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208495 REV B
Operations Manual, HPA2, Compact Outdoor SSPA
9.3 1:2 Redundant Systems with L-Band Input
The 1:2 Redundant System with L Band Input can be configured with internal Block Up
Converters that contain internal 10 MHz reference oscillators or configured for use with an
external 10 MHz reference source. Systems configured with internal 10 MHz reference are
straightforward extensions of the basic 1:2 architecture. Because the 10 MHz reference is
integral to the converter there is no possibility of an interruption of the 10 MHz during
switchover. Furthermore the standby amplifier always has 10 MHz reference and will not be
faulted. Such a system is shown in
Figure 9-23
.
The Block Up Converters used in Satcom equipment typically use some form of phase locked
local oscillator in the converter architecture. The Block Up Converter will signal an alarm
condition whenever the oscillator looses phase lock. The amplifier will go into a mute state so
that no spurious (off frequency) emissions can be transmitted to the satellite. The alarms from
the BUCs and SSPAs are sent to the RCP2-1200 system controller which determines the
proper switch conditions for the system.
RF OUT-POL 2
RF OUT-POL 1
Amp 1
Amp 2
Amp 3
RCP2-1200
Redundant Controller
BUC
L Band Input- POL 1
L Band Input- POL 2
10MHz
10MHz
10MHz
BUC
BUC
Alarm
Inputs
Switch Drive
Figure 9-23: 1:2 Redundant System with L Band Input and Internally Referenced
Block Up Converters (BUCs)
