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C.1 external connections, C.1.1 d/l switch input (j7), C.1.2 d/l switch output (j16) – Comtech EF Data SMS-758 User Manual

Page 170

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7 Downlink Option

SMS-758 Modem Protection Switch

C–2

MN/SMS758 Rev. 3

C.1 External Connections

The external connections for the 7 downlink option are slightly different than the standard
SMS-758.

Make sure the rear panel sticker supplied with this appendix has been properly installed.

The only connectors that are different are J7 through J16, the downlink inputs, and backup
demod outputs.

Table 2-1 lists the connectors for the 7 downlink option operation. All other connectors are
the same as described in Chapter 2 of the manual.

The use of each of these connectors is described in the following paragraphs.

Table 2-1. 7 Downlink Option Connectors

Name

Ref.

Desig.

Connector

Type

Function

D/L SWITCH INPUT

J7

BNC

DOWNLINK SWITCH INPUT

D/L SWITCH
OUTPUT

J16

BNC

DOWNLINK SWITCH OUTPUT

DOWNLINK INPUTS

J8 to J10
J12 to J15

BNC

DOWNLINK IF INPUTS

BACKUP DEMOD

J11

BNC

DOWNLINK OUTPUT TO BACKUP
DEMOD

C.1.1 D/L Switch Input (J7)

This is the downlink switch input connector. When using the 7 downlink option, connect a
cable from J16, D/L Switch Out, to J7, D/L Switch In. This enables downlink inputs 5
through 7.

When the 7 downlink option is not being used, this connector is a downlink input to backup
modem 1.

C.1.2 D/L Switch Output (J16)

This is the downlink switch output connector. As described above, when using the
7 downlink option, this connector enables downlink inputs 5 through 7, when connected to
J7.

When the 7 downlink option is not being used, this connector is the backup demod #2
output.