SANSUI TU - α 707i
¥ 59,800 (around 1987)
Commentary
Digital synthesizer FM/AM tuner equipped with SANSUI's own super linear system.
It is equipped with SUNSUI's original super linear receiving circuit : SLRC, which simultaneously acquires high sensitivity receiving capability at weak input and interference rejection capability at strong input.
The antenna input section uses an AGC circuit that employs a PIN diode and a dual gate MOS FET to perform optimal automatic gain control according to the input field strength and to minimize distortion that occurs in high-field areas.
In addition, a double-balanced mixer circuit integrated into an IC eliminates high-frequency interference and greatly reduces noise.
The IF section employs a WIDE/NARROW bandwidth switching mechanism.
For WIDE operation, a low-distortion wide-band ceramic filter with excellent phase characteristics is used. For NARROW operation, a high-selectivity narrow-band high-performance filter with excellent adjacent interference rejection is used.
As a result, high-quality reception with a low distortion rate is achieved in WIDE mode, and interference from neighboring stations in a strong electric field region is cut in NARROW mode, so that desired stations can be received reliably.
A newly developed Super Linear Detector Circuit (SLDC) is installed to linearly detect audio signals from FM waves.
A distortion correction circuit is incorporated into the VCO (voltage controlled oscillator) to achieve linearity over a wide bandwidth and excellent audio characteristics.
SANSUI original digital decoder SLDD IV is adopted in the MPX section.
Since demodulation is performed by digital processing, there is no harmonic component that causes demodulation of adjacent stations. Only the signal of the desired station is subjected to high-precision stereo demodulation.
As a result, the separation distortion is reduced and the anti-interference filter for cutting the adjacent station interference is out of order, and the phase and frequency characteristics are improved. Birdie characteristics are also improved.
The power supply section uses a multi-power supply circuit that supplies power to the audio, RF and control systems independently.
As a result, between the stages.
It is equipped with two antenna input systems, A / B, and a function to switch them.
It is possible to correspond to the radio wave arrival direction of each FM station, and the best reception can be achieved.
It is equipped with a direct input function that allows you to directly select the desired station by entering the desired frequency with the 10 keys.
It is also equipped with a preset memory that allows one touch channel selection, a memory scan that allows quick selection of preset stations, and a LAST-2 memory function that allows recording of two stations without a program.
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Model Rating
| Type | FM/AM Tuner |
| <FM Part> | |
| Practical sensitivity | 10.8dBf |
| SN50dB Sensitivity | mono:16.2dBf stereo:37.0dBf |
| Effective selectivity | Wide:60dB Narrow:75dB |
| Signal-to-noise ratio | mono:98dB stereo:91dB |
| Distortion factor | stereo:0.0095% |
| Separation | 60 dB or more |
| Image interference ratio | 80dB |
| Spurious interference ratio | 120dB |
| IF interference ratio | 120dB |
| Antenna impedance | 75 Ω |
| Preset memory | 10 stations |
| <AM Department> | |
| Practical sensitivity | 48dB/m |
| Effective selectivity | Wide:30dB Narrow:50dB |
| Signal-to-noise ratio | 50dB |
| Distortion factor | 0.3% |
| Preset memory | 10 stations |
| <General> | |
| Rated power consumption | 12W |
| External dimensions | Width 448x Height 98x Depth 315 mm |
| Weight | 5.1kg |