Sencore SC61 - Selecting the Proper CRT Display Pushbutton; Single Trace Operation; Automatic Dual·trace Operation; Forcing the SC61 into the Dual-Altemate Mode

The signal applied to either the channel A or B vertical input
ma~: be displayed independently. Press the CHA.'\" A or CHA.\' B
button 10 display either tra~. A signal may be connected to the
second channel .... ithout affecting the displayed channel.
Fig. 4 - The four CRT display pushbuttons select one of
six different display modes.
Slnllle Trace Operation
MODEL 5C61
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Automatic dual·trace operation
1--_ Be.m 8.,m
Adjust HORIZ POSITION
Press the" A&8" button ..... hen you ..... ant to vie ..... t ..... o ..... a\·eforms.
TheSC6t automatically
selects between the dual-chopped or the
dual·alternate display mode. depending on the setting
of the
TIMEBASE·FREQ s
.... itch. All s ..... eep rates between 100 mS and
.1 mS (enclosed with the "m sec" bar) ..... ill be shown in the dual-
chopped display mode to prevent flicker on lo ..... er s ..... eep rates.
S
..... eep rates in the "u sec" range are displayed as a dual-
alternate
trace to pre\·ent the chopping signal from causing a
segmented display
on highers ..... eepspeeds.
Forclnll the SC6I
Into the dual-aJternate mode
S .. m
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Adjust VERTICAL POSITiON
---S .. m
There ma)' be times hen the chopping oscillator causes inter-
ference in the trace hen the "A&8" mode is used on s eep
rates in the "m sec'· range of the TJ:\IEBASE-FREQ s itch.
This IOterference is common on all dual-Irace scopes and is
caused by the 500 KHz signal that qUickly moves the CRT beam
bet ..... een the channel .-\ and 8 signal. The interference only
becomes
noticeable when the chopping frequenc)' is an exact
multiple of the input
frequency, Fig. 5 sho ..... s an example of
chopping interference.
The
SCSI may be forced into the dual-alternate display mode by
releasing all four display pushbultons to their "out" positions.
Simply press lightly
on any of the buttons that is not depressed
until thes .... itch mechanism releases all of the buttons. The SC61
may be returned to its automatic dual-trace mode at any time
b)· depressing the ,. A&8" pushbutton.
Adjust INTENSITY or TRIGGER MODE
Fig. 3 - The BEAM FINDER forces the trace onto the CRT
for any control setup.
Selecting the proper
CRT displa~ pushbutton
The SC61 has six different CRT display modes selected by the
four CRT display pushbuttons located immediately below the
CRT. The display options break into single-trace. dual-teace. or
"eclor (X·'.t) modes. The follo\\ing paragraphs describe the six
different options 3\'ailable.
t ---t----r-
'::-. -:FT .-1 .. .,..?H-\
Fig. 5 - Releasing all four CRT display buttons forces the
SC61 into the dual-alternate mode and eliminates this
type
of interlerence.
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