Pioneer TX-6700
¥ 39,800 (around 1975)
Commentary
A TV/AM/FM stereo tuner with a TV audio receiver in addition to an AM/FM stereo receiver.
TV sound reception is an all-band reception of VHF 1-12ch and UHF 13-62ch.
The center tuning meter operates at the time of reception, so that the best tuning point can be obtained by using the preset fine tuning knob for VHF and the easy fine tuning knob for UHF.
The FM front-end section consists of a high-frequency amplification single-stage circuit that combines an FET with a low noise figure and a frequency linear 3-row varicon.
The IF section uses a dedicated high-integration IC developed by Pioneer, which combines more than 200 elements in total into a single IC. In addition, a phase-linear ceramic filter with excellent phase characteristics is used as the selective element to enhance the interference rejection capability.
In addition, this circuit has a 5-stage limiter that virtually eliminates AM noise.
An IC PLL circuit is used in the MPX section to improve the stability of separation characteristics.
A muting circuit for eliminating inter-station noise during channel selection is combined with a selector.
Muting is turned on for FM-auto and turned off for FM-mono. If you set the FM-auto position, muting also works for VHF and UHF TV sound reception.
A dedicated IC developed by Pioneer is used in the AM tuner section.
This IC has an excellent AGC characteristic that keeps the output constant regardless of whether the input is strong or weak, so that the sound is not distorted even in areas where radio waves are too strong.
Equipped with a multi-function meter that functions as a center tuning meter when receiving FM and TV sound, and as a signal meter when receiving AM signal to indicate signal strength.
The walnut finished wood case that can be used commonly for TX-6300, SA-6300, TX-6700, and SA-6700 was sold separately.
Model Rating
Type | TV/AM/FM stereo tuner | ||||
FM Tuner Section | |||||
Circuit system | FETRF 1-stage, 3-series varicon, 5-stage limiter, quadrature detection PLL MPX |
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Practical sensitivity | Mono : 4.5 μ V (S/N50dB) / 1.9 μ V (IHF) Stereo : 50 μ V (S/N50dB) |
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S/N | mono:70dB stereo:68dB |
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Harmonic distortion factor |
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Capture ratio | 1.0dB | ||||
Effective selectivity | 60dB | ||||
Separation | 35 dB or More (1 kHz) 30 dB or More (50 Hz to 10 kHz) |
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Frequency characteristic | 50 Hz to 10 kHz + 0. 2-0. 5 dB 20 Hz to 15 kHz + 0.2 -2.0 dB |
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Image interference ratio | 60 dB or more | ||||
IF interference ratio | 90 dB or more | ||||
Spurious interference ratio | 75 dB or more | ||||
AM suppression ratio | 50dB | ||||
Carrier leak suppression ratio | 40dB | ||||
Muting action level | 2.2 μ V | ||||
Antenna | 300 Ω Balanced Type, 75 Ω Unbalanced Type | ||||
<AM Tuner Section> | |||||
Circuit system | Untuned RF1-stage 2-train varicon | ||||
Practical sensitivity | 300 μ V/m (bar antenna) 15 μ V (IHF) |
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Selectivity | 35dB | ||||
S/N | 50dB | ||||
Image interference ratio | 40dB | ||||
IF interference ratio | 50dB | ||||
<TV Tuner Section> | |||||
Receiving channel | VHF : 1-12ch UHF : 13 ch to 62 ch |
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Practical Sensitivity (S/N30dB) | VHF : 2.5 μ V UHF : 2.5 μ V |
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S/N | VHF:60dB UHF:60dB |
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Harmonic distortion factor (100 Hz to 10 kHz) |
VHF:0.2% UHF:0.2% |
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Frequency characteristic | 50 Hz to 10 kHz + 0. 2-0. 5 dB | ||||
Image interference ratio | VHF:85dB UHF:65dB |
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IF interference ratio | VHF:90dB UHF:75dB |
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Spurious interference ratio | VHF:65dB UHF:65dB |
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<General> | |||||
Output Level / Impedance | 600 mv (TV : 400 mv) / 5k Ω | ||||
Semiconductor used | Transistor : 18 FET : 2 IC : 3 Diode, etc. : 14 Pieces |
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Power supply voltage | 100 VAC, 50Hz/60Hz | ||||
Power consumption | 13W (rated) | ||||
External dimensions | Width 350x Height 125x Depth 291 mm | ||||
Weight | 5.6kg | ||||
Sold separately : Wood Case JA-C60 (¥ 4,500) | |||||
External dimensions | Width 404x Height 167x Depth 276 mm | ||||
Weight | 2.2kg |