AUTOGRAJ? RECORDINGS ILLUSTRATING MALFUNCTIONING
OF INSTRUMENT
WRONG TEST PROCEDURE RIGHT
Set X on 750 MV range.
Set Y on 5 V range.
Rotate potentiometer of test rig
slowly in both directions.
Poor retrace indicates low gain in
Y channel.
Repeat for X channel with settings
ofX=7.5V; Y=l v.
Use same range settings for each
channel as above.
Erratic writing over whole range
indicates gain setting too high in
c hannel being te s te d .
Use same range settings for each
channel as above.
Erratic writing in one or more
portions of range indicates worn
or dirty balance potentiometer ,
Use same range settings for each
channel as above.
Three cycles of erratic retrace
indicate over -tight adjustment of
gear train mesh. See Sect. IV,
par. 3.
With 1-1 /2 volt battery connected
to Y channel input and X input
open, slowly rotate X zero control
while rapidly changing Y range
switch between the 5 and 10 volt
positions,
Excessive over shoot indicates too r
low gain in Y channel.
Fig. 13
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