Oscillator Control C-4311/PRC-47 (A8A7)

TM 11 5820-509-35

these shafts. If the shaft sticks in a

(d) Secure card assembly E1 to the

switch rotor, a slight rocking motion

module chassis with the six 2-56 x 3/16 pan head

will free it so that it can be further

screws.

withdrawn.

(e) Replace the module cover and

verify that it is seated properly before securing it in

place with the two 4-40 x 5/16 pan head screws and

(g) Carefully lift the interconnected

their associated flat washers.

switch card assemblies (E6, E7, and E8) out of the

module chassis as a unit through the bottom of the

f. Oscillator Control C-4311/PRC-47 (A8A7). ( fig

module chassis.

. 3-14, 3-15, 3-54 through 3-63)

(1) Disassembly Procedures.

NOTE

(a) Remove the module covers by

If the interconnecting wire between

loosening and removing the 4-40 screws that secure the

card assemblies E4 and E5 has not

top and/or bottom covers to the module chassis.

been disconnected, unsolder this

wire, withdraw it through the hold in

NOTE

the partition, and tag it carefully for

Several circuit card assemblies of

reconnection later.

this module are interconnected with

lead wires.

W here necessary,

(h) Loosen and remove the four 4-40 x

unsolder the interconnecting wire

1/4. flat head screws (2 per. side) that secure the

and tag it carefully so that it may be

partition (between E4 and E5) to the sides of the-module

correctly

reconnected

the

chassis; withdraw the partition through the bottom of the

appropriate

terminal

during

module chassis.

reassembly procedures.

(i) Loosen and remove the four 4-40 x

7/8 pan head screws, their associated washers, and the

(b) Remove the 4-40 x 3/16 flat head

four 1/2-inch spacers used to attach card assembly E5

screw on the right side of the chassis near the bottom

to the bearing plate; carefully back the card off the stub

that secures the nylon cable clamp to the chassis.

shaft of the gear assembly and withdraw the card

Carefully slide card assembly E1 out through the bottom

through the bottom of the module chassis.

of the module; then slide out card assembly E2 and TB1

(j) Individual card assemblies (E6, E7,

in that order.

and E8) may be serviced by disconnecting the

interconnecting wires and disassembling the cards from

unsolder the wire that connects this card to card

one another.

assembly E5 (fig. 3-14). Then remove card assembly

E4 through the bottom of the module.

NOTE

(d) To remove card assembly E5, it is

Disassemble these groups of cards

first necessary to remove switch card assemblies E6, E7

only to the extent necessary to affect

and E8. With these cards removed (as a unit), card

the required maintenance procedure.

assembly E5 can be readily withdrawn from the module

chassis using the procedures detailed in steps (e)

(2) Repair Procedures.

Replace any

through (i).

defective component or repair the circuit using the

(e) Verify that the switch couplers are

procedures outlined in section IV. Component parts

aligned as shown in figure 3-63 with the grooves in the

shown in the module schematic diagram (fig. 7-14) are

coupling half vertical and the index spots in the positions

located in figures 3-54 through 3-63.

shown.

CAUTION

NOTE

When using a soldering iron to

The coupler associated with switch

remove or replace a component part,

S2 must be positioned at its

use only enough heat to cause

maximum counterclockwise stop (10

solder to flow. Excess heat can

turns) in addition to having the

damage the component and may also

groove in the coupling half oriented

damage the printed circuit.

vertically.

(3) Reassembly Procedure.

(f) Remove the two switch shafts by

(a) Replace and solder any wires that

first loosening and removing the six 2-56 x 1/4 pan head

were removed from the module connector or from

screws (3 per plate) from the triangular-shaped switch

individual card assemblies during disassembly or repair

retaining plates behind the shaft couplers (fig. 3-63).

procedures.

Carefully withdraw these two shafts by grasping the

coupler and sliding them out through the front of the

(b) Verify that the switch rotors on card

module.

assemblies E5, E7 and E8 are in position no. 1 (fig. 3-

62).

CAUTION

Do not disturb the position of the

interconnect card assemblies E6, E7, and E8, if this unit

switch rotors when withdrawing

assembly was disassembled for maintenance or repair.

3-102