Mocomtech CRS-300 Multiple Transponder if Connections Using if Switch, From the Redundant Modem

CRS-300 1:10 Redundancy Switch	Revision 16
Cables and Connections	MN/CRS300.IOM

4.11.2 Multiple Transponder IF Connections (Using IF Switch)

The CRS-280 IF (70/140 MHz) Switch provides complete isolation of the IF signals. The Redundant Modem’s IF signals are routed to the Traffic Modem’s IF path when the RMI is online. The CRS-300 automatically senses the presence of the CRS-280. The CRS-300, upon switching, leaves the offline modem with its IF on, and the CRS-280’s relays isolate any undesired signals.

Figure 4-37provides a generic example of multiple transponder IF connections – in this instance, a 1:1 configuration using a CRS-280 IF Switch with CDM-600 modems. Using PL/0946-2 (50Ω) or PL/0813-8 (75Ω) BNC to BNC IF cables, observe the following for all modem/switch configurations:

From the Redundant Modem:

•Connect the “Rx IF” BNC connector on the Redundant Modem to the BNC connector on the CRS-280 switch labeled ‘TO REDUNDANT MODEM Rx’.

•Connect the “Tx IF” BNC connector on the redundant modem to the BNC connector on the CRS-280 switch labeled ‘Tx FROM REDUNDANT MODEM’.

From the Tx Traffic Modems:

•Connect the “Rx IF” BNC connector on each Traffic Modem to a BNC connector on the CRS-280 switch labeled ‘Rx # (where Rx # designates Rx 1 through Rx 10)

TO TRAFFIC MODEM’.

•Connect the “Tx IF” BNC connector on each Traffic Modem to a BNC connector on the CRS-280 switch labeled ‘Tx # (where Tx #designateis Tx 1 through Tx 10)

FROM TRAFFIC MODEM’.

Note: If using the CDM-Qx modem with the CRS-280 IF (70/140 MHz) Switch, or the CDM-QxL modem with the CRS-280L (L-Band) Switch, use no more than one Mod / Demod per CDM-Qx/QxL chassis.

Additionally, when using the CRS-280L (L-Band) IF Switch, detailed installation information is provided in the CRS-280L 1:N Redundancy Switch Installation and Operation Manual.

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