Operations Manual, HPA2, Compact Outdoor SSPA
208495 REV B
95
The Reference Combiner assembly couples a sample of the 10 MHz reference from each of
the two polarity inputs. It will then supply the standby amplifier with the reference from either
of the two inputs. The reference combiner will arbitrate and decide which 10 MHz signal to
supply to the standby amplifier. It will not supply both 10 MHz sources to the standby
amplifier. This allows all three amplifiers to be in a normal operating (non faulted) condition
and the RCP2-1200 controller can operate the system in normal 1:2 redundancy. This
eliminates the need for a separate 10 MHz line going to the system as the 10 MHz reference
normally exists on each L-Band cable. See
Figure 9-26
.
Amp 2 is meant to be the standard stand-by amplifier in this configuration. Should Amp 1 or
Amp 3 fault, the RCP2-1200 will automatically switch to the stand-by Amp 2. However, when
this occurs, this interrupts the 10 MHz reference to the faulted Amp/BUC, which results in a
constant BUC fault on that thread. In order to return Amp 2 to the stand-by state, the user will
need to clear the fault, switch to manual mode on the RCP2-1200 and then select Amp 2 as
stand-by.
Table 9-1
gives a step-by-step guide to returning Amp 2 to stand-by status.
1
Fault on Thread 1 or Thread 3 causes switchover to Thread 2
2
Determine cause of fault on Thread 1 or Thread 3 and remove fault condition
3
Switch to Manual mode on RCP2-1200
4
Select Amp 2 as stand-by amplifier
Table 9-1: Returning Amp 2 to Stand-by Mode After Fault on Thread 1 or 3
Step Action
5
Switch to Auto mode on RCP2-1200
Figure 9-26: Standard 1:2 Redundant System with External 10MHz Reference
using the Reference Combiner Assembly.
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
BUC
BUC
Alarm
Inputs
Switch Drive
10MHz
10MHz
-16dB
DBTC-16-5-75L+
-16dB
DBTC-16-5-75L+
ADP-2-1
3 dB
PAT-3
Reference
Combiner Assembly
L-Band Test Input
to Standby
L-Band only
Test Input
to Standby