Setting The Timebase Latches - Agilent Technologies 8935 Series Manual

Setting the Timebase Latches

The refs_DAC_coarse and ref_DAC_fine values adjust the frequency
of the Test Set's internal 10 MHz reference. They are stored in memory.
The controller reads the values and sends the appropriate adjustment
to the A2A23 Reference assembly.
The following procedure is to be used when running the program
"Timebase Reference Using a Counter" on page
1. Press ,
Shift Duplex Config
2. Select SERVICE under the To Screen menu.
3. Connect a frequency counter to the rear-panel 10 MHz REF
OUTPUT connector.
4. Select the Latch field.
5. Select refs_DAC_coarse under the Choices: menu.
6. Select the Value field.
7. Rotate the knob until the counter reads as close to 10 MHz as
possible.
8. Select the Latch field.
9. Select refs_DAC_fine under the Choices: menu.
10.Select the Value field.
11.Rotate the knob until the counter reads as close to 10 MHz as
possible.
12.Store the new DAC values (timebase calibration data) in non-volatile
memory by selecting and running the Timebase Reference Using
a Counter routine from the Periodic Calibration Menu. See
"Timebase Reference Using a Counter" on page
Chapter 7
Setting the Timebase Latches
165.
to access the CONFIGURE screen.
Periodic Adjustments
165.
169