Comtech EF Data PCB-4300 - Manual (Page 36)

PCB-4300 1:2 Phase Combiner Revision 2
Operation and Adjustment Procedures MN/PCB4300.IOM
3–6
4 • Execute remote command FRC=13 to force SSPAs #1 and #3 online. If necessary,
query the PCB-4300 via remote query FRC?.
• Apply the CW signal from the source to the input of the phase combiner system.
• Measure the output power by reading the power meter channel attached to the
Combined Output Power Test Coupler; add the input signal level, and compute the
gain.
For example, if :
A. The input frequency was 14.0 GHz;
B. The corrected power meter reading at the Combined Output Power Test
Coupler was 42.1 dBm;
C. The measured input signal level for 14.0GHz was -22.2 dBm (as per Step 2);
Then the computed gain at 14.0 GHz would be 42.1 + 22.2 = 64.3 dB for the two
SSPAs currently online.
5 Repeat Step 4 for the other two frequencies with the current SSPAs online, e.g.,
FRC=13.
6 Repeat Steps 4 and 5 for the other possible SSPA combinations, e.g., FRC=12, and
FRC=23.
7 Compare the data taken to that under the “Gain” section on the factory’s Test
Datasheet. Note that small errors or differences – probably within the range of ±1 dB –
are to be expected due to different power meters, calibration issues, etc. The factory
maintains a stringent Calibration and Test Procedure to ensure correct and accurate
data is shipped with every system. Before contacting the factory to report any notable
discrepancies, double check all connections and the calibration factors involved.
3.3.2 System P1dB Verification
Step Procedure
8 The 1 dB compression point can also be measured for each of the possible online
combinations and frequencies. Use the commands listed above to test the various
SSPA online pairs. Again, small differences between customer data and factory data
are expected due to the factors listed previously in Step 7.
The “wasted” power readings are given in the datasheet for reference purposes only.
The user should not be concerned with discrepancies in the “Wasted” power readings if
the corresponding P1dB level is satisfactory.