Comtech EF Data CRS-180 - Manual (Page 78)

CRS-180 70/140 MHz IF 1:1 Redundancy Switch MN/CRS180.IOM
Cables and Connections Revision 11
5–18
5.3 Cabling to the CDM-760 or CDM-750
1) For information on the CDM-760 or CDM-750’s 1:1 auto-enable functionality,
see:
• Chapter 4. MODEM
AND SWITCH CONFIGURATION
• CDM-760 Advanced High-Speed Trunking Modem Installation and Operation
Manual (CEFD P/N MN-CDM760)
• CDM-750 Advanced High-Speed Trunking Modem Installation and Operation
Manual (CEFD P/N MN-CDM750)
2) For information on the cables and cable assemblies specified in this section, see
Appendix A. CABLE DRAWINGS
5.3.1 CRS-180CDM-760/-750 Control and IF Interface Connections
Using Cabling Kit KT-0000177
You must order terrestrial data interface components/kits separately. See Sect. 5.3.2
for CDM-760/-750 terrestrial data interface configuration and connection examples
and details.
You must use the Comtech EF Data KT-0000177 1:1 Redundancy Control/IF Interface Cabling Kit
for your control and IF switch-to-modem cabling connections. Figure 5-17 shows the kit parts list
and connection details. Excluding the modems, the KT-0000177 kit provides all components
shown here.
CAUTION – It is ESSENTIAL that you make the control and the IF Rx and Tx
connections correctly.
Figure 5-17 NOTES:
1) You must use the XF/BNC-MF-50-75 transformers (Item 2) on the antenna side
‘J7 | Rx’ and ‘J8 | Tx’ connectors only when you supply a 75Ω Rx/Tx antenna
connection.
2) You must always use the XF/BNC-MF-50-75 transformers (Item 2) on the switch-
to-modem side Rx (‘J1’, ‘J2’) and Tx (‘J5’, ‘J6’) connectors in order to
accommodate the modem’s 75Ω Rx/Tx operability.
3) Alternate Cabling Note – CEFD Universal Control Cable CA/WR9378-8 (DB-9M 
DB-9M, 8’), sold separately, is available for use in place of CA/WR9378-4.