Tektronix 434, Instruction Manual

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Calibration—434
b. C onnect the o u tp u t o f a T im e-M ark Generator to the
CH 1 in p u t c o n n e cto r via a 42-inch 50 !T2 BNC cable.
p. A d ju s t the IN T E N S IT Y c o n tro l u n til the spot is just
e x tin g u ish e d .
c. Set the T im e -M a rk Generator fo r an o u tp u t o f 10
m icrosecond markers.
q. Erase the display, w a it a t least 3 seconds, then push
the RESET b u tto n . Repeat this procedure w h ile adjusting
the E N H A N C E L E V E L c o n tro l to o b ta in a stored display
where the background just starts to fade up.
d. A d ju s t the T R IG G E R L E V E L c o n tro l fo r a stable
display.
e. Set the T IM E /D IV sw itch and the T IM E /D IV
V ariable c o n tro l fo r one m arker per division.
r. C H E C K —CRT stored display fo r no breaks or gaps
exceeding 0.025 inch. Check the e ntire storage display area.
Proper storage o f a 2.5 ps/division sweep indicates an
enhanced storage w ritin g speed o f at least 4 0 0 centim eters
per m illisecond.
f. Set CH 1 in p u t coupling to GND.
g. P osition the trace on screen w ith the beginning o f the
trace at the le ft edge o f the graticule.
s. Set the STORE b u tto n s to Non-store (b u tto n s o u t),
E N H A N C E b u tto n s to O ff (b u tto n s o u t), Sweep M O DE to
A U T O , T R IG G E R SOURCE to CH 1, and IN T E N S IT Y
c o n tro l fo r norm al display in te n s ity .
h. Set the Sweep M O DE to S IN G LE SWEEP, the
T R IG G E R SOURCE to L IN E , and both STORE b u tto n s to
the STORE (b u tto n in) p o sitio n.
13. A d ju st G eom etry
a. Set the CH 1 in p u t coupling to DC.
i. A d ju s t the IN T E N S IT Y c o n tro l u n til the spot is ju st
extinguished.
b. A p p ly 1 ms and .1 ms tim e marks fro m the Tim e-
Mark Generator to the CH 1 in p u t connector.
j. Press both ERASE bu tto n s, w a it 10 seconds, and then
press the RESET b u tto n . A single sweep should be pre­
sented and stored.
c. A d ju s t the CH 1 PO SITIO N c o n tro l and the CH 1
V O L T S /D IV sw itch so the tim e marks extend above and
below the vertical extremes o f the CRT viewing area.
k. C H E C K —C R T stored display fo r no breaks or gaps
exceeding 0.025 inch. Check the entire storage display area.
Proper storage of a 10 p s/d ivisio n sweep indicates a storage
w ritin g rate o f at least 100 centim eters per m illisecond.
d. A d ju s t the T R IG G E R L E V E L c o n tro l fo r a stable
display w ith the T IM E /D IV sw itch set to 1 ms.
e . C H E C K —CRT display fo r no more than 0.1 division o f
bow ing o r t i l t o f tim e marks in the center 6 X 1 0 division
area, and no more than 0.2 division o f m isalignm ent in the
1. Erase the display, reduce the setting o f the IN T E N ­
S IT Y c o n tro l, and set CH 1 in p u t co upling to DC.
extrem e upper and low er 1 X 1 0 division areas.
m. Set the Sweep M O DE to A U T O , the STORE b u tto n s
to Non-Store (b u tto n o u t), and T R IG G E R SOURCE to CH
1.
f. A D J U S T —G eom etry adjustm ents R967 and R1292
(see Figs 5-5 and 5-6) fo r m in im u m bow ing and t i l t o f tim e
marks. N o rm a lly , the o p tim u m adjustm ent p o in t o f R 1292
is fo r a voltage measurement o f +230 volts at the e m itte r of
transistor Q 1292 located on the Storage c irc u it board.
n . Set the T IM E /D IV sw itch and the T IM E /D IV
Variable c o n tro l fo r one marker per fo u r divisions.
g. Disconnect all test equipm ent.
14. Check BEAM F IN D E R O peration
o. Set the CH 1 in p u t co upling to G N D , Sweep M O DE
t o S IN G L E SWEEP, T R IG G E R SOURCE to L IN E ,
T R IG G E R
L E V E L to midrange, STORE b u tto n s to
STORE (b u tto n in ), and E N H A N C E b u tto n s On (b u tto n s
in ).
a. Press the BEAM F IN D E R b u tto n .
b. R otate the CH 1 PO SITIO N and h o rizo n ta l POSI­
T IO N c o n tro ls fu lly clockw ise and then fu lly c o u n te r­
clockwise.
5-12