Attenuation Control; How To Set Attenuation - Keysight A Series User Manual

RTSA (Real-Time Spectrum Analyzer) Mode—Option 350 (CPU2 Only)
RTSA Mode Settings

Attenuation Control

Both the RF Attenuation and Preamp functions control the power level into the
RTSA.
When too much power is present at the RF Input port,
appears on the FieldFox screen. This does not necessarily mean that damage
has occurred, but that the measurement is probably compressed.
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.
268
The FieldFox can be damaged with too much power. Refer to the FieldFox
Data Sheet for your model on
https://www.keysight.com/us/en/assets/7018-03314/data-sheets/5990-
9783.pdf.
Maximum Input Voltages and Power:
RF Output Connector: 50V DC, +23 dBm RF
Ext Trig/Ref Connector: 5.5 V DC
RF Input:
+27 dBm RF, ±50 VDC Max. (N991xA/B, N9925B, N9926A,
N9928A, N993xA/B)
+23 dBm RF, ±50 VDC Max. (N9923A, N9923AN)
+25 dBm RF, ±40 VDC Max. (N995xA/B, N996xA/B)
DC Input: 19VDC, 4ADC, 60 Watts maximum when charging battery
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.
ADC Over Range
arrows, or the rotary knob.
Keysight N9927-90020 User's Guide