SPA-900 Series User Manual 31
measurement can be displayed in a proper mode for easier observation and minimum error.
2.1.3.1
Ref Level
Set the maximum power or voltage can be currently displayed in the window. The value is
displayed at the upper left corner of the screen grid.
The maximum reference level available is affected by the maximum mixing level, input attenuation
is adjusted under a constant maximum mixing level in order to fulfill the following condition:
Ref <= ATT – PA - 20dBm
Table 2-6 Ref Level
Parameter
Explanation
Default
0 dBm
Range
-100 dBm ~ 30 dBm
Unit
dBm, dBmV, dBuV, V, W
Knob Step
In Log scale mode, step = Scale/10
In Lin scale mode, step = 0.1 dB
Direction Key Step
In Log scale mode, step = Scale
In Lin scale mode, step = 1 dB
Related to
Attenuator, Preamp, Ref Offset
2.1.3.2
Attenuator
Set the front attenuator of the RF input in order to ensure big signals (or small signals) to pass
through the mixer with low distortion (or low noise).
Ref <= ATT – PA - 20dBm
Input attenuation can be set up for automatic and manual two kinds of patterns.
Automatic mode attenuation value according to the state of preamplifier and value of the
current reference level automatic adjustment.
Open the preamplifier, maximum input attenuation can be set to 51dB. When setting
parameters do not meet the above formula, can adjust the reference level.
You can modify this parameter using the numeric keys, knob or direction keys. For
more details, please refer to “
Parameter Setting
”.
Table 2-7 Attenuator
Parameter
Explanation
Default
20 dB
Range
0 ~ 51 dB
Unit
dB
Knob Step
1 dB
Direction Key Step
5 dB
Related to
Preamp, Ref level
Distributed by: Reliant EMC LLC, +1 408 916
‐
5750, info@reliantemc.com, www.reliantemc.com
