Tektronix 1L10, Инструкция по эксплуатации

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Operating Information— Type 1 LI 0
1. Set the DISPERSION-KC/CM switch to SEARCH.
2. Set the R-F CENTER FREQ and FINE R-F CENTER FREQ
controls to the point where the signal of interest is displayed
in the center of the screen.
3. Set the DISPERSION-KC/CM switch to 2.
4. Set the R-F CENTER FREQ and FINE R-F CENTER FREQ
controls to the point where the signal of interest is displayed
in the center of the screen.
5. Read the frequency indicated by the R-F CENTER FREQ
dial. Accuracy of the reading is ± (1 0 0 kc + 1% o f the
dial reading). For example, with a dial reading o f 10 me,
the actual signal frequency is 10 me ± 2 0 0 kc (i.e., 1%
of 10 me + lOOkc = ± 2 0 0 kc).
NOTE
H ig h ly accurate frequency measurements may be
o b ta in e d using an accurate reference fre q u e n cy
th a t is w ith in 20 kc o f the signal th a t is to be
measured. See the fo llo w in g in fo rm a tio n under
“ Frequency D ifference M easurem ents’ ’.
Frequency Difference Measurements
Accurate frequency separation measurements can be made
between frequencies that are up to 20 kc apart. Accuracy
of the measurement is within + 1 3 % and —7%. The DIS-
PERSION-KC/CM switch sets the dispersion or "frequency
w indow " of the display to a calibrated width. For example,
with the DISPERSION-KC/CM switch set to 2, the frequency
width of the display is 20 kc, (+ 1 3 % or —7%) or 2 kc/cm.
At a setting of 1, the width of the display is 10 kc or 1 kc/cm
and so on through the remaining settings of the DISPER­
SION-KC/CM switch.
Use the following information to
measure the frequency separation between two signals.
1. W ith the two signals displayed on the screen, set the
DISPERSION-KC/CM switch so that the signals are spaced
as far apart on the screen as possible. (Center the two
signals on the screen each time the DISPERSION-KC/CM
switch is set to a lower position.)
2. Set the sweep rate of the oscilloscope for the best
defined signal peaks.
3. Measure the distance, in graticule divisions, between
the two signals (see Fig. 2-3).
4. M ultiply the distance of step 3 by the setting of the
DISPERSION-KC/CM switch. That is:
Fig. 2-3 . Illustration of frequency difference measurement between
two signals.
fs = cm X DISPERSION-KC/CM setting
Where: fs — Frequency separation in kilocycles.
cm — Distance measured in step 3 in centimeters.
Relative Amplitude Measurements
The relative amplitudes o f two signals can be measured
by using the R-F ATTEN switches on the Type 1L10. To
measure relative amplitude, proceed as follows:
1. W ith the R-F CENTER FREQ and FINE R-F CENTER
FREQ controls, tune the smallest amplitude signal to the
center of the screen.
2. W ith all o f the R-F ATTEN switches at OFF, adjust
the G A IN control for exactly 4 cm of vertical deflection of
the smallest signal.
3. W ith the R-F CENTER FREQ and FINE R-F CENTER
FREQ controls, tune the largest amplitude signal to the
center of the screen.
4. Switch as many R-F ATTEN switches to O N as re­
quired to make the largest amplitude signal exactly 4 cm
high.
5. Add the settings of the R-F ATTEN switches that are
switched in. The total is the relative amplitude difference,
in db, between the two signals.
2 -3