HP 33120A, User Manual

Page: 70 / 118

Modulating Waveform Shape
The function generator will accept only an internal modulating signal.
•
Modulating waveform shape (internal source): Sine , Square,
Triangle, Ramp, Noise, or Arbitrary waveform. The default is Sine.
•
You can use the noise function as the modulating waveform.
However, you
cannot use the noise function or dc volts as the carrier
waveform.
•
Front-Panel Operation : After enabling
FM
, press Recall Menu to go
directly to the
FM SHAPE
command in the menu.
3: FM SHAPE (MOD MENU)
•
Remote Interface Operation :
FM:INTernal:FUNCtion {SINusoid|SQUare|TRIangle|RAMP|NOISe|USER}
Modulating Waveform Frequency
The function generator will accept only an internal modulating signal.
•
Modulating frequency (internal source): 10 mHz to 10 kHz.
The default is 10 Hz.
•
The sync signal for
FM
is referenced to the modulating signal (not the
carrier). A momentary
TTL
“high” pulse (> 200 ns) is output at each
zero-crossing point of the modulating signal. The signal is output
from the front-panel
SYNC terminal.
•
Front-Panel Operation : Press
Shift Freq
to set the modulating
frequency (the value is displayed for approximately 10 seconds).
Before setting the modulating frequency from the front panel,
you must have
FM
enabled. If you attempt to set the frequency when
FM
is not enabled, “
SELECT AM, FM
” is displayed.
•
Remote Interface Operation :
FM:INTernal:FREQuency {< frequency >|MINimum|MAXimum}
3
Chapter 3 Features and Functions
Frequency Modulation (FM)
79