Last Updated on December 8, 2025 by John Berry
Personal background
Hi, I’m John Berry. I was first interested in ham radio as a kid in the 60s and got my callsign GM8JBJ in the early 70s. I then went professional and for many years I worked in the UK, travelling worldwide, and ran radiocommunications companies. For the most part I did nothing in the hobby until 2019. My core interest now is radiowave propagation in the Earth’s atmosphere and just above into the edge of space.
This site documents my investigations and understanding of propagation. Hover over the Knowledgebase menu for a drop-down of the sub-topics.
Engineer domains
Engineers have used radio waves to communicate between two points on the Earth’s surface since the late 1800s. Today, that communication is ubiquitous across the four principle services – mobile, fixed, satellite and broadcasting – and across the emerging sub-sectors of space and radionavigation. That communication has transformed the way we all live.
Radio waves propagate from one point to another (or rather, one point to many others, as you will read here) through the Earth’s atmosphere.
The Earth’s atmosphere
The Earth’s atmosphere comprises five concentric spheres. Propagation in the lowest layer, the troposphere, is typically point to point. Propagation in the other four upper spheres (and onward to the Moon, around 384,000km away) involves some sort of reflection, refraction or scattering of the waves. There, signals from one point on the Earth’s surface typically go up, get reflected, refracted or scattered and come back down somewhere else.
Whether or not this propagation is useful depends on the efficiency of the various mechanisms. That efficiency depends in turn on the propagation mode (as a set of connected mechanisms), equipment used and frequency of the signal.
Engineers have designed communications systems to exploit particular modes. Radio amateurs (or ‘hams’) can investigate, analyse and research using low-cost equipment to probe those modes and propose new. The goal is greater understanding of the science of the atmosphere – and having some fun along the way.
Professional and amateur worlds
Engineers design systems for society. They want high effectiveness, supporting communication for high percentages of time and locations. Radio hams are happy with very low effectiveness. They will rejoice in a fleeting communication. But those fleeting communications build understanding. And understanding feeds new modes that engineers may subsequently exploit.
There is much known about the Earth’s atmosphere – particularly since mankind has launched research satellites into the thermosphere and exosphere. There is now much theory supported by research. And yet there is still much to know.
This site
On this site, I aim to add to that knowledge about the Earth’s atmosphere by explaining rather than by undertaking new research. I aim to challenge how we come to know about the atmosphere (epistemology) in order that we can enhance what we do know (ontology).
The site is a continual work in progress I started in 2021 and it will likely span many years.
In the menu above, you’ll find a note of my station, my areas of interest and how to contact me. The central body of the site, with papers, is in the Knowledgebase.