DENON TU-920
¥ 34,800 (around 1985)
Commentary
An FM/AM tuner that uses a digital synthesizer.
It employs a quartz-lock synthesizer system that synchronizes with the accuracy of the crystal oscillation. The comparison frequency of the PLL is set to 25 kHz, which is out of the audible band. It also employs a static control system that suppresses noise from the frequency display circuit. This improves the SN ratio by eliminating beat and noise in the audio band.
Equipped with a one touch random preset tuning function that can directly call up 8 stations without switching between FM and AM.
It is equipped with four channel selection methods, including automatic channel selection that automatically finds and tunes radio waves by auto-scan, manual channel selection that can receive even weak radio waves by manual scan, and last-channel memory channel selection that calls the station before OFF when the power is ON.
The front end section of the analog type uses a varactor diode equivalent to four circuits, and the input section uses a dual gate MOS FET.
The IF stage, which controls the total quality, uses a ceramic filter with constant amplitude and constant delay characteristics, and an anti-noise filter to eliminate Birdie generated during stereo operation. This improves the interference rejection capability.
It is equipped with a quality indicator that shows a good level of reception.
The AM tuner uses a 3-terminal high-selectivity ceramic filter and coil that eliminates 9 kHz beat interference and a low-impedance loop antenna that is resistant to electric field noise.
There are 2 variations, black and champagne gold.
Model Rating
Type | FM/AM Tuner |
FM Tuner Section | |
Receiving frequency | 76 MHz to 90 MHz |
Antenna terminal | 75 Ω (Terminal Type) |
Practical sensitivity | 0.9 μ V/10.3 dBf |
S/N50dB sensitivity | Stereo : 21.5 μ V/37.9 dBf Mono : 1.8 μ V/16.4 dBf |
Image interference ratio | 80dB |
IF interference ratio | 90dB |
AM suppression ratio | 60dB |
Effective selectivity | 65 dB (± 400 kHz) |
Capture ratio | 1.0dB |
Frequency characteristic | 20 Hz to 15 kHz + 0.2 -1.6 dB |
Signal-to-noise ratio (weight A) | stereo:80dB mono:84dB |
Total harmonic distortion rate (1 kHz) | Stereo : 0.08% at 90% modulation Mono : 0.05% (at 100% modulation) |
Stereo separation | 50dB(1kHz) |
Output level | 0.6 v (at 100% modulation) |
<AM Tuner Section> | |
Receiving frequency | 522 to 1,611 kHz |
Antenna | Terminal type with loop antenna |
Practical Sensitivity (S/N20dB) | 18 μ V |
Selectivity | 50 dB (± 9 kHz) |
Image ratio | 45dB |
Signal-to-noise ratio | 55dB |
Total harmonic distortion factor | 0.3%(1kHz) |
Output level | 0.2 V at 30% modulation |
<General> | |
Pwer | 100 VAC, 50Hz/60Hz |
Power consumption | 8W |
External dimensions (including knob, leg and terminal) | Width 434x Height 66x Depth 281 mm |
Weight | 3.3kg |