SANSUI TU-S707X
¥ 54,800 (released in 1984)
Commentary
FM/AM tuner equipped with SLDD (Super Linear Digital Decoder).
The demodulation circuit is equipped with SANSUI's original SLDD, which combines the advantages of the square-wave switching demodulation method and the sinusoidal demodulation method.
By digital processing using the Wallisch function sequence, this circuit completely shuts out unwanted harmonic distortion caused by noise, Birdie intermodulation, and neighboring station interference, which had to be removed by the conventional anti-RF filter. This eliminates adverse effects such as phase difference and degradation of separation caused by the anti-RF filter., by eliminating the unwanted harmonic distortion caused by the anti-RF filter. Birdie intermodulation and noise interference.
A front end equivalent to 5 series using twin varicap diodes is adopted for the front end.
A dual-gate MOS FET is used in the RF stage and mixer section to improve linearity, SN ratio and distortion factor, and to secure dynamic range for strong input.
In addition, by setting the total gain moderately, it is possible to operate with plenty of margin.
The TU-S707X quartz synthesizer employs a pulse swallow method. By setting the reference frequency generated by the quartz to 25 kHz, which is outside the audible band, the SN ratio is improved without loss of reception capability.
Equipped with an IF band switching function.
Conventional tuners have a problem that they are susceptible to interference from neighboring stations when the tuner is wide. However, TU-S707X uses SLDD to solve this problem. Since no harmonics are generated in the demodulation process, no noise is generated by neighboring stations even when the tuner is wide.
Narrow position is used as a countermeasure against interference in a limited area.
Both FM and AM antennas are balanced by a floating circuit system with separate GND.
The floating circuit system shuts out common-mode noise caused by the ground potential difference between the chassis and the system, resulting in a good signal-to-noise ratio in actual use.
Semiconductor ceramic capacitors are used in high-frequency circuits to achieve low distortion and high S/N s / N.
We also use fast recovery diodes and high-performance capacitors for the power supply.
A static drive system is adopted in which the FL frequency tube is separated from the signal line to improve the sound quality.
A total of 16 preset memories (8 FM and 8 AM) are installed.
In addition, it is equipped with a preset scan function that monitors the stored program for approximately 4 seconds by pressing the switch.
It is equipped with a memory backup function using a lithium battery and a large-capacity capacitor, and achieves memory of more than five years.
To improve the S / N ratio of the AM tuner section, the antenna input and audio output are balanced and balanced.
In addition, it is designed for high sensitivity, wide bandwidth and low noise.
An FET buffer is used in the AM tuner section, and pre-emphasis AM broadcasting is also available by switching IF bands.
Equipped with 440 Hz, 0.39 V REC calibration function.
Equipped with RF MODE function to prevent front-end saturation at large input.
Equipped with an FM noise canceller.
Equipped with last one memory that automatically calls up the station when power is OFF.
Equipped with AC cord with polarity display.
There are 2 color variations, black and silver.
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Model Rating
| Type | FM/AM Tuner |
| FM Tuner Section | |
| Receiving frequency | 76.0 mhz to 90.0 mhz |
| Practical sensitivity (IHF) | Mono : 10.8 dB (old IHF : 0.95 μ V) |
| 50 dB sensitivity | mono:16.2dBf stereo:37.0dBf |
| Harmonic distortion factor (IHF, 80 dBf, wide, 1 kHz) | mono:0.0095% stereo:0.015% |
| SN ratio (85 dBf) | mono:94dB stereo:88dB |
| Frequency characteristic | 10 Hz to 15 kHz ± 0.5 dB |
| Capsule ratio | 0.8dB |
| Selectivity | narrow:60dB wide:26dB |
| Stereo separation | 65dB(1kHz) 50 dB (50 Hz to 10 kHz) |
| Image interference ratio | 100 dB or more |
| IF interference ratio | 110 dB or more |
| Spurious interference ratio | 110 dB or more |
| AM suppression ratio | 75 dB or more |
| Subcarrier suppression ratio | 70 dB or more |
| Antenna impedance | 300 Ω equilibrium 75 Ω unbalance |
| <AM Tuner Section> | |
| Receiving frequency | 531 kHz to 1602 kHz |
| Practical sensitivity | 48dB/m (251 μ V/m) |
| Signal-to-noise ratio | 50dB |
| Image interference ratio | 45dB |
| IF interference ratio | 40dB |
| Selectivity | narrow:50dB wide:30dB |
| Harmonic distortion factor | wide:0.3% |
| <General> | |
| Output level | 0.775V |
| Memory backup | 5 + years |
| Rated power consumption (Electrical Appliance and Material Control Law) | 11W |
| External dimensions | Width 466x Height 57x Depth 306 mm |
| Weight | 4.0kg |