7- 82
Operating Concepts
Knowing the Instrument Modes
Figure 7-46 Typical Setup for External Source Mode
External Source Mode In-Depth Description
You may use the external source in automatic or manual mode. External source mode phase locks the
analyzer to an external CW signal.
NOTE The external source mode works only in CW time sweep.
External Source Auto If you press , the
analyzer turns on the external source auto mode. You should observe the following points when using this
operation mode:
• The auto mode has a wider capture range than the manual mode.
• The manual mode is faster than the auto mode.
• The auto mode searches for the incoming CW signal.
• The capture range is typically 10% of the selected CW frequency.
• This feature works only in CW time sweep type.
• The incoming signal should not have large spurs or sidebands, as the analyzer may phase lock on a spur
or not phase lock at all.
The frequency the instrument has locked onto is shown on the analyzer, and is also available via GPIB.
External Source Manual If you press
, the analyzer activates the external source manual mode. You should observe
the following points when using this operation mode:
• The manual mode has a smaller capture range than the auto mode.
• The manual mode is much faster than auto mode.
• This feature works only in CW time sweep type.
• The incoming signal should not have large spurs or sidebands, as the analyzer may phase lock on a spur
or not phase lock at all.