Tektronix 2225, Руководство оператора

Страница: 26 / 79

Operation
Table 2-1 (cont’d)
No. Title Function Recommended Use
17 POSITION
COARSE
COARSE is convenient for
moving unmagnified traces. Control trace positioning in
horizontal direction.
18 POSITION FINE FINE is convenient for
moving magnified traces
when either ALT or MAG is
selected.
19 XI-ALT-MAG XI displays only normal
(horizontally unmagnified)
waveform. ALT displays
normal and magnified
waveforms alternately.
MAG displays only the
magnified waveform.
Select normal, comparative
or expanded waveforms.
20 SEC/DIV Selects time-base speed. Set horizontal speed most
suited to requirements.
21
Variable (CAL)
Provides continuously vari­
able uncalibrated sweep
speeds to at least 2.5 times
the calibrated setting. Extend the slowest speed to
at least 1.25 s/div.
22
MAG
(X5-X10- X50)
Selects degree of horizontal
magnification.
Examine small phenomena
in detail.
23 Provides safety earth and
direct connection to signal
source. Chassis ground connection.
24 PROBE
ADJUST
Provides approximately
0.5-V, 1-kHz square wave. Match probe capacitance
to individual circuit. This
source may be used to
check the basic functioning
of vertical and horizontal cir­
cuits but is not intended to
check their accuracy.
25 SLOPE Selects the slope of the sig­
nal that triggers the sweep. Provide ability to trigger
from positive-going or
negative-going signals.
26
LEVEL
Selects trigger-signal ampli­
tude point.
Select actual point of
trigger.
27 TRIG'D Indicator lights when sweep
is triggered in P-P AUTO,
NORM, or TV FIELD. Indicate trigger state.
28
MODE
P-P AUTO/TV LINE triggers
from waveforms and televi­
sion lines having repetition
rates of at least 20 Hz.
NORM triggers from ade­
quate signal, with no trace
in absence of trigger signal.
TV FIELD triggers from TV
Field signals; trigger polar­
ity must be observed. SGL
SWP triggers sweep only
once when armed by
RESET button; used for dis­
playing or photographing
nonrepetitive or unstable
signals.
Select trigger mode.
29 RESET Arms trigger circuit for SGL
SWP.
30 HOLDOFF Varies sweep holdoff time
10:1.
Improve ability to trigger
from aperiodic signals.
2225 Operators
2-3