Hi El, this is a bit hard to tell -- are you using a direct cable or antennas between TX and RX? If you're using antennas, that might simply be something else transmitting there.
Also, if you transmit at 560 MHz, but only observe $\SI{562}{\mega\hertz}\pm\frac{\SI{0.2}{\mega\hertz}}{2}$, you can't see your transmit signal, so I can't compare the strength of that and what you see in your RX FFT plot. Best regards, Marcus On 06/21/2015 03:47 PM, El El wrote: > Hi, > I implemented the FM transmitter and receiver from the tutorials > (http://files.ettus.com/tutorials/labs/Lab_1-5.pdf), the carrier > frequency is 560 MHz, audio rate = 48 kHz, and frequency deviation = 5 > kHz. My question is why don't the FFT plots look similar? The FFT for > the transmitter is centered on 562 MHz, but for the receiver, the > highest amplitude component is centered on 561.97 MHz, also there is > one more component on 562.09 MHz. Screenshots of the FFT plots are > attached. > Thanks a lot, > > El > > > > > > > > > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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