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Model 606A
Sect.IV
Page 7
TABLE
4-2.
TROUBLESHOOTING
CHART
(CONT'D.)
Measure
Normal Indication
Possible Cause of Malfunction
RF AMPLIFIER (Cont'd.)
4. V8 (6AW8)
pin 2
0 to+4.5vde as R63isrotated
R31, 53,57, 60, 61, 62, 64, 65 and 68.
pin 6
+4,1 vde (nominal)
C29, R32, 33, 34, 35, V7, 8.
pin 9
+76 vdc (nominal)
R20, 22, 23, 29, 30, V8.
pin 3
+150 vdec (nominal)
C28, 29, R33, 34, 35, V7.
pin 8
+54 vdc (nominal)
Same as pin 3.
pin 7
0 to+4 vde as R63 is rotated
C23, 24, 25, CR2, 3, R17, 24, 25, 26, 36, V8.
5. V6 (12B4)
pin 2, 7
-10 to -25 vdcas R63 is rotated C19, R20, 22, 23, 29, 30, V7 or 8.
R10, 38, V3, 4, 6.
pin 9
+110 vde (nominal)
6. V3 and 4 (6CL6's)
pin 6
+ 295 vdc (nominal)
Shorted C12, 14,15, open T3 or contacts
on turret.
pin 3, 8
+ 295 vdc (nominal)
Check C10, 11, 14,15, 16, R10, 15
pin 2,9
+100 vdc (nominal).
If this
RII, 12, triode section of V1.
voltage is incorrect the RF
Oscillator is not functioning
properly.
pin 1
+ 112 vdc (nominal)
R13, 14, check voltage on pin 9 V6.
7. CR2, anode
6 vrms (nominal) withl1 VOLT
Check V3 and 4 plate voltage and output
output level.
Varies 0 to
voltage as given in Table 4-4,
6 vrms as ATTENUATOR
VERNIER is turned.
Possible Cause
Symptom
Defective C8, 10 ABC, 32, 33, 53 and LI, 4.
Foreign material across tuning capacitors:
C4, 5,
7, 14, 15 and 18.
Defective microswitch 57.
Feedback system defective.
. Fuse Fi, (.15 amp) burns out
9, Sharp drop (hole) in power output level,
or a sharp increase (peak) in oscillator
| Check shorting fingers in cirret.
This prevents next
or amplifier current as frequency dial
lower band coil from resonating and absorbing power,
is tuned.
10, R15 (100 ohms) burns out,
Shorted tuning capacitor C14, 15 or 18.
Open or shorted CR2, 3.
Shorted C23, 24, 25 or S3.
If this condition affects one band only, check the
turret contact and coil for that one band.
Also check
switch S3 (on rf deck) for shorts.
If this condition persists on all bands see Table 4-3.
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