Technics ST-3200
¥ 49,800 (released in 1973)
Commentary
An FM/AM tuner that improves sound quality from pursuit of waveform transmission.
The front end section uses four FM series and two AM series varicon, and it is a single and multiple 3-tuned circuit with an RF stage using a four pole MOS FET. High-frequency low-noise transistors are used for the mixer stage and the local oscillator stage, and an aluminum core is used for the oscillation coil.
The IF stage makes the control system and signal system independent. Three 2-element group delay flat filters are used for the signal system. One IC with three differential stages and two L and C filters are used for the control system. This minimizes the occurrence of high-order distortion and increases the selectivity.
In the MPX section, a PLL (Phase Locked Loop) is adopted for the subcarrier oscillation device, and the oscillation frequency and phase are always matched with the pilot signal to obtain a stable switching signal that is resistant to temperature fluctuations and secular changes.
For switching, a double-differential switching circuit with two main and sub circuits in a high-density integrated IC structure is adopted.
The low-pass filter in the latter part of the MPX section has obtained a characteristic of phase delay time of 5.5 μ s at 15 kHz.
The AF stage is a PNP-NPN2-stage direct connection structure using a low-noise transistor and is driven by a stabilized power supply.
The AM tuner uses a converter, IF2-stage amplification, and 5-tuned circuit.
In the power supply circuit, thermal fusion protection elements are used for the primary and secondary fuses and the power transformer, taking safety into consideration.
Equipped with MPX high-blend switch.
Equipped with a strength center tuning meter.
.JPG)
Model Rating
| Type | FM/AM Tuner |
| FM Tuner Section | |
| Receiving frequency | 76 MHz to 90 MHz |
| Sensitivity | 1.8 μ V |
| Selectivity | 65dB |
| Capture ratio | 1.0dB |
| Image Interference Ratio (82 MHz) | 85dB |
| IF Interference Ratio (82 MHz) | 90dB |
| Spurious interference ratio (82 MHz) | 90dB |
| AM suppression ratio | 55dB |
| Signal-to-noise ratio | 75dB |
| Frequency characteristic | 20 Hz to 15 kHz + 0.2 -0.8 dB |
| Separability | 45dB(1kHz) 35dB(10kHz) |
| Leak Carrier (19 khz, 38 khz) | 60dB |
| Output voltage | Variable : 0 ~ 1.5 V Fixed : 0.5 v |
| <AM Tuner Section> | |
| Receiving frequency | 520 kHz to 1610 kHz |
| Sensitivity | 20 μ V |
| Selectivity | 30dB |
| Image interference ratio | 45dB |
| IF interference ratio | 40dB |
| <General> | |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 16W |
| External dimensions | Width 410x Height 140x Depth 340 mm |
| Weight | 6.9kg |