Honeywell Primus 880 Pilot's Manual page 25

PRIMUSr 880 Digital Weather Radar System
12 GAIN
The GAIN knob is a single- turn rotary control and push/pull switch that
is used to control the receiver gain. Push in on the GAIN switch to enter
the system into the preset calibrated gain mode. Calibrated gain is the
normal mode and is used for weather avoidance. In calibrated gain, the
rotary portion of the GAIN control does nothing. In calibrated gain, the
color bar legend is labeled 1,2,3,4 in WX mode or 1,2,3 in GMAP mode.
Pull out on the GAIN switch to enter the system into the variable gain
mode with VAR displayed in the color bar. Variable gain is useful for
additional weather analysis and for ground mapping. In WX mode,
variable gain can increase receiver sensitivity over the calibrated level
to show very weak targets or it can be reduced below the calibrated
level to eliminate weak returns.
WARNING
HAZARDOUS TARGETS MAY BE ELIMINATED FROM THE DIS-
PLAY WITH LOW SETTINGS OF VARIABLE GAIN.
In the GMAP mode, variable gain is used to reduce the level of the
typically very strong returns from ground targets.
Minimum gain is with the control at its full ccw position. Gain increases
as the control is rotated cw from full ccw . At full cw position, the gain
is at maximum.
In variable gain, the color bar legend contains the variable gain (VAR)
annunciation. Selecting RCT or TGT forces the system into calibrated
gain.
A28- 1146- 102- 00
Operating Controls
3-10