TM 11-5840-281-35/1
B502 is connected to Antenna AS-1292/TPN-8 circuits
operated by the cams provide unblanking and az-el
as the azimuth drive signal. In the 35 EL mode, the
switching information to Remote Switching Control C-
output of 35-degree el synchro B503 is utilized as the
6989/TPN-18.
azimuth drive signal.
(5) Azimuth angle data control R1001 is a
(6) EL ANGLE DATA control R501 provides
350-degree potentiometer, geared up 3:1 with respect to
a dc voltage to the control circuits proportional to the
Antenna AS-1292/TPN-8; negative 35 volts is applied
elevation scan angle. Control R501 is geared up from
across R1001, making the scale factor 0.3 volt-per-
the antenna at a ratio of 4:1, -35 volts is applied, and the
degree of antenna position Angle voltage at the wiper
scale factor is 0.4 volt per-degree. Control R501 in
arm of azimuth angle data control R1001 is applied to
Antenna Drive TG-114/TPN-8 is mechanically aligned so
the azimuth electronic filter in Radar Receiver-
that its output is -1.5 volts when Antenna AS-1291/ TPN-
Transmitter RT-818/TPN-18. Azimuth angle data control
8 is at the bottom of its scan in the 35 EL mode. The
R1001 is mechanically aligned so that its output is -9
output of control R501 is applied to the elevation
volts when Antenna AS-1292/TPN-8 is positioned to -15
electronic filter in Radar Receiver-Transmitter RT-
degrees (15 degrees cw from 0 degree) .
d. Electronic Control Preamplifier Circuit (Fig. 7-
818/TPN-18. (Refer to paragraph 25g below.).
c. Antenna Drive TG-113/TPN-8 Circuit (Fig.
8 and 7-33). The electronic control preamplifier circuit
7-8). Antenna Drive TG-113/TPN-8 consists of motor
provides azimuth drive control signals.
assembly B1002, comprising a motor, tachometer, and
(1)In precision mode operation, summing
blower; azimuth synchro B1001; azimuth angle data
network resistors R7501, R7502, and R7503 receive the
potentiometer R1001; and three cam-operated
following three inputs: azimuth drive signal from either
microswitches S1001, S1002, and S1003.
the 10-degree el or 35-degree el synchro (B502 and
(1) Azimuth drive motor B1002 is a 2-phase
B503); azimuth position feedback from azimuth synchro
servo motor with a center-tapped control winding.
B1001: and the 30-degree azimuth reference shift signal
Reference phase power is applied by the
from 30 OFFSET control R4062 in Remote Switching
autotransformer circuit in the drive motor amplifier
Control C-6989/TPN-18.
subassembly. Directional control of azimuth drive motor
(2) The summing network output is an error
B1002 rotation is achieved by connecting the A-phase
signal that is either in-phase or 180 degrees out-of-
power to either end of the control winding. The power to
phase with the 400-Hz reference voltage. This error
the control winding of the motor is delivered by the
signal is applied to two-stage ac amplifier transistors
electronic control amplifier. The tachometer is driven off
Q7501 and Q7502. The amplifier gain is adjusted by AC
the azimuth drive motor shaft and provides rate feedback
GAIN control R7508. In the precision mode, AC GAIN
information to the azimuth drive servo loop.
The
control R7508 is adjusted for the maximum gain that will
tachometer output is either in-phase or 180 degrees out-
still allow Antenna AS-1292/TPN-8 to operate smoothly
of-phase with respect to the A-phase of 400-Hz power.
The ac amplifier output is coupled through emitter-
(2) A blower is used to dissipate the heat
follower transistor Q7503 to ring demodulator diodes
generated by the drive motor. The blower motor is
CR7501, CR7502, CR7503, and CR7504.
operated by 3-phase power received directly from MAIN
(3) Reference voltage is applied to the ring
POWER circuit breaker CBIO1 on the control panel of
demodulator by transformer T7501. With no signal out
Radar Receiver-Transmitter RT-818/TPN-18.
of the ac amplifier, and with the instantaneous reference
(3) Azimuth synchro B1001 is connected to
voltage at the junction of diodes CR7501 and CR7503
Antenna AS-1292/TPN-8 at a 1:1 ratio, The output of
negative with respect to the junction of diodes CR7502
azimuth synchro B1001 provides azimuth position
and CR7504, both sides of the ring demodulator conduct
information to the azimuth drive servo loop.
equally, dropping the voltage across resistors R7518 and
(4) Camshaft rotation is coupled to Antenna
R7519 Zero volt appears at the junction of diodes
AS-1292/TPN-8 at a 1 :1 ratio. Three cams operate
CR7503 and CR7504. If an error signal with an
switches S1001, S1002, and S1003, and each cam is
instantaneous negative polarity is applied to the junction
independently adjustable on the shaft. The switches
of diodes CR7501 and CR7502 at this
2-25
Previous Page
