Tektronix 2225, Operator'S Manual

Page: 25 / 79

Operation
Table 2-1
Summary of Controls, Connectors, and Indicators
No. Title Function Recommended Use
1
INTENSITY Adjusts trace brightness. Compensate for ambient
lighting, trace speed,
trigger frequency.
2
BEAM FIND Compresses display to
within CRT limits.
Locate off-screen
phenomena.
3
FOCUS
Adjusts for finest trace
thickness. Optimize display definition.
4
TRACE
ROTATION
Adjusts trace parallel to
centerline.
Compensate for earth’s
field.
5
POWER Turns power on and off.
Control power to the
instrument.
6
Power Indicator Illuminates when power is
turned on.
Know power condition.
7, 9
POSITION Moves trace up or down
screen.
Position trace vertically and
compensate for dc compo­
nent of signal.
8
TRACE SEP Moves the magnified trace
vertically with respect to the
unmagnified trace when
HORIZONTAL MODE is set
to ALT
Position unmagnified and
horizontally magnified
traces for convenient view­
ing and measurement.
10
CHI - BOTH -
CH 2 Selects signal inputs for
display.
View either channel inde­
pendently or both channels
simultaneously.
11
NORM - INVERT Inverts the Channel 2 signal
display.
Provide for differential
(CH 1 - CH 2) or summed
(CH 1 + CH 2) signals
when ADD is selected.
12
ADD-ALT -
CHOP
ADD shows algebraic sum
of CH 1 and CH 2 signals.
ALT displays each channel
alternately. CHOP switches
between CH 1 and CH 2 sig­
nals during the sweep at
500 kHz rate.
Display summed or indi­
vidual signals.
13
VOLTS/DIV Selects vertical sensitivity. Adjust vertical signal to
suitable size.
14
Variable (CAL) Provides continuously vari­
able deflection factors
between calibrated posi­
tions of the VOLTS/DIV
switch. Reduces gain by at
least 2.5:1.
Match signals for common­
mode readings. Adjust
height of pulse for rise-time
calculations.
The CAL control can be
pulled out to vertically
magnify the trace by a
factor of 10. Limits
bandwidth to 5 MHz.
Inspecting small signals.
15
AC-GND-DC In AC, isolates dc compo­
nent of signal. In GND,
gives reference point and
allows precharging of input­
coupling capacitor. In DC,
couples all components of
signal.
Selects method of coupling
input signals to the vertical
deflection system.
16
CH 1 OR X
CH 2 OR Y Provides for input signal
connections. CH 1 gives
horizontal deflection when
SEC/DIV is in X-Y.
Apply signals to the vertical
deflection system.
2-2 2225 Operators