sector in azimuth, within a maximum sector of 270 degrees around the true azimuth zero reference. In this mode, the
antenna elevation angle is controlled as in the manual mode. In the manual mode, synchros, driven by manually
operated handwheels on the front panel of the unit, provide the control voltages required to position the antenna in
azimuth and elevation. In the slave mode, control voltages from a radar or remote antenna system supply the azimuth
and elevation positioning control voltages through switches in the unit.
Additional controls are provided which allow the polarization of the antenna to be changed and the
beam width of the Antenna System to be increased or decreased. A meter is provided which visually indicates the beam
width by percentage of increase from the fixed focal point of the reflector. A cablewrap meter with a "0" center and two
red limit markings affords a visual indication of the azimuth cable wrap in the antenna pedestal.
THEORY OF OPERATION - This subsection contains the theory of operation for the components within the
Control Indicator. A detailed description of these components, as used in the system. is contained in paragraph 2,
of this manual. The theory
of the synchro devices used
on the Control Indicator
paragraph 2 of this section.
FUNCTION OF OPERATING CONTROLS AND INDICATORS (See Figure 5-13)
SERVO DRIVE SWITCH AND INDICATORS - The SERVO DRIVE switch (item 8), S1, which is
interlocked with the SAFE-RUN switch on the antenna pedestal, provides 28-volts DC to operate relays K2 and/or relay
K3 on the Power Supply, depending on the position of switch S3. The indicator light, D64 (item 7), illuminates when the
switch S1 is in the ON position and power is being applied to the servo drive. The SAFETY ON indicator light, DS18
(item 18), illuminates if the SAFE-RUN switch on the antenna pedestal is in the SAFE position.
ANTENNA OPERATION CONTROLS AND INDICATORS - The antenna operation controls and
indicators consist of the MODE SELECT switch (item 16), S2; the AZIMUTH MODE SCAN (item 13), MANUAL (item 14),
and SLAVE (item 15) indicator lights, DS8, DS7 and DS6, respectively; the ELEVATION MODE MANUAL (item 25) and
SLAVE (item 26) indicator lights DS21 and DS20, respectively; and the azimuth and elevation handwheels (items 10 and
The MODE SELECT switch, S2, with SCAN MANUAL and SLAVE positions, provides
selection of the desired mode of system operation. The selected mode of operation is indicated by illumination of the
associated AZIMUTH MODE and ELEVATION MODE indicator lights. DS8, DS7 or DS6, and DS20 or DS21.