Tektronix 434, Инструкция по эксплуатации

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Operating Instructions—434
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1. Press the BEAM F IN D ER b u tto n .
2. W hile the B EA M F IN D E R b u tto n is held in, increase
the vertical d e fle c tio n fa c to r u n til the vertical d e fle c tio n is
reduced to about three divisions. The h o rizo n ta l d e fle ctio n
needs to be reduced o n ly in the E X T H O R IZ mode of
ope ra tio n . T h is can o n ly be accomplished by reducing the
a m p litu d e o f the external h o rizo n ta l signal applied to the
E X T H O R IZ in p u t connector.
3. A d ju s t the vertical and h o rizo n ta l POSITION
c o n tro ls to center the display a bout the vertical and h o ri­
zontal center lines.
4. Release the BEAM F IN D E R b u tto n ; the display
should remain w ith in the viewing area.
Fig . 2-3. D e fin itio n o f m e a su re m e n t lin e s o n 4 3 4 g ra tic u le .
filte r, press dow n at the b o tto m of the fram e and pull the
to p o f the filte r away fro m the CRT faceplate (see Fig.
2-4).
Beam Finder
The BEAM' F IN D E R switch provides a means o f locating
a display w hich overscans the viewing area either ve rtic a lly
o r h o riz o n ta lly . When the BEAM F IN D E R push b u tto n is
pressed, the display is compressed w ith in the graticule area.
T o locate and reposition an overscanned display, use the
fo llo w in g procedure.
Bandw idth L im ite r
The 5 MHz BW sw itch provides a m ethod o f reducing
interference fro m unwanted high-frequency signals when
viewing low -frequency signals. When set to the 5 MHz posi­
tio n (o u t), the upper —3 dB ba n d w id th p o in t o f the V e r­
tical D e fle ctio n system is lim ite d to about five megahertz.
Then unw anted high-frequency signals (such as television
broadcast ra d ia tio n interference) are reduced in the
displayed w aveform . Fig. 2-5 illustrates the use o f this
feature. The w aveform in Fig. 2-5A is the display produced
when a low-level, low -frequency signal is viewed in the
presence o f strong 50-megahertz rad ia tio n (sw itch pressed
in ). Fig. 2-5B shows the resultant C RT display when the
high-frequency interference is reduced by setting the BW
sw itch to the 5 MHz p o sitio n (o u t).
Fig . 2-4. R e m o v in g th e f ilt e r .
V ertical Channel Selection
E ith e r o f the in p u t channels can be used fo r single-trace
displays. A p p ly the signal to the desired in p u t connector
and set the V e rtica l Mode sw itch to display th e channel
used. However, since CH 1 triggering is provided o n ly in
Channel 1 and the IN V E R T feature is provided o n ly in
Channel 2, the co rre ct channel m ust be selected to take
advantage
o f these features. For dual-trace displays,
connect the signals to both in p u t connectors and set the
V e rtica l M ode sw itch to one o f the dual-trace positions.
V ertical Gain A djustm ent
To check the gain o f either channel, set the V O L T S /D IV
sw itch to .1 and connect the PROBE C A L 0.6 V 1 kH z
connector to the in p u t connector o f the channel used. The
vertical d e fle c tio n should be exactly six divisions. If n o t,
adjust the front-panel G A IN adjustm ent fo r e xa ctly six
divisions o f d e fle ctio n .
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