Comtech EF Data SMS-301 - Manual (Page 34)

Installation SMS-301 Redundancy Switch
2–12 Rev. 3
2.3.3 Transmit IF Connectors (J4, J5, J6)
The transmit IF switch connectors are as follows:
• The TX IF output of the prime modem connects to TX IF A.
• The TX IF output of the backup modem connects to TX IF B.
• TX IF COMM is the transmit IF output connector and connects to the uplink IF
equipment. The TX IF output of the on-line modem will be available at
this connector.
• The characteristic impedance of these BNC connectors is 75Ω (50Ω optional).
• If the backup or prime modem is disconnected for any reason, place a 75Ω (50Ω
optional) termination on the unused connector for a 75
Ω (50Ω optional) system,
respectively.
2.3.4 RX IF Connectors (J7, J8, J9)
The Receive IF splitter connectors are as follows:
• The RX IF of the prime modem connects to RX IF A and the RX IF of the
backup modem connects to RX IF B.
• RX IF COM connects to customer-furnished equipment.
• The characteristic impedance of these BNC connectors is 75Ω (50Ω optional).
• There will be less than 4 dB loss between the common input and the A or B
output connectors.
• If the backup or prime modem is disconnected for any reason, place a 75Ω
(50
Ω optional) termination on the unused connector for a 75Ω (50Ω optional)
system, respectively.