Tektronix 2225 User Manual

Operation
To display Field 1 and Field 2 at the same time, connect the same
television signal to both the CH 1 and CH 2 inputs; set VERTICAL
MODE to BOTH and ALT; set the SEC/DIV control to 0.5 ms or
faster sweep speed.
If you magnify the vertical display beyond the graticule, the trig
ger may be degraded. To avoid trigger overload, use either CH 1
or CH 2 for display and use the EXT INPUT channel with an
appropriate video signal as the trigger source. A composite sync
signal can be used for the trigger source as well as composite
video.
Source
Choose a single trigger source to correctly display the timing rela
tionships between two channels. Choose the channel with the
lowest-frequency signal to avoid ambiguous displays.
With VERT MODE TRIGGER SOURCE and either P-P AUTO TRIG
GER MODE or CHOP VERTICAL MODE, the triggering signal is
the algebraic sum of the Channel 1 and Channel 2 input signals.
Use a composite trigger source only to compare asynchronous
signals. To generate a composite trigger: select VERT MODE
TRIGGER SOURCE, BOTH-ALT VERTICAL MODE, and any
TRIGGER MODE except P-P AUTO.
Coupling
For signals with strongly interfering components, HF Reject and
LF Reject coupling give added selectivity. When AC coupling is
selected, triggering continues as the dc level of the signal
changes.
Slope
Use the SLOPE control to select either the rising (v~) or the falling
(~v) edge of the signal to trigger the sweep.
Level
The LEVEL control gives you complete freedom to choose the
most appropriate threshold voltage on a signal to initiate sweeps
whenever any trigger mode except P-P AUTO is selected.
Holdoff
With irregular signals such as bursts, the HOLDOFF setting can
improve display stability. Also, if the signal has a fixed pattern of
variation from cycle to cycle, some modes of the signal may be
omitted from the display. Changing the HOLDOFF setting can
force the instrument to display all the modes of the signal. Nor
mally, the HOLDOFF control should be set at MIN.
2-10
2225 Operators

Tektronix 2225 Specifications

General

Brand	Tektronix
Model	2225
Category	Test Equipment
Language	English