How to configure USRP X310 with UBX160 to normal noise level after stop Tx?

[Dor Ratz]

Hey,

 

I have usrp x310 and daughterboard UBX-160. It is connected to ADC and I measured the noise level after the ADC.

 

I try to understand how to  configure it to normal noise level after stop Tx.

 

I got 2 cases with different noise level at the RF output:

 

 

Case A - the usrp is turned on without Tx since then.

 

Case B - the USRP is turned on, it Tx for several seconds,then I stop tx from gnuradio , the USRP is turned on but without Tx.

 

Why the noise level in case B is 2.4 times higher than Case A?

 

And is there a way to lower the noise level without physically turn off the USRP? Any API commands to send?

 

Seemed like there is a configuration loading to the RF chain so the noise level increases and stays like that even after stop Tx.

 

Thanks a lot