Keysight N9927-90001 User’s Guide 493
System Settings
System Configuration
Hold-over mode
When the GPS signal is lost, the last GPS reading is used as a hold-over
correction value for the internal reference. The hold-over correction value is no
longer used, but instead the factory-set correction value is used, when any of
the following occur:
— when GPS is disabled.
— when Reference Source is set to Internal.
— when the FieldFox resumes from Standby mode or shut down.
Frequency Reference Status
When switched to Ext or GPS, one of the following annotations appears in the
lower-left corner of the screen:
— EXT R – External reference is selected.
— GPS R – GPS reference is selected.
— GPS H – Internal Reference is used with last ‘hold-over’ correction reading.
If the FieldFox does NOT find an appropriate Ext or GPS reference signal, then
Ext Ref UNLOCKED is displayed in the lower-left corner of the graticule area.
This can occur when any of the following conditions exist:
— NO reference signal is present.
— A low or very high-level external reference signal is present. For best
results, the signal should be between –5 dBm and +5 dBm.
— The external reference is off-frequency.
To learn the expected measurement accuracy when connected to a frequency
reference source, see the FieldFox specifications in “Specifications/Data
Sheet” on page 549.
Reference OUT
The internal 10 MHz frequency reference is available from the Ref/Trig output
connector on the right-side panel. Use this signal as a common frequency
reference when making measurements using external equipment. See this
connector in “Top Panel” on page 36.
To Next Page
Loading...
