TM 11-5820-921-40-1
performed after completing the Ip ALC alignment procedure (paragraph 3-117).
1.
After completing step 7 of the Ip ALC ALIGNMENT procedure, apply a CW key signal again.
2.
Adjust RF ALC potentiometer 1A7A2R22 for a level of 136 volts on the HP-410C RF Voltmeter.
3.
Tune the receiver-transmitter to 2.150 MHz and to 29.995 MHz. Observe that the power amplifier
tunes properly with a resultant output level on the rf voltmeter of 125 to 159 volts.
4.
Remove the CW key signal and de-energize the power amplifier.
3-121. If unijunction transistor 1A12A1Q1 or potentiometer 1A12A1R14 of Static Power Inverter
Assembly 1A-12 have been replaced, the following procedure must be performed (refer to figure 3-27).
1.
Remove the cover (P/N 755017A4804) from Static Power Inverter Assembly 1A12 and reinsert the
assembly into the Power Amplifier Case Assembly 1A14.
2.
Establish the adjustment setup shown in figure 3-27.
3.
Operate power amplifier in the continuous transmit mode until the 55C thermostat 1A14A3S1 is
energized.
4.
Carefully adjust potentiometer 1A12A1R14 on Static Power Inverter Assembly 1A12 to obtain a
2.5 millisecond interval between the 400 Hz spikes observed on the oscilloscope.
5.
De-energize the equipment and disconnect the adjustment setup.
3-123. Tank Circuit Module Assembly 1A8, with its associated servo motor (1A8A3B1) and end stop
switches (1A8A3S1 and S2) will not require adjustment unless the assembly has been disassembled to
FORCE end stop
repair or replace a damaged part. As shown in figure 3-28, the function of the
FORCE end stop switch 1A8A3S2 is to limit the number of mechanical
switch 1A8A3S1 and the
turns of the Variable Inductor 1A8A5L1center shaft, thus preventing the contact attached to the shaft
from running off the ends of the inductor coil assembly, damaging the rotor. The amount of travel between
the end stop switches is the tuning range of inductor 1A8A5L1. The end stop switches are not adjusted to
actuate at any significant value of inductance.
3-124. The following definitions and parameters apply to Tank Circuit Module Assembly 1A8:
1.
The home end of the 1A8A5L1 inductor corresponds to the point of maximum inductance. This
point is reached when the coil contact on the rotor assembly is rotated in a maximum counterclock-
wise direction looking from the 1A8A3B1 servo motor end of the assembly.
2.
GND is the ground signal generated when the coil (1A8A5L1) is in its home position.
FORCE signal causes the servo system to drive
When the automatic tune cycle is initiated, an
3.
end stop switch
the rotor of coil 1A8A5L1 clockwise until it reaches a tune position or the
18A3S2.
4.
GND is the ground signal generated when the coil (1A8A5L1) is at its minimum inductance.
The effective tuning range of coil 1A8A5L1 (the operating range between the end stop switches) is
5.
twenty-three revolutions of the coil contact.
