Spectrum analyzer Reference level problem

[enkaar01]

I have been facing problem wit spectrum analyzer, when I change the reference level ,amplitude changes drastically or just signal vanishes. At some manual attenuation it gives correct readings. Is it a measurement error or something has malfunctioned
plaese help to resolve the problem

 

[emresel]

after changing reference level then change the scale division, it should help...

 

[goal]

its the correct function of SA. there is a relation ship between both reference level and attenuation.
ref level sets max input range. do not set reference level more and just keep it at a level where your signal is not clipped and can be viewed comfortably.
increase ref level will increase attenuation.
attenuation sets the input range. if input signal is high attenuation will be adjusted inside SA. attenuation is set based on ref level.