Spectrum Analyzer Mode
R&S
®
Cable Rider ZPH
218
User Manual 1321.0950.02 ─ 07
1. Press the [SCALE/AMPT] key.
2. Select the "Ref Offset"" softkey.
The R&S Cable Rider ZPH opens an entry box to define input field.
3. Enter the offset you need.
The R&S Cable Rider ZPH includes the offset in puts in the measurement.
To indicate an offset other than 0, the R&S Cable Rider ZPH puts a blue dot at the
"REF" field displays in the "Parameter View".
8.2.3.5
Setting the RF Attenuation
RF attenuation adjusts the input range inside the analyzer. It is coupled directly to the
reference level. If you have set a high reference level, RF attenuation is turned on in 10
dB steps according to the table below so that the input mixer always remains in the lin-
ear range.
The R&S Cable Rider ZPH provides three attenuation modes.
●
Auto Low Distortion
If this mode is active, the R&S Cable Rider ZPH sets the RF attenuation 10 dB
higher according to the table below, making the stress of the input mixer 10 dB less
at the specified reference level. If the spectrum is densely occupied with signals,
e.g. in a television cable network, the input mixer reduces the R&S Cable Rider
ZPH inherent spurious products. However, the inherent noise display of the R&S
Cable Rider ZPH increases due to the increased attenuation in front of the input
mixer.
●
Auto Low Noise
If this mode is active, the R&S Cable Rider ZPH sets the RF attenuation 10 dB
lower. This increases the sensitivity of the R&S Cable Rider ZPH, which means
that the inherent noise display decreases due to the lower attenuation in front of
the input mixer.
●
Manual
Manual selection of the attenuation.
You can check the status of the RF attenuation and the preamplifier in the "Configura-
tion Overview" dialog and in the "Parameter View" area.
Reference Level
Preamplifier OFF
RF Attenuation
Preamplifier ON
RF Attenuation
Low Noise
Low Distortion
Low Noise
Low Distortion
<=-40 dBm
0 dB
0 dB
0 dB
0 dB
-39 dm to -35 dBm
0 dB
0 dB
0 dB
5 dB
-34 dm to -30 dBm
0 dB
0 dB
0 dB
10 dB
-29 dBm to -25 dBm
0 dB
0 dB
0 dB
15 dB
-24 dBm to -20 dBm
0 dB
0 dB
0 dB
20 dB
-19 dBm to -15 dBm
0 dB
5 dB
5 dB
25 dB
Configuring Spectrum Measurements
