Circuit Description. 7~9 - Kenwood KR-7400 Service Manual

CIRCUIT DESCRIPTION
FM-RF (X01-1160-10)
Two dual-gate MOS FETs are used for RF stage. FET in
the mixing stage, too, are of this type and produces ideal
mixing effects. A buffer follows the local oscillator
(OSC) to inject a stable oscillator output into the mixer,
so that the front end is high in both stability and
sensitivity.
FMMPX (X04-1040-10)
The MPX has PLL MPX integrated circuit (Refer to
page 8). Unlike the conventional circuitry by which a
38-kHz switching signal is derived from the 19-kHz pilot
signal contained in the incoming signal, this MPX produces
a very accurate switching signal by error voltage of phase
difference between the incoming signal and VCO (Voltage
◄ TA7060P
CIRCUIT
(ICbl)
PREAMP (X08-1270-00)
Metal can sealed monolithic 1C is used here. This 1C
consists of the differential amplifier of the first stage
and emitter followers of next stage, operating to provide
Class A drive and pure complementary output. The circuit
is a wide dynamic range circuit, operating with high input
impedance and low output impedance and drawing two
power supplies, positive and negative, and thus ensures
stabilized equalizer characteristics.
7