Anritsu 681XXC - Manual (Page 94)

The ALC Mode menu lets you perform the following:
q Go to the leveling menu (select the ALC mode
of operation).
q Go to the attenuation menu (decouple the
attenuator, if equipped, from the ALC system
and set the power level and attenuation).
q Select either the front panel or rear panel ex-
ternal ALC input.
Internal Leveling
This is the normal (default) leveling mode. Output
power is sensed by the internal detector in the
681XXC. The detector output signal is fed back to
the ALC circuitry to adjust the output power level.
Internal ALC is selected from the leveling menu.
To go to the Leveling Menu from the ALC Mode
menu, press
Leveling Menu . The Leveling Menu
(below) is displayed.
To select internal ALC, press Internal .
Pressing one of the other leveling menu soft-keys
External Detector , Power Meter , or Fixed Gain will
turn off internal leveling.
Press Previous Menu to return to the ALC Mode
Menu display.
External Leveling
In external leveling, the output power from the
681XXC is detected by an external detector or power
meter. The signal from the detector or power meter
is returned to the ALC circuitry. The ALC adjusts
the output power to keep the power level constant at
the point of detection. The external ALC source in-
put is selected from the leveling menu.
681XXC OM 3-61
LOCAL (FRONT LEVELING
PANEL) OPERATION OPERATIONS