TM11-5840-360-14-1-1
4.7.2 RF Switch Control and Position Sensing Circuit
The resolver drive circuits compare a feedback
(V2)
signal from the resolver compensating winding and a
900-Hz square-wave reference signal from the
interswitch units to produce a highly stabilized resolver
The spring-loaded waveguide switch will be in
drive output signal which is added to the resolver stator
position 1 (modes DP-1 or DP-2) until the switch
via the receiver transmitter.
solenoid is energized by selection of modes DP-3 or DP-
Position information (antenna resolver output
4. When DP-3 or DP-4 is selected, a +24V position 2
signals) are applied to two buffer amplifiers to provide
command signal is applied to the switch solenoid from
low-impedance outputs to the switching units.
the switching unit via the interface unit. When the
solenoid is energized, the switch is moved to position 2
4.8.3 Acknowledge Pulse Circuit (V2, V3, V4)
(receiver transmitter II state), a position 2 status signal
is applied to the interface unit, and a resistor is added in
the solenoid line to reduce the solenoid current from a
The acknowledge pulse circuit employs a
high switching level to a lower holding level
passive splitter with an input and output impedance of
75 ohms. The acknowledge signal from the receiver
4.7.3 Dummy Load V2
transmitter is split into two half--amplitude acknowledge
signals and applied to the switching units.
During the normal operating modes, DP-1
through DP-4, the off-line receiver transmitter is
connected to the dummy load but no power is applied to
4.8.4 Signal Feedthrough Circuits (V2, V3, V4)
the dummy load as the off-line receiver transmitter is
turned off. During the two maintenance modes, DP-5
The junction terminals serve as tie points for the
and DP-6, it is possible to have both receiver
various control signals required to interface the receiver
transmitters turned on and the off-line receiver
transmitter with the switching units.
transmitter RF output will be applied to the dummy load.
The dummy load has a frequency range of 8200 to
12400 MHz, a rated average power rating of 500 watts,
4.8.5 Power Supply Circuits (V2, V3, V4)
a test peak power of 290 kW and a VSWR of 1.10
(max.) .
A regulated power supply in the video amplifier
assembly provides 12 Vdc as operating voltages for
4.8 VIDEO AMPLIFIER AM-6932 (V2, V3, V4)
the modules in the assembly.
4.9 RECEIVER TRANSMITTER RT-1241 (V4)
The video amplifier provides resolver signal,
video signal, acknowledge pulse, and control signal
interface coupling between the receiver transmitters
The modulator, transmitter, and receiver
receiver transmitters and switching units. Figure 4-9 is a
sections for the S-band are contained in RT-1241. Solid-
functional block diagram of the video amplifier.
state electronics are utilized throughout except for the
magnetron and the hard-tube modulator. The primary
4.8.1 Video Amplifier Circuits (V2, V3, V4)
functions of the receiver transmitter are to generate and
transmit short pulses and to amplify the echoes received
The video amplifier circuits comprise three 6 dB
by the antenna.
video amplifiers and a passive 70-ohm splitter. The
The receiver transmitter inputs are: the trigger
video signal from the receiver transmitter is amplified by
and control signals from the indicator; the microwave
one of the video amplifiers and applied to the passive
signal returns from the antenna; and ship's power. The
splitter. The two outputs from the passive splitter are
amplified by the other two video amplifiers and applied
receiver transmitter outputs are: the transmitter pulse to
to switching units.
the antenna; the video output and the acknowledge
pulse to the indicator; and the ship's power (fused) to the
antenna motor.
4.8.2 Resolver Drive Circuits (V2, V3, V4)
A functional block diagram of the receiver
The resolver drive circuits provide the gain
transmitter is shown in Figure 4-10. A description of the
necessary to drive the antenna resolver from the master
receiver transmitter subassemblies, subdivided
indicator via the switching unit, receiver, transmitter,
functionally and keyed to Figure 4-10, is given below:
and interconnecting cables. The circuits also provide
the gain and isolation necessary to drive multiple
indicators from the antenna resolver.
4-15
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