ROTEL RT-2000
¥ 60,000 (around the late 1970 s?)
Commentary
FM/AM tuner using quartz lock system.
Quartz lock system with crystal oscillator is adopted.
The quartz-locked system constantly compares the accurate 10.7 MHz produced by the crystal oscillator with the intermediate-frequency amplified (IF) 10.7 MHz. When a difference occurs, the phase comparator produces a plus / minus difference signal, and a low-pass filter controls the local oscillator. Quartz is insensitive to changes in humidity or temperature, so the oscillation frequency remains locked, eliminating post-tuning drift.
In addition, a touch lock-off system is adopted, and the lock is released while the tuning knob is touched, and the quartz lock works the moment the hand is released.
The front-end section uses a frequency linear precision five series varicon, and the RT-2000 uses a single dual-gate MOS FET.
The bandwidth of the IF section can be switched in two stages, and conditions can be set according to reception conditions.
By selecting NARROW when radio wave conditions are poor, high selectivity characteristics can be obtained.
The MPX section is equipped with a carrier canceler circuit that cuts the pilot signal (19 kHz). The LC block filter and PLL IC, which take care of the attenuation of the sub-carrier signal (38 kHz), ensure a wide range by suppressing the high-frequency degradation.
Equipped with multipath detection function.
For RT-2000, the indicator of the tuning meter is displayed.
It is equipped with a high-blend switch that demonstrates power in weak electric field reception.
The AM tuner uses a 16-pin dual in-line IC pack circuit.
Model Rating
| Type | FM/AM Tuner | ||||
| FM Tuner Section | |||||
| Sensitivity (IHF) | Mono : 9.8dBf/1.7 μ V (S/N 26 dB) Stereo : 36dBf/35 μ V (S/N 50 dB) |
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| Signal-to-noise ratio (IHF) | mono:80dB stereo:75dB |
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| Harmonic distortion factor |
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| Capture ratio | 1dB | ||||
| Effective selectivity (IHF) | narrow:80dB | ||||
| Frequency characteristic | 30 Hz to 15 kHz ± 0.2 dB | ||||
| Stereo separation | 45dB(1kHz) | ||||
| Image interference ratio | 100dB | ||||
| IF interference ratio | 100dB | ||||
| AM suppression ratio | 60dB | ||||
| Muting | 5 μ V | ||||
| <AM Tuner Section> | |||||
| Sensitivity (IHF) | 200 μ V/m | ||||
| Signal-to-noise ratio | 55dB | ||||
| Image interference ratio | 50dB | ||||
| Selectivity | 40dB | ||||
| <General> | |||||
| External dimensions | Width 482x Height 143x Depth 328 mm | ||||
| Weight | 7.5kg | ||||