I trying to measure the frequency drift between two N210 USRPs using GNURadio Companion. I used one USRP as a TX and the other one as an RX. The transmitted signal is a complex sinusoidal.
The issue that I am facing is how to get the modulated signal from the TX before the transmission through the antenna. In other words, I am trying to connect the UHD:USRP Sink to a frequency sink to see the FFT of upconverted/modulated signal to be compared with the signal received at the RX. However, the UHD:USRP Sink cannot be connected to the Frequency sink in GNURadio.
So, is there anyway to check the modulated signal from the TX?
Can I connect the USRP to a real oscilloscope?