Preamplifier Control (Opt 235) - Keysight N9913A User Manual

RTSA (Real-Time Spectrum Analyzer) Mode—Option 350 (CPU2 Only)
RTSA Mode Settings
When high power levels are present at the RF Input port, internal attenuation
can be switched in to keep the FieldFox receiver from compressing. At
extremely high power levels, use external attenuation to protect the internal
circuitry from being damaged.
The displayed power level is automatically adjusted for RF Attenuation. As the
attenuation value changes, the displayed power level should NOT change.
How to set Attenuation
— Press Scale/Amptd.
— Then
—
—
#Atten xx dB is shown at the top of the screen. (#) means manual setting.

Preamplifier Control (Opt 235)

When very low-level signals are analyzed, an internal preamplifier can be used
to boost the signal level by approximately 15 to 20 dB (depending on model).
The gain of the preamp is NOT adjustable. The displayed signal level is
automatically adjusted for the increase in system gain, therefore turning the
Preamp ON should NOT cause a change to the displayed signal.
How to control the Preamp
By default, the preamp is OFF.
— Press Scale/Amptd.
—
208
The FieldFox can be damaged with too much power. Refer to the FieldFox
Data Sheet for your model on
http://literature.cdn.keysight.com/litweb/pdf/5990-9783EN.pdf.
RF Damage Level: +25 dBm (N995xA & N996xA) and +27 dBm (all others)
DC Damage Level: ±50 VDC
RF Atten Man Auto
Auto RF Attenuation is set by adjusting the acquisition. As the acquisition is
lowered, for example from –10 dBm to –30 dBm, the FieldFox assumes that
you are looking at low-level signals. The RF Attenuation value is
automatically lowered in 5 dB steps to allow low-level signals to be viewed.
Man RF Attenuation is set manually. Enter a value between 0 to 30 dB in
5 dB steps using the numeric keypad, the
Then press Enter.
Preamp ON OFF When ON,
display.
arrows, or the rotary knob.
PA is shown to the left of the graticules on the
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