JS8Call FT8Call for Grid Down Communications?

Hello Operators
Recently my buddy Gil F4WBY the Radio Prepper, sent a text letting me know he could hear my station on 20m. Although it was an impromtu QSO, I wanted to take the opportunity to open the discussion regarding FT8Call for Grid Down communications, after a disaster. Even if this post isn’t what you expected, I am couraging you to watch this initial video from a grid down Communications perspective, since it will also help in one’s understanding of the requirements for grid down Communications after a disaster.

Let’s be clear what I’m talking about. I’m not talking about organised ARES, EMCOMM, Agency, … I mean commo for families, groups, individuals wanting a way to reach out, communicate or ask for help, independent of infrastructure.

FT8Call is not reliant on external infrastructure

Despite some misconceptions, FT8Call is not reliant upon external infrastructure. It can certainly leverage grid tied services like PSKReporter, APRS.fi, send a short email through APRS, … but those systems are augmenting FT8Call, and FT8Call is not dependent upon them at any point, to deliver reliable communications.

Why is FT8Call so slow?

If you have ever heard the analogy of the laser beam versus the floodlight, it is easy to understand the idea that a highly focused, narrow beam of light, can travel further with less power, than an unfocused “flood” light of the same output level. The cost of a narrow bandwidth, highly efficient mode is throughput. For weak signal grid down communications, keyboard to keyboard messaging and anything supporting it, is the priority. That means a “text based” messaging system very similar in many ways to Messenger, Skype, Telegram, or any other chat client. There are other modes which allow sending images, large file attachments,… but they all suffer from the same problem. They all require a substantial amount of bandwidth and transmit power to deliver the payload. In a grid down scenario, it isn’t practical to use modes requiring higher output levels, since we have a finite amount of energy available to power our comms gear. This might be solar power, a diesel generator, or some other means of generating power. With this in mind, we keep communications simple by focusing on delivering text effectively.

The reason we see most amateur radio Mesh networking systems on UHF or SHF, is their desire to recreate the internet. This is great for small localized communities or groups, but the amount of power it would take to expand that Network Beyond a potential disaster area, is mind-boggling.

Goals for a reliable grid down comms:

  • Station to Station messaging independent of infrastructure.
  • Very modest hardware requirements.
  • Supports simultaneous multi-station messaging on the same frequency
  • Is not dependent upon external infrastructure.
  • The ability to send detailed coordinates to a station or group of stations.
  • Not dependent upon accurate time.
  • Unless being relayed, no requirement for an intermediary connection for message exchange
  • As easy as using Skype, Messenger, Telegram, or any of the common messaging apps used today.

Common mistakes in grid down comms strategy

There are many common mistakes made when planning a grid down communications strategy. The first Buzzword out of the mouths of many YouTubers, bloggers and forum commandos are “Baofeng”, then quickly followed up with “Tactical”. Another common mistake is trying to dumb down advanced communications, instead of investing in training and getting experience in the field. We also fail to take into account the relationships between modulation, bandwidth, efficiency, power consumption, and output power. For the most part, if we ignore the physics of it all, our grid down strategy will be out of power (literally) long before the crisis is over. So our grid down strategies must consider:

  • How long can I transmit with a certain mode?
  • How long will it take me to send or receive a message?
  • How much current do I need for each transmission?
  • How much battery capacity do I require?
  • Can I recharge my radio and battery packs once they are depleted?
  • How will I recharge my batteries?
  • Is my solar/gas/diesel generator able to keep up with my messaging?

It is not enough to base our grid down strategy solely on the opinion of “some guy” in a popular survival forum. We need to do the math, field test, then optimize. There is no other way!

Can FT8Call be deployed off of common QSO frequencies?

In my opinion, FT8Call is useful anyehere on 160, 80, 60, 40, 30, 20, 15, 12, 10, 6, and 2 meters SSB. Whichever band you decide to deploy on, depends on your Communications strategy. An individual may want to leverage the strength of hundreds of station scattered around the globe, while a family or group may want to focus on activating a unique frequency. Remember the network of FT8Call stations around the globe are its strength. If you don’t leverage that Network, you’ll have to create your own.

Related video series

As I have often mentioned, it is difficult to undertstand the relationship between one video or the next, so here is a breakdown and explanation of my YouTube playlists, including why they are relevant to a grid down communications strategy.

X days off grid series

The X days off grid series takes all of the projects and ideas from the channel and blog, putting them to the test out in the field.

Portable Off Grid power for amateur field communications

Portable off-grid power for amateur field communications teaches us about DIY portable power, powering our stations in the field, and keeping them charged up with solar power.

Raspberry Pi for Digital HF Radio

The Raspberry Pi for digital HF radio series shows us how to take a cheap computer, integrating it with our HF radio, creating an interoperable system we can use with any smartphone tablet or laptop. Even if interoperability is not your thing, the tutorials in this series are useful nevertheless.


My FT8Call playlist includes videos promoting and supporting the idea of weak signal digital Communications, which is actually what the mode was intended for.

Although there are lots of YouTubers and bloggers talking about grid down Communications, I haven’t found one channel or blog yet from a preparedness perspective, which understands the big picture for grid down Communications. Everyone is talking about cheap Chinese this and cheap Chinese that, but no one is talking about a grid down Communications strategy. Even some of the channels on YouTube that I watch and enjoy for the most part, are getting it wrong. When we are talking about and planning for grid down Communications, we must do so with the 95% approach. That is to say, we must prepare for the 95% of likely eventualities eg, the Hurricanes, the tornadoes, the earthquakes, the wildfires, rather than the 5% WROL, Zombie apocalypse, teotwawki

In my opinion, amateur radio has come a long way over the past hundred years. It has evolved into many things, yet emergency communications remains one of its key pillars. Finally, let’s stop confusing emergency communications with Amateur Radio Emergency Services.
Julian oh8stn
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