Tektronix 2A61 Instruction Manual page 45

12. Check Gain Adjust Range
a. Test equipment setup is shown in Fig. 6-18.
b. Connect the Special Input Cable, 4 pin connector at one
end and BNC connector at the other, from the Standard
Amplitude Calibrator output to the Type 2A61 INPUT.
c. Adjust the Type 2A61 front panel GAIN ADJ control
for 5cm of display on the Type 561A CRT.
d. Connect the Test Oscilloscope 10X Probe to one of the
vertical deflection plates on the 561A CRT.
e. Observe the amplitude of the deflection on the test
oscilloscope CRT.
f. Double the observed amplitude and divide by 5 to
obtain the vertical volts/div sensitivity of the CRT.
g. Check the GAIN ADJ control range as follows:
lf the Vert Volts/Div Minimum GAIN ADJ range
sensitivity is: should be:
18.5 | 45 to 69 divisions
19.5 4.3 to 6.55 divisions
20.5 4.1 to 6.25 divisions
Calibration—Type 2A61
13. Check mV/div Variable Ratio
a. Test equipment setup is given in Step 12.
b. Rotate the Type 2A6] Millivolts/Div VARIABLE control
fully counterclockwise.
c. Check for not more than two divisions of display on
the Type 561A CRT.
d. Note that the UNCAL neon on the Type 2A61 lights
when the VARIABLE control is not in the CALIB position.
14. Check Position Range
a. Test equipment setup is given in Step 13.
b. Adjust the Millivolts/Div VARIABLE control for 4 divi-
sions of display on the Type 561A CRT.
c. The Type 2A61 POSITION control must position the top
of the display below the bottom graticule line when fully
counterclockwise.
d. The Type 2A61 POSITION control must position the
bottom of the display above the top graticule line when fully
clockwise.
e. Return the Millivolts/Div VARIABLE control to CALIB
and center the POSITION control.
f, Remove the Special Input Cable from the Standard
Amplitude Calibrator.
NOTES
6-17