Returnlossofcables - Agilent Technologies HP 8719D Service Manual

Check the Test Port Cables
The following series of cable tests (return loss, insertion loss, magnitude stability,
phase stability, and connector repeatability) can be done to check the stability
of a test port cable. These checks are not required, but are recommended to
avoid spending a considerable amount of time on the verilhtion only to have a
failure caused by the cables.
Return Loss of Cables
1. Press [j] LjJ
2. Perform an S11 l-port measurement calibration at test port 1. Use a lowband
and sliding load combination, or a broadband load for the loads portion of
the calibration. If necessary, refer to the operating manual for a detailed
measurement calibration procedure.
Note If the llxed load in your calibration kit is labeled BROADBAND,
you can use this load in the lowband portion of the
measurement calibration.
3.
Connect the test port cable to port 1 and tighten to the specified torque for
the connector type.
4. Connect a broadband termination to the end of the cable.
5.
find the worst case S11 measurement.
See F'igure 2-3 for an example of a return loss measurement. Refer to the cable
manual to see if the cable meets the return loss specification. If it doesn't, the
cable should be either repaired or replaced.
System Verihation and
to activate the marker search tracking and
to activate step sweep.