Modulation Source - Agilent Technologies 8648A Operation And Service Manual

Operation
Quick Overview

7. Modulation Source

Press to turn on or off the modulation source. Press or to
MOD ON/OFF INT 400 kHz INT 1 kHz
select one of the internal source tones for modulating the RF output signal. These tones
are also available as an output signal at the MOD INPUT/OUTPUT port when they are
selected. Press or to ac- or dc-couple an external audio source via the MOD
EXT AC EXT DC
INPUT/OUTPUT port.
Press to frequency modulate the RF signal with the internal 1 kHz tone and
1kHz + EXT DC
an external source at the same time. (Additional internal plus external modulation
capabilities are available for GPIB operation.) will also amplitude or phase
1kHz + EXT DC
modulate the RF signal with the internal 1 kHz tone but it will not be dc-coupled.
If Option 1EP is present, the (FREQUENCY) key, or if Option 1E2 is present, the
INT 1kHz
(FREQUENCY/WAVEFORM) key scrolls between five states: a fixed 1 kHz
INT 1kHz
internal source and a variable-frequency internal source with four different waveform
selections. The four modulation waveforms are sine, triangle, square, and sawtooth (or
ramp).
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