External Gain; Attenuation And Preamp Control - Keysight N9912A User Manual

How to set Y-axis Units
The Unit setting appears for the reference line, marker readouts, and trigger level. All
Unit choices are available in both Log and Linear Scale Types.
The UNIT setting survives Mode Preset, but NOT Preset.
 Press Scale / Amptd , then More, then
 Then choose from the following:
Antenna correction units are available ONLY by loading or editing an Antenna file
that contains the desired units setting. Learn more on page 76.

External Gain

When using an external amplifier or attenuator, the SA Mode trace amplitude values
can be offset to compensate for the effect of the external device. This effectively
moves the reference plane of the SA measurement port out to just beyond the
external device. For example, when using an external preamp with gain of +10 dB,
enter this value for External Gain, and the data trace across the displayed frequency
span will be adjusted down by 10 dB.
When RF Atten is set to Auto, you may see a change in the RF Attenuation value.
This is an attempt to measure the signal at top of screen (the Reference Level)
without overloading the SA first mixer.
How to set External Gain
 Press Scale/Amptd .
 Then
 Then
 Enter a value using the numeric keypad, the ▲|▼ arrows, or the rotary knob
ExtGain xx dB is shown at the top of the screen.
Attenuation Control
Both the RF Attenuation and Pre Amp functions control the power level into the SA.
SA (Spectrum Analyzer) Mode
Manually adjust the scale per division to view specific areas of the current
Scale
o
trace. Enter a value using the numeric keypad, the ▲|▼ arrows, or the rotary
knob. Then press Enter.
Manually set the value of the reference line. Enter a negative value by
Ref Level
o
pressing Run/Hold (+/-) either before or after typing a value. This can also
change the RF Attenuation setting. See Attenuation Control – Auto.
Manually set the position of the reference line. Values must be
Ref Position
o
between 0 (TOP line) and 10 (BOTTOM line). Default position is zero (top).
Press More, then
Autoscale
o
the Min and Max amplitude of the trace on the screen.
dBm (default setting), dBmV (dB milli Volts), dBuV (dB microVolts), W (watts), V
o
(volts), A (amps), dBmA (dB milliAmps), dBuA (dB microAmps).
More
External Gain
(positive for gain; negative for loss). Values less than 5 dB must be typed using the
numeric keypad. Then press Enter
Automatically adjusts the Y-axis to comfortably fit
Unit
73