Repair of Transmitter Frequency Multiplier Group lA10

TM 11-5820-695-35

separate the coupling and cup; there are three small nylon

(2) Using long nose pliers, extract crystal diode

spacers between them which must not be lost.

1A9A1CRL from connector 1A9A1J2.

(4) Remove the spring from the sleeve. Rotate

b. Replacement of Crystal Diode 1A9A1CR1.

the sleeve one turn clockwise, as viewed from cavity

NOTE

1A1OAIZ1C.

Check choke solder connections on

(5) Remove the hex-nut securing the contact

connector 1A9AlJ2 for signs of cracks or

plunger in cavity 1A10A1Z1C. Unscrew the contact

looseness. If there is any sign of cracks

plunger and remove it from cavity 1A10A1Z1C.

or looseness, Resolder connections

(6) Remove the setscrew from access hole in

outside wall of cavity 1A10A1Z1C.

(1) Observe diode orientation when replacing

(7) Insert a small screwdriver through the

the crystal diode 1A9A1CR1.

The correct diode

access hole (step (6)) and unscrew the nut securing

orientation is shown in figure 5-71 and stamped on the

coupling disc and washer (B, fig. 4-1) to capacitor

cover of the 1A9A1 assembly. Coat the cathode of diode

1A1OA1C3 assembly. Remove the nut, coupling disc,

1A9A1CR1 with Dow Corning No.

340 heat sink

washer, diode holder strap, and varactor diode

compound and insert the anode end into diode holder on

1AlOAlCR1.

connector 1A9A1J2.

(8) Apply a small amount of heat sink

(2) Insert 1A9A1J2, with 1A9A1CR1, into

compound Dow Corning No. 340 to the cathode of

cavity 1A9A1Z1, being certain that the cathode of

replacement varactor diode 1A1OA1CR1 (see fig.4-1 to

1A9A1CR1 is seated properly within 1A9A1Z1 and that

determine varactor diode orientation) and insert the

the choke is installed in the upward position.

cathode end of varactor diode 1A1OA1CR1 into seat in

(3) Secure connector 1A9A1J2 in place with

wall of cavity 1A1OAZ1C.

the four screws removed in a(l) above and replace 1A9A1

(9) Replace diode holder strap, washer,

in 1A9 case.

coupling disc and tighten nut on shaft of capacitor

4-5.

Repair of Transmitter Frequency Multiplier

1A1OA1C3 assembly.

Group lA10 (fig. 41 and 5-72)

(10) Replace contact plunger in cavity

1A10A1Z1C. Be sure it is screwed all the way in, then

Transmitter 2nd stage frequency multiplier 1A1OA1 and

secure it in place with the hex nut removed in ('5) above.

transmitter 3rd stage frequency multiplier 1A1OA2 are

Tighten hex-nut firmly.

replaced at the organizational maintenance level (TM

11-5820-695-12). Coaxial circulator 1A10HY1 is replaced

(11) Rotate sleeve (step (4) above) one turn

at the direct support maintenance level (para 3-27). Depot

counterclockwise.

repair of these assemblies consists of replacing defective

(12) Insert spring into sleeve, then insert cup

piece parts. Precautionary measures should be observed

and coupling over spring and replace coupling over the

in replacement of vacator diodes 1,A1OA1CR1 and

spring.

lArlOA2CR1. Removal and replacement procedures for

(13) Replace setscrew, removed in step (6), in

lA1OA1CRI and 1AIOA2CR1 are provided below.

the access hole. Check that setscrew is flush with inside

a. Removal and Replacement of Varactor Diode

surface of cavity wall and does not extend into cavity

1A10A1CR1.

To replace varactor diode lAlOAlCR1

1A1OA1Z1C.

proceed as follows:

(14) Replace cover and secure with the 10

(1) Loosen the 10 screws and washers securing

screws and washers removed in step (1) above.

cover on transmitter 2nd stage frequency multiplier

b. Removal and Replacement of Varactor Diode

1A10A1 and remove cover (fig. 5-72).

lAlOA2CR1.

(2) Rotate tuning plunger and adjustment

(1) Hold transmitter 3rd stage frequency

screw for cavity 1A10A1Z1C counterclockwise to pull

multiplier 1A10A2 in the vertical position with connector

tuning plunger (C, fig.

4-1) into contact plunger.

lA10A2J1 facing up and unscrew diode holder (center

Continue until tuning plunger is inside contact plunger.

screw, fig. 4-2) approximately three complete turns.

(3) It should be noted that as step (2) was

(2) Unscrew plunger and pull plunger, diode

performed, a spring within the sleeve pushed out on the

holder, and varactor diode 1A10A2CR1 out of the cavity.

coupling and kept the cup in contact with TM 11-5820-

(If necessary, use tweezers to extract 1A10A2CR1 from

695-35 the tuning plunger. The end of the spring is now

seat in crossbar.)

out well beyond the end of the sleeve and is flexible Lift

the coupling and cup (as a unit) off end of spring. Do not

Change 6

4-2.1/(4-2.2 blank)