NO RCV LEVEL READING ON METER M1. RECEIVE CHANNEL MALFUNCTIONING

TM 11-5805-387-34-2

MALFUNCTION/SYMPTOM

PROBABLE CAUSE

TEST PROCEDURE

INDICATION

YES

3. Remove transmitter module A3. Check

Continuity

Go to 4.

Replace

continuity of 50-ohm mike keying circuit

defective

components external to module A3: diode

component.

CR4, RCV/SEND switch S5, circuit board

A6, feed through capacitors C4, C9, C17,

C18 (fig. FO-11).

4. Connect AN/USM-207 across terminal 1 of

200-2,300 Hz

Continue test

Go to 5.

filter FL3. Speak into mike.

Connect AN/USM-207 across terminal 3 of

200-2,300 Hz

------------------

Replace

filter FL3. Speak Into mike.

defective filter

FL3 (para 3-9).

5. Connect ANIUSM-281 between terminal 8

Mike Input

Replace

--------------------

(ground) of XA3 and terminal 12 of XA3.

signal

module A3

present.

(para 2-8).

(8) NO RCV LEVEL READING ON METER

Defective: One way-duplex switch S1

M1. RECEIVE CHANNEL MALFUNC-

TIONING

NOTE

There will be no RCV LEVEL indication when using test cable No. 3.

Check continuity of ONE WAY/DUPLEX

Continuity

---------------

Replace

switch (fig. FO-8).

defective

switch S1

(para 3-8).

2-16