Regulator Board 2A3 Detailed Functional Operation

TM 11-5820-873-34

associated circuitry. A positive amplitude signal triggers

related components. An input above + 10 VDC, to the

2A2Q13 to provide a drive signal at 2XA2-17. A

Amplitude Level Changer, controls 2A2Q10 conduction

negative amplitude signal triggers 2A2Q14 to supply a

Transistor 2A2Q10 then regulates 2A2Q12 which

drive signal at 2XA2-V. Transistor 2A2Q14 is cutoff,

generates a drive signal to the Amplitude Servo Preamp

terminating the L4 home function, through 2A2CR30

positive drive. If the Amplitude Level Changer input is

when a 50 ohm point is detected. Similarly, 2A2Q14 is

below + 10 VDC, 2A2Qll conducts to establish a drive

cutoff at L min through 2A2CR23 and by an inhibit

signal to the Amplitude Servo Preamp negative drive.

signal through 2A2CR27. Transistor 2A2Q13 is cutoff at

i. L4 Home Flip-Flop. Diodes 2A2CR14, 2A2CR15,

L max through 2A2CR22 and by an inhibit signal

2A2CR17, gates 2A2U4A-B and associated components

through 2A2CR26

make up the L4 Home flip-flop. A logic 0 is established

at 2A2U4A-3, by 2A2C32, when power is first applied.

m. Phase/Amplitude Brake. The Phase/Amplitude

An L4 home signal, logic 0 at 2XA2-14, to 2A2U4A-2

Brake is made up of 2A2CR18, 2A2CR19, 2A2CR31,

sets the FF for logic 1 at 2A2U4A-3. Amplitude Servo

2A2Q8, 2A2Q9 and related components Normal

Preamp transistor 2A2Q14 is triggered by the logic 1 to

operation is with both 2A2Q8 and 2A2Q9 conducting. A

generate a drive signal at 2XA2-V. At the same time,

ground is maintained at 2XA2-12 by 2A2Q8 and at

the logic 0 at 2A2U4B-6 is fed to L4 Drive Inhibit. The

2XA2-T by 2A2Q9. Braking occurs when one and/or the

2A2U4A-3 logic 1 is maintained until L4 mm is

other transistor is cutoff. Both transistors are cutoff by a

achieved. Either an L minlogic 0 or positive phase

logic 0, on the 50 (-) line, at 2XA2-10. The logic 0 is fed

angle logic 0 applied to 2A2U4A-3 resets the L4 Home

through 2A2CR18 to 2A2Q8 and through 2A2C19 to

FF.

2A2Q9. An L mm logic 0 will also cutoff 2A2Q19

through 2A2CR31. When cutoff, the output of the cutoff

j. L4 Force Flip-Flop. The L4 Force Flip-Flop

transistor goes positive. This positive voltage that is the

consists of 2A2CR12, 2A2CR16, 2A2U4C-D, 2A2U5B-

braking signal to the Servo Motor Control Assembly

C-D and related components. When power first comes

2A6.

on, 2A2C31 causes the FF to reset with logic 0 at

2A2U4C-8. A reset also occurs with an L4 Home signal.

2-16. Regulator Board 2A3 Detailed Functional

This logic 0 signal is applied to 2A2U4C-8 through

Operation

2A2CR12. It is necessary to prevent L4 Home and L4

(Fig FO-32)

Force flip-flops from being on simultaneously. The FF

The Regulator Board contains an RF detector comprised

is not set, logic 1 at 2A2U4C-8, unless 2C1 reaches max

of 2A3R2, 2A3CR1, 2A3CR2 and 2A3C4 and a voltage

and 2L4 reaches min and an untuned condition still

regulator The RF detector senses the presence of RF on

exists. Since both 2C1 and 2L4 have reached limits, a

the transmission line The detector output is a reduced

force function is required to drive 2L4 toward maximum.

level of the positive signals only The voltage regulator

This action is necessary to create a positive phase angle

provides a filtered + 5 VDC level It also provides some

so tuning can continue. The C max and L mm logic 0

filtering for the + 10 VDC line and the + 28 VDC

signals are applied to 2A2U5B after being inverted by

switched line.

either 2A2U5C or 2A2U5D. The 2A2U5B-6 logic 0 is

2-17.

Filter Board 2A3A Detailed Functional

applied to 2A2U4C-9 and sets the L4 Force FF. The

Operation

logic 1 on 2A2U4C-8 is fed to the Amplitude Servo

(Fig FO-32)

Preamp to drive 2L4 toward maximum inductance.

The Filter Board provides RF filtering to keep RF off the

When a positive phase angle occurs, L4 Force FF will

antenna coupler control cable. Each input and output of

be reset by logic 0 through 2A2CR16 to 2A2U4C-8. If

the antenna coupler passes through a separate filter

the force function continues until L max, the FF will be

network on this board. The filters are standard pi type

reset by logic 0 through 2A2CR24 to 2A2U4C-8.

configuration with capacitors and choke.

k. Drive Inhibit. Gate 2A2U5A, diode 2A2CR25,

2-18. Phase and Amplitude Detectors 2A4 Detailed

transistor 2A2Q15 and associated resistors comprise

Functional Operation

this circuit. If either L4 Home FF or L4 Force FF is set,

(Fig FO-32)

then 2A2U5A-3 has a logic 1 output. The logic 1

Board 2A4 provides the outputs necessary to initiate

triggers 2A2Q15 to short out any drive signals to the

driving 2C1 and 2L4 for tuning Its outputs are

Amplitude Servo Preamp. Transistor 2A2Q15 is also

proportionate to inductive and/or capacitive phase

triggered through 2A2CR25 with a logic 1, 50 (+) signal.

differences and amplitude variations above and below

Again, the drive signals to the Amplitude Servo Preamp

are shorted out. This action stops the drive to the servo

preamp anytime reflected power is below threshold.

l. Amplitude Servo Preamp. Contained in the

Amplitude Servo Preamp are 2A2CR22, 2A2CR23,

2A2CR27, 2A2CR28, 2A2CR30, 2A2Q13, 2A2Q14 and

2-20