2 MHz LCR Meter Kit AU2019 Assembly Manual
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Do not connect anything to the BNC sockets!
R_Hold must be OFF
5.1 Sinewave generator offset adjustment
Using your multimeter, measure the DC voltage at TP7 (this is the out-
put of U26C). Using R146, adjust it as close as possible to 0 V.
Press [OK] to exit the menu.
5.2 Measured value of Vref (DDS)
Measure the DC voltage at TP6 with your multimeter. With the rotary
knob, now adjust the displayed value to the measured value.
Press [OK] to confirm the entry or [Exit] to leave the menu
without changes.
5.3 CMRR of the differential amplifier U7C
This setting provides the maximum common-mode rejection of the
U7C differential amplifier.
Insert a jumper on headers J9 and J17. Adjust the displayed value to a
minimum value, first R31 for low frequencies (10 kHz) and then C44 for
high frequencies (1 MHz). Change the frequency with the rotary knob.
Due to a slight interaction, repeat these two settings at least once.
Press [OK] to exit the menu.
Any subsequent changes to these settings will require the steps in
§5.4 to 5.11 to be repeated.