NorthStar 958 Operator's Manual page 144

Chapter 10 - Understanding Radar Functions
Adjust radar page 2
Page 136
The GAIN key controls the strength of all echoes, and should
be adjusted for a pleasing and useful image. You can set the
gain for manual adjustment (by you) or automatic adjustment
(by the 958). If you're adjusting the gain manually, you can
change the gain value.
Certain types of interference (for example, from radar operated
by other vessels) can be lessened by using the interference
rejection filter. Press the INTERFERENCE REJECTION key
repeatedly to select off, 1 (low), 2 (medium), or 3 (high).
Press the following keys to adjust the radar transmitter, the
transparency (fade) of the radar overlay on a chart, the radar
trails, and the visibility of echoes.
Press the RADAR TX key repeatedly to turn the radar trans-
mitter on or off. the radar transmitter is automatically turned
off every time you shut down the 958; therefore, you must
turn the RADAR TX key to ON every time you power up the
958. Turning the transmitter off when it is not in use can save
electrical power and allows you to work safely in the vicinity of
the rotating antenna.
When you overlay a radar image on a chart, you can choose
whether the radar should be opaque (the chart doesn't show
through) or transparent (the chart shows through faintly).
Press the FADE key repeatedly to select off (no transparency),
1, or 2 (maximum transparency).
Trails on the radar image help you track the motion of moving
targets. You can select the trail that appears at a target's loca-
tion. Press the TRAILS key repeatedly to turn the trails off
completely or select a 15-second, 30-second, 1-minute,
3-minute, 6-minute, or continuous trail.
Press the EXPAND key repeatedly to turn echo expansion off
or on. Select ON to make very small echoes appear larger and
easier to see.
958 Operator's Manual, Rev. A