Audio Database

The

Lo-D FT-4700
35,000yen(1979 release)

Description
 
The FM/AM tuner which thought the basic performance as important.

While adopting the dual gate MOS FET as a front end part, the selectivity of the RF stage is raised and the distortion property is raised with the falloff of the inter-modulation stonewalling at the time of a strong input.

Rather than before, using three two-element ceramics filters with a still more sufficient phase response, high integration IC (HA11211) is used for the IF section, and the distortion property and the selectivity property are raised in it.

The low distortion is realized by adopting as a multi-circuitry PLL(phase lock troop) IC which concentrated and developed IC technology of the Hitachi.

In order that the radio wave of two broadcast stations which approached, and a stereo control may prevent distortion from occurring, the anti birdie filter is carried.

The loop antenna only for AM is carried.

What has a band larger than before is adopted as the ceramics filter of AM tuner part, and sound which has an elongation to a high region is realized to it.
Moreover, a 9kHz traps coil is adopted and the stonewalling of an adjacency office is eliminated.

The mode muting switch which summarized the mode switching and the muting functionality to one is carried.

The termination for FM75ohm coaxial cables is carried.


Rating of a mode
Form FM/AM tuner
<FM tuner part>
Received frequency 76MHz - 90MHz
Practical speed 1.05 microvolts (75 ohms, IHF)
11.7dBf (new IHF)
SN ratio a sensitivity of 50dB mono: 3 microvolts / 14.8dBf
stereo: 40 microvolts / 38dBf
Effective selectivity (IHF) 70dB
SN ratio mono:75dB
stereo:70dB
distortion (400Hz) mono:0.04%
stereo:0.08%
Separation (1kHz) 50dB
Frequency characteristic 30Hz-15kHz+1 -2 dB
<AM tuner part>
Received frequency 530kHz - 1,605kHz
Practical speed 12 microvolts (IHF)
300 microvolt/m (loop antenna)
Selectivity (±9dB) 32dB
SN ratio 53dB
Distortion (400Hz) 0.4%
<Others>
Power consumption 8W
Dimensions Width 435x height ?x depth of 319mm
Weight 6.0kg