SONY ST-J60

Commentary

Digital synthesizer tuner that uses crystal lock.

The Crystal Lock Digital Synthesizer system controls the tuning with crystal accuracy. It has accurate tuning accuracy and stability and demonstrates the performance of each tuner block.
The digital display of the reception frequency is based on the counting down of the controlled local oscillation frequency. Since the display instruction is issued, there is basically no indication error. Therefore, the increase of tuning deviation and distortion due to the indication error of the frequency is prevented.

Equipped with an FM/AM random 8-station preset. Once tuned, you can preset by pressing the memory switch and any button simultaneously. The memory circuit uses a permanent memory that does not lose memory even when the power is turned off or the plug is removed.

With bi-directional auto-tuning, you can automatically select the neighboring station with one touch of a button.
If you keep pressing the button, even if a station is received, it stops for a moment and keeps moving.

Manual step tuning is possible, and 100 kHz tuning point moves by one touch of button.
Press and hold the button to move quickly enough to clearly read the digitally displayed frequency.

Equipped with the last station memory, it is possible to store the music you have listened to until the end when the power is turned off.

The front end is equipped with a varicap that is equivalent to the 4-train tuning of a varicon to improve characteristics such as spurious interference.
In order to solve the problem of low resonance gain (Q), technology from Sony's Semiconductor Research Division was introduced and Q, which cannot be compared with conventional varicaps, was successfully obtained.
In addition, in order to reduce cross modulation interference, a dual gate MOS-FET is adopted, and the cross modulation interference is reduced by wiring with electromagnetic induction eliminated as much as possible and by using carefully selected parts.

The IF section employs a uniphase IF filter developed by Sony's proprietary semiconductor engineering technology, which greatly improves group delay characteristics and provides excellent distortion and selectivity.

PLL-IC is used in the MPX section.

It is equipped with 5-step LED signal indicator and multi-pass indicator which can check multi-pass with one touch.

Uses an auto-dimmer that changes the brightness of the digital display according to the surrounding brightness.

It is equipped with a CAL-TONE switch that generates a 400 Hz test tone at a level corresponding to 50% modulation and makes it convenient to adjust the air check level.

It is equipped with a muting switch that cuts the noise between stations when selecting channels.

Model Rating

Type	Crystal lock digital synthesizer tuner
Circuit system	FM/AM superheterodyne system
FM Tuner Section
Receiving frequency	76.0 mhz to 90.0 mhz
Antenna terminal	300 Ω Balanced Type 75 Ω unbalanced type (coaxial cable connector)
Practical sensitivity	1.8 μ V (IHF) / 10.3 dBf (new IHF)
SN ratio 50 dB sensitivity	Mono : 3.5 μ V (IHF) / 16.1 dBf (new IHF) Stereo : 40 μ V (IHF) / 37.3 dBf (new IHF)
Signal-to-noise ratio	mono:77dB stereo:72dB
Harmonic distortion factor	mono: 0.06%(100Hz) 0.06%(1kHz) 0.06%(10kHz) stereo: 0.08%(100Hz) 0.08%(1kHz) 0.15%(10kHz)
Stereo separation	48dB(100Hz) 50dB(1kHz) 45dB(10kHz)
Frequency characteristic	30 Hz to 15 kHz + 0. 2-0. 5 dB
Effective selectivity	85dB(400kHz) 45dB(300kHz)
Capture ratio	1.0dB
AM suppression ratio	60dB
Image interference ratio	90dB
IF interference ratio	100dB
Spurious interference ratio	100dB
Output Level / Impedance	750mV/4k Ω
<AM Tuner Section>
Receiving frequency	531 kHz to 1611 kHz
Antenna	With ferrite bar antenna and external antenna terminal
Sensitivity	250 μ V/m (1000 kHz when bar antenna is used)
Signal-to-noise ratio	50dB(50mV/m)
Harmonic distortion factor	0.5% (50mV/m, 400 Hz)
Selectivity	35dB(9kHz) 40dB(10kHz)
Image interference ratio	35dB(1000kHz)
<General>
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	12W
External dimensions	Width 430x Height 80x Depth 325 mm
Weight	Approx. 4.1 kg
Attachment	Connection code FM feeder antenna F-type coaxial plug Station name display label set