Accuphase T-106
¥ 145,000 (released in January 1984)
Commentary
An FM/AM tuner equipped with an FM section that incorporates new technologies such as electronic tuning circuits and DGL FM detectors, and an AM section for synchronous detection.
A crystal oscillator is used for tuning, and it can be tuned to the desired signal with an accuracy of ± 0.002%. In addition, there is almost no deviation due to time or temperature change, and it locks at the point of minimum distortion and maximum sensitivity.
Because of electronic tuning, there is no modulation distortion or noise due to external vibration, and the digital frequency display uses a static method that does not generate noise.
It is equipped with 14 stations of random memory, 7 feather touch buttons can be used in multiple forms, and 14 FM and AM stations can be randomly stored to the desired button.
In addition, it is equipped with a rotary knob type tuning that applies optics and has the same feeling as the varicon type tuning. It is also possible to continuously select the channel every 100 kHz (AM every 9 kHz) along with the beep sound.
The front end section is double-tuned between the input and amplifier stages, greatly improving the interference caused by large input interference (RF intermodulation).
By combining a newly developed DGL detector with a specially selected group delay flat IF filter, excellent characteristics can be obtained.
The DGL detection method is a circuit that focuses on the delay time of the output of a high-speed logic IC. It consists of 19 high-speed logic ICs in series. The phase angle is delayed by 114 ° to minimize distortion and optimize S/N. By adding this delayed signal and input signal to an exclusive OR circuit, the potential between the two signals is selected and the circuit is opened and closed. The density of the signal wave generated by modulation is digitally detected (logical multiplication) and an audio signal is extracted. Since the linear region of the delay circuit is as wide as ± 5 MHz and moreover it is a non-adjustable circuit, stable and excellent linear differential gain characteristics can be obtained.
Two sets of IF filters, Normal and Narrow, are used. When interference is intense, switching to Narrow enables selective reception.
The FM stereo demodulation circuit incorporates the latest technologies and has excellent characteristics.
It also emphasizes AM broadcast reception, and employs synchronous detection with less distortion and excellent interference removal capability.
The synchronous system extracts audio signals at a stroke by making the local oscillation frequency injected into the mixer the same as the input carrier wave. The selectivity is determined by the characteristics of the low-pass filter installed in the audio circuit, making it an excellent system with less detection distortion.
In addition, another feature of synchronous detection is that the Sideband can be selected depending on whether the interference wave is higher or lower than that of the receiving station. Therefore, it is effective at night when sky waves are strong or in areas where interference from overseas stations is a problem.
The T-106 uses synchronous detection in addition to the standard wideband super system, and has frequency characteristics that match the NHK sound equalization (pre-emphasis) characteristics. Therefore, pre-emphasis broadcasting can be received with good frequency characteristics.
A 9 kHz filter is used to remove the beat of the adjacent station.
The signal meter that shows the signal strength and the peak modulation meter that displays the modulation degree up to 200% indicate the state of the input radio wave.
In addition, the modulation depth meter becomes a multi-path meter by switching the switch, and the direction of the antenna with minimum distortion can be known.
Included functions include a noise filter to reduce the noise of a weak stereo station, a Selectivity switch to be used when interference occurs frequently, a muting switch to remove inter-station noise, a sideband selector to select the AM sideband when interference occurs, and a level control to adjust the level to the volume of another program source.
The natural rosewood cabinet used in the picture was sold separately.
Also, there is a black model T-106B.
Model Rating
Type | AM/FM Tuner | ||||||||||||
FM MonAural Characteristics | |||||||||||||
Receiving frequency | 76.0 mhz to 90.0 mhz | ||||||||||||
Practical sensitivity | 11dBf(IHF) | ||||||||||||
S/N 50 dB sensitivity | 17dBf(IHF) | ||||||||||||
Standing-wave ratio | 1.5 | ||||||||||||
S/N (80 dBf input, A-correction) | 90dB | ||||||||||||
Total harmonic distortion factor (80 dBf input, ± 75 kHz shift, Normal) |
20Hz:0.04% 1kHz:0.04% 10kHz:0.04% |
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IM Distortion Factor (80 dBf input, ± 75 kHz shift) | 0.01% | ||||||||||||
Frequency characteristic | 10 Hz ~ 16000 Hz + 0 -1.0 dB | ||||||||||||
Two signal selectivity (IHF) |
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Capture ratio | 1.5dB | ||||||||||||
RF intermodulation | 80dB | ||||||||||||
Spurious interference ratio | 120dB | ||||||||||||
Image ratio | 120dB | ||||||||||||
IF/2 spurious response | 100dB | ||||||||||||
AM suppression ratio (65 dBf input) | 80dB | ||||||||||||
Subcarrier suppression ratio | 70dB | ||||||||||||
SCA interference ratio | 80dB | ||||||||||||
Output voltage (± 75 kHz deviation) | 1.0V | ||||||||||||
FM Stereo Characteristics | |||||||||||||
Sensitivity (IHF) | S/N 40dB:29dBf S/N 50dB:37dBf |
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S/N (80 dBf input, A-correction) | 85dB | ||||||||||||
Total harmonic distortion factor (80 dBf input, ± 75 kHz shift, Normal) |
20Hz:0.04% 1kHz:0.04% 10kHz:0.08% |
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IM Distortion Factor (80 dBf input, ± 75 kHz shift) | 0.03% | ||||||||||||
Frequency characteristic | 10 Hz ~ 16000 Hz + 0 -0.5 dB | ||||||||||||
Stereo separation factor | 100Hz:50dB 1kHz:50dB 10kHz:45dB |
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Stereo switching input voltage | 20dBf | ||||||||||||
<AM Tuner Section> | |||||||||||||
Receiving frequency | 522 kHz to 1611 kHz | ||||||||||||
Practical Sensitivity (S/N 20 db) | 20 μ V/m | ||||||||||||
Image interference ratio | 50dB | ||||||||||||
Total harmonic distortion rate (1mV/m, 1 kHz, 30% modulation) | 0.3% | ||||||||||||
S/N ratio (1mV/m, 1 kHz, 30% modulation) | 50dB | ||||||||||||
De-emphasis | 100 μ S | ||||||||||||
Output Voltage (30% Modulation) | 0.3V | ||||||||||||
<General> | |||||||||||||
Antenna | FM : 75 Ω unbalanced (with 300 Ω balanced converter) AM : Air Core Loop Antenna |
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Tuning system | Quartz synthesizer system 14 stations random memory tuning |
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Detection system | FM : DGL method AM : Synchronous System |
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Output impedance | Fixed Output : 200 Ω Variable Output : 1.25k Ω (maximum) |
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Meter | Signal Strength, Multipath / Modulation Switchable | ||||||||||||
Semiconductor used | Transistor : 38 FET : 6 IC : 50 Diode : 63 units LED : 10 pcs Opto-coupler : 2 pcs |
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Pwer | 100 VAC, 50Hz/60Hz | ||||||||||||
Power consumption | 23W | ||||||||||||
External dimensions | Width 445x Height 128x Depth 370 mm (Including Legs) | ||||||||||||
Weight | 9kg | ||||||||||||
Sold separately : Wood Cabinet A-9 (¥ 16,000) | |||||||||||||
External dimensions | Width : 466x Height 153x Depth 385 mm |