Agilent Technologies N5242A, Руководство по обслуживанию, Страница: 49 / 342

Service Guide N5242-90001 3-17
PNA Series Microwave Network Analyzers Tests and Adjustments
N5242A Preliminary Checks
Cable Connector Repeatability Check
NOTE The connector repeatability measurement should be done at the test port as
well as at the end of the test port cable.
1. With the test port cable still connected to Port 1, connect a broadband load to the other
end of the cable.
2. Press UTILITY .
3. Press RESPONSE . Verify that is ON . If not, press the
softkey to toggle it ON .
The Averaging Factor box will appear directly above the display. In the Averaging
Factor
box, type
100
or click the arrows to select
100
, and then press ENTRY .
4. Wait for the analyzer to average the measurement 100 times (approximately five
seconds).
5. To normalize the data trace: press MARKER/ANALYSIS , then ,
then , then , then ENTRY .
6. To adjust the display scale:
a. Press RESPONSE , then .
The
Scale Per Division
box will appear directly above the display. Set the
Scale Per
Division for 0.5 dB . Press ENTRY .
b. Press .
The Reference Level box will appear directly above the display. Set the Reference
Level
for
0 dB
. Press ENTRY .
7. Disconnect and then reconnect the cable to the test port. Tighten the connection to the
specified torque for the connector type.
8. Press RESPONSE , then .
9. Look at the trace for spikes or modes.
10. To re-normalize the data trace of the reconnected cable: press MARKER/ANALYSIS
, then , then ENTRY .
11. Repeat steps 7 through 9 at least three times to look for modes. Modes appear when a
harmonic of the source fundamental frequency is able to propagate through the cable or
connector. It is helpful to print a plot of the trace each time to compare several
connections. If any mode appears each time the cable is connected and reconnected,
measurement integrity will be affected.
For a typical response of cable connector repeatability, see Figure 3-7 .
Preset
Avg
Average ON/off
Average on/OFF
Enter
Memory Data Trace
Data Math Data/Memory Enter
Scale Scale
Enter
Reference Level
Enter
Avg Averaging Restart
Memory Data->Memory Enter