Tektronix 2715, User Manual

Page: 32 / 360

Getting Started
2–6
2715 User Manual
To ensure a common starting point for the calibration signal measurement, you
must restore the factory-default power-up settings.
4. Press [UTIL] [1] [1].
This restores the factory-default settings whenever the 2715 is in normal
spectral display mode (and most other modes). It is a handy method of
returning to a fixed set of conditions if you get lost.
Figure 2–1 shows what the spectrum analyzer screen looks like after initializing
the instrument settings.
600 kHz
Noise
Floor
10 dB
186 MHz
Center Frequency
183 MHz 180 MHz
Reference
Level
68.8 dBmV
Figure 2–1: Display with Factory Default Power-Up Settings
The displayed spectrum represents the noise floor of the spectrum analyzer. The
noise floor is the amplitude of the noise generated internally by the spectrum
analyzer itself and passed through the resolution bandwidth filter. Narrowing the
resolution bandwidth lowers the noise floor, because noise power is directly
proportional to the resolution bandwidth.
The noise appears as a thick, irregular band across the bottom portion of the
screen. To achieve this appearance, digital display storage is used. The unique
max/min display shown here is designed to resemble the analog spectra that the
spectrum analyzer inherently produces.
Restoring the Factory
Default Settings
The Initial Display