The Accutouch system
seizes the exact tuning point including that at the RF stage and offers total,
stable reception even against ambient fluctuation.
In this system, the
accurate center tuning point is detected by means of a control voltage at the
quartz circuit, which activates a mechanical lock function. As the tuning knob
is gradually turned to locate the FM station, a positive lock occurs for about
1 second at the exact tune-in point inclusive of the RF stage.
Generally speaking,
a quartz-locked FM tuner has the advantage of offering very stable reception
against ambient fluctuation such as temperature, etc. But this system functions
to control only the local oscillator, and does not extend to the RF stage. Moreover,
depending onn the method of tuning operation, tuning error is triggered at a
max. 100 kHz, so that various characteristics are deteriorated (such as
distortion, separation, rejection etc.) in other words, only our
"Accutouch" makes it possible to make the most of the quartz lock
system to prevent possible tuning error. When the power is turned off with the
Quartz Lock on, the proper receiving condition is automatically obtained the
next time power is turned on.
IF Bandwidth
Selector
If the IF stage a
2-step bandwidth selectoris provided. In the "wide" position, 2 pairs
of LC block filter are combined providing exceptionally good phase
characteristics, and realizing ultra low distortion. Conversely in the
"narrow" position a combination of block and ceramic ffilters
achieves high selectivity.
The IF filters
adopted here have excellent group-delay characteristics, however, to make the
ultra low distortion tuner perfect, even small deviation of the components used
should be controlled. Therefore to solve this, a phase compensation circuit is
provided in the IF stage, and the units are checked one by one to realize
excellent distortion characteristics.
Sonic Excellence
In the front end an
exclusive FM 5-gang variable capacitor is used to make the most of the various
superb characteristics in the IF and
following stages. Also high selectivity in each RF amp circuit ensures satisfactory
interference rejection. In the detector circuit, a new quadrature IC and a
special detector transformer are adopted to realize a low-distortion
characteristic through wide bandwidth and high Signal-to-Noise ratio.
Distortion at the detector stage has been suppressed down to a level below that
of most test equipment. Thus no more than 0,02% distortion is realized for a
deviation of ±50 kHz, or no more than 0,05% even through ±100 kHz.
A pilot signal
cancellor circuit is arranged in the multiplex stage to improve frequency
response and phase characteristics.
Specifications
Receiving
Frequency: 87,5 MHz - 108 MHz
50 dB Quieting
Sensitivity:
50 µS : 16,0 dBf 93,3 µV)
75 µS : 14,2 dBf (2,8 µV)
IHF Usable
Sensitivity: 10,7 dBf (1,8 µV)
Signal-to-Noise
Ratio: 80 dB
Frequency
Response: 20 Hz - 17,000 Hz (within -0,5
dB, mono & stereo)
Total Harmonic
Distortion:
100 Hz (wide) : 0,05% (mono); 0,07% (Stereo)
1 kHz (wide) : 0,05% (mono); 0,06% (stsreo)
6 kHz (wide) : 0,07% (mono); 0,1% 9stereo)
1 kHz (narrow)
: 0,2% (mono); 0,5% (stereo)
Capture Ratio:
Wide : 0,8 dB
Narrow : 2 dB
Adjacent Channel
Selectivity: 12 dB (narrow ±200 kHz)
Alternate Channel
Selectivity:
60 dB (narrow, ±300
kHz)
90db (narrow ±400
kHz)
30 dB (wide, ±400
kHz)
Spurious Response
ratio: 100 dB
IF response
Ratio: 100 dB
Image Response
ratio: 100 dB
AM Suppression
Ratio: 62 dB
Stereo Separation:
100 Hz (wide) : 45 dB
1 kHz (wide) : 50 dB
10 Hz (wide) : 45 dB
1 kHz (narrow)
: 30 dB
Output Voltage: 1 V (fix);
0 V - 1 V (variable)
Output
Impedance: 100 Ω (fix); 100 Ω - 1,25 k Ω
(variable)
Muting
Threshold: 10 µV - 500 µV (variable)
Power
Consumption: 20 W
Dimensions (W x H x
D): 438 x 322 x 78 mm (17-1/4" x
12-11/16" x 3-1/16")
Weight: 7 kg (15,4 lbs) net
No comments:
Post a Comment