Tektronix 442, Instruction Manual

Page: 61 / 170

2. TRACE ROT (Trace Rotation)
a. Set the Vertical POSITION control to move the trace
to the center horizontal graticule line.
Calibration Procedure— 442 Service
Adjustment Procedure
b. ADJUST—The TRACE ROT control (located on the
front panel) with a smali-bit screwdriver to align the trace
with the center horizontal graticule line.
f. INTERACTION—Set the Channel 1 AC-GND-DC
switch to GND and set the Channel 1 POSITION control to
move the baseline to the center horizontal graticule line.
Check that the baseline trace aligns with the center
horizontal graticule line. If not, repeat Steps 2 and 3 until
optimum Trace Rotation and Y-Axis alignment is achiev­
ed.
3. Y-Axis Alignment
a. Set the Channel 1 AC-GND-DC switch to DC.
b. Connect .1 ms markers from the time-mark
generator through a 50 O cable and 50 O termination to
the Channel 1 input connector.
4. Geometry
a. Set the Channel 1 AC-GND-DC switch to DC and
set the other controls to obtain a display as described in
Step 3, parts c and d. Set the Horizontal POSITION control
as required.
c. Set the channel 1 VOLTS/DIV, VAR, and POSITION
controls to obtain a display of slightly more than 8
divisions of vertical deflection with the baseline about 1
division below the bottom of the graticule area and the tips
of the time markers extending to the top graticule line.
d. Set the SEC/DIV switch to display time markers
spaced about 1 division apart. Set the Horizontal
POSITION control to align the center time marker with the
center vertical graticule line.
e. ADJUST—R474 (Y-Axis Adjust, see Figure 4-8) to
align the center time marker with the center vertical
graticule line.
b. ADJUST— R473 (Geom Adjust, see Figure 4-8) for
best overall alignment of thetimemarkers withthevertical
graticule lines (minimum bowing of time markers),
c. INTERACTION—Repeat all of Steps 3 and 4 to
achieve optimum Geometry and Y-Axis Alignment adjust­
ment.
d. Disconnect the time-mark generator cabletermina-
tion from the Channel 1 input connector and return the
Channel 1 VOLTS/DIV VAR control to the fully clockwise
calibrated detent position.
Figure 4-8. Interface board adjustment locations (board shown in access position).
4-18
REV A MAY 1980