
Accuphase T-108 |
|
120,000 yen(April, 1990 release) |
The synthesizer FM stereo tuner which concentrated the outstanding technology
and was developed in order to realize the ultimate grade as a tuner.
Alignment by a crystal oscillator is used for alignment for tuning, and
the gap by time or a temperature change has decreased. Moreover, the abnormal-conditions distortion and noise by external vibration are hardly made
for electronic tuning.
Since it corresponds to many office-ization, a
memory is possible to 16 games.
When an electric wave needs to turn ON a
filter weakly by an office or the degree of selection needs to be changed, it is
possible to set the function according to the radio wave state of the office
beforehand.
Besides memory tuning, the manual alignment machine by the
rotating knob of a pulse tuning system is carried.
This was developed
especially as being the same as that of the Lord of electronic tuning, it
produces a pulse, counts this pulse and is controlling alignment frequency by
the radiate slit attached to the shaft of a rotating knob.
The input and
magnification stage of the front end part used the mixer of double alignment
composition and also frequency conversion as the differential FET balance abnormal-conditions machine which used the balun trans, respectively, and
interference by the Dainyuu power disturbance is prevented.
Moreover, in
order that the PIN diode Attenuator may be carried and the transmitting tower
may operate as variable attenuator to near excess Dainyuu power, interference and distortion are not generated in any areas.
Little stable and
distorted characteristic has been acquired by combining with the original DGL
wave detector of an Accuphase the group delay flat IF filter chosen especially.
A DGL detection system is what paid its attention to the delay time of the
output of a high-speed logic IC,A phase angle is delayed 114 degrees so that
this may be made into 19-piece series and the minimum and S/N may become best
about distortion,This group delay signal and incoming signal were applied to the
exclusive OR circuit, the electric potential between two signals was chosen,
circuit opening and closing were carried out, the compression wave of the signal
wave produced by abnormal conditions was detected in digital one, and the audio
signal is taken out. The linear region of a delay circuit is very as large as
±2.5MHz, and, moreover, the differentiation profit straight line characteristic
of it having been stable and having excelled is acquired for a non-equalization
circuit.
IF filter is using 2 sets, Normal and Narrow, and when contiguity
interference is intense, sharp reception focused on a selection degree can be
performed by changing to Narrow.
In the stereo recovery part, using the
pilot signal for a synchronization included in the incoming signal, the internal
oscillating circuit was locked by the PLL circuit, and the exact 38kHz switching
signal has been acquired.
In T-108, the system which combined the
positive/negative variable reactive circuit controllable on control voltage with
a ceramic resonance child with the internal oscillating circuit of this PLL is
adopted, and an exact switching signal is acquired in the lock frequency range
narrower than before.
For this reason, in this circuit, no adjusting-ization
of the stereo recovery circuit was realized, and the characteristic maintenance
over a long period of time was attained, and also a temperature change and
change of the separation rate by change of line voltage are almost lost.
Moreover, since the lock frequency range is narrower than before, the beat
distortion in high frequency is decreased.
The first balance output
circuit in a tuner is carried in the output terminal.
The check of
incoming signal meter and a multipass is possible for meter by a changeover
switch.
A multipass will indicate that a good electric wave is receivable by
the multipass minimum, if a meter guide goes into the range of a clear mark.
The noise filter which reduces the noise of the weak stereo office of an
electric wave, the muting switch which removes the noise between offices, the
mono-switch compulsorily used as a monophonic recording, the output level
control which unites volume with other program sauce, etc. are carried.
Remote control is attached so that it can be operated from the distant
place.
Surface finishing is traditional champagne gold scratch hair line
finishing, and supports both sides on the board of the natural persimmon.
|
Form |
Synthesizer FM tuner |
<Monophonic characteristic>
|
Received frequency |
76.1MHz - 89.9MHz |
Practical speed |
11dBf(IHF) |
S/N 50dB sensitivity |
17dBf(IHF) |
Standing-wave ratio |
1.5 |
S/N (80dBf input, A compensation)
|
90dB |
THD
(at the time of 80dBf input, ±75kHz
deflection, and Normal) |
20Hz:0.02%
1kHz:0.02%
10kHz:0.02%
|
IM distortion (80dBf input, ±75kHz
deflection) |
0.01% |
Frequency response |
10Hz-16000Hz+0 -1.0 dB |
The degree (IHF) of 2 signal selection
|
Disturbance wave |
Normal |
Narrow |
400kHz |
70dB |
100dB or more |
300kHz |
30dB |
100dB |
200kHz |
10dB |
40dB
|
|
Capture ratio |
1.5dB |
RF inter-modulation |
80dB |
Spurious disturbance ratio |
120dB |
Image ratio |
100dB |
AM oppression ratio (65dBf input)
|
80dB |
Subcarrier oppression ratio |
70dB |
SCA disturbance ratio |
80dB |
Output voltage (±75kHz deflection)
|
1.0V |
<Stereo characteristic>
|
Sensitivity |
S/N 40dB sensitivity: 29dBf (IHF)
S/N
50dB sensitivity: 37dBf (IHF) |
S/N (80dBf input, A compensation)
|
85dB |
THD
(at the time of 80dBf input, ±75kHz
deflection, and Normal) |
20Hz:0.04%
1kHz:0.04%
10kHz:0.04%
|
IM distortion (80dBf input, ±75kHz
deflection) |
0.03% |
Frequency response |
10Hz-16000Hz+0 -1.0 dB |
Stereo separation |
100Hz:50dB
1kHz:50dB
10kHz:40dB
|
Stereo change inlet pressure |
20dBf |
<Synthesis> |
Antenna |
75-ohm disequilibrium (with a 300-ohm
balance transducer) |
Alignment system |
Quartz synthesizer system
16-game random
memory tuning |
Detection system |
DGL system |
Output load impedance |
Balanced (balanced XLR type) : |
200ohms (100ohm/100ohm)
|
Unbalanced (disequilibrium) |
Fixed (fixed output): 200ohms
Controlled(variable output): 1.25kohm (maximum)
|
|
Meter |
Signal strength, a multipass change type
|
The semiconductor used |
Transistor: 15 pieces
FET: Five pieces
IC: 32 pieces
Diode: 36 pieces |
Power source |
AC100V/117V/220V/240V, 50Hz/60Hz
|
Power consumption |
15W |
Dimensions |
Width 475x height 115x depth of 351mm
|
Weight |
9.4kg |
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