NARDA SignalShark - Setting the Reference Level; Attenuation Value (Ref. Level; Attenuator); Setting the Reference Level (Ref. Level)

SignalShark User Manual
96
Setting the reference level / attenuation value
(Ref. Level / Attenuator)
Here you can do the following:
•
Set the Reference Level (RL) or Attenuator value (depends on the Entry Mode setting).
•
Select the RF input
•
Select the Entry Mode
•
Select +5 dB / -5 dB
The Reference Level is an indirect way to set the current attenuator value. It defines the
maximum measurable level. For better convenience it also sets the upper axis limit of the
view.
You can stop this coupling by setting the entry mode to Abs.in the Display settings:
1. Tap the header of the desired view.
2. Tap the Display button.
3. Long tap the Lmax button.
4. Tap the Entry Mode button to select Abs.
5.
Press the Esc key twice to close the menus.
Background information about the Reference Level
The sensitivity of the system depends on the input attenuator setting. This setting is
determined by the Reference Level (RL) parameter. High measurement sensitivity avoids
falsification of the results due to noise generated internally by the device. On the other
hand, it is important that the device is not overloaded (saturated). Saturation can also be
caused by signals outside the frequency band, e.g. high power radio transmitters when
measuring mobile telephone signals. The reference level setting covers up to 25 dB
depending on the attached components (handle, type of antenna, etc.) and is coupled to
the setting of the input attenuator (Attenuator, Atten). The input attenuator can be
matched ideally to the measurement signal by means of its fine adjustment in steps of
0.5 dB. At the highest reference level setting, Atten = 2 dB; at the most sensitive
reference level, Atten = 0 dB.
It is possible to decouple the reference level and the input attenuator indirectly using the
Y-Scale Ref parameter in the Display menu.
Setting the reference level (Ref. Level)
 You selected the desired view.
 RL is selected as entry mode.
1.
Tap the Ref. Level button.
 The settings dialog opens.
2.
Enter the required value and tap the unit button.
 The settings is accepted immediately and the dropdown list is closed.
Or use the Rotary knob to change the value.