Agilent Technologies E4438C - Manual (Page 102)

Adjustments
Internal Source Calibration
4-10
Internal Source Calibration
Description
This adjustment is used to calibrate the internal source amplitude versus frequency. The values for offset and
gain are set to their default values in the internal source calibration arrays. Next, the offset calibration factor
is determined by connecting the DVM to the ABUS and measuring the dc offset of the motherboard common
ground ABUS node and the offset of the DSP ABUS node with the DSP set to 0 Vdc. The calibration factor is
the difference between these two measurements. The scaling factors are determined by setting the DSP to
output a full-scale sinewave with the DVM connected to the front panel LF OUTPUT port. Measurements are
then made in 1 kHz steps and the calibration factors are calculated to achieve 2 V
peak
on the motherboard by
accounting for the nominal gain presented by the A17 Synthesizer (Option 501, 502, 503, 504). Upon
completion, the calibration factors are stored in the signal generator’s firmware.
Required Test Equipment
• Agilent 3458A Option 002 digital multimeter
Procedure
Figure 4-4 Internal Source Calibration Setup
1. Connect the equipment as shown above.
2. Preset all of the equipment.
3. Follow the instructions as they appear on the controller’s display.