Tektronix 323, Instruction Manual

Page: 25 / 170

Operating Instructions— Type 323
VOLTS/DIV
5 DIV CAL
INPUT GND
X lO VERT GAIN In
POSITION (Vertical)
Midrange
X lO HORIZ MAG In
POSITION (Horizontal) Midrange
TIME/DIV 1 mS
VARIABLE (TIME/DIV) CAL
TRIGGER + AUTO
Trigger Coupling
INT TRIG AC
POWER ON
INTENSITY
Optimum
Set the Oscilloscope on its left side to allow access to the
bottom adjustments.
ASTIG
Adjust the VARIABLE (VOLTS/DIV) to obtain 3 divisions
of vertical amplitude. Center the trace as shown in Fig. 2-8.
Fig. 2 -8 . Focus and Astigm atism adjustm ent w aveform .
CHECK—The horizontal and vertical lines of the square
wave should provide optimum sharpness at the same setting
ot the FOCUS control.
VERT X 1 0 BAL
CHECK— No vertical position shift of the trace occurs
when the X 10 VERT GAIN control is switched in and out.
ADJUST—VERT X lO BAL until minimum trace shift oc­
curs when the X 1 0 VERT GAIN control is switched in and
out. Return the X10 VERT GAIN control to its in position.
VAR V/DIV BAL
CHECK— No trace shift occurs as the VARIABLE V/DIV
BAL control is rotated from limit to limit.
ADJUST— VAR V/DIV BAL control until no trace shift oc­
curs as the VARIABLE (VOLTS/DIV) control is rotated from
limit to limit.
Return the VARIABLE (VOLTS/DIV) control to CAL.
Repeat the VERT X 10 BAL and the VAR V/DIV BAL ad­
justments until interaction is no longer noticeable.
VERT X l GAIN
Switch the TIME/DIV control to the 5 DIV CAL position.
Using the Vertical POSITION control, center the square
wave.
CHECK—The square-wave presentation has 5 divisions
±0.15 division vertical amplitude. The measurement should
be made from trace center to trace center to avoid the effect
of trace width.
ADJUST— VERT X I GAIN to provide a 5 division square-
wave presentation.
VERT X lO GAIN
Pull the X lO VERT GAIN control out.
CHECK—The square-wave presentation has 5 divisions
±0.15 division vertical amplitude.
ADJUST— VERT X lO GAIN to provide a 5 division square-
wave presentation.
SIGNAL TRANSPORTING METHODS
ADJUST— ASTIG and FOCUS controls until the corners of
the square wave provide optimum sharpness. Concentrate on
the areas contained in the ovals in Fig. 2-8 to obtain best
overall focusing. Once FOCUS and ASTIG have been set,
changes in intensity should only require readjustment of the
focus control.
TRACE ROTATION
Set the VOLTS/DIV switch to 20 and position the trace to
graticule center line.
CHECK—The trace should be parallel to the graticule
center horizontal line.
ADJUST—TRACE ROTATION as necessary to set the trace
parallel to the graticule's center horizontal line.
VOLTAGE and waveform observations normally require
that the oscilloscope be placed in parallel with the load
across which the observation is being made. Numerous
methods of connecting signal sources (signal pick-off points)
to the oscilloscope are available. The method to be used is
basically determined by signal amplitude and/or signal fre­
quency or risetime compared to the combination of signal
source impedance and oscilloscope input impedance.
Signal Amplitude
Signals in excess of the display range of the oscilloscope
(120 V peak to peak calibrated, 300 V peak to peak un­
calibrated) can be reduced to an observable value by means
of an attenuator placed in the signal-to-oscilloscope path. The
P6049 Probe provided with the Type 323 Oscilloscope makes
2-13