HP 70000 series, User Manual

Page: 234 / 447

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SAMPLE
When manually changing the responsivity value , use the numeric keypad to enter a new value
and the
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V/W softkey to terminate the entry . Use the 4 8 5 and 4 9 5 step softkeys to change the
responsivity value in increments or make small changes using the front panel knob .
Functional Type:
lightwave
Firmkey A ccess:
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Amptd
Preset State:
A uto
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SAMPLE
displays the instantaneous signal level detected at the beginning of the sample period.
Sample detection is useful during zero-span mode when measuring modulation with
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PERSIST On Off set to on.
Pulse responses less than one sample interval might not appear , depending on the span setting.
Figure 4-9 is an example of signal loss when using the sample function with the frequency span
set too wide . Compare Figure 4-6 and Figure 4-9. The only dierence in instrument setting
between the two gures is that the detector mode has been switched from normal to sample .
The video-averaging and marker-noise softkeys ,
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VID AVG On Off and
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MKNOISE On Off , also
activate sample detection.
Figure 4-9. Measurement Using Sample-P eak Detection
Softkey Descriptions 4-139