Dup Rx (05P0777) - Furuno FM-8800D Service Manual

5.4.2 DUP RX (05P0777)

This board is to be installed in FM-8800D and converts 160 MHz band RX signal of
DUPLEX RX frequency to 2
board detects Un-Lock/Lock signal upon assessing the function of PLL circuit of 1
local on this board. When installing this board and if J3 - #11 (DUP INST) is "L" level
then, CPU recognizes FM-8800D is in use and switches its program to one compatible
with DUPLEX. The main specifications are below.
Item
RX frequency
Antenna input (J1) Impedance
st
1 IF frequency
nd
2 IF frequency (DUP IF OUT)
st
1 Local frequency
nd
2 Local frequency
Sensitivity
R15V
DUP RX
BPF(L/C)
Q1
J1
2SC3356
+15V
R15V
Q8
Q7
TP5
+3.3V
REG.
U7
(TA48L033F)
DUP RX
05P0777
nd
IF and outputs it into CPU board. The self-test of this
Table 5.4.2 Main Specification of DUP RX PCB
160.625 MHz to 162.025 MHz
160 MHz/50 ohm
51.2375 MHz
37.5 kHz/5 kohm, - 60 to +10 dBm output
Fo + 51.2375 MHz
TP4: VCO cont ! 4 to 5VDC at CH18(161.5MHz)
51.2 MHz (0 dBm, 50 ohm)
SINAD 20 dB: below 2 dBuV.
NOTE: Loss of DUPLEXER somewhat lowers RX sensitivity
on TX/RX board compared to (SIMPLEX).
R15V
BPF(L/C)
Q13
CR10/11
PMBFJ310
TP1 ISS271
Rx 1st Lo
(Fo+51.2375MHz)
+15V
BPF(L/C)
RX ON
+5V
TP2
Fig. 5.4.3 DUP RX (05P0777) Block Diagram
Specification
R15V
CR8/9
FL1
MA2J728
(51.2375MHz)
Q14
2SK882
Rx 2nd Lo
TP3 (51.2MHz)
VCO
U5
Q5
Q6, CR3/4
uPC2745TB
2SC3356
2SC3356
1SV229
TP4
LPF
Q11
PMBFJ310
51.2MHz
BPF(L/C)
PLL
U8
(LMX2353TMX)
Q10
TP6 +12V
REG.
U10
(TA78L12F)
5-8
5.4 Block Description
TP1 level: +3 to 5 dBm
TP3 level: -2 to -1 dBm
DUP IF OUT
37.5kHz
J3-#14
Q15
2SC3324
U3
TC75HU04F
25.6MHz
Q4
X2 J2
DUP INST
J3-#11
J3-#10 RX ON
J3-#1 +15V
J3-#3 +5V
PLL2 DATA
J3-#6, 7, 8 (CLK/DATA/STB)
J3-#9 PLL2 UN-LOCK
+15V
st
CPU
05P0773
U17
CODEC
U20
Ref.
DSP
OSC
U30
CPU