Hello,I am trying to see the spurs arround the signal by lowering the attenuation of the spectrum analizer.
but i notice that my noise floor rises for some reason when i lower the attenuation.
also there is the offset parmeter that plays a role in controlling the attenuation.
my spectrum analizer stops attenuation lowering if my offset is too high for some reason??
Why lowering attenuation gives us a more accurate result?
Thanks.

 

Hello,I am trying to see the spurs arround the signal by lowering the attenuation of the spectrum analizer.
but i notice that my noise floor rises for some reason when i lower the attenuation.
also there is the offset parmeter that plays a role in controlling the attenuation.
my spectrum analizer stops attenuation lowering if my offset is too high for some reason??
Why lowering attenuation gives us a more accurate result?
Thanks.

to look at the spurs in more detail,
you need to lower the span such that you are not receiving the main ,

 

Yes i know that,also we can lower the RBW,
but why reducing the attenuation makes the spurs more clearer?