TB 9-4931-444-35
(3) Adjust DRIVE BAL R40 (fig. 21 for equal pulse
amplitude on test oscilloscope at test points A and B.
(4) Disconnect test oscilloscope.
(5) Connect dc voltmeter (A2) between oscilloscope
(A3) J11 pin 10 (inside cover) and chassis ground.
Using test lead (BS). Record dc voltmeter indication.
(6) Calculate upper and lower limits as follows: 66%
vdc recorded in (5) above = lower limits. 69% vdc
recorded in (5) above = upper limits.
(7) Connect dc voltmeter between junction of TI R41
and R54 (fig. 2). using test lead (BS).
(8) Adjust TI PULSE DC LEVEL R30 (fig. 2) for dc
voltmeter indication between upper and lower limits
calculated in (6) above.
(9) Due to interaction of adjustments, repeat (2)
through (8) above until no further adjustments are
required.
Figure 6. Chopped waveform--blanked.
24. Pulse Repetition Rate (S/N 3994 and below)
Oscilloscope crt will display a negative pulse with
amplitude of 5.6 centimeters or greater.
a. Performance Check
(5) Turn TI AMPLITUDE control fully clockwise.
(1) Adjust oscilloscope (A3) controls for stable
Oscilloscope will display a negative pulse with amplitude
display on crt.
of 5.6 centimeters or greater.
(2) Adjust TI AMPLITUDE control for 4 centimeters
(6) Set TI FUNCTION switch to +PULSE.
of positive pulse display on oscilloscope crt.
Oscilloscope crt will display a positive pulse with
(3) Set TI REPETITION RATE switch and
amplitude of 5.6 centimeters or greater.
oscilloscope TIME/CM switch to settings listed in table 5.
b. Adjustments
Oscilloscope ill display waveform within limits specified
(1) Adjust TI AMPLITUDE control for 4 centimeters
in table 5.
of positive pulse display on oscilloscope crt.
(2) Connect test oscilloscope (A7) alternately to TI
TEST FUNCTION switch test points A and B (fig. 7),
using XI0 probe supplied with test oscilloscope.
Table 5. Repetition Rate Switch (S/N 3994 and Below)
Test Instrument
Oscilloscope (A3)
REPETITION RATE
ME/CM
Display Waveforms
Switch Settings.
Switch Setting
Within 10 cm.
LOW
.2 mSEC
7.5 to 12.51
10SEC
2
MED
9 to 152
2SEC
HIGH
9 to 15
1
Dlsplav be from to 12 cycles for types with S/N 1409 and below.
2
Dtplav will be from 8 to 12 cycles with S/N 1410 to 3994.
(4) Adjust TI VERTICAL POSITION control to display
a. Performance Check
top of waveform on center vertical graticule line on
oscilloscope crt.
(1) Adjust oscilloscope (A3) controls for stable
(5) Set TI TEST FUNCTION switch to -PULSE.
display on crt.
Oscilloscope will display bottom of waveform within 1l
(2) Adjust TI AMPLITUDE control for a 4-centimeter
centimeter of center graticule line.
positive pulse display on oscilloscope crt. (3) Set TI
REPETITION RATE switch and oscilloscope TIME/CM
b. Adjustments. No adjustments can be made.
switch to settings listed in table 6. Oscilloscope will
display waveforms within limits specified in table 6.
25. Pulse Repetition Rate (S/N 3995 and above)
10
