SANSUI TU-777
¥ 37,800 (released in March 1968)
Commentary
An FM/AM tuner equipped with a front-end FET and RF2-stage 4-row varicon, 3-stage AGC, 5-stage IF, 4-stage limiter, etc., and various functions as a top-of-the-line tuner.
The FM front-end uses a junction-type FET at the first stage of the RF, a mixer at the second stage of the RF, and a silicon transistor and four variable capacitor for the oscillator circuit.
It boasts a wide Takamasu, high stability, low noise, and low distortion rate with 5-stage IF and 4-stage limiter using silicon transistors.
A 3-stage AGC with two stages in the front end and one non-tuned stage in the IF section, especially for the AGC, ensures selectivity in a strong electric field.
The power supply for the IF stage and the front-end uses a stabilized Zener diode. In particular, the front-end completely compensates the temperature of the local oscillator. Furthermore, by stabilizing the power supply, the drift of the local oscillator is minimized and the AFC circuit is eliminated.
The noise canceler replaces the conventional high-cut method with a new method that eliminates noise without cutting high-frequency audible range. Combined with the 4-stage limiter, the noise canceler enables comfortable reception without noise.
A meter and a special amplifier for muting are installed, and a large meter with a green ring circular dial is used for the tuning instruction to make it easier to see. The tuning point can be sharpened to match the center of the radio wave.
In addition to siliconization of the multi-circuit, the switching system with the highest stability and reliability is adopted to improve channel separation.
Equipped with pure electronic FM stereo / monaural switching.
In FM-AUTO, the electronic switch automatically operates when the FM broadcast changes from mono to stereo.
The FM antenna is equipped with a 20 dB-down attenuator with a local variable switch, so it is not distorted even if an input of up to about 3 V is input to the antenna.
Two circuit impedance terminals of 300 Ω and 75 Ω are provided.
The AM tuner section also uses an RF1-stage 3-row varicon and a ferrite bar antenna is built in, so it is sufficient without an antenna wire.
The output circuit is equipped with semi-fixed output level adjustment so that it can be connected to any amplifier, and with FM multiplex separation adjustment.
Model Rating
| Type | FM/AM Tuner |
| FM Tuner Section | |
| Receiving frequency | 76 MHz to 90 MHz |
| Sensitivity | 20 dB quieting : 1.4 μ V ± 3 dB IHF : 1.8 microvolts + / - 3 db |
| Total harmonic distortion factor | 0.8% or Less (Input 60 dB, 100% MOD) |
| Signal-to-noise ratio | 65 dB (input 60 dB, 100% MOD) |
| Selectivity | 50 dB or more |
| Image ratio | 80 dB or more |
| IF Rejection | 95 dB or more |
| Capture ratio | 2.5dB(IHF) |
| Spurious response | 90 dB or more |
| FM stereo / separation | 35 dB or more |
| Unwanted radiation | 34 dB or less |
| Local / Distant Switch | Local 20 dB down Distant Direct |
| <AM Tuner Section> | |
| Receiving frequency | 535 kHz to 1605 kHz |
| Sensitivity | 15 μ V ± 3 dB (20 dB, 1000 kHz) |
| Image ratio | 50dB(1000kHz) |
| IF Rejection | 100 dB or More (1000 kHz) |
| Selectivity | 20 dB (input 60 dB, 1000 kHz) |
| <General> | |
| Rated output voltage | 2 V (0 ~ 2 V Variable) |
| Load impedance | 100k Ω or more |
| Semiconductor used | Transistor : 28 FET:1 Diode : 24 |
| Power supply voltage | 100 V, 50Hz/60Hz |
| Power consumption | 10W |
| External dimensions | Width 345x Height 155x Depth 334 mm |
| Weight | 7.7kg |