Furuno FM-8800D - Duplexer

5.4 Block Description
5-16
5.4.4 DUPLEXER
Duplexer is to be installed in FM-8800D. TX is composed in LPF and RX in HPF.
Estimated attenuation of effective frequency range for both from TX range to RX range
and RX range to TX range is approximately -60 to -70 dB. Since RX signal of simplex
channel attenuates in DUPLEXER, FM-8800D receives RX of duplex channels on DUP
RX board and RX of simplex channel on TX/RX board.
Fig. 5.4.10 DUPLEXER Connection Diagram
TX FIL part (LPF)
- Frequency Range : 156.0 to 157.5 MHz
- Insertion Loss : Within 1.8 dB
- Attenuation of Signal : 160.6 MHz/‐59.3 dB, 161.5 MHz/‐66 dB,
162 MHz/‐60.5 dB
RX FIL part (HFP)
- Frequency Range : 160.6 to 162.1 MHz
- Insertion Loss : Within 1.8 dB
- Attenuation of Signal : 156 MHz/‐65 dB, 157.5 MHz/‐65 dB
PA
Rx RF
U2
J3 : ANT R/T ANT
J2 : DUP IN 1
J4 : DUP IN 2
J1 : DUP OUT
TX/RX
05P0774
R/T ANT
TX FIL
DUP RX
(05P0777)
RX FIL
SIMPLEX
(JUMPER)
DUPLEXER
T/R
SW