Tektronix 434, Инструкция по эксплуатации

Страница: 86 / 222

Calibration—434
b. C H E C K —Test oscilloscope display fo r 40 m ic ro ­
second tim e period between c u rre n t peaks.
c. A D J U S T —C u rre n t Sense adjustm ent R 1074 (see Fig.
5-3) fo r 40 microseconds, ±one m icrosecond tim e period
between c u rre n t peaks.
d. D isconnect all test e q u ipm e n t and re-install tbe
Power Supply c o m p a rtm e n t shields.
e. IN T E R A C T IO N —May a ffe c t the operation o f all
circuits w ith in the 432.
4. A djust High-Voltage Power Supply
a. C onnect the DC V o ltm e te r between the —3940 v o lt
test p o in t TP962 (see Fig. 5-5) and ground.
b. C H E C K —M eter reading o f —3940 volts, ± 98.5 volts
(±118.2 volts if the measurement is being made outside o f
the + 2 0 °C to + 3 0 "C tem perature range).
c. A D J U S T —High Voltage A d ju s t R 963 (see Fig. 5-5)
fo r a m eter reading o f —3940 volts, ± 78.8 volts.
d. D isconnect the DC V o ltm e te r fro m the 432 under
test.
. irj? J U ? JC R T„ r ,'s c v i\ l9 fV ^ '.'3 t~?.,i+.a'^usXTO p/?*. Io c ? tio .o 5
e. IN T E R A C T IO N —May a ffe c t vertical gain, h o rizo n ta l
tim in g accuracy and C RT focus, astigmatism and geom etry.
N O T E
I f the lin e voltage is w ith in the operating lim its o f the
432, (90 V A C to 26 4 V A C RMS), the 43 2 can be
connected d ire c tly to the lin e , i f n o t, leave the 43 2
connected to the a u to tra n sfo rm e r fo r the rem ainder
o f this procedure.
5. A d ju st CRT G rid Bias and Z-A xis Compensa­
tio n
a. A tta c h a 10X probe to the test oscilloscope and
connect the tip o f the probe to test p o in t TP 924 on the Z
A x is c irc u it board. See Fig. 5-5.
b. Set the CH 1 P O S ITIO N c o n tro l fu lly c o u n te r­
clockw ise and the Sweep M O DE to A U T O .
c. T u rn the IN T E N S IT Y c o n tro l fu lly clockw ise.
d. Measure and note the m axim um voltage level th a t can
be attained w ith the IN T E N S IT Y c o n tro l fu lly clockwise.
e. Reduce the setting o f the IN T E N S IT Y c o n tro l to a
level 70 volts below the m axim um level measured in step d.
f. Set the T IM E /D IV sw itch to 5 s /D IV and CH 1 POSI­
T IO N c o n tro l to midrange.
s c. a u T t t ! N <
To avo id possible damage to the C R T p h o sp h o r, do
n o t a llo w a b rig h t s p o t to rem ain s ta tio n a ry fo r an
extended p e rio d o f time.
*V AQJA 1STi—ORT. 'T rirl.R i^ s ^ ^ c tv jrs tm ra t.R P fK L ^ je e T ig .
5-5) so the spot on the C R T ju st disappears.
h. Set the T IM E /D IV sw itch to 1 ms and increase the
IN T E N S IT Y c o n tro l setting to obtain a visible display of
nom inal in te n s ity .
i. O btain a stable display on the test oscilloscope o f the
unblanking w aveform present at test p o in t TP924.
j. C H E C K —Test oscilloscope display fo r o p tim u m wave-
.for.m. riset.ijne„and.fiat.tpo.
<8>
5-8