LUXMAN T-660
¥ 49,800 (released in October 1974)
Commentary
AM/FM stereo tuner developed as a tuner with modern and unique design and orthodox circuit structure.
The FM tuner section combines the front end with a high-frequency amplifier circuit using a four link varicon and FET, interstage double-tuning circuit, mixer circuit and oscillator circuit to improve various characteristics.
The intermediate frequency amplifier circuit employs two pairs of linear phase ceramic filter elements, an LC double-tuned circuit, and a wide-band discriminator transformer to improve phase and distortion characteristics over a wide band.
The MPX circuit uses a phase-locked loop (P. L. L) IC, which can automatically compensate for phase shifts caused by various conditions, preventing distortion and degradation of separation.
A constant voltage power supply and ripple filter circuit are used for the power supply.
As an attached circuit, an FM high blend circuit, multi-path detection terminal, output level control, etc. are mounted.
The FM muting circuit uses a pure electronic FET circuit. The muting width set at ± 50 kHz does not change regardless of whether the high frequency input level is strong or weak. There is no fluctuation in DC voltage caused by muting on/off, so there is almost no pop-up noise.
The AM tuner uses a double varicon type without a high frequency amplifier circuit.
A ceramic filter is used in the intermediate frequency amplifier circuit.
Model Rating
| Type | FM/AM Tuner |
| FM Tuner Section | |
| Practical sensitivity of IHF | 2 μ V (83 MHz, 100% mod) |
| Two signal selectivity | 60 dB (83 MHz, 100 μ V, ± 400 kHz) |
| Amplitude modulation suppression | 50 dB (83 MHz, 1 mV) |
| Capture ratio | 1.8 db (83 mhz, 1 mv) |
| Image ratio | 90dB(83MHz) |
| IF interference rejection ratio | 90dB(83MHz) |
| Signal-to-noise ratio | Mono : 70 dB (83 MHz, 1 mV) |
| Frequency characteristic | 50 Hz to 12 kHz -0.5 dB 20 Hz to 15 kHz -2dB |
| Total harmonic distortion rate (400 Hz) | mono:0.3% stereo:0.4% |
| Stereo separation | 40dB(400Hz) 30 dB (50 Hz to 10 kHz) |
| Carrier leak | -63dB |
| Antenna impedance | 300 Ω (balanced) 75 Ω (unbalanced) |
| Output voltage | 1.6 v (400 Hz, 100% mod, mono) |
| <AM Tuner Section> | |
| Practical sensitivity of IHF | 230 μ V/m (1 MHz, 30% mod) |
| Image ratio | 50 dB (1 MHz, INT. ANT.) |
| IF interference rejection ratio | 40 dB (1 MHz, INT. ANT.) |
| Effective selectivity | 35 dB (1 MHz, ± 10 kHz, 30% mod) |
| Signal-to-noise ratio | 50 dB (1 MHz, 10mV/m) |
| Frequency characteristic | 80 Hz to 3 kHz -3dB |
| Total harmonic distortion factor | 0.7% (400 Hz, 30% mod) |
| Output voltage | 450 mv (400 Hz, 30% mod) |
| <General> | |
| Attachment | FM muting circuit FM high blend circuit Multipath detection terminal Output level adjustment |
| Semiconductor used | Transistor : 24 FET : 2 IC : 2 Diode : 21 |
| External dimensions | Width 443x Height 153x Depth 273 mm |
| Weight | 6.7kg |