In the global game of nuclear brinksmanship, secrets are the coin of the realm. This was especially true during the Cold War, when each side fielded armies of spies to ferret out what the other guy was up to, what their capabilities were, and how they planned to put them into action should the time […]
Using digital techniques has caused a resurgence of interest in VLF — very low frequency — radio. Thanks to software-defined radio, you no longer need huge coils. However, you still need a suitable antenna. [Electronics Unmessed] has been experimenting and asks the question: What really matters when it comes to VLF loops? The answer he […]
People have long been interested in very low frequency (VLF) radio signals. But it used to be you pretty much had to build your own receiver which, luckily, wasn’t as hard as building your own VHF or UHF gear. But there is a problem. These low frequencies have a very long wavelength and, thus, need […]
It probably comes as little surprise that our planet is practically buzzing with radio waves. Most of it is of our own making, with cell phones, microwaves, WiFi, and broadcasts up and down the spectrum whizzing around all the time. But our transmissions aren’t the only RF show in town, as the Earth itself is […]
If you want to talk about antennas, the amateur radio community has you covered, with one glaring exception. Very low frequency and Extremely Low Frequency radio isn’t practiced very much, ultimately because it’s impractical and you simply can’t transmit much information when your carrier frequency is measured in tens of Hertz. There is more information […]