I recently built an inmarsat receiver with an active gps antenna, but I can't get any signal on 1541.5 Mhz. There are many other signals on different frequencies looks very similar to inmarsat signal, but my decoder can't decode any of them. So I am wondering what went wrong, maybe the SNR is not high enough to decode the signal or because I didn't tune to the right frequency? I went through the whole inmarsat spectrum and here is the video. https://streamable.com/fipdb I live in Australia and can receive Inmarsat 3-F1, Inmarsat 3-F3, Inmarsat 4-F1, Inmarsat 4-F2, Inmarsat 5-F1 and Inmarsat 5-F3.