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Problem
4.
Gauge tube filament turns on as
soon as ac power is turned on.
Filament light is not on. Filament
glows very brightly indicating high
emission current.
5.
Gauge tube filament turns on as
soon as power is applied. (Emission
normal with filament I ight on.)
6.
Gauge tube filament turns on as
soon as power is applied. (Emission
normal with filament light off.)
7.
Erroneous indication of emission
current on meter but operation
of the filament appears normal.
.
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Possible Causes
I.
Shorted triac S CR I, Fig. 5-4. Apply
a short from gate to anode I (across
C23).
2.
Defective synchronous pulse generator.
I.
Transistor Q 14· shorted, Fig. 5-4.
2.
Relay K3 pins 6 to pin 7 shorted.
3.
External filament remote control
applying a ground to
or J3-H.
I.
Defective relay K3. (Pins 14 and
15 open.
I.
Defective emission current amplifier
IC I 0-B or related circuit component,
Fig. 5-4.
6.6 Electrometer Circuit (Refer to Fig. 5-5 and Fig. 6-1)
I.
Zero meter indication in any range.
(Emission normal.)
2.
With only the power switch on, the
electrometer will not zero in any
range.
I.
Collector cable not connected to gauge
tube and/or controller.
2.
Collector cable open. Check continuity
of collector cable.
I.
Defect in collector cable.
2.
Power supply problem.
3.
Defect in electrometer circuit. Check
Q20, IC9 or related circuit component.
Cure
lace triac.
T roub I eshoo t and repair.
Replace relay.
Replace relay.
Correct external remote control
circuit. It must be a momentary
type of input.
Replace relay K3.
Troubleshoot and repair.
Connect cable to controller.
Repair or replace as necessary.
�epair or replace gauge cable.
Refer to section on power supplies
and repair same.
Replace or repair as necessary.
