Our original C.L.L.
system which has realized quite accurate and stable tuning condition.
We employed our
original Closed Loop Locked (C.L.L.) circuit in the 5T10 to realize extremely
accurate and stable tuning conditions at all receiving FM frequencies. With the
C.L.L. circuitry, total control is effected throughout all the stages, from the
front end to the IF and detector circuits in accordance with the crystal
controlled transmission frequency of a broadcasting station. Therefore, this
may be called the ideal tuning system offering accurate and stable tuning
conditions even if ambient conditions such as temperature fluctuate. Generally,
in the case of quartz lock and synthesizer systems, only the local ascillator
or front end is partially controlled by the P.L.L. circuitry. Therefore it is
necessary to design the IF stage and the detector stage with additional
stability. In addition, C.L.L. circuitry, like the P.L.L. ciruit, has the
capture range near the center frequency of the broadcasting station and the
required lock range to achieve a stable receiving condition. Thus, C.L.L.
circuitry always provide the perfect receiving condition thanks to powerful
feedback once the signal wave of an FM station is within the capture range and
firmly locked at the lock range. Even if the receiving frequency drifts,
feedback is applied to bring it back to follow the crystal controlled
transmission frequency, and stable reception is always obtained. In addition, the C.L.L. circuitry
incorporates a lock-retaining circuit, and no new locking is needed when power
is turned off and on once the station has been tuned in.
The
"Accutouch" System which makes the most of the C.L.L. Tuning System
The 5T10 employs the
"Accutouch" system. This system makes it possible to tune in all the
tuning circuits easily to the accurate center frequencies of broadcasting
stations. To obtain more precise tuning, an extremely narrow capture range is
set for the C.L.L. circuit of the 5T10.
It would be hard for a conventional tuning method to obtain such a precise
tuning point, since such tuning method requires observation of a center tuning
meter, which is seldom accurate enough.
The
"Accutouch" system detects the exact center tuning point utilizing a
control voltage at the C.L.L. circuit, which triggers a mechanical lock on the
tuning knob. This is a very unique system in mhich the tuning knob is
temporarily locked with a positive response at the exzct tune-in point as the
knob is gradually turned to locate an FM station. Precise tuning to a station
is possible with an incomparable accuracy compared with that of current visual
tuning systems.
IF bandwidth
Selector
In the IF stage, a
2-step bandwidth selector is provided to provide both excellent distortion and
selectivity. In the "wide"
position, 2 pairs of wide-bandwidth block filters of good group-deley
characteristics are employed to realize lower distortion, while in the
"narrow" position an additional 2 pairs of narrow-bandwidth ceramic
filters are added to offer high selectivity.
DC amp configuration
is employed at the Audio Output Stage. The basic design theme is Sonic
Excellence.
A 5-gang variable
capacitor exclusively designed for FM reception is adopted at the front end to
make the most of the excellent characteristics realized after the IF
stage. Also superb interference
rejection characteristic is obtained by improving the selectivity at each RF
amplifing circuit. The IF stage is so
designed as to be inherently low in distortion, but to make it perfect, a
quadrature wide-bandwidth detector circuit is combined with it, which not only
realizes low distortion but high S/N ratio as well.
Of course, a pilot
canceller circuit is provided in the multiplex circuit, but further the phase
characteristic of the low-pass filter is improved. A DC amp configuration is
employed at the audio output stage. All of these circuit features are specially
considered in terms of good sonic quality.
Specifications
Receiving
Frequency: 87,5 MHz - 108 MHz
50 dB
Quieting Sensitivity: 16,0 dB (3,3 μV)
IHF
Usable Sensitivity: 10,3 dB (1,8 μV)
Signal-to-Noise
Ratio: 80 dB
Frequency
response: 20 - 17,000 Hz (-0,5 dB, mono
and stereo)
Total Harmonic
Distortion Mono
0,5% (wide) at 100
Hz - 1 kHz
0,7% (wide) at 6 kHz
0,2% (narrow) at 1
kHz
Total Harmonic
Distortion Stereo
0,07% (wide) at 100 Hz
0,06% (wide) at 1 kHz
0,1% (wide) at 6 kHz
0,5% (narrow) at 1 kHz
Capture Ratio: ),8 dB (wide); 2 dB (narrow)
Adjacent Channel
Selectivity: 12 dB (narrow, ±200 kHz)
Alternate Channel
Selectivity: 90 dB (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:
45 dB (wide, 100
Hz); 50 dB (wide, 1 kHz)
45 dB (wide, 10
kHz); 30 dB (narrow, 1 kHz)
Muting
Threshold: 30 μV - 500 μV (variable)
Output
Impedance: 100 Ω (fixed); 100 Ω to 1,25 kΩ (variable)
Output Voltage: 1V (fixed): 0 - 1 V (variable)
Additional Features:
Tuning Lock System,
IF Bandwidth Selector, Center Indicator, Signal Strength Indicator, Multipath
Check Circuit, recording Test Tone Circuit, FM Muting Circuit, Muting level
Adjuster, Time-delay Muting, output level Control, 75-ohm Coaxial Connector
Power
Consumption: 20 W
Dimensions (W x H x
D): 442 x 101 x 400 mm ( 17-13/22 x 4 x
15-3/4 inch)
Weight Net: 7,0 kg ( 15,4 lb)