WSJT-X MSK144 Demodulator – Scicos Simulation

Introduction In a previous post (Ref.1), I simulated an MSK144 modulator with Scicos. In this post, I will simulate the demodulator. Recalling the design parameters: -SSB Transceiver_USB interface (300,2700)Hz = 2400Hz-Baud Rate = 2000bdps, Tbaud = 0.500msec -MSK = Minimum Shift Keying, Frequency Shift = 0.5*BdRate = 1000Hz-Centre Freq = 1500Hz, Lower Freq = 1000Hz,… Continue reading WSJT-X MSK144 Demodulator – Scicos Simulation

RTL-SDR for EPIRB

Introduction EPIRB or Emergency Position Indicating Radio Beacon Station is an emergency transmitting device that blue water sailors or explorers can use in case of distress. They have proven their worth over the years and are absolutely essential for anyone wanting to wander off the grid (Ref.1). At least 2000 people have been saved every… Continue reading RTL-SDR for EPIRB

HF SSB vs. Digital Voice

Introduction In a recent YouTube video I saw a demonstration of a commercial HF radio communicating over a distance of 90Km using NVIS and digital voice. Using SSB the received signal was barely above noise level, and hardly decipherable. However, when the digital voice modem was switched on, the signal was very clear. I decided… Continue reading HF SSB vs. Digital Voice