TM 11-5840-281-35/1
brator is a positive gate (cursor trigger) which is applied
cutoff) terminates the cursor pulse.
to cursor pulse generator circuit to initiate the cursor
(2) The fill-in sawtooth cutoff pulse is
pulse.
applied to the fill-in sawtooth generator shutoff gate to
(2) The cursor trigger is also applied to
disable the fill-in sawtooth generator.
h. Cursor Pulse Generator Circuit (fig. 7-12 and
cursor sawtooth generator shutoff gate Q2608 to disable
the cursor sawtooth generator. The complimentary
7-57). The cursor pulse generator circuit consists of
output (fill-in sawtooth gate) from the collector of
emitter-follower transistors 02901, Q2903, Q2904, and
transistor Q2707 is applied to the fill-in sawtooth
amplifier transistor Q2902 on the cursor generator
generator circuit to initiate the fill-in sawtooth.
subassembly. Prior to arrival of the cursor trigger,
f. Fill-in Sawtooth Generator Circuit (fig. 7-12,
emitter-follower transistor 92901 is near cutoff due to
7-5, and 7-58). The fill-in sawtooth generator circuit
ground potential supplied through diode CR2902 at its
consists of AND gate transistors Q9710 and Q9711;
base and the conducting half of cursor trigger
clamp transistor Q9712 on the cursor control
multivibrator transistor Q2707 and Q2708 on the cursor
subassembly; and fill-in sawtooth generator transistors
trigger generator (fig. 7-56). When the cursor trigger
Q2614, 0Q2615, 0Q2616 and emitterfollower transistor
multivibrator changes state, emitter-follower transistor
Q2617 on the sawtooth generator subassembly.
Q2901 is forward-biased and conducts until the negative
(1) The fill-in sawtooth generator stage
cursor trigger cutoff gate is applied to the circuit through
consists of current-adder transistor Q2614, temperature-
diode CR2901. With FILL-IN switch S2901 in the ON
compensating
transistor
Q2615,
emitter-follower
position, the output of transistor Q2901 is coupled
transistor Q2616, and associated components.
It
through capacitor C2902 and resistor R2904 to the
develops a sawtooth waveform the same as the cursor
emitter of ground base amplifier transistor Q2902. With
sawtooth generator stage except that the sawtooth is
FILL-IN switch S2901 in the OFF position, the signal is
developed on a pedestal. The pedestal is developed by
differentiated by capacitor C2903 and resistor R2905 and
charging capacitor C2605 through resistor R2628.
provides a narrow pulse rather than a cursor pulse to the
(2) Since the fill-in sawtooth is generated
input of transistor Q2902. The output of transistor
later than the cursor sawtooth, the pedestal provides an
Q2902 is applied to emitter-follower transistor Q2903.
immediate voltage increase at close range to provide an
The output of transistor Q2903 is applied across
immediate cursor solution (in effect a cursor pulse with
CURSOR INTENS control R2907. A portion of the
no fill-in). The slope of the fill-in cursor sawtooth is
cursor pulse is tapped off at resistor R2907 and applied
determined by the sum of fill-in angle no. 1 and fill-in
through level-shift Zener diode CR2904 to the base of
angle no. 2 currents supplied by the control circuits.
emitter-follower transistor Q2904.
The output of
g. Cursor Trigger Cutoff Generator Circuit (fig.
transistor Q2904 is mixed with the range marks and
applied to the mixer amplifier.
7-12 and 7-56). The cursor trigger cutoff generator
amplifier transistor Q2709, emitter-follower transistor
2-10.
Cursor Control Circuit Description
Q2710, and multivibrator transistors Q2711 and Q2712
(fig. 7-13)
on the sawtooth comparator subassembly.
(1) The variable-slope sawtooth output of
a. General. The cursor control circuit functions
the fill-in sawtooth generator is applied to fill-in sawtooth
as part of the control-indicator section, and consists of
comparator diode CR2703 which compares the fill-in
Pulse Generator O-1333/TPN-18 components which
sawtooth to the reference sawtooth in a manner similar
make up the input to the cursor generator. The cursor
to the cursor trigger generator sawtooth comparator.
control circuit consists of relays, switches, controls, and
The comparison point of the fill-in sawtooth comparator
transistor stages which supply reference voltages and
is adjusted by FILL-IN CO-I control 2723. The voltage
control the application of antenna angle data and
pulse from the fill-in sawtooth comparator is amplified by
reference voltage to the cursor generator. The cursor
transistor Q2709, coupled through emitter-follower
control group consists of the courseline, glidepath,
transistor Q2710, and applied as a trigger pulse to
multivibrator transistors Q2711 and Q2712. The output
from the collector of transistor Q2711 (cursor trigger
2-45
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