|
| Lo-D FT-620 |
|
| 55,000yen(around the 1976 time) |
The AM/FM stereo tuner in which the sensor
automatically locking tuning organization was carried.
A frequency
linear-line type 4-unit variable condenser and the dual gate MOS FET of a low
noise are adopted as front end, and high sensitivity-ization is attained.
High selectivity has been obtained, while adopting the 4 steps of
differentials amplification by IC, and three ceramics filters excellent in the
phase response as a middle cycle amplifying circuit and giving the limiter
property of a high level.
Furthermore, wide band quadrature detection was
adopted as the detection stage, and the capture ratio is improved while
realizing a low distortion.
In order to hold the best receiving point correctly, the sensor automatically
locking tuning organization is carried.
Once this automatically lockable organization catches a radio wave at the
best receiving point and receives a radio wave, it can always hold that
received frequency. Furthermore, many properties, such as distortion and
a separation, are stably received and held in the best status.
It is based on
work of the automatic control by IC, a dial pointer shines red throughout this
automatically locking, and this tells the best point reception and a stable hold
without finger.
If a hand touches a tuning thumb at the time of tuning, an
automatically lockable organization will separate, and the manual tuning by a
center tuning meter can be performed.
The PLL (phase locked loop)
circuitry by IC HA-1156 is adopted as a MPX circuitry.
The muting
circuit by the reed relay and IC is carried.
AM tuner part is attaining
low noise-ization.
The MPX noise filter, FM multipath termination, and
the band indicator are carried.
The level adjustment organization is
carried in each AM/FM.
4ch out termination is carried.
The wood
case of the photograph was sold as an option option.
|
| Form |
FM/AM tuner |
| <FM tuner part>
|
| Circuit system |
Dual gate MOS FET using One step of RF
4-unit variable condenser Four-step differential IF amplification
Super-wide band linear detection machine PLL MPX |
| Practical speed |
1.6microv (IHF)
3.0 microvolts (S/N
50dB, mono)
40 microvolts (S/N 50dB, stereo) |
| S/N |
mono:73dB
stereo: 68dB (13.6kHz, LPF
using) |
| THD |
| mono: |
0.2%(100Hz)
0.15%(1kHz)
0.2%(10kHz)
|
| stereo: |
0.3%(100Hz)
0.25%(1kHz)
0.5%(10kHz)
|
|
| Capture ratio |
1.0dB |
| Effective selectivity |
80dB |
| Frequency characteristic |
20Hz-15kHz+0.2 -2 dB |
| Separation |
50dB(1kHz)
38dB (50Hz - 10kHz)
|
| Image stonewalling ratio |
85dB or more |
| IF stonewalling ratio |
90dB or more |
| Spurious stonewalling ratio |
100dB |
| AM supression ratio |
52dB |
| Carrier leakage supression ratio
|
65dB |
| Muting operation level |
24dB |
| Antenna |
A 300-ohm balance type, a 75-ohm unbalance
type |
| <AM tuner part>
|
| Circuit system |
One step of aligned type RF, a triple
variable condenser |
| Practical speed |
18 microvolts (IHF)
300 microvolt/m (bar
antenna) |
| Selectivity |
40dB |
| S/N |
50dB |
| Image stonewalling ratio |
65dB or more |
| IF stonewalling ratio |
85dB or more |
| <Synthesis>
|
| An Output voltage/impedance |
Fixed: Below 0.65V/6kohm
Variable:
Below 0.04V - 1.2V/1kohm
4ch out: Below 0.2V/1kohm |
| The semiconductor used |
Transistor: 24 pieces
FET: One piece
IC: Four pieces
Diode: 25 pieces |
| Supply voltage |
AC100V, 50Hz/60Hz |
| AC outlet |
Power-switch un-interlocking.: One line
|
Power dissipation
(Electrical Appliance and Material Control Law) |
19W |
| Dimensions |
Main unit: Width 435x height 144x depth of
394mm
At the time of a wood case using: Width 467x height 179x depth of
400mm |
| Weight |
7.8kg |
| Option |
Wood case LA-200 (6,500yen) |
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