Aurex ST-910
¥ 280,000 (around 1976)
Commentary
An FM stereo tuner that employs a crystal oscillator PLL frequency synthesizer system.
The circuit uses a PLL frequency synthesizer that uses the accurate oscillation frequency of quartz crystal.
It uses a purely electronic touch switch arranged on the front panel for operation.
Two tuning methods, manual and auto, are used.
Auto tuning automatically searches for radio waves when a switch is pressed and automatically stops when a radio wave is found. Manual tuning can change the frequency at 0.1 MHz and 1 MHz intervals.
It is equipped with a preset system that can store up to 7 stations.
After searching for a radio wave with the tuning switch, turn ON the switch labeled "Memory" and turn ON the preset switch while the memory is on.
The muting level can be switched in three stages, so that only radio waves of a certain strength can be selected for auto-search.
The signal strength can be checked with the 3-stage indicator.
This indicator has three levels of 20, 40 and 60 dB.
Equipped with a stereo signal and mono signal selector switch.
If you set the stereo signal switch to ON, you can select only the radio wave of the stereo broadcast transmission during auto search.
Digital display is used for the frequency, and switches are LED display.
Actually measured data sheet is included.
In this data sheet, you can check 4 items such as sensitivity, SN ratio, stereo separation and harmonic distortion factor.
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Model Rating
| Type | FM stereo tuner |
| Circuit system | Frequency synthesizer system using crystal oscillator |
| Receiving frequency | 75.5 mhz to 89.9 mhz |
| Practical sensitivity | 1.8 μ V (IHF) |
| Harmonic distortion factor (400 Hz, 100%) |
stereo:0.2% mono:0.15% |
| Signal-to-noise ratio | 75dB |
| Frequency characteristic | 20 Hz to 15 kHz ± 0.5 dB |
| Effective selectivity | 70dB |
| Image interference ratio | 100dB |
| IF interference ratio | 110dB |
| Capture ratio | 1.0dB |
| Spurious interference ratio | 100dB |
| AM suppression ratio | 65dB |
| Stereo separation | 40dB(1kHz) |
| Rated output | Fixed : 400 mv (400 hz, 100% modulation) Variable : 0 ~ 1.5 V (400 Hz, 100% modulation) |
| Antenna terminal | 300 Ω balanced, 75 Ω unbalanced |
| Semiconductor used | Transistor : 32 FET : 9 Diode : 100 units IC : 96 LED : 24 pcs |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 25W |
| External dimensions | Width 450x Height 147x Depth 340 mm |
| Weight | 8.0kg |
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