Operations Manual, HPA2, Compact Outdoor SSPA
208495 REV B
109
10.5.1 Phase Adjustment
Each 1:2 Fixed Phase Combined SSPA System has been factory set for optimal Phase
Combining before shipment and should not need adjustment during installation and operation.
In the event that an amplifier is replaced, it may then be necessary to make additional phase
adjustment.
Connect a power meter or spectrum analyzer to the cross-guide coupler at the output of the
system after removing the detector and attenuator. See
Figure 10-13
. You may alternately
use the FPRC-1200 controller’s output power display, available by pressing the
Main Menu
key; select
5.Options
and press the
Enter
key; select
6.More
and press the
Enter
key; select
5.SSPA
and press the
Enter
key; select
3.View
and press the
Enter
key. The System
Forward RF Output Power is shown in the upper right of the display.
The two phase adjusters are located inside the Signal Box and are labeled PA1 and PA2. To
make adjustments, loosen the 7/16” locking nut at the bottom of the phase adjuster.
To adjust the phase combining, un-mute all amplifiers and, using the FPRC-1200, set HPA #1
as the standby amplifier. Vary phase adjuster 2 (PA2) to peak the power reading on the
power meter or spectrum analyzer, or from the FPRC-1200 controller’s output power display.
With HPA #2 and #3 power combined, phase adjuster (PA2) will be used to maximize the
output power. Next, select HPA #2 as the standby. This combines HPA #1 and HPA #3. Use
phase adjuster (PA1) to optimize power.
It may be necessary to repeat the steps above to verify the power with all HPA
combinations. Choose the best compromise in power for all combinations so that if switch
over on fault does occur there is no noticeable increase or decrease in output power.
After phase combining is complete use the locking nut on each phase adjuster to secure the
adjustment knob so no accidental changes to the combining occur.
Figure 10-13: Connect to coupler
Remove detector and
attenuator; connect to
cross-guide coupler.
