Agilent Technologies X Series Manual page 455

Notes
Preset
Min
Max
Default Unit
Initial S/W Revision
External Reference Lock BW
This control lets you adjust the External Reference phase lock bandwidth. This control is available in
some models of the X-Series.
The PXA variable reference loop bandwidth allows an external reference to be used and have the
analyzer close-in phase noise improved to match that of the reference. This could result in an
improvement of tens of decibels. The choice of "Wide" or "Narrow" affects the phase noise at low offset
frequencies, especially 4 to 400 Hz offset. When using an external reference with superior phase noise,
we recommend setting the external reference phase-locked-loop bandwidth to wide (60 Hz), to take
advantage of that superior performance. When using an external reference with inferior phase noise
performance, we recommend setting that bandwidth to narrow (15 Hz). In these relationships, inferior
and superior phase noise are with respect to 134 dBc/Hz at 30 Hz offset from a 10 MHz reference.
Because most reference sources have phase noise behavior that falls off at a rate of 30 dB/decade, this is
usually equivalent to 120 dBc/Hz at 10 Hz offset.
Key Path
Scope
Remote Command
Example
Dependencies
Preset
State Saved
Still available with Internal selected, to allow setup for when External is in
use.
This is unaffected by a Preset but is set to 10 MHz on a "Restore Input/Output
Defaults" or "Restore System Defaults->All"
CXA: 10 MHz
EXA: 10 MHz or 13 MHz, depending on whether N9010A-R13 is licensed
MXA: 1 MHz
PXA: 1 MHz
CXA: 10 MHz
EXA: 10 MHz
MXA: 50 MHz
PXA: 50 MHz
Hz
Prior to A.02.00
Input/Output, Freq Ref In
Mode Global
[:SENSe]:ROSCillator:BANDwidth WIDE|NARRow
[:SENSe]:ROSCillator:BANDwidth?
ROSC:BAND WIDE
This key only appears in analyzers equipped with the required hardware.
This is unaffected by a Preset but is set to Narrow on a "Restore Input/Output
Defaults" or "Restore System Defaults -> All"
Saved in Input/Output state.
Input/Output
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