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avoid the drive signal being too strong. Before this kind of test, all the attenuators and
cables should be connected in series to do the calibration.
To start the user calibration, choose “Re CAL” in the function menu and then
follow the guilds.
Chart 3-1B: Connect two cables in calibration
Parameters of calibration kit (or other adaptors which their electric length are
known) can be set in FUNC menu. Set the calibration kit’s electric length in the in-
strument so that instrument can compensate calibration kit’s phase shift automati-
cally. For the testing system which has several cables and adapters, the thru adaptor’s
electric length in the FUNC menu should be set as the sum of the adapters’ electric
lengths which are removed from the actual test.
If user wants to change the frequency after the calibration, system calibration is
automatically choosen.
3.4 Calibration before S11 Measurement
Function S11 has various display modes, but it needs calibration only one time.
Calibration parameters can be used in all modes.
User calibration should be done in following situations:
1. Verifying important devices (e.g. antennas for broadcasting and TV station).
2. When DUT can’t be connected to the instrument directly and it is connect-
ed with extra cables.
After calibration, test if the curve of open and load are shown normally. If there
are some obvious errors, redo the calibration. In VSWR mode, curves in open circuit
should be over than 10 and it should be under 1.2 connecting to the load.
Attention
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