I am trying to capture the FM frequencies using HackRF-one. I don't have the regular antenna, so I am using a different antenna (shown below). When I tried to record the FFT plot for the range of frequencies the receiver is able to capture, I obtained a plot as shown in the image below. I am a bit curious as to why the number of peaks and the height (length) of each peak is small. Can it be due to the antenna that I am using or the place where the SDR is operated? I am unable to receive any FM signal from the audio sink. If you have any ideas, please let me know.
Sample rate : 20 MHz
Channel center freq : 104.3 MHz