Comtech EF Data CRS-180 - Manual (Page 99)

CRS-180 70/140 MHz IF 1:1 Redundancy Switch MN/CRS180.IOM
Cables and Connections Revision 11
5–39
5.6 Cabling to the CDM-710
1) For information on configuring the CRS-180 70/140 MHz 1:1 Redundancy Switch
with the CDM-710 Broadcast Satellite Modems for 1:1 operation, see:
• Chapter 4. MODEM
AND SWITCH CONFIGURATION
• CDM-710 Broadcast Satellite Modem Installation and Operation Manual
(CEFD P/N MN/CDM710.IOM)
2) For information on the cables and cable assemblies specified in this section, see
Appendix A. CABLE DRAWINGS
5.6.1 CRS-180  CDM-710 Control and IF Interface Connections Using
Cabling Kit KT/12551
You must order terrestrial data interface components/kits separately. See Sect.
5.6.2 for more information.
You must use the Comtech EF Data KT/12551 CRS-180 70/140 MHz IF 1:1 Redundancy Kit for all
control and IF connections. Figure 5-34 shows these Switch-to-Modem control and IF interface
connections.
Figure 5-34 NOTES:
1) Use of the XF/BNC-MF-50-75 transformers (Item 2) is required on the ‘J7 | Rx’
and ‘J8 | Tx’ connectors, located on the antenna side of the switch, when you
supply a 75Ω Rx/Tx connection.
2) Use of the XF/BNC-MF-50-75 transformers (Item 2) on the Rx ‘A’ and Rx ‘B’
ports, located on the modem side of the switch, is dependent on the CDM-710’s
factory configuration for 50Ω or 75Ω Rx operability. If the modems in use are
configured as 50Ω Rx units, the transformers will not be used on the Rx side and
the 50Ω cable (Item 4) will be used in place of the 75Ω cable (Item 3).
3) To provide User access to modem “Fault Summary Relay,” Control ‘Y’ Cable
CA/WR13011-4, sold separately, is available for use in place of the
CA/WR12135-1 cable.
4) Control Cable CA/WR12135-1 will mute the Offline Modem’s Tx IF. If this is not
desired, then an alternate cable, Control Cable CA-0000187, sold separately, is
available for use in place of the CA/WR12135-1 cable.