SANSUI TU-7500
¥ 54,300 (around 1973)
Commentary
This FM/AM tuner uses the newly developed D. D. C. (differential demodulation circuit) to achieve higher sound quality.
The FM fm front end, dual gate MOS FET with low NF (noise figure) and frequency number line type 4 series varicon are adopted.
The IF stage consists of three stage amplification using a newly developed uni-wafer-type two element ceramic filter with excellent selectivity and a limiter circuit using three highly integrated ICs.
In addition, this circuit emphasizes the phase problem that affects sound quality and separation, thoroughly investigates the distortion caused by the phase shift, and has a unique circuit configuration with excellent phase linearity.
The MPX section employs a unique D. D. C. (differential demodulation circuit) to electronically cancel the SCA filter to prevent phase shift and improve separation.
The AM IF section is equipped with a newly developed coil + 2-element ceramic filter to improve selectivity and other characteristics.
Equipped with a newly developed noise suppressor switch, it works as a whistle filter to suppress beat noise of 7 khz or higher when receiving AM broadcasting, and as an MPX noise canceller circuit without cutting the high frequency band of 10 khz when receiving FM broadcasting.
Stabilization is achieved by using a transistor and a zener diode for the power supply circuit.
In order to support 4-channel discrete broadcasting, it is equipped with a dissonate Krimi to a 4-channel adapter.
The FM muting switch and muting adjustment function are transparent.
The FM input sensitivity can be switched between two levels : Local and Distant.
.JPG)
Model Rating
| Type | FM/AM Tuner |
| FM Tuner Section | |
| Receiving frequency | 76 MHz to 90 MHz |
| Sensitivity (IHF) | 1.9 μ V |
| Total harmonic distortion factor | Mono : 0.3% or less Stereo : not more than 0.5% |
| Signal-to-noise ratio | 70 dB or more |
| Selectivity | 70 dB or more |
| Capture Ratio (IHF) | 2dB |
| Image Frequency Rejection | 75 dB or More (83 MHz) |
| IF Rejection | 90 dB or more |
| Spurious response rejection | 80 dB or more |
| Stereo separation | 40 dB or More (400 Hz) |
| Unwanted radiation | 34 dB or less |
| Antenna attenuation | 20dB |
| Frequency characteristic | 30 Hz ~ 15 kHz + 0.5 -2dB |
| Antenna input impedance | 300 Ω (Balanced Type) 75 Ω (Unbalanced Type) |
| <AM Tuner Section> | |
| Receiving frequency | 535 kHz to 1605 kHz |
| Sensitivity (bar antenna) | 50dB/m |
| Selectivity | 25 dB or More (± 10 kHz) |
| Image frequency rejection | 80dB/m or More (1000 kHz) |
| IF Rejection | 80dB/m or More (1000 kHz) |
| <General> | |
| Output voltage | 0 V ~ 1 V Tape rec output : 0.3 V |
| Power consumption | 20W |
| External dimensions | Width 440x Height 140x Depth 322 mm |
| Weight | 8kg |