Agilent Technologies E4438C - Manual (Page 99)

Adjustments
Internal Reference Oscillator Calibration
4- 7
Internal Reference Oscillator Calibration
Description
This is a manual adjustment. An automated version of this adjustment is also provided.
This procedure is used to calibrate the internal reference DACs (Digital-to-Analog Convertors). The internal
reference oscillator is adjusted with two DACs, one for coarse tuning and one for fine tuning. Using the two
DACs, the internal reference oscillator can be adjusted to the resolution of the frequency counter used.
Required Test Equipment
• Agilent 53132A Option 050 frequency counter
• Use a 10 MHz house standard. (For example, an Agilent 5071A primary frequency standard or equivalent
can be used.)
Procedure
Figure 4-1 Internal Reference Oscillator Calibration Setup
1. Connect the equipment as shown above.
2. Preset all of the equipment.
3. Set the universal counter input to 50
Ω.
4. On the signal generator press, Preset > Amplitude > 0 > dBm > RF ON/OFF > Utility > Instrument Adjustments
> Reference Oscillator Adjustment > Ref Osc Fine .
5. Center the fine tuning DAC setting for a value of 128.
6. Press Ref Osc Coarse on the signal generator.
7. Adjust the coarse tuning DAC setting for a universal counter reading of 100 MHz.
8. Press Ref Osc Fine and adjust the fine tuning DAC setting for a frequency counter reading of 100 MHz,
within 0.1 Hz resolution.
9. After adjusting both of the DAC settings, press Store Ref Osc Setting > Confirm Store .