Scale And Units; External Gain - Keysight Technologies C Series User Manual

Fieldfox analyzers

RTSA (Real-time Spectrum Analyzer) Mode—Option 350

RTSA Mode Settings

Scale and Units

Adjust the Y-axis scale to see the relevant portions of the data trace.

The Y-axis is divided into 10 graticules. A acquisition is shown on the screen as

a solid horizontal bar that can be placed at any graticule.

RTSA always uses logarithmic scale. The Y-axis reference line represents the

specified absolute acquisition (dBm). Y-axis graticules show dB below or above

the reference line.

When RF Attenuation set to Auto, the RF Attenuation is coupled to acquisition.

How to set Scale

Press Scale / Amptd. Then choose from the following:

Manually set Scale, acquisition, and Reference Position.

When using an external amplifier or attenuator, the RTSA mode trace

amplitude values can be offset to compensate for the effect of the external

device. This effectively moves the reference plane of the RTSA 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

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

acquisition) without overloading the RTSA first mixer.

How to Set External Gain

— Press Scale/Amptd.

Keysight N9915-90020 User's Guide

Manually adjust the dB scale per division to view specific areas of the

current trace. Enter a value using the numeric keypad, the

the rotary knob. Then press Enter.

Manually set the value of the reference line. Enter a negative

value by pressing Run/Hold (+/-) either before or after typing a value. This

can also change the RF Attenuation setting. See

Manually set the position of the reference line. Values must be

between 0 (top line) and 10 (bottom line). Default position is zero (top).

External Gain

"Attenuation Control" on