Filter
Top Products
Square Wave
Modulation
Operating
Modes
The 681XXC provides square wave (pulse) modula
-
tion of the output signal using modulating signals
from either its internal square wave generator or an
external signal generator.
The signal generator’s internal square wave genera
-
tor outputs modulating signals of 400 Hz, 1 kHz,
7.8125 kHz, and 27.8 kHz. The modulating signals
are selectable from a menu.
The 681XXC accepts modulating signals from an ex
-
ternal signal generator that are TTL-compatible
with the minimum pulse width of >5 ms.
Providing
Square Wave
Modulation
The following are the menu selections necessary to
provide square wave (pulse) modulation of the out
-
put signal using a modulating signal from both the
internal and external sources.
Press MODULATION . At the resulting menu dis-
play, press SqWave . The Square Wave Status
Menu (below) is displayed.
This menu contains the square wave status window
that shows the current menu selections. This menu
lets you perform the following:
q
Turn square wave modulation on/off.
q
Select Internal or External source for the
modulation signal.
q
Select the polarity of the signal (High or Low)
that turns the RF on.
q
Go to an additional menu (to select the fre
-
quency from the internal source or to select the
front or rear panel input connector).
681XXC OM 3-77
LOCAL (FRONT SIGNAL
PANEL) OPERATION MODULATION