Hi All,

and thank you All for your Answers in my last thread.

Now i want to know, how i can convert the showing

values in the Y-Axis of the FFT-Plot Sink to dB, so that

i can interpret this correctly.

Do i have to define the max and min input value first ?

Results an input voltage 3.3V in the max Value(0dBFS)

i can watch in the FFT-Plot sink ?

Results an input voltage 0V in the min Value i can

watch in the FFT-Plot sink ?

As Stefan BrÃ¼ns said in my last Thread:

"The reference point is 0dbFS - FS meaning Full Scale,

-32768…32767. The signal power you need to get this

readings from the ADC, or more exactly from the FPGA

depends on the daughterboard, PGA setting on the daughterboard,

decimation …

You have to calibrate your USRP to get from the sampling

values to input power in Watts."

So if i read for example the value +7.079 from my FFT-Plot

Sink, what does this mean ?

Is this higher than the reference(0dBFS) Point ?

I thouht the reference is the highest point.

How can i calibrate my USRP to get from the sampling values

to input power in dBW ?

I experimented with an example(See Attachment), but

this example use a virtual signal(software generated signal)

Amplitude of Signal: Value of FFT-Plot:

10e-3 -12.921

100e-3 7.079

1000e-3 27.079

So inreasing the Value with the multiply of 10 let the

y-Axis of the FFT-Plot increase by 20dB.

This behaves like dBW not dBV ?

Regards Markus