User`s guide

16 User’s and Service Guide Supplement
E4438C Option HEC
Repeatable Triggering for Multiple Baseband Sources
3. Select ARB Setup > More (1 of 3) > More (2 of 3) > VCO CLOCK Ext > [Return] ARB
“On.” Refer to Figure 11.
4. Adjust the trigger level control on the oscilloscope for a stable display.
5. Align the DACs:
[Mode] Dual ARB > ARB Setup > More (1 of 3) > More (2 of 3) > Align DAC
NOTE Changing or disrupting the external clock frequency can cause the DACs to
become misaligned. Press the align DACs softkey after changing the clock
frequency.
Figure 11 I & Q Output for the “Master” Instrument