Tektronix 2715, Руководство пользователя

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Dedicated Controls
4–2
2715 User Manual
The span controls change the total display frequency span range symmetrically
about the center frequency, select channel table entries, and set the 2715 in the
maximum span or zero span modes.
1. Press [INPUT] [9] to turn on the calibration signal.
2. Press [MKR/ /OFF] twice to turn off the markers.
3. Press [CHAN/FREQ] [4] [0] [0] [X] to set the 2715 center frequency to
400 MHz.
4. Press [MAX] and [AUTO] RES BW. Remember that in MAX SPAN the
marker changes position and not the frequency at screen center.
5. Press [REF LEVEL] [3] [8] [ ] [8] [Y] to set the reference level to
38.8 dBmV.
Arrow Keys.
The arrow keys to the right of [SPAN/DIV] change the frequency
span represented by one horizontal division on the screen. The arrows directly
increase or decrease the span per division.
6. Beginning with maximum span, press [
b
] to the right of [SPAN/DIV]
several times to decrease the span/div to 20 MHz
1
.
This causes the 2715 to zoom in on the spectral display.
7. Now press [
y
] until the span/div increases to 180 MHz.
Watch the spectral display zoom out just as though it was moving away from
you.
The up arrow increases the span/div, compressing or squeezing the spectrum
together. The down arrow decreases the span/div and expands or stretches the
spectrum. The arrow keys are active whenever the 2715 is in the spectral display
mode. Experiment by pressing each arrow key until the span/div no longer
changes. You will notice two characteristics of the 2715:
H
Span/div changes in a 1–2–5 sequence between 1 kHz and 100 MHz, plus
180 MHz/div in maximum span
H
Resolution BW changes automatically as the span changes (later, we show
how this can be changed)
1
If you request a narrow span before the 2715 is completely warmed up, you may get
a NORMALIZATION SUGGESTED message. This message should not appear after
the 2715 warms up.
SPAN/DIV