LUXMAN T-300X
¥ 98,000 (released in December 1978)
Commentary
A dedicated FM tuner with contents similar to 5T10 of the laboratory reference series.
A proprietary C. L. L method (Closed Loop Locked System) is used for tuning.
This system is based on the transmission frequency of the crystal-controlled FM station and controls everything from the front end, which is the center of the tuner, to the IF stage (intermediate frequency amplification stage) and the detection stage. It is not affected by fluctuations in external conditions such as temperature conditions such as temperature.
To further improve the tuning accuracy, the capture range of the C. L. L. circuit is set to a narrow range.
Because conventional tuning methods that rely on the center meter make tuning difficult, the T-300X uses the control voltage of the C. L. L. circuit to detect an accurate center point, which is then mechanically locked by the Accu-touch mechanism.
The front end is equipped with a 5-row varicon dedicated to FM, and each high-frequency amplifier circuit is highly selective, ensuring sufficient interference removal capability.
In addition, bandwidth switching is provided at the IF stage, and ultra-low distortion characteristics are achieved by two LC-type block filters with excellent group delay characteristics at the wide position, and high selectivity characteristics are achieved by adding a narrow-band ceramic filter at the narrow position.
In addition, by reducing the distortion factor of the quadracher wide-band detection circuit, a high S / N ratio is achieved.
The MPX circuit is equipped with a pilot signal canceler circuit.
The audio stage uses a DC amplifier configuration.
Model Rating
| Type | FM stereo tuner | ||||
| Practical sensitivity of IHF | 1.7 μ V/9.8 dBf | ||||
| 50 dB quieting sensitivity | 3.2 μ V/15.2 dBf | ||||
| Signal-to-noise ratio | 80dB | ||||
| Frequency characteristic | Mono, stereo : 20 Hz to 17 kHz -0.5 dB or less | ||||
| Strain Rate (wide) |
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| Capture ratio | wide:0.8dB narrow:2dB |
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| Two signal selectivity (± 400 kHz) |
wide:30dB narrow:90dB |
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| Spurious characteristic | 100dB | ||||
| IF interference rejection ratio | 100dB | ||||
| Image ratio | 100dB | ||||
| Amplitude modulation suppression | 62dB | ||||
| Stereo separation | 50 dB (wide, 1 kHz) 45 dB (100 Hz to 10 kHz) |
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| Output level | Fixed : 1 V Variable : 0 v ~ 1 v |
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| Output impedance | Fixed : 100 Ω Variable : 100 Ω ~ 1.25k Ω |
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| Accessory circuit | IF bandwidth switching Switch for multi-path confirmation Test tone switch for recording Center indicator Signal strength indicator FM muting switch Muting level adjustment Output level control Coaxial connector for 75 Ω Time muting circuit |
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| Power supply voltage | 100 VAC, 50Hz/60Hz | ||||
| Power consumption | 20W (Electrical Appliance and Material Control Law) | ||||
| External dimensions | Width 481x Height 104x Depth 325 mm | ||||
| Weight | 6.9kg |
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