Author: Jeremy Clark

Introduction In previous posts I looked at decoding GMDSS/DSC signals using Multipsk (Refs.1/3). Recently I have been able to use my balcony again and receive HF & VHF signals. This evening I was able to receive a VHF Ch70 GMDSS/DSC coastal signal on 2m using SDR# & Multipsk. GMDSS/DSC VHF Reception Parameter MF/HF VHF Frequency… Continue reading RTL-SDR for VHF Marine GMDSS/DSC

Introduction In a previous post I looked at decoding GMDSS/DSC signals using Multipsk (Ref.1). Recently I have been able to use my balcony again and receive HF signals. This evening I was able to receive a GMDSS/DSC coastal signal on 36m using SDR# & Multipsk. GMDSS/DSC HF Reception Parameter MF/HF VHF Frequency 2187.5, 4207.5, 6312.0,… Continue reading RTL-SDR for HF Marine GMDSS/DSC

Introduction Recently my apartment balcony reconstruction was finished and I was itching to use my L band dish again. I read in a newsgroup that the NOAA satellites have an L band transmitter, so I thought measuring the Doppler shift as the satellite comes into view and leaves would be an interesting experiment. Last year… Continue reading RTL-SDR for LEO L Band Doppler Shift

Introduction In previous posts I tested the various HF/VHF/Microwave antennas that I have using the versatile NanoVNA (Ref.1/5). For the past six months my apartment balcony has been under construction and finally it’s finished. Unfortunately when I setup my HF Buddipole antenna there was no reception, so I suspected that the transmission line which was… Continue reading HF Tx Line Testing with NanoVNA

Introduction In the previous post (Ref.1) I examined how we can create an embedded python block on GNU Radio to communicate with the RaspberryPi4 GPIO. In this post I build on the concept by adding a Python module to enable us to create a Marine VHF channel scanner. I struggled with how to time step… Continue reading RTL-SDR for Marine VHF Scanner on GNU Radio