Audio Database

The

SANSUI TU-777
37,800yen(March, 1968 release)

Description
 
The FM/AM tuner which began the front end of FET and 2 steps of RF 4-unit variable condenser, and equipped various functionalities as a highest-class tuner besides being three-step AGC, five steps of IF, four steps of limiters, etc.

FM front end has adopted the silicon transistor and the 4-unit variable condenser as the 2nd step of junction types FET and RF, a mixer, and an oscillator circuitry at RF first rank.

It is proud of high amplification degree, high stability, the low noise, and the low distortion with the intermediate frequency of five steps of IF and four steps of limiters of silicon transistor adoption.

The selectivity in the strong electric field has also taken all possible measures against front end at two steps and especially the IF section by three-step AGC which established one step of non-aligning stage only in AGC.

It has succeeded in IF stage and the power source of front end adopting the stabilizing supply of zener diode, and especially front end carrying out temperature compensation of a from office completely, and also being a stabilization of a power source, making the drift from an office into a minimum, and removing an AFC circuit.

The comfortable reception which a noise does not have is made as for a four-step limiter and an interval to a noise cancellar by adopting the new method for which a noise can be removed, without stopping the conventional high cut scheme and cutting the audible range where a frequency is high.

While forming meter and especially the amplifier only for a muting, the large-sized meter of the circular dial of a green ring is adopted as a syntony indication, it is made legible, an aligning point is made sharp, and it is united with the hub of a radio wave.

The multi-circuitry attained silicon-ization, and also switching with highest stability and reliability was used for it, and it has improved the channel separation.

FM stereo monophonic switching of a pure electronic formula is carried.
In FM-AUTO, if an FM broadcast becomes a stereo from a monophonic recording, the electronic switch will operate automatically.

Since FM antenna carries the attenuator of a 20dB down with a local distant switchpoint, even if the input up to about 3V goes into an antenna, it is not distorted.
Moreover, the impedance termination of two circuitries (300ohm and 75ohm) is prepared.

Since AM tuner part has also adopted 1 step of RF triple variable condenser and the ferrite bar antenna is built in, it is enough without an antenna wire.

Output-voltage adjustment of a semipermanent is attached so that it can connect with any amplifier, and an output circuit is with of FM Multiplex separation adjustment.


Rating of a mode
Form FM/AM tuner
<FM tuner part>
Received frequency 76MHz - 90MHz
Sensitivity 20dB quieting: 1.4microvolt±3dB
IHF: 1.8microvolt±3dB
THD 0.8% or less (an input of 60dB, 100%mod)
SN ratio 65dB (an input of 60dB, 100%mod)
Selectivity 50dB or more
Image ratio 80dB or more
IF rejection 95dB or more
Capture ratio 2.5dB(IHF)
Spurious response 90dB or more
FM stereo separation 35dB or more
Unnecessary radiation 34dB or less
A local/distant Switchpoint Local 20dB down
Distant Direct
<AM tuner part>
Received frequency 535kHz - 1605kHz
Sensitivity 15microvolt±3dB (20dB, 1000kHz)
Image ratio 50dB(1000kHz)
IF rejection 100dB or more (1000kHz)
Selectivity 20dB (an input of 60dB, 1000kHz)
<Synthesis>
Output-power voltage 2V (0 - 2V variable)
Load impedance 100 or more kohms
The semiconductor used Transistor: 28
FET:1
Diode: 24
Supply voltage 100V, 50Hz/60Hz
Power consumption 10W
Dimensions Width 345x height 155x depth of 334mm
Weight 7.7kg