Pioneer TX-710

Commentary

An FM/AM tuner developed using the latest technologies at that time, such as dual gate MOS FET and high-integration IC.

The front-end section combines a dual-gate MOS FET with a small feedback capacitance and a 4-series frequency linear varicon to improve interference rejection performance such as cross modulation.

The IF section employs a specialized high-density IC developed with proprietary technology to significantly improve the IF characteristics.
The 5-stage limiter has excellent characteristics.
In addition, a phase linear ceramic filter (2 elements, 2 pieces) with an emphasis on phase characteristics is adopted to improve signal selectivity.

The quadrature detection method is adopted for the detection method, and the characteristics with good linearity and little distortion are obtained.

The MPX section employs a double-balanced differential demodulation circuit using a dedicated IC. This circuit improves the separation and is less susceptible to SCA beat interference.
It also uses a sharp low-pass filter to minimize carrier leakage.

The AM tuner section uses a dedicated IC for AM including one stage untuned RF amplification.
Because of the AGC characteristic that provides a constant detection output at all times, there is no distortion even at strong input, and excellent stability is obtained.
In the mixer stage, a balanced type is the mixer stage to improve spurious characteristics, and a ceramic filter is employed in the IF stage to obtain sharp selectivity characteristics.

The linearity of the signal meter has been improved so that it does not saturate even in the middle field area and gradually ascends to the tuning center point.
This is due to the level detector of the limiter stage. Unlike the meter method which has a high saturation point, it enables more accurate tuning by correctly indicating the signal strength.

There are two types of output terminals, fixed and variable.
FM and AM are independently provided for the variable output level control.

Equipped with an FM muting circuit that suppresses unpleasant noise during tuning and detuning.

It is equipped with a multi-path terminal. If you connect a stereo display SD-100 or an oscilloscope, you can easily find the best point in the antenna direction.

It is equipped with an MPX noise filter that cuts noise without losing sound quality when receiving an FM stereo broadcast transmission.

Model Rating

Type	AM/FM stereo tuner
FM Tuner Section
Circuit system	MOS FET RF1-stage, 4-series varicon 5-speed limiter quadrature detection
Practical sensitivity (IHF)	1.9 μ V
Capture Ratio (IHF)	1dB
Effective selectivity (IHF)	60dB
Signal-to-noise ratio	70dB
Image Interference Ratio (82 MHz)	85 dB or more
IF Interference Ratio (82 MHz)	100 dB or more
Spurious interference ratio	100 dB or more
AM suppression ratio	55dB
Harmonic distortion factor	Mono : not more than 0.2% Stereo : not more than 0.4%
Frequency response (stereo)	20 Hz to 15 kHz + 0.2 -2.0 dB 50 Hz to 10 kHz + 0. 2-0. 5 dB
Stereo separation	1 kHz : 40 dB or more 50 Hz to 10 kHz : 30 dB or more
Carrier leak suppression ratio	65dB
Antenna	300 Ω Balanced Type 75 Ω Unbalanced Type
Muting	ON-OFF
MPX Noise Filter	ON-OFF
<AM Tuner Section>
Circuit system	Untuned RF1-stage 2-train varicon
Practical sensitivity (IHF, bar antenna)	300 μ V/m
Practical sensitivity (IHF)	15 μ V
Selectivity	35dB
Signal-to-noise ratio	50dB
Image interference ratio	45 dB or more
IF interference ratio	55 dB or more
Antenna	Ferrite bar antenna included
<General>
Output Level / Impedance	Fixed : 650mV/4.7k Ω Variable : 70 mv ~ 2V/300 Ω
Semiconductor used	Transistor : 13 FET : 1 IC : 3 Diode, etc. : 8 pcs
Power supply voltage	100 VAC, 50Hz/60Hz
Power outlet	Power switch not linked : 1 system
Power consumption	25W
External dimensions	Width 430x Height 138x Depth 345 mm
Weight	7.7kg