Instrument Options—455/A2/B2
OPERATING INFORM ATION
Typical operation of an Option 5 instrument uses A sweep to establish a basic field and frame-related display. Then, all detail
measurements are made using B Sweep.
INSTALLA TIO N AND SET-UP
OF VIDEO GRATICULE
To install a video graticule, loosen the 4 captive screws hold
ing the crt bezel in place, and remove the bezel. Snap the
standard light filter from the bezel and replace with the de
sired graticule. Install the desired graticule with the markings
on the outside and with the extended tab, at the bottom of
the graticule, at the slightly wider (BOTTOM) margin of the
bezel. While reinstalling the bezel, move the video graticule
horizontally slightly so the video graticule lines up with the
crt graticule.
With the video graticule installed, the 10 horizontal divisions
along the 0 (zero) line correspond to the internal crt graticule
divisions. The horizontal (time) calibration of the oscillo
scope is correct.
The vertical divisions of the video graticule represent propor
tions of the 100-unit (CCIR) or 140-unit (NTSC) video wave
form. To calibrate the vertical divisions for a standard TV
(nominal) studio video signal, apply the 300 mV calibrator
signal to the vertical input, then adjust the VOLTS/DIV
and VAR controls so the displayed waveform occupies 30
units with the CCIR graticule or 42 units with the NTSC
graticule.
SYNC SEPARATOR
OPERATING REQ UIREM ENTS
The operation of the sync separator requires the performance
of the following 3 steps: 1
1. Set the A COUPLING switch to TV FIELD or TV LINE.
2. Set the A SOURCE switch to the desired position. Be
certain the SOURCE selected provides a trigger signal which
meets the sensitivity requirements listed in Table 1. Adjust
ment of the VAR VOLTS/DIV control changes the amplitude
of the signal supplied to the sync separator. 3
3. Set the A SLOPE switch to negative (—) for sync-negative
input signals and positive (+) for sync-positive input signals.
NOTE
If the A SOURCE switch is set to CH 2 and the
CH 2 INVERT button is set to INVERT (button
in), the setting of the A SLOPE switch just dis
cussed reverses. See Single Trace Modes under
Vertical Operating Modes—Special Considerations.
TRIG G ERING A SWEEP
If the sync separator operating requirements are met, adjust
ment of the A LEVEL control is all that is needed to trigger
A Sweep on video waveforms.
In 405-line systems, the A LEVEL control may need to be
rotated more clockwise to avoid line-rate artifacts on the
field-sync signal. Adjustment of the A TRIGGER HOLDOFF
control may also be helpful in obtaining a stable display.
To obtain displays free of interlace jitter for systems having
2:1 interlace, set the A TIME/DIV switch for an unmagnified
display of an odd number of fields plus a fraction of a field.
For 50 and 60 Hz field rates, set the A TIME/DIV switch to
2 ms. For some PAL system observations, an A TIME/DIV
switch setting of 5 ms (2-1/2 field display), with the A
TRIGGER holdoff control adjusted for an additional 1 field
holdoff, may be desirable to maintain a stable display relation
ship to the 4-field PAL burst-blanking sequence.
TR IGG ER ING B SWEEP
To trigger B Sweep on video waveforms, perform the follow
ing procedure:
1. Be certain the Sync Separator Operating Requirements
are met and A Sweep is triggered.
2. Set the B SOURCE switch to STARTS AFTER DELAY
and the HORIZ DISPLAY switch to A INTEN.
3. Adjust the B TIME/DIV and DELAY TIME POS controls
so the portion of the A Sweep display to be displayed in the
B DLY'D mode is intensified.
Option 5 Page 2
REV. A, OCT 1975
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