Keysight N9912A FieldFox RF Analyzer

Keysight N9912A FieldFox RF Analyzer

Quick Reference Guide

Keysight N9912A

FieldFox RF Analyzer


Do You Have Everything? ............................ 2

The Power Button and LED ......................... 2

Battery Usage ............................................... 3

Measure Return Loss .................................. 4

Measure Cable Loss (1-Port) ..................... 5

Measure DTF ................................................ 6

Calibration .................................................... 7

Spectrum Analyzer Mode ............................ 8

Channel Measurements ............................... 9

Record Playback ........................................ 10

Power Meter Mode .................................... 11

Save and Recall Files ................................. 12

Do you have everything?

FieldFox –To check for installed options, press



System Configuration




Show Options

Phase stable jumper cable or adapters – Used to connect the FieldFox to devices with various connector types and gender.

Attenuators – Reduces power and prevents damage to the FieldFox at the RF IN port.

Cal Kit – OSL Tee or other calibration devices.

Mini SD card or USB flash drive – Save files to these devices for quick download to a PC.

USB Power Sensor – For making Power Meter measurements. (Opt 302)

Battery charger or extra battery

The Power Button and LED

To turn power ON, briefly press the power button.

The LED is green. The boot-up takes about 60 seconds.

To switch to Stand by power (low battery drain) briefly press the power button. The LED is amber and blinks slowly. To turn power ON, briefly press the power button. Power and settings are restored instantly.

To turn Power OFF (very low battery drain) press and hold the power button until power is shut OFF - about 4 seconds. The LED is OFF.


Battery Usage

A fully charged battery should last about four hours.

Battery charge status is viewable:

In the upper-right corner of the screen.

On the battery. To view the LCD gauge on the

Inspired Energy battery, open the FieldFox battery compartment door.

To conserve battery power:

Use Hold mode to trigger a measurement only when needed. Hold is shown on the display.

Press System then




then dim the FieldFox display as much as possible.

Briefly press the power button to switch to Stand by mode when not being used. Press again to restore power. All current settings are preserved.

The FieldFox will shutdown automatically when battery power is very low to prevent it from being completely discharged.

Use ONLY a FieldFox charger to recharge a battery.

The battery can be fully charged while in the FieldFox in about 4 hours with the FieldFox either ON or OFF.

A fully discharged battery takes about 1.5 hours to recharge to 80%.

The battery can be fully charged in about 4 hours using the external battery charger (Opt 872).


Measure Return Loss

Return loss can be thought of as the absolute value of the reflected power as compared to the incident power.

When measuring an OPEN or SHORT, all incident power is reflected and 0 dB return loss is displayed.

When measuring a LOAD, very little power is reflected and values of 40 dB to 60 dB are displayed.

1. Connect the Device Under Test (DUT).

2. Select Preset then


Returns the FieldFox to known settings.

3. Select Mode then


(Cable and Antenna Test)

4. Then

Return Loss

(Default measurement).

5. Press Freq/Dist and enter




frequency values of the measurement.

6. Press Meas Setup 4 then


to make appropriate settings before calibrating.

7. Disconnect the DUT and press Cal 5 then follow the calibration prompts.

8. Reconnect the DUT (cable to be tested).


Add Markers – All Modes except Power Meter

Add Limits – All Modes

Save Settings and Data – All Modes


Measure Cable Loss (1-Port)

Required Equipment:

LOAD with correct connector type and gender to terminate the end of the DUT.

Optional phase stable jumper cable or adapter to connect the beginning of the DUT to the FieldFox.

1. Press Preset then


2. Then



Cable Loss (1-Port)

3. Connect the DUT.

4. Press Freq/Dist and enter




frequency values of the measurement.

5. Press Sweep 3 then

Min Swp Time

Increase the sweep time until a stable trace is visible on the screen.

6. Press Cal 5 then follow the calibration prompts.

7. Connect the DUT (cable to be tested) to the FieldFox and connect a LOAD at the end of the DUT.

Depending on the DUT, the following three steps may improve the amount of ripple visible on the screen.

8. Press Trace 6 then



9. Remove the LOAD and leave the end of the DUT open.

10. Press

Data Math



– Mem

. Use Averaging for high-loss measurements. Press BW 2 then


11. Read Avg Cable Loss on the FieldFox screen.


Measure Distance to Fault

Required Equipment:

LOAD with correct connector type and gender to terminate the end of the DUT.

Known length and cable type or Cable Loss

(dB/Meter) and velocity factor of the DUT.

Optional phase stable jumper cable or adapter to connect the beginning of the DUT to the FieldFox.

1. Connect any necessary jumper cable or adapter to the

FieldFox RF OUT port.

2. Press Preset then


3. Then Mode then


4. Then

Distance to Fault

5. Press Freq/Dist then

Stop Distance

and enter the length of the DUT.

6. If a diplexer or other filter is in the measurement path, press Freq/Dist and manually type the

Min Start


Max Stop

frequencies. Otherwise, press Meas


then select

Frequency Mode [Lowpass]

7. Press Cal 5 and follow the Cal prompts.

8. Disconnect any components or antenna that should

NOT be measured and connect a LOAD at the end of the DUT.

9. Press Meas Setup 4 then

DTF Cable



10. Either press

Recall Coax Cable

or enter the

Velocity Factor


Cable Loss

of the DUT.

11. Connect the start end of the DUT to the FieldFox. The

DTF measurement is displayed.



Calibration is performed in CAT and NA Modes.

A calibration is performed automatically when the

FieldFox is powered ON and when Preset. This Preset Cal

(also known as CalReady) sets the reference plane at the

RF OUT connector.

For highest accuracy, perform a QuickCal or O,S,L when any of the following occur:

The temperature changes significantly.

The Frequency Range, Resolution, Min Swp Time, or

Power Level is changed.

When using a phase stable jumper cable or adapter to connect the DUT to the FieldFox. These should be high-quality components.

Press Cal 5 then follow the prompts.

During a QuickCal, press

Skip Load

when NOT using a jumper cable or adapter.

Cal ON

is shown on the screen when a Preset Cal is correcting the measurement.

Cal ON Q

is shown on the screen when a QuickCal is correcting the measurement.


is shown on the screen when an O,S,L Cal is correcting the measurement.

When a calibration is being interpolated, an asterisk is added to the screen annotation as follows:

Cal ON*

A Normalization Cal is REQUIRED when making 2-port

CAT or NA Mode measurements.


Spectrum Analyzer (SA) Mode

SA measurements require NO calibration.

Check for a Compressed Measurement

1. Using a marker at the signal peak, make note of the signal power level.

2. Increase the RF Attenuation level by 5 dB.

If the signal level does NOT change, then NO compression exists. This indicates that the signal is in the linear region of the receiver.

If the signal level DOES increase with more attenuation, then compression DID exist. Set the RF

Attenuation value at the setting when further increases no longer result in an increase in the displayed power level.

Set RF Attenuation

1. Press Preset then


2. Press Mode then


3. Press Scale/Amptd then

RF Atten


RF Attenuation is set by adjusting the Ref



Change the RF Attenuation level manually.

Display up to four types of traces

SA settings are applied to all traces.

1. Press Trace 6 then

Trace 1,2,3,4

repeatedly to select a trace number to display.

2. Then


to select a trace type.


SA Mode – Channel Measurements

Optionally apply a Radio Standard which changes frequency settings, Res BW, and other relevant settings to that of the selected standard. Then change the frequency range by selecting channel numbers.

1. Press Freq/Dist then



Radio Standard


Scroll to select the standard and press Enter.

2. Then press

Unit Freq Chan

3. Press

Chan Direction

to toggle between





4. Optionally, change the

Channel Step

size which allows you to use the


arrows to increment the channel number by the specified value.

5. Then






, or

Stop Channel


6. Press Measure 1 then

Channel Measurements

and choose from the following:

Channel Power (CHP) - Measures total power over the specified Integrated BW.

Occupied Bandwidth (OBW) - Measures the power of the current frequency span and displays vertical posts between which the specified percentage of power is contained.

Adjacent Channel Power (ACPR) - Measures the power of a carrier channel and one, two, or three adjacent (offset) channels.

Tune and Listen (AM/FM) – Plays potentially interfering AM or FM signals through the FieldFox speaker or headphones.


Record Playback (Opt 236)

Allows you to record SA traces and play them back at a later time. You are allowed to change most SA settings during a recording. Setting changes are recorded along with the traces.

To record a new session:

Press Trace 6 then

Record Playback Setup


New Session


Recorder Player

, then


Optionally set the following

Recording Configuration


Record Time

– limits record time.

Record Source

– choose where in the FieldFox data flow that data is recorded. RawMeas is easiest.

Record Interval

– sets the amount of time to wait between individual trace recordings.

Segment Count

– sets the number of traces to record.


– sets the power level which will trigger a recording.

To play a session:


Recall Session

select a session, press




Recorder Player





can be used to Pause and Resume during

Record or Playback.

The maximum recording time is determined largely by the amount of available memory. To maximize recording time, select

Storage Device



(flash drive) or

SD Card



Power Meter Mode

Power Meter measurements are made using a Keysight

USB Power Sensor.

For a complete list of supported Keysight USB Power

Sensors, visit:

Damage levels are:

+25 dBm (320 mW) average

+33 dBm peak (2 W) <10μs


Use an Attenuator between the DUT and the power sensor when measuring power levels that are higher than

+20 dBm. The attenuator value can be subtracted from the measurement using Offset as follows:

Select Offset

Press Scale / Amptd then

Offset On Off


Offset Val

Enter a value by which the power meter display is offset. A positive value compensates for a component with loss, such as an attenuator.


The Keysight USB Power Sensors perform internal zeroing automatically. Internal zeroing does NOT require that the power source be turned OFF.

Perform external zeroing when measuring power levels below -30 dBm. During external zeroing, the power source MUST either be turned OFF or the power sensor be disconnected from the DUT.

Press Cal 5


External Zero


Save and Recall Files

Save current settings and calibration, trace data (CSV) and .S1P), or a picture of the FieldFox screen.

Press Save/Recall 9

1. Then

Select Device

to set the LOCATION where the file is to be saved. Choose from the following:


Saves/Recalls files to or from the FieldFox internal memory.

SD Card

Saves/Recalls files to or from the mini SD card.


Saves/Recalls files to or from a USB Flash drive.

2. Then

File Type


Saves ALL FieldFox instrument settings and calibration for ALL Modes to an *.sta file.

Trace + State

Saves the current trace (all traces in

SA mode) and instrument settings to an *.sta file.


Saves the FieldFox screen to a *.png file.

Data (S1P)

Saves CAT and NA Mode trace data to an *.S1P file.

Data (CSV)

Saves trace data from the current mode to a *.csv file.

3. Then press


to save the specified file type to the specified device location.

4. Press


to read an *.sta file into the FieldFox.


Manufacturing Part Number:


Print Date: October 1, 2014

Supersedes: May 11, 2010

©Keysight Technologies, Inc.

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