Comtech EF Data CPA - Manual (Page 133)

CPA C-Band Indoor Solid State Power Amplifier Revision 1
Appendix B MN/CPA-IN.IOM
B–11
B.4 Gain Equalization of Redundant Units
Chapter 5. FRONT PANEL OPERATION
To equalize the gain between the Backup Unit and the Online Unit(s), Gain Offset adjustment is
accomplished via the Backup Unit.
Before continuing, make sure that:
1. All external interface connections have been completed as outlined in
Sect. B.2, and
2. The Online Unit is online and transmitting – this can be verified by
observing the Online Unit’s front panel LEDs, and through the pertinent
configuration menus.
To determine the relative gain of the Backup Unit versus the Online unit(s):
Step Task
1 Apply an RF signal to the RF redundancy input isolator. Monitor the output power level at the
waveguide switch o utput. (Make sure n ot t o apply t oo l arge of an input s ignal w hich will
saturate the amplifiers. Also be sure to have a properly rated load to measure the output
power.)
2 Adjust the input signal power level and attenuation of the Online Unit to arrive at the desired
output power level.
3 Record the output level of the Online Unit in dBm.
4 Force the Backup Unit to be the active path as outlined in the CONFIG: menu. Ensure the
Offset Value at this point is 0.0 dBm. Record the output level in dBm of the Backup Unit.
5 If t he ou tput l evels a re e qual, n o m ore a djustment is ne cessary. O therwise p roceed a s
follows.