[Discuss-gnuradio] nonexisted peaks USRP N210 Connection

[s k]

Hi All,

I want to do a transmit receive application with USRP Network series, with USRP N210s. I have used WBX TX/RX as transmitter and TVRX2 TX/RX part as receiver. I used 206MHz as center frequency. Here is my transmitter blocks

 

And my receiver blocks in GRC

 

My receiver graph before transmitter begin to transmit:

    

My transmitter graph when i begin to transmit, first one is zoomed up part



and zoomed in down part.



And finally my receiver graph is the following graph. As you see there is a DC peak that i didn't send in the transmitter end.

  

I tried so much time but each time i saw this peak when i work in this frequency (also other high frequencies). When i shift center frequency a little bit then four of them shifting together. So it is together with other three.

What is the reason of this peak. İs it because of transmitter or receiver? When i use relatively low frequencies as center frequency (for example 50MHz or 60MHz) then the DC peak is disappearing. (I attached the images.)

Any help would be kindly appreciated.

Sema