User Manual

Waveform Setup
R&S
®
Scope Rider RTH
39User Manual 1326.1578.02 ─ 08
You can also shortly press the channel key to select a channel. If you press and hold
the channel key, the corresponding channel menu opens.
Channel <n>
Switches the selected channel on or off.
Remote command:
CHANnel<m>:STATe on page 252
Coupling
Selects the connection of the input signal. The current coupling of each channel is
shown in the channel label at the display bottom.
AC coupling. A high-pass filter removes the DC offset voltage from
the input signal if the DC component of a signal is of no interest. The
waveform is centered on zero volts.
DC coupling, the signal passes the input unchanged.
Remote command:
CHANnel<m>:COUPling on page 254
Probe Setting
Selects the attenuation factor of the connected probe. The vertical scaling and mea-
sured values are multiplied by this factor so that the displayed values are equal to the
actual signal values.
Make sure to set the attenuation factor on the instrument according to the probe being
used. Otherwise, the measurement results do not reflect the actual voltage level, and
you might misjudge the actual risk.
Bandwidth
Selects the bandwidth limit. The full instrument bandwidth indicates the range of fre-
quencies that the instrument can acquire and display accurately with less than 3 dB
attenuation.
For analog applications, the highest signal frequency determines the required oscillo-
scope bandwidth. The oscilloscope bandwidth should be at least 3 times higher than
the maximum frequency included in the analog test signal to measure the amplitude
with high accuracy.
Most test signals are more complex than a simple sine wave and include several spec-
tral components. A digital signal, for example, is built up of several odd harmonics. For
digital signals, the oscilloscope bandwidth should be at least 5 times higher than the
clock frequency to be measured.
The oscilloscope is not an autonomous system. You need a probe to measure the sig-
nal, and the probe has a limited bandwidth, too. The combination of oscilloscope and
probe creates a system bandwidth. To reduce the effect of the probe on the system
bandwidth, the probe bandwidth should exceed the bandwidth of the oscilloscope, the
recommended factor is 1.5 x oscilloscope bandwidth.
See also: Chapter 2.2.2, "Effect of the Bandwidth Filter", on page 41.
Vertical Setup