DETAILED
PARAMETERS
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260
USER
GUIDE
4.4 Automatic Gain Control(AG)
The AGC is used to keep the average level of a signal at a constant level.
This is done by selecting a desired Target output level and Window. The
AGC keeps the signal within the Window about the selected Target by
slowly adjusting the gain. The maximum gain that can be applied to the
signal is selected by the Gain parameter. When the input signal falls
below the Low Threshold the AGC releases the gain and returns to unity.
This prevents the AGC from adding gain when there is no signal present
and raising the system noise floor. High level signals are reduced by a
fast limiter to prevent distortion by clipping. The AGC Threshold meters
show what region of the AGC the input signal is in.
The parameter setting interface is illustrated in the following diagram.
There are three points and two parallel horizontal lines on the interface.
The top point stands for the "Target", and the middle one stands for the
"MAX Gain", while the bottom one represents the "Low Threshold". The
area between the horizontal lines stands for the "Window". If selected,
the point or line segment will ne displayed in red; if not, the point or line
segment will ne displayed in green.
Bypass
When "Bypass" is "on", the box behind it is highlighted in green; when the
box is in white, it means that "Bypass" is off. When "Bypass" is "on", the
Automatic Gain Control is turned off; when "Bypass" is "off", the
Automatic Gain Control is turned on.
