Introduction In a previous post, I discussed how to use the Friis equation to determine the free space loss and receive level between a transmitter and receiver (Ref.1). Let’s consider an example that I saw in a recent sailing forum. The discussion was around the range of a typical marine VHF transmitter using a quality… Continue reading Splat! – Marine VHF Propagation
Category: Telecommunications
Telecommunications: Propagation, HF, VHF, UHF, uWave
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
RTL-SDR for LF Beacons
Introduction In my previous post (Ref.1) I examined how the RTL-SDR with the up converter can be used to receive the LF/MF/HF bands. Low power radio navigation beacons are located in the LF band and can be received by the RTL-SDR. Figure 1 shows a table of LF radio navigation beacons located in the Toronto… Continue reading RTL-SDR for LF Beacons
RTL-SDR for HF 0-30MHz
Introduction The standard RTL-SDR receives from 25 – 1725MHz, which does not include the LF band from 30-300KHz, the MF band from 300KHz – 3MHz and the HF band from 3 – 30MHz. However with the use of an up-converter, these bands can be received (100KHz – 65MHz). Fig.1 shows the 1st version of the… Continue reading RTL-SDR for HF 0-30MHz