![background image](http://html1.mh-extra.com/html/icom/ux-9100/ux-9100_service-manual_2038212009.webp)
• FREQUENCY SYNTHESIZER CIRCUITS
3 - 3
The doubled 1st RX/TX LO signal is passed through the
BPF (L611, L613, L615–L618, C622, C624, C626, C628,
C630, C633–C638), amplified by the AMP (IC601), passed
through the LPF (L621, C644–C646), and then applied to
the doubler (D601, L606), resulting in the 498.05–538.05
MHz signal.
The doubled 1st RX/TX LO signal is passed through the
BPF (L609, L610, L612, L614, L622, C617, C619, C620,
C621, C623, C625, C627, C629, C632, C647, C648),
amplified by the AMP (IC651), passed through the LPF
(L659, C672–C674), and then applied to the doubler (Q651,
Q652, L651), resulting in the 996.1–1076.1 MHz signal.
The doubled 1st RX/TX LO signal is passed through the
BPF L653–L656, L658, L660, C656–C665, C670, C671,
C676, C677) and HPF (L185, C191, C194, C195), amplified
by the LO AMP (IC181).
The amplified 1st RX/TX LO signal is passed through the
LPF (L181, L182, C181–C185) and HPF (L196, C190,
C196, C197), and then applied to the 1st RX IF mixer
(IC241) or 1st TX IF mixer (IC131), through the LPF
(L361–L363, C361–C368).
2ND TX/RX LO CIRCUITS
The 30.2 MHz reference frequency signal from the MAIN-B
UNIT of IC-9100 is passed through two LPFs (L751, L752,
C751–C753, C755–C757 and L761, C742, C761, C762)
and applied to the AMP (Q701). The amplified reference
signal is applied to the PLL IC (IC701) as the reference
frequency signal, through the LPF (L709, C746, C747).
The VCO (Q703, D702, D703), which is controlled by the
PLL IC (IC701), generates the 233 MHz 2nd LO signal
signal, by using the applied 30.2 MHz signal as the
reference.
The generated 233 MHz 2nd LO signal is passed through
the LPF (L772, L773, C773–C775), buffer (Q705) and LPF
(L771, C771, C772), and then applied to the AMP (IC201).
The amplified 2nd LO signal is passed through the LPF
(L201, L202, C201–C205), and then applied to the 2nd RX
IF mixer (Q221) through the LPF (L371, L372, C371–C373)
or 2nd TX IF mixer (D82).
3-3 FREQUENCY SYNTHESIZER CIRCUITS
(MAIN-B UNIT)
REFERENCE FREQUENCY SIGNAL
The 30.2 MHz reference frequency signal from the MAIN-B
UNIT of IC-9100 is applied to the MAIN-B UNIT of UX-9100,
through J312. The reference signal is used as the reference
frequency signal for the PLL or DDS.
1ST TX/RX LO CIRCUITS
The 30.2 MHz reference frequency signal is passed through
the LPF (L751, L752, C751–C753, C755–C757), amplified
by the AMP (IC901), passed through the LPF (L902, L907,
C904, C905–C908), and then applied to the doubler (D901,
L903), resulting in the 60.4 MHz signal.
The doubled reference signal is passed through the BPF
(L911–L913, L921, L922, C911–C917, C921–C925),
amplified by the AMP (IC931), passed through the LPF
(L932, C934–C936), and then applied to another doubler
(D931, L933), resulting in the 120.8 MHz signal.
The doubled reference signal is passed through the BPF
(L941–L943, L951, L952, C941–C947, C951–C955),
amplified by the AMP (IC961), and then applied to the
tripler (L971–L973, L981–L983, C971–C977, C981–C985),
resulting in the 362.4 MHz signal.
The tripled reference signal is amplified by the AMP (IC991),
passed through the BPF (L995–L998, C995–C1000, C1004)
and LPF (L507, C538–C540), and then applied to the DDS
(IC504) as the master clock signal, through the BPF (L535,
L536, C536, C544, C545).
Using the applied DDS master clock signal as the reference,
the DDS (IC504) generates the 124.5125–134.5125 MHz
1st RX/TX LO signal. The generated 1st RX/TX LO signal is
passed through the BPF (L601–L603, C601–C606, C608,
C609, C639, C640, C678–C680) and applied to the AMP
(IC602).
The amplified 1st RX/TX LO signal is passed through the
LPF (L620, L624, C641–C643, C641, C643, C681, C682),
and then applied to the doubler (D602, L608), resulting in
the 249.025–269.025 MHz signal.
BPF
AMP
IC601
AMP
IC651
LO
AMP
IC181
X2
X2
Q651/Q652
X2
Q703
LPF
X3
LPF
BPF
BPF
BPF
LPF
BPF
AMP
IC931
BPF
LPF
AMP
IC991
LPF
PLL
IC
IC701
1R2REF
AMP
IC602
BUFF
Q705
LPF
LPF
LPF
AMP
Q701
LPF
AMP
IC201
X2
LPF
BPF
AMP
IC901
DDS
IC504
AMP
Q706
X2
BPF
AMP
IC961
60.4 MHz
249.025-269.025 MHz
IC241
MAIN-B UNIT
996.1-1076.1 MHz
D82
2nd TX IF mixer
1st TX IF mixer
1st RX IF mixer
2nd RX IF mixer
From IC-9100 PLL
233 MHz
Q221
120.8 MHz
124.5125-134.5125 MHz
498.05-538.05 MHz
362.4 MHz
2Lo oscillator
30.2 MHz
IC131
2nd LO signal
1st LO signal
233 MHz