Audio Database

The

DENON TU-400
29,800yen(around the 1986 time)

Description
 
The AM/FM stereo tuner pursued on the theme of a quality and the ease of using.

While tuning operation is easy and using as a basic base the digital synthesizer system from which exact alignment accuracy is acquired, the random 16-game preset function is carried so that it can fully cover also in area with many receiving stations.
The memory has equipped the memory backup function which saves the contents of a memory for about one month from the time of the power source OFF without using batteries.

"4 Way tuning mechanism" to which the feature of the digital system was fully applied is used for a memory mechanism, and it is raising the ease of using, and practicality.
The office which he wishes by one-touch random-pre-set tuning out of 16 games which carried out the memory without the change of FM/AM can be called direct.
Auto tuning discovers an electric wave automatically with an auto scan, and aligns.
Moreover, a manual scan is also possible.
At the time of the power source ON, it tunes in automatically to the office received at the end.

In order to receive the electric wave of FM with high precision, the Quartz lock synthesizer system which aligns in the accuracy of the crystal oscillation is adopted as frequency arrangement of a broadcasting station.
While setting the comparison frequency of PLL as 25Hz outside an audio frequency band, the high basic engine performance, such as adopting a static control system without the noise from a frequency-spectrum-designation circuit etc. canceling the beat and noise in an audio zone, and improving the signal to noise ratio, is realized.

By the analog formula, the front end part used the Bala Cuthah diode of a triple, and has adopted J-FET as the input unit.
Moreover, the ceramics filter of constant amplitude and constant delay characteristic is used for IF stage.

The filter of one step of 2 steps of 3 terminal type high selection degree ceramics filter + coil type filter which eliminates a 9kHz beat obstacle, and the low impedance type loop antenna strong against the electric-field nature noise from a fluorescent light etc. are being used for the AM section.

The

Rating of a mode
Form AM/FM stereo tuner
<FM section>
Received frequency 76-90MHz
Intermediate frequency 10.7MHz
Antenna terminal Terminal type
75-ohm disequilibrium, a 300-ohm balance
Practical speed 11.2dBf
Signal to noise ratio sensitivity of 50dB stereo:38.5dBf
mono:21.6dBf
The degree of execution selection 50dB (±400kHz)
Capture ratio 1.5dB
IF disturbance ratio 85dB
Image disturbance ratio 70dB
AM oppression ratio 50dB
Muting operating-limits level
Stereo automatic change operation level
-94.8dB(mW)
Frequency response 20Hz - 15kHz, and +0.2 -1.5 dB
Auditory-sensation-weighting signal to noise ratio stereo:75dB
mono:80dB
THD (1kHz) stereo: 0.15% (at the time of 90% abnormal conditions)
mono: 0.08% (at the time of 100% abnormal conditions)
Separation rate 40dB(1kHz)
Output voltage 0.6V (at the time of 100% abnormal conditions)
<AM section>
Received frequency 522-1,629kHz
Intermediate frequency 450kHz
Antenna terminal Terminal type (loop antenna attachment)
Practical speed 18 microvolts (300 microvolt/m)
The degree of 1 signal selection 35dB (±9kHz)
IF disturbance ratio 60dB
Image disturbance ratio 45dB
Signal to noise ratio 52dB
THD 0.6% or less
Output voltage 0.2V (at the time of 30% abnormal conditions)
<Synthesis>
Power consumption 7W
Power source AC100V, 50Hz/60Hz
Dimensions (a base, a knob, a terminal included) Width 434x height 72x depth of 281mm
Weight 3.2kg