I tried this article https://www.rtl-sdr.com/rtl-sdr-tutorial-measuring-filter-characteristics-and-antenna-vswr-with-an-rtl-sdr-and-noise-source/ - take a look at my post from February - The BIG and SMALL ANTENNA topic part 1
I tried this article https://www.rtl-sdr.com/rtl-sdr-tutorial-measuring-filter-characteristics-and-antenna-vswr-with-an-rtl-sdr-and-noise-source/ - take a look at my post from February - The BIG and SMALL ANTENNA topic part 1