orient control for the Antenna Position Control Indicator.
The configuration illustrated in Figure 1-2 is the normal
(5) The major functional circuits in the Antenna System are discussed in the succeeding paragraphs. These
circuits are the antenna drive and positioning circuits, the cable-wrap circuit, the polarization selection circuits, the beam-
broadener circuit, the radome blower, deicer, and safety circuits.
ANTENNA POSITIONING AND DRIVE CIRCUITS (See Figure 1-3) - The simplified schematic diagram of
Figure 1-3 illustrates the antenna drive and positioning circuits for the Antenna Position Control Indicator with both
azimuth and elevation positioning capability, and the power and azimuth orient circuits on the associated Antenna
Control Power Supply.
(1) ANTENNA SYSTEM DRIVE CIRCUITS - Drive power is interlocked with a SAFE-RUN switch S1 on the
antenna pedestal, the SERVO DRIVE switch S1 on the Control Indicator, and a SAFE PRESSURE switch in the radome.
When the switches are in the positions indicated on Figure 1-3 (i. e., the SAFERUN switch in the RUN position and the
SERVO DRIVE switch in the ON position), 28-volt DC is applied through the closed circuit to energize relays K2 and K3
in the Power Supply. With K2 and K3 energized, 115-volts AC is applied through the mated contacts of the relays to
(2) MANUAL MODE OF OPERATION
Since the azimuth and elevation channels function the same in the manual mode of operation,
only the azimuth channel is discussed herein.
In the manual mode of operation, the azimuth positioning voltage is generated by rotation of the azimuth handwheel,
located on the front panel of the Control Indicator. Mode selection is accomplished by placing the MODE SELECT switch
S2 to the MANUAL position. This allows 28-volts DC to be applied to the azimuth handwheel clutch, L1, energizing the
clutch and connecting the azimuth handwheel to the manual/scan control transmitter synchro, B3, in the Control
Indicator. The stator leads of B3 are connected through other contacts of MODE SELECT switch S2 to the azimuth
orient differential control transmitter synchros B1 and B2 in the Power Supply. The differential control transmitters allow
a preset factor, which compensates for misorientation of the antenna pedestal to true north or a selected reference point,
to be added to the error voltage generated by the manual/scan control transmitter synchro in the Control Indicator. The
stator leads of the differential control transmitters are