Attenuation Control - Keysight FieldFox B Series User Manual

SA (Spectrum Analyzer) Mode (Option 233–Mixed Analyzers)
SA Mode Settings

Attenuation Control

Both the RF Attenuation and Preamp functions control the power level into the
SA.
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
1. Press Scale/Amptd.
2. Then
Keysight N9938-90006 User's Guide
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.p
.
df
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 Auto Man.
— 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. The RF Attenuation value is never
automatically lowered below 5 dB.
— Man RF Attenuation is set manually. The default Attenuation setting
is 10 dB. Enter a value between 0 to 30 dB in 5 dB steps using the
numeric keypad, the
Enter
ADC Over Range
arrows, or the rotary knob. Then press
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