TB 9-6625-2024-24
10. Vertical High Frequency Compensation and Risetime
a. Performance Check
(1) Set calibration adapter TEST switch to VERT OR HORIZ + STEP RESP and
REP RATE switch to 1 MHz.
(2) Adjust calibration adapter AMPLITUDE and POSITION controls for a 6
division display centered vertically on crt.
(3) Release dual time base MAG pushbutton to X10 (OUT).
(4) Adjust dual time base TIME/DIV or DLY TIME switches for .05 Ps and
LEVEL control for a stable display triggered on rising portion of pulse. If displayed pulse
does not have a square leading corner and a flat top with aberrations within 0.5 minor
division, perform b below.
(5) Measure risetime using standard risetime technique. Risetime will be 3.5 ns or less.
(6) Remove calibration adapter from right vertical compartment and install in left
vertical compartment.
(7) Press VERT MODE LEFT pushbutton.
(8) Adjust calibration adapter AMPLITUDE and POSITION controls for a 6
division display centered vertically on crt.
(9) Adjust dual time base TIME/DIV or DLY TIME switches for .05 Ps and
LEVEL control for a stable display triggered on rising portion of pulse. If displayed pulse
does not have a square leading corner and a flat top with aberrations within 0.5 minor
division, perform b below.
(10) Measure risetime using standard risetime technique. Risetime will be 3.5 ns or less.
b. Adjustments. Perform appropriate adjustments listed in table 3.
Table 3. High Frequency Compensation
Test instrument
Adjustments (fig. 2) (R)
Area of pulse most affected
1st 50 ns
C420 and R421
1st 20 ns
R425 and C425
1st 5 ns
C427 and R427
NOTE
Due to slight differences in electrical characteristics of the left
and right vertical compartments, it may be necessary to press
VERT MODE RIGHT pushbutton and repeat a (2), (4), and
(5), and b above for best intolerance compromise.
11. Horizontal Amplifier Gain
a. Performance Check
(1) Install dual time base in left vertical compartment and calibration adapter in
horizontal (right) compartment.