Hello! I am trying to decode data send from a DRA818v (1W) module at 144.39Mhz by connecting it through an 80dB attenuator (SWR is about 1.2) to an RTL based SDR. When I look at the data the SDR is receiving, I noticed the channel with of the signal is much larger then the 2.5Khz channel I configured. I don't have a LPF on the end of the module so I am getting a harmonic components. I am receiving the data with the SDR on a RPI. The RPI is hosting a rtl_sdr server which I am connecting to with GQRX on my main computer.
Why is the bandwidth of the signal I am receiving so large? is there some other harmonic component here that I am missing? Attached is my settings, the signal I am receiving and my setup.
Thanks