Radio Apocalypse: HFGCS, The Backup Plan For Doomsday

To the extent that you have an opinion on something like high-frequency (HF) radio, you probably associate it with amateur radio operators, hunched over their gear late at night as they try to make contact with a random stranger across the globe to talk about the fact that they’re both doing the same thing at the same time. In a world where you can reach out to almost anyone else in an instant using flashy apps on the Internet, HF radio’s reputation as somewhat old and fuddy is well-earned.

Like the general population, modern militaries have largely switched to digital networks and satellite links, using them to coordinate and command their strategic forces on a global level. But while military nets are designed to be resilient to attack, there’s only so much damage they can absorb before becoming degraded to the point of uselessness. A backup plan makes good military sense, and the properties of radio waves between 3 MHz and 30 MHz, especially the ability to bounce off the ionosphere, make HF radio a perfect fit.

The United States Strategic Forces Command, essentially the people who “push the button” that starts a Very Bad Day™, built their backup plan around the unique properties of HF radio. Its current incarnation is called the High-Frequency Global Communications System, or HFGCS. As the hams like to say, “When all else fails, there’s radio,” and HFGCS takes advantage of that to make sure the end of the world can be conducted in an orderly fashion.

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Radio Apocalypse: The BBC Radio Program That Could(n’t) Have Started WWIII

Here’s a question for you: if you’re the commander of a submarine full of nuclear missiles, how can you be sure what not receiving a launch order really means? If could — and probably does — mean that everything is hunky dory on land, and there’s no need to pull the trigger. Or, could radio silence mean that the party already kicked off, and there’s nobody left to give the order to retaliate? What do you do then?

One popular rumor — or “rumour,” given the context — in the UK holds that BBC Radio 4, or the lack thereof, is sort of a “deadman’s switch” for the Royal Navy’s ballistic missile subs. [Lewis (M3HHY)], aka Ringway Manchester on YouTube, addresses this in the video below, and spoiler alert: it’s probably not true.

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Radio Apocalypse: Hardening AM Radio Against Disasters

If you’ve been car shopping lately, or even if you’ve just been paying attention to the news, you’ll probably be at least somewhat familiar with the kerfuffle over AM radio. The idea is that in these days of podcasts and streaming music, plain-old amplitude modulated radio is becoming increasingly irrelevant as a medium of mass communication, to the point that automakers are dropping support for it from their infotainment systems.

The threat of federal legislation seems to have tapped the brakes on the anti-AM bandwagon, at least for now. One can debate the pros and cons, but the most interesting tidbit to fall out of this whole thing is one of the strongest arguments for keeping the ability to receive AM in cars: emergency communications. It turns out that about 75 stations, most of them in the AM band, cover about 90% of the US population. This makes AM such a vital tool during times of emergency that the federal government has embarked on a serious program to ensure its survivability in the face of disaster.

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Radio Apocalypse: The GWEN System

Recent developments on the world political stage have brought the destructive potential of electromagnetic pulses (EMP) to the fore, and people seem to have internalized the threat posed by a single thermonuclear weapon. It’s common knowledge that one bomb deployed at a high enough altitude can cause a rapid and powerful pulse of electrical and magnetic fields capable of destroying everything electrical on the ground below, sending civilization back to the 1800s in the blink of an eye.

Things are rarely as simple as the media portray, of course, and this is especially true when a phenomenon with complex physics is involved. But even in the early days of the Atomic Age, the destructive potential of EMP was understood, and allowances for it were made in designing strategic systems. Nowhere else was EMP more of a threat than to the complex web of communication systems linking far-flung strategic assets with central command and control apparatus. In the United States, one of the many hardened communications networks was dubbed the Groundwave Emergency Network, or GWEN, and the story of its fairly rapid rise and fall is an interesting case study in how nations mount technical responses to threats, both real and perceived. Continue reading “Radio Apocalypse: The GWEN System”

Radio Apocalypse: The Emergency Broadcast System

Some sounds are capable of evoking instant terror. It might be the shriek of a mountain lion, or a sudden clap of thunder. Whatever your trigger sound, it instantly stimulates something deep in the lizard brain that says: get ready, danger is at hand.

For my part, you can’t get much scarier than the instantly recognizable two-tone alert signal (audio link warning) from the Emergency Broadcast System (EBS). For anyone who grew up watching TV in the 60s and 70s in the US, it was something you heard on at least a weekly basis, with that awful tone followed by a grave announcement that “the broadcasters of your area, in voluntary cooperation with the FCC and other authorities, have developed this system to keep you informed in the event of an emergency.” It was a constant reminder that white-hot death could rain from the sky at any moment, and the idea that the last thing you may ever hear was that tone was sickening.

While I no longer have a five-year-old’s response to that sound, it’s still a powerful reminder of a scary time. And the fact that it’s still in use today, at least partially, seems like a good reason to look at the EBS in a little more depth, and find out the story behind the soundtrack of the end of the world.

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