Product specifications

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

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 50

Ω

or 75

Ω

Rx operability. If the modems in use are

configured as 50

Ω

Rx units, the transformers will not be used on the Rx side and

the 50

Ω

cable (Item 4) will be used in place of the 75

Ω

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.