Comtech EF Data SMS-758 - Manual (Page 38)

Installation SMS-758 Modem Protection Switch
2–10 MN/SMS758 Rev. 3
2.4.11 IF Outputs (J28 through J35)
J28 through J35 are the modulator IF switching matrix output connections. They connect
to the external uplink power combiners. Up to 8 uplinks can be connected to the switch,
or as few as 1.
During normal operation, the prime modulator IF outputs are switched here. During a
fault condition, the backup modulator’s IF output will be switched here.
The frequency range is 50 to 180 MHz, with an output impedance of 75
Ω
. The typical
output power level is equal to the modem TX output level, which is from -5 dBm to
-30 dBm.
Any IF outputs that are not being used must be terminated into 75
Ω
.
2.4.12 AC Power (J37, J38)
Two independent, non-locking, 3-prong power cords connect AC power to the two power
supplies.
Normal input voltage is 90 to 264 VAC (self-adjusting) at 47 to 63 Hz. Maximum power
consumption is 40W.
It is recommended that each power supply be plugged into a different power source, to
provide continuous power to the switch if one source fails.
2.4.13 DC Power (J37, J38)
Two terminal blocks are provided for optional -48 VDC (
±
4.8V) power supplies.
Customer supplied power wires should be fitted with standard #6 screw lugs.
Maximum power consumption is 40W.
It is recommended that each power supply be plugged into a different power source, to
provide continuous power to the switch if one source fails.
Note: Applying incorrect input voltage to these connectors can cause severe damage to
the switch and will void the product warranty. Verify that the source voltage is correct
before connecting the switch.
2.4.14 Ground (J37)
A #10-32 stud is available on the rear panel for connecting the chassis to ground.