
Accuphase T-104 |
|
250,000 yen(October, 1978 release) |
FM stereo tuner which adopted the synthesizer system.
The tuning circuit of a synthesizer system makes standard frequency from
a crystal vibrator, and aligns a front end with the signal of choice electronically
with the program divider which makes preset required received frequency,
and the combination of a PLL circuit. Moreover, like a variable condenser
system, received frequency does not change continuously and is aligning
at intervals of 100kHz.
Since the accuracy of the received frequency of a synthesizer system is
decided by accuracy of the crystal vibrator which is making standard frequency,
it is aligning with received frequency in less than 0.002% of accuracy in the
T-104 type.
Tuning of a broadcasting station carries the memory tuning
which is made to memorize the office wishing dirt じ and is called by one-touch, and the pulse tuning (PAT.PEND) which can align with the same feeling as the
conventional rotation knob type manual tuning.
A memory is possible to four
games and can call a memory even from 5m beyond with an attached remote station
selector.
Moreover, there are an infrared generator and an electric eye on both sides
of a circuit screen, a pulse signal is generated by rotation of a screen,
whenever frequency changes, the pip tone "Pi" can be heard, and the manual pulse tuning can know alignment frequency
from both eyes and a lug. This pip tone can also be erased.
Calculation of received frequency and
instructions of the write-in call of a memory are performed by 4 bit, mu, and
the computer of internal organs. Moreover, the nickel cadmium battery is built
in the memory, and also where the power switch is turned off, a memory is held
for about one year.
And by turning on a power switch, it charges
automatically and a battery can be used semipermanently.
The front end
part serves as a pure electronic control system which used the Barak Tarr
element combined with the PLL circuit.
The design strong against spurious
disturbance is carried out to an input and high frequency magnification with
composition called a two-step double alignment system, local oscillation
alignment, and an alignment buffer.
Since it is compatible in the high
selection degree characteristic and the low distortion characteristic, the
circuit which combined the SAW (Surface Acoustic Wave) filter (surface elastic
wave filter) which was excellent in the degree of selection and delay
characteristics, and LC filter has been adopted as IF circuit.
2 sets of things which made the electrode of the shape of a gear tooth of a comb counter on the piezo-electric body are made, and a SAW filter carries out piezo excitation of the oscillation side, considers it as surface vibration, it tells an oscillation electrode and carries out electric conversion. Frequency and bandwidth can be decided in the elasticity of a material, or the form of an electrode, and the stable engine performance is maintained over a long period of time.
The degree of selection serves as Normal (low distortion)
and two-step switching of Narrow (the degree of high selection).
In the
detection circuit, in order to acquire the outstanding differentiation profit
characteristic, the broadband ratio wave detector of a special design is
adopted, and the stereo characteristic is improved.
The PLL demodulator
which contained the circuit which removes a pilot career is adopted as a stereo
recovery circuit.
The linear phase IF filter, the broadband wave detector, and the separation that was excellent by the PLL recovery circuit are gained.
It has the degree-of-modulation meter which monitors S meter which sees
incoming signal intensity, and the depth of abnormal conditions. The character
of "Tuned" is displayed and the point aligning [ perfect ] is displayed in the
character of "Stereo" during stereophonic broadcast reception.
Moreover, S
meter can detect a multipass with a push switch.
The remote station
selector to which a 5m cord was attached is attached so that memory tuning
tuning can be performed even from a distance.
The function of the noise
filter which reduces the noise at the time of stereo reception, the mode switch
which uses a stereo as a monophonic recording compulsorily, the muting switch
which removes the noise between offices, the dimmer switch which lowers
intensity of illumination according to the brightness of the room, and erases a
pip tone simultaneously, etc., etc. is carried.
The number of output
terminals is two and volume control is possible for one line by the level
control of the front panel.
It is stored by the native wood rosewood
cabinet.
|
Form |
Synthesizer FM tuner |
<Monophonic characteristic>
|
Sensitivity |
Practical speed: 11.2dBf (2.0 microvolts)
S/N50dB sensitivity: 17.3dBf (4.0 microvolts) |
Standing-wave ratio |
1.5 |
S/N (65dBf (1mV) input) |
77dB |
THD
(at the time of 65dBf input and the
Selectivity switch Normal) |
100Hz : 0.03% or less
1kHz : 0.03% or
less
10kHz : 0.04% or less |
IM distortion (14Hz:15kHz=1:1) |
0.01% or less (antenna input 65dBf, 100%
abnormal conditions) |
Frequency response |
20Hz-15000Hz+0 -0.5 dB |
The degree of 2 signal selection (45dBf (100
microvolts) input) |
Disturbance wave |
Selectivity Normal |
Selectivity Narrow |
400kHz |
50dB |
100dB |
200kHz |
6dB |
20dB |
|
Capture ratio |
1.5dB |
RF inter-modulation |
75dB |
Spurious disturbance ratio |
120dB |
Image ratio |
120dB |
IF/2 spurious response |
100dB |
AM oppression ratio (65dBf (1mV) input)
|
80dB |
Subcarrier oppression ratio |
80dB |
SCA disturbance ratio |
80dB |
Output voltage (100% abnormal conditions)
|
1.5V |
<Stereo characteristic>
|
Sensitivity |
S/N 40dB sensitivity: 28.8dBf (15
microvolts)
S/N 50dB sensitivity: 37.3dBf (40 microvolts) |
S/N (65dBf (1mV) input) |
75dB |
THD (65dBf (1mV) input) |
100Hz : 0.03% or less
1kHz : 0.03% or
less
10kHz : 0.1% or less |
IM distortion (9kHz:10kHz=1:1) |
0.03% or less (antenna input 65dBf, stereo
100% abnormal conditions) |
Frequency response |
20Hz-15000Hz+0 -0.5 dB |
Stereo separation |
100Hz:50dB
1kHz:50dB
10kHz:45dB
|
Stereo change inlet pressure |
19.2dBf (5.0 microvolts) |
<Synthesis> |
Received frequency |
76.1MHz - 89.9MHz |
Alignment system |
The Quartz lock フリケンシー synthesizer tuning
|
Frequency accuracy |
Less than ±0.002% |
Output load impedance |
Fixed output terminal: 200ohms
Variable
output terminal: 2.5kohm |
Antenna input impedance |
Balance: 300ohms
Unbalance: 75ohms
|
Meter |
Two pieces
A signal strength meter /
multipass / modulation change type |
The semiconductor used |
Transistor: 43 pieces
FET: Three pieces
IC: 42 pieces
Diode: 58 pieces
Optocoupler: Three pieces
|
Power source |
AC100V, 50/60Hz |
Power consumption |
25W |
Dimensions |
Width 466x height 188x depth of 391mm
|
Weight |
14.1kg |
|
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