RTL-SDR for HF Beacons Propagation Prediction

Introduction In a previous post, I looked at how the RTL-SDR can be used to receive HF stations in the NCDX/IARU HF Beacon network (Ref.1). These stations transmit on a schedule and can be used for HF propagation analysis. Various programs can also be used for HF propagation prediction (Ref.2), such as VOACAP (Ref.3) and… Continue reading RTL-SDR for HF Beacons Propagation Prediction

VHF Marine Antenna Testing with NanoVNA

Introduction Recently I discovered the NanoVNA vector network analyzer. I had seen articles in QST magazine over the last several years and was intrigued (Ref.1/2). My first experiment was with my HF vertical antenna. I calibrated the unit for the HF band from 1MHz – 30MHz and tested the SWR (Ref.3). The results were exactly… Continue reading VHF Marine Antenna Testing with NanoVNA

HRF1 as a Signal Generator for Amateur Radio

Introduction About 20 years ago I was building various SDR receivers and I needed a signal generator to test their performance. I decided like most hams to build my own using the latest Analog Devices 8 bit DDS chip AD9850. The unit was controlled by a simple Atmel ucontroller, was battery powered/portable and worked up… Continue reading HRF1 as a Signal Generator for Amateur Radio

HF Antenna Testing with NanoVNA

Introduction Recently I discovered the NanoVNA vector network analyzer. I had seen articles in QST magazine over the last several years and was intrigued (Ref.1/2). I remember years ago testing VHF/UHF/uW antennas with large signal generators, directional couplers and scopes all weighing hundreds of pounds. Now the same thing and more can be done with… Continue reading HF Antenna Testing with NanoVNA