Anritsu 681XXC - Manual (Page 111)

Press On/Off to turn square wave modulation on
and off. Both the Square Wave status display and
the Square Wave modulation status area will reflect
your selection.
Press Internal/External to select the source of the
modulating signal. If you select Internal, the status
display shows Source as Internal and Frequency
lists the actual source frequency. If you select Exter-
nal, the display shows Frequency as Ext (external)
and Source as Front or Rear to indicate which input
connector is selected.
Press L RF On/H RF On to select the polarity of the
signal that triggers the RF on.
Press More to go to the additional menu.
Internal Source Frequency Selection
If you have selected Internal to use the modulating
signal from the internal source, then when you
press
More the menu shown below is displayed.
Use the cursor control key to chose the desired
modulating signal frequency, then press
Select to
enter the selection into memory. The Square Wave
status display will reflect your selection.
Press Previous Menu to return to the initial Square
Wave Status Menu display.
3-78 681XXC OM
LOCAL (FRONT SIGNAL
PANEL) OPERATION MODULATION