TM 11-5840-281-35/1
Figure 2-16. Video amplifier ftc circuit,
(3) In SEARCH operation, the elevation drive motor is
verse direction, and so to allow time fr Antenna AS-
disabled. The azimuth drive motor turns Antenna AS-
1292/TPN-8 to scan through its 30-degree precision
1292/TPN-8 at approximately 16 rpm in a cw rotation.
sector. A servo loop, with Antenna AS-1291/TPN-8
When operating in NORM (10-degree elevation) or 35'
input, controls the position of Antenna AS-1292/TPN-8 to
EL modes, the elevation drive motor runs at full speed
alternate scans with Antenna AS-1291/TPN-8. Each
and nods Antenna AS-1291/TPN-8 through a crank
antenna passes through its scan area while the other
linkage at one look per second. The terms 10-degree
antenna Is in overscan. When operating in 60 AZ mode,
elevation and 35 EL describe the upper limits of the
the elevation drive motor is reduced to half-speed to
elevation display. The scan area is actually 11 degrees
allow time for the additional 30-degree azimuth sector
and 36 degrees, since the lower limit is -1 degree (or 1
scan. The additional 30-degree azimut sector extends in
degree below the horizon). The antenna nods through
a ccw direction from the normal 30degree precision
several degrees above and below the scan area (called
sector. When in SIMULT mode, the elevation drive
over- scan) to allow the antenna to slow down and re-
motor runs at full speed but does not control Antenna
AS-1291/TPN-8,
2-22
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