TB-9-6625-1968-24
(2) Position controls as listed in (a) through (e) below:
FUNCTION square wave pushbutton pressed.
(a)
RANGE Hz 1M pushbutton pressed.
(b)
FREQUENCY dial to 3.
(c)
AMPLITUDE switch to 10 and AMPLITUDE VERNIER control fully cw.
(d)
All MODULATION pushbuttons released to out.
(e)
(3) Measure risetime. If risetime is not less than 18 ns, perform 10 b below.
(4) Repeat (3) above for falltime.
(5) Measure pulse aberrations.
Pulse aberrations will not exceed 10 percent of
pulse amplitude.
b. Adjustments. Adjust C505 (fig. 2) for best overall risetime, falltime, and pulse
aberrations (R).
11. Modulation Symmetry
a. Performance Check
(1) Connect TI MOD INT-EXT to frequency counter CHANNEL A input.
(2) Position controls as listed in (a) through (d) below:
(a) RANGE Hz 1k pushbutton pressed.
(b) FREQUENCY dial fully cw.
(c) MODULATION square wave pushbutton pressed.
(d) MODULATION RANGE Hz switch to 100 and MODULATION RANGE
Hz VERNIER control fully cw.
(3) Using the time interval function of frequency counter, measure width of both
positive and negative half-cycles of output square wave. If difference between two intervals
is not less than 10 s, perform 11 b (1) and (3) below.
(4) Set MODULATION RANGE Hz switch to 10k and MODULATION RANGE
Hz VERNIER control fully ccw. Repeat technique of (3) above. If difference between
intervals is not less than 10 s, perform 11 b (2) and (3) below.
b. Adjustments
(1) Adjust R307 (fig. 2) for a difference of less than 10 s (R).
(2) Adjust R302 (fig. 2) for a difference of less than 10 s (R).
(3) Repeat 9 a (8) through (16) above and 11 a above as necessary, adjustments
affect both checks.
