Chapter 2 55
Instrument Functions: A - L
AMPLITUDE / Y Scale
Instrument Functions: A - L
2.0.6 Presel Adjust
Allows you to manually adjust the preselector filter frequency to optimize its response on
the signal of interest. This function is only available when measuring signals ≥2.85 GHz in
band 1 and higher bands.
For analyzers that have both millimeter wave and microwave types of bands (E4448A and
E4446A analyzers) the adjustment is band specific. If the currently active marker, or the
center frequency, is in one of the four lower bands (bands 1 to 4) the preselector adjustment
specified is used for the microwave bands. However, if the active marker or center
frequency is in one of the two upper bands (bands 5 to 6), then the preselector adjustment
is applied for those millimeter bands.
NOTE In the 26.4 to 26.8 GHz range there is an overlap between bands 4 and 5 that
causes the boundary between these two bands to shift dynamically. You must
be aware that the preselector adjustment is applied to the correct band
(either 4 or 5) based on the current settings of the analyzer.
When the preselector adjustment is being changed, the active function area of the display
shows a third line (mm-wave bands preselector,orMW bands preselector)dependent
on the preselector applied. The preselector applied is determined by the analyzer settings
of the start, stop, and marker frequency settings as shown below. Note that applied
preselector will be notated in the active function block of the display.
Key Path: AMPLITUDE / Y Scale
State Saved: Saved in Instrument State
Factory Preset: 0 Hz
Range: –250 MHz to 250 MHz
Remote Command:
[:SENSe]:POWer[:RF]:MW:PADJust <freq>
[:SENSe]:POWer[:RF]:MW:PADJust?
[:SENSe]:POWer[:RF]:MMW:PADJust <freq>
PSA Frequency Setting Preselector Applied
Start: >26.8 GHz Millimeter
SItop: <26.8 GHz Microwave
Start: >26.4 GHz Millimeter
Start: <26.4 GHz
Marker: <26.8 GHz
Microwave
Start: <26.4 GHz
Marker: >26.8 GHz
Millimeter