Tektronix 5441 Instruction Manual page 20

Operating Information-5441lR5441
GENERAL OPERATING INFORMATION
Graticule
The graticule of the 5441 is internally marked on the face-
plate of the crt to provide accurate, parallax-free measure-
ments. The graticule is marked with eight vertical and ten
horizontal divisions. Each division is 0.9 cm by 0.9 cm. In
addition, each major division is divided into five minor divi-
sions. The vertical gain and horizontal timing are calibrated
to the graticule so that accurate measurements can be
made from the graticule. The illumination of the graticule
lines can be varied with the GRAT ILLUM control.
INTENSITY Control
The intensity of the display on the crt is controlled by the
INTENSITY control. This control is adjusted so the display
is easily visible, but not overly bright. It will probably require
readjustment for different displays or sweep rates. Particu-
lar care should be exercised when only a spot is displayed.
A high-intensity spot may burn the crt phosphor and cause
permanent damange to the crt if allowed to remain too long.
Display Focus
If a well-defined display cannot be obtained with the FO-
CUS control, even at low intensity settings, adjustment of
the internal astigmatism control may be required.
To check for proper setting of the Astig control, slowly
turn the FOCUS control through the optimum setting with a
signal displayed on the crt screen. If the Astig control is
correctly set, the vertical and horizontal positions of the
trace will come into sharpest focus at the same position of
the FOCUS control.
Trace Alignment Adjustment
If a free-running trace is not parallel with the horizontal
graticule lines, set the Trace Rotation adjustment (rear pan-
el) as follows: position the trace to the center horizontal line
and adjust the Trace Rotation adjustment so that the trace
is parallel with the horizontal graticule lines.
BEAM FINDER
The BEAM FINDER switch provides a means of locating
a display that overscans the viewing area either vertically or
horizontally. When the BEAM FINDER switch is pressed,
the display is compressed within the graticule area and the
display intensity is increased. To locate and reposition an
overscanned display, use the following procedure:
1. Press the BEAM FINDER switch, hold it in, then in-
crease the vertical and horizontal deflection factors until the
display is within the graticule area.
2. Adjust the vertical and horizontal position controls to
center the display about the vertical and horizontal
centerlines.
3. Release the BEAM FINDER switch; the display
should remain within the viewing area.
Readout (Works Only With 5400-Series Plug-In
Units)
The readout system of the power supplylamplifier and
display modules allows alphanumeric display of information
on the crt, along with the analog waveform displays. The
information displayed by the readout system is obtained
from the plug-in units that are installed in the plug-in com-
partments. The characters of the readout display are written
by the crt beam on a time-shared basis with the signal
waveforms.
The Readout System operates in a free-running mode to
interrupt the waveform display to present characters. The
waveform display is interrupted for only about 20 ~s for
each character that is displayed.
The readout information from each plug-in is called a
word. Up to six (eight with Option 03) words of readout
information can be displayed (a seventh and eighth word are
available when Option 03 is installed). The location at which
each readout word is presented is fixed and is directly relat-
ed to the plug-in unit and channel from which it originated.
Figure 2-2 shows the area of the graticule where the read-
out from each plug-in unit channel is displayed (external
readout programming is available only with Option 03). No-
tice that the readout from channel 1 of each plug-in unit is
displayed within the top division of the graticule and the
readout from channel 2 is displayed directly below within the
bottom division of the graticule. Only the readout from plug-
in channels that are selected by display switches, or by the
mode switches of dual-channel plug-ins, appears in the
readout display.
The READOUT INTENS control determines the intensity
of only the readout portion of the display independent of the
other traces. The readout system is inoperative in the fully
counterclockwise OFF position. This may be desirable when
REV MAY 1982