Tektronix 613 Instruction Manual page 41

Cali bration-61 3
Fig.
3-12.
Test points and adjustment locations on the
613
Hard Fig.
3-13.
Test oscilloscope waveforms produced after Hard Copy
Copy Amplifier boards.
Threshold
R137
adjustment.
d. Set both test oscilloscope lnput switches to Gnd
position and superimpose the two traces at a selected
horizontal graticule line on the test oscilloscope display
near the bottom of the screen, then switch the lnput
switches to DC. Set the trigger source switch to Ext.
e. Press the 61 3 ERASE button so that the crt of the 613
is ready to write, with no information stored, and set the
INTENSITY at mid-range. Shift the Test Display
Generator Mode switch to Single to store a line display.
g. Press the 4610 Copy button and adjust Hard Copy
Threshold control R137 to obtain a display similar to Fig.
Fig.
3-14.
Test oscilloscope waveforms showing the area of
3-13. ~h~ ,,i d eo
information at the points of the two
adjustment that is controlled by Dynamic Focus control
R134.
Adjust for even spacing between the waveforms.
waveforms must overlap to generate a TARSIG signal to
obtain a hard copy; but too much overlap will include
noise, which darkens the copy.
h. Connect the external trigger probe to the fast ramp
signal at J13 pin 4 (613-1: J13 pin 3) on the Deflection
j. Adjust the Dynamic Focus control R137 for uniform
Amplifier board. spacing between the waveforms (see Fig. 3-14). This
affects the corner focus.
i. Set the test oscilloscope Time/Div at 1 ms and
trigger the display. Raise the upper waveform so that there k. The adjustments interact. Reconnect the trigger
is no overlap between the two traces.
probe to J18 pin 4 and check the first waveform.
REV. B DEC 1974
3-2 I