Transmitter Circuits - Icom UX-9100 Service Manual

3-2 TRANSMITTER CIRCUITS

2ND TX IF CIRCUITS (RF-C and MAIN-B UNITs)
The 10.95 MHz 2nd TX IF signal from the MAIN-B UNIT
of IC-9100 is passed through the BPF (L401–L403, C401,
C403, C404) and BPF (FI451) and amplified by the IF
AMPs (Q501). The amplified 2nd TX IF signal is applied to
the MAIN-B UNIT.
The amplified 2nd TX IF signal from the RF-C UNIT is
amplified by the IF AMP (Q81), and then applied to the 2nd
TX IF mixer (D82), through the LPF (L82, L83, C80, C85–
C89), to be mixed with the 2nd TX LO signal from the PLL
circuits, resulting in the 243.95 M Hz 1st TX IF signal.
The 1st TX IF signals applied to the 1st TX IF circuits.
• 2ND TX IF CIRCUITS
RF-C UNIT
Q501
FI451
10.95MHz
2nd TX IF
XTAL IF
From the MAIN-B
AMP
BPF
UNIT of IC-9100
10.95 MHz
1ST TX IF CIRCUITS (MAIN-B UNIT)
The 1st TX IF signal from the 2nd TX IF circuits is passed
through the LPF (L121, L122, C121–C125), amplified by the
IF AMP (IC111), and then passed through the BPF (FI101).
The filtered 1st TX IF signal is applied to the 1st TX IF mixer
(IC131) to be mixed with the 1st TX LO signal from the PLL
circuits, resulting in the TX signal (TX frequency itself).
The TX signal is passed through the BPF (FI141) and LPF
(L141, L142, C142–C146), and then applied to the TX
amplifier circuits.
• 1ST TX IF CIRCUITS
IC111
From the 2nd TX
IF
IF circuits LPF
AMP
MAIN-B UNIT
Q81
D82
AMP LPF To the 1st
TX IF circuits
2Lo
233 MHz
243.95 MHz
1st TX IF
FI101
IC131
To the TX
BPF
AMP circuits
1LO
996.1-1076.1 MHz
TX AMP CIRCUITS (MAIN-B UNIT)
The TX signal from the 1st TX IF circuits is applied to the
YGR AMP (IC141). The amplified TX signal is passed
through the BPF (FI1), and amplified by the pre-drive AMP
(Q36) and power AMP (IC21).
The amplified TX signal is passed through the TX/RX SW
(RL51), power detector circuit (D502, D503), and then
applied to the antenna connector (J1).
• TX AMPLIFIER CIRCUITS
FI141
From the 1st TX
IF circuits BPF LPF
3 - 2
Q36
IC141 IC21
FI1
RL51
YGR
PRE PWR
BPF
AMP DRV AMP
TX/RX SW
To the RX circuits
D502
D503
PWR
LPF
DET