Audio Database


FM stereo tuner using quartz PLL synthesizer system.

A quartz PLL synthesizer method is used. In this method, a 100 kHz reference signal is produced by reducing the frequency of a 6.4 MHz signal obtained from a crystal oscillator with high frequency accuracy to 1/64 with a frequency divider. The phase of this 100 kHz pulse is compared with the phase of the local oscillator output, and if there is a phase difference, the local oscillation frequency is controlled so that the phase difference becomes small.

A pilot cancel type stereo demodulator is used.
This pilot cancellation method cancels the pilot signal by adding a pilot signal of opposite phase to the input of the decoder, so that the output of the stereo demodulator does not leak the 19 kHz pilot signal.

The front end section uses a special precision 5-row varicon for FM to obtain accurate dial accuracy and stability.
We have also obtained excellent spurious and intermodulation interference characteristics by using carefully selected dual-gate MOS FETs with low noise figure for the high-frequency amplification stage and mixing stage, a double-tuned circuit for the RF tuning circuit, and a 4-pole phase-linear LC filter for the mixer transformer.
The local oscillator circuit uses an oscillation coil with an aluminum core and a Teflon trimmer capacitor, and these components are mounted on a glass-epoxy board.

The IF stage employs a 4-pole phase-linear LC filter with a linear phase over a wide frequency range.
The new design of the discli-transformer and PLL MPX IC realizes excellent characteristics.

It has a built-in air check oscillator (calibrator) that oscillates the signal sound of 440 Hz at the same output as that of 50% FM modulation.

Model Rating
Type FM stereo tuner
Circuit system Quartz PLL synthesizer system
MOS FET 5-series varicon
Practical sensitivity 1.8 μ V
Capture ratio 1.0dB
Effective selectivity 70dB
Signal-to-noise ratio mono:80dB
Image interference ratio 110dB
IF interference ratio 110dB
Spurious interference ratio 100dB
AM suppression ratio 65dB
Harmonic distortion factor mono:0.08%
Stereo separation 50dB(1kHz)
Frequency characteristic 30 Hz ~ 16 kHz + 0.5 -1.0 dB
Output Level / Impedance 150mV/5k Ω
0 ~ 500mV/5k Ω
Pwer 100 VAC, 50Hz/60Hz
Power consumption 11W
External dimensions Width 270x Height 70x Depth 249 mm
Weight 3.5kg
Attachment PIN-PIN code
T-shaped FM antenna
Hex Wrench