Comtech EF Data SMS-758 - Manual (Page 171)

SMS-758 Modem Protection Switch 7 Downlink Option
MN/SMS758 Rev. 3 C–3
C.1.3 Downlink Inputs
These are the downlink input connectors. These connections provide the inputs to the
downlink switching matrix.
Connectors J12 through J15 are the downlink inputs 1 through 4.
When the 7 downlink option is being used, connectors J8 through J10 are the downlink
inputs 5 through 7.
When the 7 downlink option is not being used, connectors J8 through J10 are downlink
inputs to backup modem 1. Downlink inputs that are not being used must be terminated in
75
Ω
.
C.1.4 Backup Demod (J11)
This is the backup demod output connector. It connects to the backup modem RX IF input.
When the 7 downlink option is being used, there is only one backup demod output.
C.2 Front Panel Operation
Refer to Chapter 3 for front panel operation information.