Kenwood TM-D700A Service Manual

TM-D700A/E
CIRCUIT DESCRIPTION
2-3.Sub VHF Receiver
The signat distributed from the RF amplifier (Q205) at the
main VHF receiver circuit passes through a filter circuit. Then it
enters the RF amplifier (Q507). The amplified signal goes to
the single balanced mixer (Q501, Q502). The frequency of the
signal is converted by the first local oscillator generated by half
of the UHF VCO oscillator frequency, using the prescaler
(1C303). It converts to the upper heterodyne frequency to
generate a 45.05MHz first IF signal. The signal passes through
the MCF (XF400). Then it is amplified by the IF amplifier
(Q406), and enters the IF IC (IC400). The signal is converted to
the 455kHz second IF signal, using the second local oscillator
(Upper heterodyne). Then the signal is detected to generate an
audio signal.
SINGLE BALANCED
ANT
Y LPF RF AMP LPF HPF RF AMP
Q205
= F'esxaa9a oe ma
MIXER
IF AMP
MCF IF IC
Q406
2SC510B IC400 He AF
{Y)
1C303 tt
UPB | 12 a
15086 45.505MHz [1
LO
Fig.4 Sub VHF Receiver circuit
2-4.Sub UHF Receiver
The signal distributed from the RF amplifier (Q508) at the
main UHF receiver circuit passes through a filter circuit. Then it
enters the single balanced mixer (Q200, Q201). The signal
frequency is converted by the first local oscillator, generated by
doubling the VHF VCO oscillator frequency (Lower
heterodyne) by Q7, to generate a 38.85MHz first IF signal. The
signal passes through the MCF (XF100). Then it is amplified by
the IF amplifier (Q112), and enters the IF IC (IC 100). The signal
is converted to the 450kHz second IF signal by the second
local oscillator generated by tripling the 12.8MHz reference
oscillator frequency (Lower heterodyne). Then the signal is
detected to generate an audio signal.
ANT SINGLE BALANCED
Y HPE LPF RF AMP HPF MIXER MCF IF AMP Fic
ae Q508 6200,201
=e ps = 3SK239A Se 25K302 1C100 pe A
(GR) 7
CF
a7 =
2505108 | x2 —~e
(Y)
Qio2
2804649 } x3
(N.P)
12.8MHz
Fig.5 Sub UHF Receiver circuit

Kenwood TM-D700A Specifications

General

Brand	Kenwood
Model	TM-D700A
Category	Transceiver
Language	English