S7ct. IV Pag? 7
TROUBLE SHOOTING CHART
SYMPTOM AND
POSSIBLE CAUSE TEST PROCEDURE REM EDY
(2) To check capacitors C8D and
C 14:
A. Connect one ohmmeter
terminal to C8D rotor and
other to C7 stator.
B. With -hp-207Adisconnec-
ted from line ohmmeter
should indicate > 80 meg-
ohms.
e. Capacitor C8 shorted to e. (1) Connect ohmmeter common e. If resistance measurement indi-
ground. to instrument chassis and the cates short, check for defect in
other lead to C8D stator. insulation betweenC8 and instru-
C8ABCD rotors, or C8ABC ment chassis.
stators.
(2) Resistance to ground is nor-
mally:
18K from C8D stator.
80M from C8ABCD rotors.
20M from C8ABC stators.
f. Defective lamp (R16). r. See paragraph 4-4.
3. Distortion in output.
a. Bad tube in oscillator cir- I. See paragraphs 4-3 and 4-8.
cuits.
b. Incorrect potentials on tube 3. Check as described in 2a, c above.
pins.
c. Dust on plates of tuning cap- 3. Inspect visually. c. With air hose, gently blow out dust.
acitor C8.
d. Defective lamp (R16). i. See paragraph 4-4.
i. Noise present in output waveform
when AMPLITUDE control is ro-
tated; output voltage unstable when
AMPLITUDE control is rotated.
a. Defective AMPLITUDE con- a. ReplaceR36 (see paragraph 4-6).
trol (R36). |