ESTACION DE 10 METROS ,SDR , RX SATELITE RUSO RS-15,
For me this looks like very strong interferences. A good signal looks like this (if it’s still sending):
Your FFT doesn’t show a signal imho.
Looks like how FM radio stations images get into the RTLSDR at these low freqs to me.
Plus tuning the RTLSDR down that low will give all sorts of noise because your getting to the very edge that it can receive. (Might even be slightly past that spec)
I have recorded audio of reception qso in 10 meters between Uruguay and Spain, I received in sdr and notebook.