Tektronix 434, Инструкция по эксплуатации

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Operating Instructions—434
5. T o measure the am p litu d e o f an u n kn o w n signal, dis­
connect the reference signal and connect the u n k n o w n
signal to the in p u t co nnector. Set the V O L T S /D IV sw itch
to a setting th a t provides s u ffic ie n t vertical d e fle c tio n to
make an accurate measurement. Do n o t readjust the
Variable V O L T S /D IV c o n tro l.
6. Measure the vertical d e fle c tio n in divisions and
calculate the a m p litu d e o f the u n kn o w n signal using the
fo llo w in g fo rm u la :
any setting o f the T IM E /D IV sw itch, the re p e titio n rate o f
the reference signal m ust be know n. I f it is n o t kn o w n , it
can be measured before the Variable T IM E /D IV c o n tro l is
set in step 2.
4. Divide the re p e titio n rate o f the reterence signal
(seconds) by the p ro d u c t o f the h o riz o n ta l d e fle c tio n estab­
lished in step 2 (divisions) and the setting o f the T IM E /D IV
sw itch. This is the h o rizo n ta l conversion fa c to r.
Signal
A m p litu d e
V O L T S /D IV vertical vertical
switch X conversion X d e fle ctio n
setting fa c to r (divisions)
H orizontal reference signal re p e titio n rate
Conversion = _____________ (seconds)_____________
F a cto r h o rizo n ta l d e fle c tio n T IM E /D IV
(divisions) sw itch setting
E X A M P L E . Assume a reference signal a m plitude o f 30
volts, a V O L T S /D IV sw itch setting o f 5 V , and the V ariable
V O L T S /D IV co n tro l is adjusted to provide a vertical d e fle c­
tio n o f fo u r divisions.
S u b stitu tin g these values in the vertical conversion fa c to r
fo rm u la (step 4 ):
V ertical
Conversion =
Factor
30 V
4 X 5 V
1.5
5. T o measure the re p e titio n rate o f an u n kn o w n signal,
disconnect the reference signal and connect the u n kn o w n
signal to the in p u t connector. Set the T IM E /D IV sw itch to
a setting th a t provides s u ffic ie n t h o riz o n ta l d e fle c tio n to
make an accurate measurement. Do n o t readjust the
Variable T IM E /D IV c o n tro l.
6. Measure the h o riz o n ta l d e fle ctio n in divisions and
calculate the re p e titio n rate o f the u n k n o w n signal using
the fo llo w in g fo rm u la :
Then, w ith a V O L T S /D IV sw itch setting o f 10, the peak-to-
peak am p litu d e o f an u n kn o w n signal w hich produces a
vertical d e fle c tio n o f five divisions can be determ ined by
using the signal a m p litu d e fo rm u la (step 6):
Signal
A m p litu d e
= 10 V X 1.5 X 5
75 volts
Sweep Rates. T o establish an a rb itra ry h o rizo n ta l sweep
rate based upon a specific reference frequency, proceed as
fo llo w s :
R e p e tition
Rate
T IM E /D IV h o rizo n ta l
= sw itch X conversion X
setting fa cto r
h o rizo n ta l
d e fle ctio n
(divisions)
E X A M P L E . Assume a reference signal frequency o f 455
hertz (re p e titio n rate 2.19 m illiseconds), and a T IM E /D IV
switch setting o f .2 ms, w ith the Variable T IM E /D IV co n ­
tro l adjusted to provide a h o rizo n ta l d e fle ctio n o f eight
divisions. S u b s titu tin g these values in the h o rizo n ta l co n ­
version fa c to r fo rm u la (step 4 ):
1. C onnect the reference signal to the IN P U T connec­
to r. Set the V O L T S /D IV sw itch fo r fo u r or five divisions o f
vertical d e fle ctio n .
H o rizo n ta l
Conversion
Factor
2.19 m illiseconds
.2 X 8
1.37
2. Set th e T IM E /D IV sw itch and the Variable T IM E /
D IV c o n tro l so one cycle o f the signal covers an exact
num ber o f h o riz o n ta l divisions. Do n o t change the Variable
T IM E /D IV c o n tro l after obtaining the desired d e fle c tio n .
T his display can be used as a reference fo r frequency co m ­
parison measurements.
Then, w ith a T IM E /D IV sw itch setting o f 50 jus, the re p e ti­
tio n rate o f an u n kn o w n signal w h ich com pletes one cycle
in seven h o rizo n ta l divisions can be determ ined by using the
re p e titio n rate fo rm u la (step 6 ):
R e p e tition = 50 p S
x
1.37 X 7 = 480 jus
3. T o establish an a rb itra ry sweep rate so the re p e titio n
rate o f an u n kn o w n signal can be measured accurately at
T his answer can be converted to frequency by taking the
reciprocal o f the re p e titio n rate (see app lica tio n on D eter­
m ining F requency).
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