Tektronix 434, Инструкция по эксплуатации

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Calibration—434
C A L IB R A T O R C IR C U IT A D JU S T M E N T
E quipm ent Required
1. Precision DC V o ltm e te r
3. 42-Inch 50 Q. BNC Cable
2. T im e-M ark Generator
4. 3-1 nch Screw driver
C ontrol Settings
Preset the In stru m e n t c o n tro ls to the settings given
under P relim inary C o n tro l Settings except as fo llo w s :
Sweep M O DE ' A U T O
IN T E N S IT Y V isible Display
V e rtica l Mode A L T
44. A d ju st C alibrator O u tp u t Voltage A m p litu d e
a. Remove Q 905 fro m its socket (see Fig. 5-13).
e. D isconnect the Precision DC V o ltm e te r and replace
Q 905 in its socket.
45. A d ju s t C alibrator R epetition Rate
N O T E
I f a frequency c o u n te r w ith an accuracy o f a t least
0.1% is available (such as T e k tro n ix 7D 14 D ig ita l
C ounter), i t can be used to check the accuracy o f the
C alibrator.
b. C onnect the Precision DC V o ltm e te r between the
PROBE C A L 0.6 V 1 kH z connector and ground.
a. C onnect a 10X probe (432 standard accessory) to the
CH 1 in p u t connector. C onnect the tip o f the probe to the
to p o f R 918 (see Fig. 5-13).
c. C H E C K —DC voltage measurement o f 0.6 v o lt w ith in
0.003 v o lt (0.009 v o lt if this measurement is being made
outside o f the +20° C to +30"'C tem perature range).
d. A D J U S T —R 9 1 5 (see Fig. 5-13) fo r a DC voltage
measurement o f 0.6 v o lt.
b. C onnect the o u tp u t o f the T im e -M a rk Generator to
the CH 2 in p u t c o n n e cto r via a 42-inch 50 Cl BNC cable.
Set the T im e -M a rk Generator fo r 1 m illisecond tim e marks.
c. A d ju s t the V O L T S /D IV switches fo r a p p ro xim a te ly
tw o divisions o f display o f each signal.
Fig. 5 -1 3 . L o c a tio n o f C a lib r a to r c ir c u it c o m p o n e n ts .
d. Set the V e rtica l Mode to A D D .
e. A d ju s t the T R IG G E R L E V E L c o n tro l so a triggered
trace is presented o n ly when the tim e marks occur during
the positive p o rtio n o f the ca lib ra to r square wave.
f. Set the T R IG G E R C O U PLIN G to LF REJ, the Sweep
MODE to N O R M , and the T IM E /D IV to .2 S /D IV .
g. C H E C K —The am o u n t o f tim e required fo r a tim e-
m ark to d r if t across the positive level o f the ca lib ra to r
square wave to the negative level and back to the positive
level m ust be at least 0.4 second (0.1 second if this
measurement is being made outside o f the +20°C to + 3 0 ^
tem perature range). T his tim e can be measured d ire c tly
fro m the display by observing the num ber o f divisions th a t
the tim e m ark moves across the display area before it
returns to the positive level.
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