33

3.2 Checking Magnetron Heater Voltage

Magnetron heater voltage is formed on the PTU or MD Board of the antenna unit, and
preadjusted at the factory. Therefore, no adjustment is required. However, check magnetron
heater voltage for confirmation as follows. This procedure should only be performed by
a qualified technician.
NOTICE
For MODEL1724C,
lift the radome cover slowly.
The antenna radiator may be
caught by the screw holes in
the radome cover.
If you feel the radiator is caught
by the screw holes, lower
the cover, turn it a few degree
and then lift it again.
Screw holes
(4 places)
1. Open the antenna unit.
2. Turn on the power. Do not transmit the radar.
3. Connect a multimeter, set to 10VDC range, to appropriate test point on the MD Board
(MODEL 1724C) or PTU Board (MODEL 1734C) Board in the antenna unit, referring to
the table below for test points.
4. Confirm that the multimeter indication is as shown in the table.
MODEL 1724C MODEL 1734C
Check point TP804#6(+) and #4(-) on MD Board TP802#4(+) and #6(-) on PTU Board
Multimeter
indication 7.9 to 8.1 V 7.4 to 7.6 V
Adjustment
point VR801 on MD Board R106 on PTU Board