ONKYO Integra T-415
¥ 39,800 (around 1980)
Commentary
FM/AM tuner using super servo amplifier and servo lock IC
The Super Servo system is used in the audio section of FM and MPX and later.
In this method, the basic circuit is composed of a DC amplifier, which is controlled by the servo amplifier of the operational amplifier IC. It is also called servo operational DC amplifier.
As a result, while taking advantage of the advantages of DC amplifiers, we have succeeded in eliminating the disadvantages of servo amplifiers by cutting out unnecessary ultra-low frequencies.
Servo lock system using high-gain operational amplifier IC is adopted.
With lock accuracy within ± 5 khz of the best sound quality point, the best sound quality point with minimum distortion and maximum separation is maintained severely.
It is equipped with a just-chain touch sensor for quick and accurate channel selection operation.
As a result, the locked indicator lights when the tuning knob is within the lock range of ± 100 kHz from the tuning point. When the tuning knob is released, the tuning knob is immediately locked at the optimum tuning point.
In the front end section, a wide-air-gap frequency linear 4 series varicon is adopted to improve the scale accuracy. In addition, a wide dynamic range, low-noise dual-gate MOS FET is used in the RF stage and mixer stage to reduce RF intermodulation interference and cross modulation.
In addition to the temperature, a local variable capacitor is used to suppress the effect of humidity drift and prevent the slight tuning deviation.
A wide-band linear phase filter selected by the differential gain direct-viewing method is used for the IF section, and a differential type IC is adopted for the IF amplifier to obtain a sufficient limiter effect.
In addition, the differential gain direct-viewing method is used to obtain wide-band linear characteristics for the detector, which improves sound quality.
The MPX section, which separates audio signals into left and right signals, uses a highly stable PLL IC to obtain a separation signal with good separation.
In addition, by adding a strengthening filter and NFB, the distortion factor is also reduced thoroughly.
The AM section includes the RF stage to the audio section. The AM section is completely independent of the FM section, and uses a dedicated high-fidelity AM / IC.
A 3-stage delay type AGC is built in, with 2 stages to the RF amplifier and 1 stage to the IF amplifier, to prevent beat disturbance and shock sound at tuning while maintaining a low distortion rate against strong input.
Equipped with multi-path detection terminal useful for antenna installation.
With Output Level Control
Equipped with two output terminals.
Built-in air check and calibrator for recording.
.JPG)
Model Rating
| Type | Super Servo / Servo Lock System FM/AM Stereo Tuner | ||||||||
| FM Tuner Section | |||||||||
| Receiving frequency | 76 MHz to 90 MHz | ||||||||
| Practical sensitivity | 0.9 μ V/10.3 dBf (75 Ω / IHF) | ||||||||
| S/N50dB sensitivity | 2.0 μ V/17.3 dBf (75 Ω / IHF) | ||||||||
| Intermodulation interference ratio | 90 dB (± 2.5 MHz) | ||||||||
| Image interference ratio | 83dB(83MHz) | ||||||||
| IF interference ratio | 95dB(83MHz) | ||||||||
| Signal-to-noise ratio | mono:77dB stereo:73dB |
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| Spurious interference ratio | 95dB | ||||||||
| 2-signal selectivity (± 400 kHz detuning) | 75dB | ||||||||
| AM suppression ratio | 57dB | ||||||||
| Capture ratio | 1.0dB | ||||||||
| Distortion factor |
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| Frequency characteristic | 20 Hz ~ 15000 Hz + 0 -1dB | ||||||||
| Antenna impedance | 75 Ω | ||||||||
| Stereo separation |
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| Carrier leak | -60dB | ||||||||
| Output Voltage / Impedance | Variable Output : 0 ~ 1000 mV / Maximum 2.5k Ω 450mV/3k Ω |
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| <AM Tuner Section> | |||||||||
| Receiving frequency | 530 kHz to 1605 kHz | ||||||||
| Practical sensitivity (bar antenna) | 150 μ V/m | ||||||||
| Image Interference Ratio (1 MHz) | 52dB | ||||||||
| IF Interference Ratio (1 MHz) | 38dB | ||||||||
| Two signal selectivity | 35dB | ||||||||
| Signal-to-noise ratio | 60dB | ||||||||
| Strain Rate (400 Hz) | 0.4% | ||||||||
| Output Voltage (400 Hz, 30% Modulation) | Variable Output : 0 mv ~ 400 mv Recorded output : 150 mV |
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| <General> | |||||||||
| Semiconductor used | 6 ic, 20 tr (4 fet), 23 di | ||||||||
| Pwer | 100 VAC, 50/60Hz | ||||||||
| Power consumption | 12W (Electrical Appliance and Material Control Law Standard) | ||||||||
| External dimensions | Width 435x Height 91x Depth 398 mm | ||||||||
| Weight | 5.2kg | ||||||||