Category: Electronics

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

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). Next I tested my… Continue reading HF Loop 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

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