Keysight CXG, EXG, and MXG X-Series Signal Generators Service Guide 213
RF Assembly
A3 RF Assembly Troubleshooting
18.If either of the EXT inputs is not working run the External Mod Inputs
Calibration adjustment from the performance verification software. If this
does not correct the problem, replace the A3 RF assembly.
LF OUT
This procedure is only applicable with option 303, Multifunction Generator or
option UNT, AM, FM, Phase Modulation.
This procedure will verify that the LF output is functioning properly. It will
require the use of an oscilloscope.
1. Return the instrument to a known state by pressing Preset.
2. Turn the modulation on by pressing Mod On/Off so that the LED below it
comes on.
3. Connect the source rear panel LF OUT connector to channel 1 of an
oscilloscope.
4. Setup the oscilloscope with the following settings:
— Channel 1 volts per division = 500 mV
— Horizontal Scale per division = 500 µs
5. Set the LF output impedance to 1 MΩ by pressing LF Out, More, Load
Impedance 1 MOhm.
6. Set the LF amplitude to 1 Vpp by pressing More, LF Out Amplitude Into 1
MOhm, 1 V.
7. Set the LF frequency to 1 kHz by pressing Setup LF Out Source, LF Out
Freq, 1 kHz.
8. Turn the LF output on by pressing LF Out, LF Out On.
9. The signal on the oscilloscope display should now be a 1 kHz sinewave
signal, as shown in Figure 10-7.