Selecting A Range; Adjusting Receiver Sensitivity; Adjusting Tuning - JRC 1500 MKII Instruction Manual

4.3 SELECTING A RANGE

Press the J-DIAL until RANGE is highlighted in the upper right corner of the
display. The range scale and range rings setting in use is shown in the upper left
corner. Rotate the J-DIAL clockwise to increase the range and anti-clockwise
to decrease it. The range rings are automatically set to correspond with this
selection.

4.4 ADJUSTING RECEIVER SENSITIVITY

Press the J-DIAL until GAIN appears highlighted in the upper right corner of
the display. Rotate the J-DIAL clockwise or counterclockwise, to vary the gain
and thus control the strength of echo returns on the radar screen. An on-screen
bar indicates the gain level selected. The proper setting is when the background
noise is just visible on the screen. (i.e. a light speckled effect)

4.5 ADJUSTING TUNING

Press the J-DIAL until the TUNE appears highlighted at the upper right corner
of the display. Rotate the J-DIAL clockwise or counterclockwise, to maximize
the target echo. If there is no large, identifiable target (e.g. big ship or land)
within range, select SEA CLUTTER and turn the control to maximum. Use
these echoes from wave crests to adjust the tuning bar for fullest attainable
deflection. This is best done with the range set to 3 nm or 6 nm.
When the radar has warmed up, it may be necessary to make a further fine tune
adjustment.
AUTO TUNE
The RADAR 1500 MK2 has an automatic tuning feature. In this mode, the
radar automatically tunes itself for best efficiency at all ranges. (refer to 4.24)
OPERATION 25