Receiver l~/~udio Circuit Board
TROUBLESHOOTING
CHART
-
-
Refer to the "X-Ray View" and "Voltage Chart" (fold-out
from this page).
SYMPTOM
No Audio output
Audio distorted or weak.
I
No AGC.
No
S meter deflection.
No IF output.
+
,
POSSIBLE CAUSE
1.
Q513, 0514. 0515, 0516. Q517,Q618.
Check voltages.
2.
IC502.
3.
Posltive voltage on tTX line in recelve.
4.
Audio Level control shorted.
5. RF
Ga~n fully counterclockw~se.
1.
0513 through
Q518. Check voltages
2.
Insufficient carrier injection (pin 14).
3.
IC502. Check voltages.
4.
AGC not working. Voltage at pin 8 does
not change for strong signals.
5.
0501,
IC501, 0502,0503. Check voltages.
6.
D506, D507, D508,
D509
defective or
improperly installed.
7.
T502.
-
1.
0504,
0505,0506. (3507, Q508. Q509.
Q510, Q611.
2.
Pin 10 grounded.
3.
Coaxial jumper cable open or shorted.
4.
R559 or R561 wrong value.
1.
Smeter control. R534. needs adjustment.
2.
No
AGC.
3.
AGC switch in Off position.
1.
0501, IC501.0502, 0503
2.
Voltage at
ptn 8 in excess of 6V.
3.
Pin
4
at ground potent~al.
4.
RF Gain fully wunterclockwise.
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