GE MDS Master Station Technical Manual page 29

Figure 4-1. Internal Duplexer, Triple N connectors
Figure 4-2. Internal Duplexer (or internal T/R switch), Single N connectors
Figure 4-3 External duplexer or dual antennas
(TX and RX ports pass directly through)
MDS 05-6399A01, Rev. E MDS™ Master Station 25