SANSUI TU-S507X
¥ 38,000 (released in 1984)
Commentary
FM/AM tuner pursuing basic performance and ease of use.
Front end equivalent to 4-train is adopted.
Here, the antenna input is used as a floating receiver to prevent external noise from entering, and at the same time, a dual gate MOS FET is used for the RF amplifier to achieve a design with excellent linearity and low distortion.
In addition, the AM suppression ratio is greatly improved by the FET buffer in the local oscillator.
The IF stage uses a linear phase type high-selectivity ceramic filter with excellent group delay characteristics.
A total of 16 preset memory functions (8 FM and 8 AM) are installed.
In addition, the preset scan function allows you to recall the stations from 1 to 8 in sequence. Each station automatically stops for about 4 seconds, allowing you to check the broadcast contents.
A memory backup function that combines a lithium battery and a large-capacity capacitor enables memory with a long life of five years or more.
Equipped with the last one memory function, the station set at power-off can be called up automatically at the next power-on.
The SN ratio is improved by adopting a pulse swallow method in which the reference frequency is set at 25 kHz, which is higher than the audible band.
The AM tuner section is equipped with an FET buffer to improve reception sensitivity.
In addition, a large loop antenna with high sensitivity and strong resistance to electric field noise is used in the antenna section.
A floating circuit system has been introduced, and the FM and AM antennas are balanced by special coils to eliminate external influences.
The output of the AM section is also balanced.
The AM tuner section has been completely separated from the FM tuner section in order to improve the quality.
It supports AM pre-emphasis broadcasting.
Equipped with an FM noise canceler that is effective in weak electric fields.
Noise generation is suppressed by adopting FL tube of static drive.
Uses an 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:16.0dBf stereo:36.0dBf |
| Harmonic distortion factor (IHF, 80 dBf, wide, 1 kHz) | mono:0.05% stereo:0.06% |
| SN ratio (85 dBf) | mono:86dB stereo:80dB |
| Frequency characteristic | 20 Hz to 15 kHz ± 0.5 dB |
| Capsule ratio | 1.0dB |
| Selectivity | 60dB |
| Stereo separation | 50dB(1kHz) 40 dB (50 Hz to 10 kHz) |
| Image interference ratio | 80 dB or more |
| IF interference ratio | 100 dB or more |
| Spurious interference ratio | 100 dB or more |
| AM suppression ratio | 65 dB or more |
| Subcarrier suppression ratio | 65 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 | 35dB |
| Harmonic distortion factor | wide:0.5% |
| <General> | |
| Output level | 0.775V |
| Memory backup | 5 + years |
| Rated power consumption (Electrical Appliance and Material Control Law) | 10W |
| External dimensions | Width 430x Height 51x Depth 261 mm |
| Weight | 2.8kg |