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Chapter 2 39
Basic Operation
Configuring the RF Output
6. Preset either instrument.
Presetting one of the instruments should automatically preset the other as well. If both instruments do
not preset, check the GPIB connection, GPIB addresses, and ensure the 8757D is set to system interface
mode (
SYSINTF set to ON).
The PSG automatically activates a 2 GHz to maximum frequency ramp sweep with a constant amplitude
of 0 dBm. Notice that the RF ON, SWEEP, and PULSE annunciators appear on the PSG display. The
PULSE annunciator appears because the 8757D is operating in AC mode.
The PSG also switches its remote language setting to 8757D System, allowing the PSG to talk to the
8757D during ramp sweep operations. You can confirm this by pressing
Utility > GPIB/RS-232 LAN and
observing the selection under the
Remote Language softkey.
NOTE During swept RF output, the FREQUENCY and/or AMPLITUDE areas of the signal
generator’s display are deactivated, depending on what is being swept. In this case,
since frequency is being swept, nothing appears in the FREQUENCY area of the display.
7. Press
Frequency > Freq CW.
The current continuous wave frequency setting now controls the RF output and ramp sweep is turned off.
8. Press
Freq Start.
The ramp sweep settings once again control the RF output and the CW mode is turned off. Pressing any
one of the softkeys
Freq Start, Freq Stop, Freq Center, or Freq Span activates a ramp sweep with the current
settings.
NOTE In a frequency ramp sweep, the start frequency must be lower than the stop frequency.
9. Adjust the settings for
Freq Center and Freq Span so that the frequency response of the device under test
(DUT) is clearly seen on the 8757D display.
Notice how adjusting these settings also changes the settings for the
Freq Start and Freq Stop softkeys. You
may need to rescale the response on the 8757D for a more accurate evaluation of the amplitude. Figure
2-3 on page 40 shows an example of a bandpass filter response.