Ionospheric D Layer absorption attenuates radio signals, mainly below 10 MHz. Here is how it is caused and when. Read more
Category: Shortwave Radio
Why Ionosphere Virtual Height is Important in HF Propagation
You have probably heard people talk about ionosphere virtual height. What is it and why is it important for HF propagation? Read more
Oblique Radio Rays Bend Back to Earth
So, how exactly do oblique radio rays bend as they transit the ionosphere and return to earth? Let’s find out. Read more
Radio Wave Refraction in the Ionosphere
Radio wave refraction depends on density of free electrons and frequency. Skip distance is tied to refractive index and height. Read more
Understand Radio Waves in Various Media
Let’s understand radio waves, and how they behave is different media including solid wire, free space and plasma. Read more
Basic HF Radio Propagation Refresher
Let’s do a level set on basic HF radio propagation through the ionosphere and around the world. Read more
My Radio Propagation Explorations
My radio propagation explorations have driven me to understand more about how this wonderful phenomena actually works. Read more
High Frequency Aircraft Antenna
So, how does a modern airplane use shortwave radio successfully? You may wonder what kind of high frequency aircraft antenna are used. Read more
Shortwave Aircraft Radio Listening
If you want something else to listen to on your SDR, try shortwave aircraft radio listening for trans-oceanic flights. Read more
Test Your Cables Regularly with NanoVNA
You should test your cables regularly. Some may go bad, especially cheap or older ones, with poor connectors or breaks. Read more









