Lo-D FT-8000
¥ 75,000 (around 1979)
Commentary
A digital synthesizer tuner exclusively for FM with improved operability such as high-precision characteristics by quartz lock digital synthesizer and 6-station preset tuning by microcomputer control.
By introducing a microcomputer, automatic tuning is realized. Two automatic tuning key buttons, up and down, enable quick tuning to the desired station.
When the button is pressed, the receiving frequency is swept every 100 kHz, and the computer catches the broadcast wave. After that, the station is selected simply by issuing a tuning command.
You can also select a 6-station preset. The memory method is completed by pressing the memo Leaky while receiving the station you want to store, and pressing the desired channel button of the 6-station memory while the memory write display is on.
By adopting the quartz synthesizer method, the receiving frequency is quartz-locked at every 100 kHz to which the broadcast wave is assigned, and the tuning point coincides with the minimum distortion point.
In addition, it maintains stable tuning regardless of temperature and humidity.
In the front-end section, an RF amplifier using a dual-gate MOS FET and double tunes are used for both the input stage and the stage to achieve high sensitivity and high selectivity.
In addition, the structure is strong against Radio noises by installing an RFAGC circuit.
A PLL IC with pilot signal cancellation is used to eliminate the 19 kHz pilot signal transmitted by the broadcasting station in stereo.
In order to improve basic performance, we use carefully selected high-precision parts for each part.
The de-emphasis circuit uses high-precision parts with a tolerance of ± 1% to achieve high quality.
The digital display that displays the received frequency can also be used as a quartz clock by pressing the time display switch.
In addition, the clock automatically displays the time when the power switch is turned off, so it can be used as an accurate quartz clock except for broadcast reception.
A TV trap circuit is mounted on the back of the set to prevent interference from intermodulation with the TV when receiving radio waves from a building common antenna.
The muting circuit uses a Schmidt trigger circuit to drive the reed relay switch to increase the mute suppression effect by more than -85dB and to prevent the pop sound at the time of tuning.
Equipped with 5-stage signal indicator by LED.
Equipped with Rec level check switch.
Equipped with a multi-path switch.
75 Ω coaxial connector is used for the antenna input.
Gold-plated output terminal and cable are included.
In addition to the black model, there was also a silver model.
Model Rating
| Type | FM digital synthesizer tuner |
| Circuit system | Microcomputer control Digital synthesizer system RF stage with MOS FET Five electron tuned front end Quadrature detection PLL MPX |
| Receiving frequency | 76 MHz to 90 MHz |
| S/N50dB sensitivity (IHF / new IHF) | Mono : 4.8 μ V/18.7 dBf Stereo : 45 μ V/38.2 dBf |
| Total harmonic distortion rate (400 Hz) | mono:0.12% stereo:0.12% |
| Capture ratio | 1.0dB |
| Effective selectivity | 80dB |
| Intermodulation interference ratio | 95dB(2.5MHz) |
| S/N | mono:75dB stereo:72dB |
| Stereo separation | 50dB |
| Frequency characteristic | 20 Hz to 15 kHz + 0.2 -0.6 dB |
| Image interference ratio | 110dB |
| IF interference ratio | 94dB |
| AM suppression ratio | 60dB |
| Antenna | 300 Ω unbalance 75 Ω equilibrium |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Rated power consumption (Electrical Appliance and Material Control Law) | 17W |
| External dimensions | Width 435x Height 78x Depth 369 mm |
| Weight | 6.1kg |