TB 9-6625-096-50
(d) A and B switches to AC.
(e) A and B TRIGGER LEVEL controls fully clockwise
(f) A and B RANGE selectors to 1.
(6) Turn AUDIO SELECTOR switch to 30 - VAR ∅ and VOR switch to 180.
(7) Turn A TRIGGER LEVEL control of frequency counter slowly counterclockwise
until frequency counter begins to count.
(8) Adjust oscilloscope (A4) controls to display 1-1/2 cycles on channel 1.
(9) Slowly readjust frequency counter A TRIGGER LEVEL control to obtain the
most stable negative portion of channel 1 display. Note the exact width of negative portion
of channel 1 display.
NOTE
It may be necessary to use the magnifier function of the
(10) Slowly adjust frequency counter B TRIGGER LEVEL control until the counter
stops counting. Readjust B TRIGGER LEVEL control until the negative portion of channel
2 display is identical in width to the width noted in (9) above.
NOTE
It may be necessary to slightly readjust both A and B
TRIGGER LEVEL controls to obtain (10) above.
NOTE
Insure that the conditions of (10) above are maintained while
recording the counts in the following steps.
(11) Set display control on counter so that the count is displayed long enough to read
and record. Record five counts. Average the counts and record the average.
(12) Turn TI VOR switch to 135 position. Record five counts of counter. Average the
counts and record the average. Subtract this average from the average recorded in (11)
above. The difference will be between 3,981.5 and 4,351.9 microseconds. If not, perform b
below.
(13) Repeat (12) above for TI 'VOLTS switch settings of 90 and 45. The differences
will be between 8,148.1 and 8,518.5 microseconds for 90 settings, and between 12,314.8
and 12,685.2 microseconds for the 45 setting. If not, perform b below.
b. Adjustments.
Adjust VOR TRACK
adjustment (fig. 3) until the
indications in
a(12)
and (13) above are within tolerance. Repeat a above.
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