TB 9-6625-2293-35
NOTE
Crt termination, high frequency transient response, vertical
gain, vertical centering, and readout jitter adjustments are
interactive.
This procedure optimizes these adjustments
together.
(4) Press CH 2 pushbutton off and adjust CH 1 VOLTS/DIV VAR control for a
RATIO readout.
(5) Adjust ∆REF OR DLY POS control ccw until RATIO readout is constant
(>130 percent).
(6) Adjust ∆ control until readout display indicates 130.0 percent.
(7) One cursor should be near bottom horizontal graticule line and the other cursor
near dotted graticule line marked 100(percent).
(8) Adjust ∆REF OR DLY POS control until the readout displays 100.0 percent.
Cursors should now be on or near dotted graticule lines marked 0 percent and 100 percent.
(9) Return CH 1 VOLTS/DIV VAR control to detent position.
NOTE
Controls adjusted in (4) through (7) above should not be moved
during the balance of this procedure. If they are accidentally
moved, repeat the procedure from the beginning.
(10) Connect oscilloscope calibrator SOURCE/MEASURE CHAN 1 to TI CH 1
using a Xl0, and X2 attenuator.
(11) Set oscilloscope calibrator for a CHAN 1, EDGE mode output of 600 mV at
100 kHz frequency.
(12) Adjust TRIGGER LEVEL control for a stable display and rotate oscilloscope
calibrator knob below EDIT field pushbutton to adjust waveform to 5 divisions of vertical
deflection on TI.
(13) Adjust CRT TERMINATION R1501 (fig 2) for best flat-top approximately 5 ns
past rising edge of waveform. Squeezing the output leads of the termination inductors
(LR1513 and LR1514) (fig. 2) toward each other will reduce the spike which may be present
approximately 6 ns behind the leading edge.
(14) Adjust C404 and R403 (fig 1) alternately for best flat top on first 10 ns of
waveform.
(15) Repeat technique of (12) and (13) above as necessary for best flat top over first
20 ns of waveform.
(16) Adjust GAIN (R638) (fig 1) and VERTICAL CENTERING (R639) (fig. 1) to align
cursors with dotted 0 percent and 100 percent graticule lines.
(17) Press ∆V pushbutton off (cursors off ).
(18) Adjust R411, C403, and HF ADJUST R417 (fig. 1) alternately for best square
front corner and best flat top of waveform. If front corner is overshot, adjust small coil
32
