Section VII
ab. Set index error computed in step f in on the
e. Rotate Monitor to headings of 90, 180, and 270
MISAL dial.
degrees. Record readout ERROR at each heading.
ac. Conduct a four-heading electrical swing as in
f. Compute average index error.
g. Subtract index error of step f algebraically from
ad. Subtract error at 180 degrees obtained in step g
readings obtained in steps d and e.
from error at 180 degrees obtained in step ac:
( 1 8 0 ac - 180g).
h. Calibrate E1 VOLTAGE for the Monitor.
ae. Repeat step ad for 90-degree errors.
i. Change the following switches and controls:
af. Repeat step ad for 270-degree errors.
E1 NORM. -REV. to E1 NORM.
HEADING SELECTOR to 90 DEGREES.
ag. Add results of steps ae and af.
READOUT SELECT to 90.
ah. Set ∆180 control to value obtained in step ad.
j. Set Monitor to a 0-degree heading and adjust E1
VOLTAGE controls to null the NULL INDICATOR.
ai. Set ∆270 control to value obtained in step ag.
k. Record E1 VOLTAGE control reading.
aj. Perform a 24-heading electrical swing using
l. Set Monitor to 180 degrees and E1 NORM. -REV.
the Monitor. Refer to paragraph 4-50.
switch to E1 REV.
ak. Set El and E2 to OFF.
m. Adjust E1 VOLTAGE controls to null the NULL
al. Perform a 24-heading manual swing using the
INDICATOR.
Monitor instead of the Turntable. Refer to paragraph
n. Record E1 VOLTAGE control reading.
o. Average the readings obtained in steps k and n.
am. Compute the average Monitor index error for
0-, 90-, 180-, and 270-degree computed headings and
subtract algebraically from readings obtained in
p. Set E1 VOLTAGE control to value obtained in
step al. Refer to paragraph 4-50.
step o.
q. Calibrate E2 VOLTAGE for Monitor.
an. Compare corrected manual readings obtained
in step am with respective electrical readings ob -
r. Set Monitor to 90 degrees, E1 switch to OFF,
tained in step aj. The differences should not exceed
E2 switch in REV, and READOUT SELECT to 0.
8 minutes on any heading. However, one heading may
exceed 6 minutes if the average deviation is 4 minutes
or less.
S. Adjust E2 VOLTAGE controls to null the NULL
INDICATOR.
Note
t. Record E2 VOLTAGE control reading.
These tests shall be performed within a
u. Set Monitor to 270 degrees and E2 NORM. -REV.
period of 30 minutes or less. By completing
to E2 NORM.
the test in as short a period of time as
possible, the diurnal effect (daily shift in
v. Adjust E2 VOLTAGE control to null the NULL
magnetic field) will be minimized. The test
INDICATOR.
shall be performed in an area free of mag-
netic disturbances. As the test is repeated
w. Record E2 VOLTAGE control reading.
from time to time using the same Monitor,
the ∆180 and ∆270 readings should remain
x. Average the readings obtained in steps t and w.
fairly constant (within 6 minutes).
y. Set E2 VOLTAGE controls to value obtained in
ao. If the results in step ap are out of tolerance,
step x.
return Console to depot for repair.
z. Calibrate ∆160 and ∆270 settings.
ap. After performing the 24-heading swing, check
MISAL, ∆270, and ∆180 switches as directed in
as. Set E1 and E2 switches to NORM. and Monitor
to 0 degrees.
7-11
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