Frequency Selection Mechanism

TM 11-5820-509-35

against their stops and rotate scales (3) and (22) using

knobs (1) and (21) respectively so that the index marks

NOTE

are at 0; then tighten setscrews (2) and (20).

Stub shaft (35), in addition to being

pressed into the front panel of the

NOTE

receiver-transmitter, is secured in

Repeat step (29) until both controls

place by 6-32x 5/16 flat head screw

are set at 0 when the inductors are

(10) that is accessible by removing

against their respective stops.

the front panel unit nameplate.

(30) Insert LOCK knob (15), with washer (16)

(6) Bevel gear assemblies (24) and (65) are

attached, into the hole in dial stop (14) and screw the

removable by withdrawing either shaft out of the rear of

knob into place on stud (18). Then install E-ring (17) in

the panel until it is removed from panel bearing (23) or

the groove of the LOCK knob shaft.

(66). Do not remove retaining rings (89) or (64) unless

these bearings are defective.

3-16. Frequency Selection Mechanism

(fig. 3-90)

CAUTION

Do not attempt to disassemble gear-

shaft assemblies that are pinned

a. Disassembly Procedures.

together. If either the gear or the

shaft is defective, replace the entire

NOTE

assembly as a unit.

Disassemble the frequency selection

mechanism only to the extent

necessary to accomplish repair or

(7) Loosen and remove 6-32 x 1/2 flat head

maintenance. Before beginning, set

screws (7),18), (9), (11), and (12) to remove sleeve nuts

the KILOCYCLES indicator on the

(25), (39), (42), 175) and (100).

front of the receiver-transmitter to

2000.

NOTE

Sleeve nuts (42) and (100) have

shoulders provided to index the

(1) Remove Signal Data Translator CV-

mounting holes in gear plate (103)

1377A/PRC-47 (A3) and Oscillator Control C.

for alignment.

4311/PRC-47 (A7) from their locations in the RT.

671/PRC-47 using the procedures of paragraph 3-126

(2) Loosen setscrews 12), (4), and (6), two

(8) Remove panel bearings (23), (66), and

per knob, and remove frequency control knobs (1),(3),

(79) only if they are defective. Whenever any one of

and (5) from their shafts.

these panel bearings is replaced, replace gasket (221

(67), and/or (80) with it.

(3) Loosen and remove 6-32 x 3/8 pan head

screws (102), (108),(119),(134), and (137) and washers

(9) The spur gear-pinion assembly consisting

(101), (107), (118), (132),1133), and (136) that attach

of gear (72), shaft collar (70), bearing (68), and

the gear plate (103) to sleeve nuts (25),(39),(42), (75),

gearshaft (127) is removed by pressing the pinion end of

and (100).

the shaft through the gear plate. Further disassembly of

this spur gear-pinion assembly is performed as follows:

NOTE

(a) Remove washer (73) from the end

Before proceeding, dress the cable

of the shaft.

away from the back of the gear plate

(b) Loosen setscrews (71) in shaft

as far as possible so that the gear

collar (70) and withdraw spur gear (72) from the shaft.

plate can be withdrawn sufficiently to

disengage the center frequency-

shaft and release C-ring (69).

control shaft (78).

(d) Remove panel bearing (68) from

the pinion shaft.

(4) Carefully withdraw gear plate (103) from

the shoulders of sleeve nuts no. 2 (42) and (100) to

NOTE

provide access to all gears and gearshaft assemblies.

If either the pinion or its gearshaft

(127) is defective, replace the pinion-

NOTE

gearshaft assembly as a unit.

When withdrawing the gear plate, do

not lose flat washer (27); it may

(10) Remove the center frequency-control

adhere to sleeve bearing (26). Place

gearshaft assembly (78) as follows:

this washer on spur gearshaft (28)

(a) Release pawl spring (111) from eye

for future installation.

(b) Remove E-ring (124) from stub

shaft (122) and rotate gear and stop assembly (123)

(5) Remove idler gears (18), (29), (37), and

until it can be removed from the stub shaft.

(43) only if the gear or its stub shaft 114),(15), (17), or

135) is defective. Remove E-ring (19) (30), (38), or

and

144) to remove the defective idle; gear.

3-107