Introduction Several years ago I looked at calibrating the RTL-SDR receive level in dBm in connection with LoRa transmission (Ref.1). The same can be done for receive levels for AIS. In my last post I looked at AIS reception from my new QTH along with signal levels (Ref.2). Measurement Setup GNURCTx Level SigHoundRx Level GqrxRx… Continue reading RTL-SDR Rx AIS Power Calibration
AIS on RaspberryPi4 QTH+
Introduction In a previous post I was able to receive AIS contacts from my home location even though surrounded by huge new condos (Ref.1). Recently I moved because my radio horizon was now completely blocked. My new QTH looks due south with no buildings in the immediate vicinity. So I wanted to see how the… Continue reading AIS on RaspberryPi4 QTH+
Marine GMDSS/DSC VHF Decoder_c
Introduction In previous posts I looked at various aspects of GMDSS/DSC using Scicos & GNU Radio (Ref.1/9). In this post I look at the underlying specification ITU M.493-16 and how the frame structure is assembled (Ref.10). The specification covers everything in great detail! It reminds me of working with X.25. I will generate a basic… Continue reading Marine GMDSS/DSC VHF Decoder_c
HF OLIVIA 64-2000 Channel on GNURadio
Introduction In the previous post I received an OLIVIA 64-2000 transmission as part of a ShortWave Radiogram broadcast (Ref.1). I know from my work with MFSK how robust this mode is, so I thought it would be interesting to see how the OLIVIA 64-2000 compares to MFSK64 using the same channel model I used to… Continue reading HF OLIVIA 64-2000 Channel on GNURadio
HF SDR-IQ for Olivia 64-2000
Introduction During the past several years I have received broadcasts from Short Wave Radiogram using the RTL-SDR and SDR-IQ receivers. These broadcasts featured transmissions using MFSK32/64 which I decoded with FLDIGI and Multipsk (Ref.1/3). These broadcasts illustrated the amazing noise performance of MFSK. Last week Short Wave Radiogram added a segment using OLIVIA 64-2000 (Ref.4).… Continue reading HF SDR-IQ for Olivia 64-2000