SONY ST-5140
¥ 49,800 (released in 1972)
Commentary
ES series FM/AM tuner.
Uses SONY's original direct mixer system.
This method does not use any active elements such as transistors that cause intermodulation at high frequencies. Instead, three tuning circuits using four variable capacitors directly feed radio waves into the FET mixer. This method improves sensitivity, interference rejection characteristics, and strong electric field characteristics.
The IF stage uses a 6-element solid-state filter.
As a result, the separation from adjacent channels is extremely sharp, and characteristics such as passband characteristics are improved, and weak radio waves immediately adjacent to strong radio waves can also be received stably.
By using a highly reliable semiconductor, specially designed varicon and new circuit, initial drift characteristics and temperature drift characteristics have been improved, and tuning point is stabilized and channel selection deviation is suppressed.
In addition to the input meter that shows the strength of the radio wave, it is equipped with the meter of Center 0 that can be accurately tuned.
Equipped with 5-stage limiter circuit including 3-stage symmetrical diode limiter.
It is robust against pulse noise and has an excellent capture ratio.
The AM tuner section is designed to be highly selective and resistant to strong electric fields using triple tune IFT and forward AGC including solid state filters.
Equipped with a large dial with green edge light illumination and evenly spaced FM scale.
The low-pass filter eliminates carrier leakage and provides beat-free recording.
FET switch is used for muting circuit.
It comes with a connector and a terminal to which a 75 Ω coaxial cable, which is advantageous for noise, can be attached.
Equipped with an output terminal that can be connected to an oscilloscope for visual observation of multipath phenomena.
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Model Rating
| Type | FM/AM Tuner | ||
| Circuit system | Superheterodyne system | ||
| FM Tuner Section | |||
| Antenna terminal | 300 Ω Balanced Type 75 Ω unbalanced type (coaxial cable connector) |
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| Receiving frequency | 76 MHz to 90 MHz | ||
| Intermediate frequency | 10.7MHz | ||
| Practical sensitivity | 2.0 μ V (IHF) | ||
| Sensitivity | 1.6 μ V (S/N = 30 db) | ||
| Signal-to-noise ratio | 70dB | ||
| Capture ratio | 1.0dB | ||
| Selectivity | 80dB(IHF) | ||
| Image interference ratio | 76dB | ||
| IF interference ratio | 100dB | ||
| Spurious interference ratio | 100dB | ||
| AM suppression ratio | 56dB(IHF) | ||
| Frequency characteristic | 20 Hz to 15 kHz, ± 1.0 dB | ||
| Distortion factor | Mono : 0.2% at 400 Hz, 100% modulation Stereo : 0.5% at 400 Hz, 100% modulation |
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| FM stereo separation | 40 dB or More (400 Hz) | ||
| 19 khz and 38 khz suppression ratio | 60dB | ||
| Output Voltage / Impedance | Fixed output : 750mV/10k Ω (at 100% modulation) Variable output (Variable) : 0 ~ 2V/1.8k Ω (at 100% modulation at maximum output)
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| <AM Tuner Section> | |||
| Antenna | Ferrite bar antenna With External Antenna Terminal |
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| Receiving frequency | 530 kHz to 1,605 kHz | ||
| Intermediate frequency | 455kHz | ||
| Sensitivity | 50dB/m (when bar antenna is used) 30 μ V (when external antenna is used) |
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| Signal-to-noise ratio | 50dB | ||
| Image interference ratio | 45dB(1,000kHz) | ||
| IF interference ratio | 41dB(1,000kHz) | ||
| Distortion factor | 0.6% | ||
| <General> | |||
| Semiconductor used | Transistor : 26 (Receiving circuit x19, attached circuit x7) FET : 4 (2 circuit FETx2, attached circuit FETx2) Diode : 33 |
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| Pwer | 100 VAC, 50Hz/60Hz | ||
| Power consumption | 15W | ||
| External dimensions | Width 400x Height 149x Depth 344 mm | ||
| Weight | 7.2kg | ||
| Attachment | One FM feeder antenna Connection code RK-74x1 One Policing Cross 1 x 75 Ω F type plug |
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| Sold Separately | Eurasian Cheek Finish Wooden Case TAC-1 (¥ 4,600) Mount Plaquette MB-5 (¥ 2,800) |
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