging is suppressed.
The AM section consists of one stage high-frequency amplifier circuit and uses a 3-stage variable capacitor.
The IF section employs a high-selectivity triple-tune IFT, and a specially designed AGC circuit enables reception with high sensitivity and less spurious beats.
.JPG)
Model Rating
| Type | FM/AM Tuner |
| Circuit system | Superheterodyne system |
| FM Tuner Section | |
| Antenna terminal | 300 Ω Balanced Type 75 Ω Unbalanced Type |
| Receiving frequency | 76 MHz to 90 MHz |
| Intermediate frequency | 10.7MHz |
| Practical sensitivity | 2.2 μ V (IHF) |
| Sensitivity | 1.7 μ V (S/N = 30 db) |
| Signal-to-noise ratio | 68dB |
| Capture ratio | 1.0dB |
| Selectivity | 70dB(IHF) |
| Image interference ratio | 45dB |
| IF interference ratio | 95dB |
| Spurious interference ratio | 75dB |
| AM suppression ratio | 45dB(IHF) |
| Frequency characteristic | 30 Hz to 15 kHz, + 1-3 dB |
| Distortion factor | Mono : 0.4% at 400 Hz with 100% modulation Stereo : 0.6% at 400 Hz, 100% modulation |
| FM stereo separation | 35 dB or More (400 Hz) |
| Output Voltage / Impedance | Fixed output : 750mV/10k Ω Variable output : 0 ~ 1.5V/1.8k Ω |
| <AM Tuner Section> | |
| Antenna | Ferrite bar antenna With External Antenna Terminal |
| Receiving frequency | 530 kHz to 1,605 kHz |
| Intermediate frequency | 455kHz |
| Sensitivity | 46dB/m (when bar antenna is used) 100 μ V (when external antenna is used) |
| Signal-to-noise ratio | 50dB(50mV/m) |
| Image interference ratio | 70dB(1,000kHz) |
| IF interference ratio | 65dB(1,000kHz) |
| Distortion factor | 0.5% |
| <General> | |
| Semiconductor used | Transistor : 21 (16 receiving circuits, 5 attached circuits) FET:2 Diode : 14 IC:2 |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 17W |
| External dimensions | Width 416x Height 120x Depth 285 mm |
| Weight | 4.8kg |