Tektronix 2246 User Manual

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selected
and
with
each
additional
press
of
the
down-arrow
MODE
button
after
selection.
When
triggered,
the
sweep
runs
to
produce
a
sin-
gle
sweep
of
each
of
the
traces
as
required
by
the
setting
of
the
VERTICAL
MODE
and
TRIGGER
MODE
switches,
but
each
displayed
sweep
in
the
sequence
requires
a
distinct
A
Sweep
triggering
event.
The
READY
front
panel
light
remains
on
until
the
final
trace
in
the
sequence
is
completed.
The
readout
and
cursors
may
be
turned
on
for
only
a short
period
of
time
at
the
end
of
sequence
for
use
with
a
camera,
or
they
may
be
set
to
remain
on
by
changing
the
instrument
configuration
from
the
CONFIGURE
menu
(see
SERVICE
MENU
in
Section
6).
B TRIGGER MODES
AUTO LEVEL—Sets the range of the Trigger
LEVEL control to the peak-to-peak limits of the
signal selected as the B Trigger source if the sig-
nal amplitude and repetition rate are adequate.
This mode is very useful for quickly setting the
Trigger Levei to obtain stable triggering.
The B Sweep is triggered as for NORM triggering
after all the trigger signal conditions and the delay
time set by the t- or DELAY control have been
met. If a trigger is not found (trigger source signal
amplitude is not sufficient or if the repetition rate
of the applied signal is too slow), the B TRIGGER
MODE operation reverts to RUNS AFTER to pro-
duce an untriggered baseline display. (See Table
3-1 for critical triggering intervals that will result in
a free running B Sweep.) The resulting trace will
appear to be triggered if the A Sweep is trig-
gered, but the TRIG'D LED will not be on and the
DELAY control will move the displayed B trace
signal smoothly rather than from trigger point to
trigger point as would be expected for a triggered
B Sweep.
Peak signal levels will be measured from the start
of the delay time to the end of the A Sweep if the
measurement time interval does not exceed
500 ms. If the measurement time exceeds
500 ms, the peak signal limits will be measured
over the entire A Sweep. The signal trigger level
is reacquired for the same conditions described in
A TRIGGER MODES for AUTO LEVEL. The B
Trigger signal AUTO LEVEL peak measurements
will not be done if the A Trigger MODE is SGL
SEQ,
RUNS AFTER--Starts the B Sweep immediately
after the delay time selected by the l- OR DELAY
control. l
REV APR 1987
Controls, Connectors, and Indicators— 2246 Operators
RUNS AFTER Trigger MODE is forced on if tim-
ing measurements other than Delay are selected
when the Horizontal Mode is ALT or B Delayed.
NORM— The B Sweep is initiated when an ade-
quate trigger signal is received after the delay
time condition has been met. In the absence of a
trigger signal, no B Sweep trace occurs,
TV LINE FROM A SOURCE—Starts the B Sweep
at the beginning of a the video signal line received
after the delay time has been met.
SLOPE polarity must match the composite sync
polarity (same as A Trigger SLOPE) to obtain
correct triggering on the horizontai sync pulse.
SOURCE (Up-Arrow and Down-Arrow) Buttons and
Indicators— Select the trigger source for either the
A or the B Trigger system and indicate the selected |
source as directed by the A/B SELECT button.
The Up/Down SOURCE buttons are used to select
the trigger source, and the Trigger SOURCE front-
panel lights indicate the selected trigger signal
source for the trigger system selected by the A/B
SELECT button.
VERT—Selects the trigger signal from the
displayed waveforms.
The selection of the trigger signal source is deter-
mined by the TRIGGER MODE and VERTICAL
MODE switch settings. With VERT selected, one
or more of the SOURCE front-panel lights will be
on to indicate the trigger signal source. See
Table 3-2 for VERT Trigger SOURCE selections.
Table 3-2
VERT Trigger SOURCE
Trigger ADD Trigger
and Mode SOURCE
Vertical Selected
Modes
AUTO On Algebraic sum of CH 1 and
LEVEL Ch 2 input signals.
or
CHOP Off Lowest numbered vertical
| on | channel displayed.
NON- On Alternates between
AUTO or displayed vertical channels
LEVEL Off in the following order:
and CH 1, CH 2, CH 3, CH 4,
ALT and ADD.
3-9

Tektronix 2246 Specifications

General

Brand	Tektronix
Model	2246
Category	Test Equipment
Language	English