TB 9-6625-2099-24
(22) Adjust standardizer for optimum square corner and flat top. If standardizer
cannot be adjusted for optimum square wave, adjust CH 1 C134 (fig. 3) (CH 1 C130 (fig. 3)
for SN B160000 and above) to midrange and readjust standardizer for optimum square wave.
Figure 3. AM-6785/U and Tektronix, Type 7A26 - left side view.
(23) Adjust oscilloscope calibrator output for 6 divisions of display at each
VOLTS/DIV switch setting listed in table 10. If oscilloscope does not display square
corners and flat tops, perform appropriate adjustments listed in table 10.
(24) Remove 5-80 pF standardizer from oscilloscope calibrator CHAN 1 and TI CH 1.
(25) Set DISPLAY MODE switch to CH 2, and repeat technique of (16) through (23)
above for CH 2.
f
(26) Ensure oscilloscope calibrator CHAN 2 is connected to TI CH 2 using a 50
eedthrough termination. Ensure oscilloscope calibrator CHAN 2 output is selected by
using technique in step (1) above.
(27) Set DISPLAY MODE switch to CH 2 and CH 2 VOLTS/DIV switch to 10 mV.
(28) Set oscilloscope calibrator to EDGE, and output a 60 mV, 1 kHz output.
(29) Adjust CH 2 POSITION and time base controls as necessary to view display.
(30) Rotate oscilloscope calibrator knob located below EDIT FIELD pushbutton to
obtain 6 divisions on oscilloscope display. If displayed waveform does not have flat tops,
perform b (14) below.
13