TM 11-5985-284-15
Procedure
Probable trouble
Indication
Item
a. Make resistauce check of cable; if
a. Shortcd or open coaxial cable - - - - - - - - -
No output signal supplied
1
shorted, replace cable.
to associated receiver.
b. Clean and check continuity of switch
b.
Defective
ATTENUATOR
switch.
A3S1 ; if defective, replace assebly
A3.
Note. Assembly A3 includes switch and resis-
tors (fig. 4-4).
c. Check resistors R1 through R9 on
c. Defective attenuation pi-network cir-
assembly A3 ; if any resistor is defec-
cuit.
tive, replace assembly
Clean and make continuity check of A2S1
Defectivc BANDSWITCH switch (A2S1).
No output during 30-MHz
2
if switch is defective, replace assembly
operation.
A2.
Note. Assembly A2 includes switch and circuit
components (fig. 4-4).
a. Defective switch A2S1 - - - - - - - - - - -
No output during 40-
3
a.
replace assembly A2.
MHz operation.
b. Inductor A2L4 open or A2C4 shorted . . .
A2C4. If defective, replace assembly
Make resistance check of associated in-
Defective inductor and/or capacitor on
No output during 50-,
4
ductor and capacitor. If defective,
assembly A2 : L3 or C3 for 50-MHz
60-, or 70-MHz opera-
replace assembly A2.
operation, L2 or C2 for 60-MHz opera-
tion.
tion, L1 or C1 for 70-MHz operation.
Repair bent plates. If capacitor is
Capacitor C1 plates bent (rub against
Rotation of FINE TUNE
5
defective, higher category repair is re-
each other), or shaft bearing is noisy.
control C1 causes noise
quired. (Alinement of circuit is re-
in receiver.
quired if C1 is replaced.)
Change 1
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