TS-590S
6
and then goes through BPF and is output as LO1. When
RX-2 path is selected or when transmitting, 36.5625MHz to
66.5475MHz is output, amplifi ed by the broad band ampli-
fi er (IC804), and then doubled in the multiplier (D652), goes
through BPF, and is output as 73.120MHz to 133.095MHz
LO1.
■
LO2 (the second local oscillator)
The reference oscillating circuit’s output signal 15.6MHz
signal passes through a buffer (Q502) and is doubled in
a multiplier (Q503) to generate a 31.2MHz signal. The
31.2MHz signal is also used as the DDS (IC601)’s reference
Fig. 2 Reference signal generator, LO1/ LO2/ LO3
frequency, and therefore its resistance is divided. Then, the
31.2MHz signal is doubled in multipliers (Q504, Q505) to
generate a 62.4MHz signal.
The 62.4MHz signal’s high harmonic is cut in the BPF
and the signal is amplifi ed in the amplifi er (Q506) to gener-
ate LO2. If IFB is selected, the diode switch (D501) cuts the
LO2 output.
■
LO3 (the third local oscillator)
The LO3 used in the modulator and the detector is gen-
erated in the DDS (IC601). The DDS output signal passes
through the buffer (Q602) and LPF to generate LO3.
Q808
Q663
AMP
Buffer
IC803
DDS
IC804
AMP
IC801
PLL
Q806
VCO
Doubler
IC601
DDS
LPF
LPF
LPF
LPF
LPF
LPF
LPF
LPF
D651
D652
L651
BPF
BPF
HPF
D659
D670
D671
D669
D655
D660
D654
D663
D661
BPF
BPF
BPF
D653
D680
D681
D667
LO1
LO2
LO3
D657
D679
D662
D668
X502,Q501
15.6MHz
Option
SO-3
Q502
Buffer
Q506
Buffer
Doubler
Q503
Doubler
Q504,Q505
Buffer
Q601
Buffer
Q602
D501
Buffer
Q801
Q804
FM MOD
Buffer
CIRCUIT DESCRIPTION
Summary of Contents for TS-590S
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