Many listeners have wondered about the mysterious Perseus SDR Preamp that seems to do nothing much. Mystery solved. Here’s how. Read more
Modulation Dependent Carrier Level – Saving Energy
Although you don’t know it, most AM broadcasters rapidly adjust their power up and down to save energy costs. The technique is called Modulation Dependent Carrier Level. Read more
About VITA 49 – Discovering Radio Transport Protocol
Why should you care about VITA 49? I may just be the next big thing in software defined radio. Here is a gentle introduction. Read more
SDR Spatial Filtering Demo – Watch It Work
This GNURadio SDR spatial filtering demo shows how you can eliminate local RF interference using coherent sampling on two radio channels with different antennas. Read more
Implementing a DSP Noise Canceller
A DSP Noise Canceller is easily the most useful Spatial Interference Filtering Technique for hams and shortwave listeners. Here’s how its done. Read more
Dual Coherent SDR Receivers – Current State
This article describes the current state of hardware and software solutions for coherent SDR receivers within reach of hams and hobbyists. Take a look. Read more
Narrowband Digital Beamforming – A Spatial Filter
Read this article to learn how to do narrowband digital beamforming in software defined radio. In my opinion, it’s the next big thing for hams and shortwave listeners. Read more
Ham Radio Beamforming with Phased Arrays

Antenna phasing is used for ham radio beamforming and shortwave listening, especially on the lower bands where conventional beams are not feasible. Read more
More About Beamforming – Questions and Answers

Let’s learn more about beamforming. We dig into some of the key assumptions and terminology, including the difference between time delay and phase shift. Read more
Understanding Beamforming – Proven for Decades
Understanding beamforming is actually quite simple. It used to be about analog delay lines. Now it’s just a matter of complex math in your computer. Read more