Reassembly Procedures.

TM 11-5820-509-35

proper location on the card during

module chassis before inserting

reassembly procedures.

these cards in their respective slots.

(2) Repair Procedures.

Replace any

(e) With all switches installed, carefully

defective component or repair the circuit using the

replace the frequency range switch shaft with the groove

procedures outlined in section IV. Component parts

in the coupling end of it oriented as shown in figure 3-

shown on the module schematic diagram (fig. 7-12) are

44.

located on figures 3-22 through 343).

CAUTION

When inserting the frequency range

When using a soldering iron to

switch shaft be careful that the rotor

remove or to replace a component

position of the switches is not

part, use only enough heat to cause

disturbed. Do not use excess force

the solder to flow. Excess heat can

when threading this shaft through

damage the component and may also

the switch rotors; switch parts can

damage the printed circuit.

be damaged unless extreme care is

used.

(a) Vacuum tubes V1 and V2 (part of

card assemblies TB1 and TB2 respectively) are

(f) Replace the C-shaped retaining ring

connected directly to terminals on the card. To remove

in the groove at the rear end of the frequency range

these tubes, unsolder each electrode lead carefully from

switch shaft.

the terminal and then remove the tube from its shield.

(g) Replace the top and bottom covers

(Install a new tube and solder each electrode lead to its

on the module and secure them with the 4-40 screws

proper terminal location as shown in figures 3-22 and 3-

removed in step c(1)(a).

23).

(h) Before installing the module in the

(b) To replace driver tube V3 (fig. 3-9),

main chassis of the receiver-transmitter, observe the

remove the four screws that secure the heat sink to the

CAUTION in step 3-12c.

right side of the module chassis. Remove the heat sink

d. Power Supply PP-3518/PRC-47 (A8A5) (fig. 3-

and the tube from socket XV3. (Install the new tube in

11, 3-45 through 3-51).

the tube socket and replace the heat sink and its

(1) Disassembly Procedures.

corrugated contactor over the replacement tube before

(a) Loosen and remove the two 4-40 x

again installing the four retaining screws.

5/16 pan head screws and the one 4-40 x 5/16 flat head

screw that secure the plastic cover of the module to the

(3) Reassembly Procedures.

chassis: remove the cover.

(a) Replace and solder any wires

removed from the module connector or between card

WARNING

assemblies during the disassembly and repair

Before further disassembly. short-

procedures.

circuit connector pins Pl-A1 and P1-

A2 to ground to discharge the high-

CAUTION

voltage filter capacitors. Personal

Before replacing the switch cards in

injury or death can result from these

the module, make sure that each

voltages.

switch rotor is placed in position no.

1 (fig. 3-42). Equipment damage can

(b) To remove subassembly no. 1 (fig.

result if the band switches are not

346, 3-47), loosen and remove the four 4-40 x 1/4 pan

properly oriented before insertion in

head screws and carefully fold the subassembly down

the module.

and out of the way.

(b) Reassemble switch group Sl-S2-S3

3-48), loosen and remove the four 4-40 x 3/8 pan head

(fig. 3-24, 3-25) and vfo-S6-S7 (fig. 3-31, 3-321 if they

screws and carefully fold the subassembly up out of the

were disassembled.

way.

(d) To remove subassembly no. 3 (fig.

E46, E47, E48 nod the vfo subassembly in their proper

3-49). loosen and remove the two 4-40 x 5/16 net head

locations in the module chassis using the appropriate

screws, their flat washers and stop nuts: carefully lift the

hardware.

subassembly out 0 f the chassis.

(d) Install the switch cards and switch

(e) The remove voltage regulator

card groups in their respective slots if they have been

subassembly TB1 (fig. 3-51). loosen and remove the 4-

removed.

40 x 1/16 pan head screw that secures the bracket and

the terminal post to the chassis; then loosen the 6-32 x 1

NOTE

6-32 p an head screw that secures T2 and the other

The

keyway

switch

card

voltages regulator bracket to the module e chassis

assemblies S6-S7 and S10 must be

There is a flat washer under the.

oriented toward the bottom of be

3-100