Extreme Low-Tech Communication


This has to be the ultimate achievement in low-powered long-distance communication. Ham radio operator Michael Rainey, AA1TJ, transmitted a message over a distance of over 1,000 miles by yelling Morse code with his own voice into this primitive home-made transmitter, nicknamed “El Silbo.” No power was used other than that generated by his own voice vibrating the microphone (which was a re-purposed speaker).

If you want to build your own here’s the circuit schematic and more details.

And here’s Rainey, back in 2009, using El Silbo:

On a side note, can we please apply Ham radio’s level of detail and open source spirit to the world of backyard vegetable gardening?

It’s official: I’m a Ham

How blog posts will be issued from now on. Image: Library of Congress.

How blog posts will be issued from now on. Image: Library of Congress.

It’s been on my to-do list for years–get my ham radio licence. I took a six week class offered by the Pasadena Radio Club to study for the technician class licence and on a whim crammed for the general class. I passed both tests and as of yesterday am now also known as KK6HUF.

Many thanks to W6MES, who volunteered his time to teach the class and to the major memory system for helping with all those numbers. It was a lot of fun to review basic math and electronics.

So why do this in an age of Skype and cellphones? I find the DIY ethos of ham radio empowering. We are surrounded by electronic devices and it’s good to know a little something about what’s going on “under the hood.” I wish I had discovered amateur radio when I was younger–I might have struggled with math less had I had a hobby to motivate studying.

My interest in appropriate technology was another reason. There is a ham I met online who is constructing a website that will be of interest to readers of this blog–he was inspired by John Michael Greer’s writing on ham radio. I’ll share that website when it’s ready to go public.

Passing the test was easy, but I’ve got a lot of work to do. I have no radio, nor do I have any experience using one. And I’d like to learn morse code. I’m all ears if any of you have advice.

Primitive Grain Storage Technique

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When thinking about technology, I like to play with the idea of what is the absolute minimum you need to get the job done.  This may be because I’m not very handy at building things, but yet have survivalist tendencies. So while I’m pretty sure I’ll never actually have any need for these skills, it’s fun to think about how I’d get by in a DIY world.

So I was delighted when I ran across this minimalist grain storage technique on the BBC documentary series, A History of Celtic Britain (2011), hosted by Neil Oliver of the Delicious Scottish Accent. (I am watching it on YouTube. Fingers crossed the BBC will not take it down before I finish it!)  I love this technique because while it is simple, it is far from stupid.

The technique is described by the Dave Freeman of the Butser Ancient Farm in Hampshire, where they’ve been experimenting with grain storage iron-age style (c. 400 BCE.).  Turns out all you need to do is dig a pit in the soil. The pits they dug are circular, and look to be 2 or 3 feet in diameter, and maybe 3 or 4 feet deep.

So you may ask, how can you pour grain into a hole in the ground and expect it to keep? The secret is a clay cap on the top. In the screen grab below you can see the cap and some feet for scale:

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If you go to YouTube,  you can watch this sequence starting around 52:36, but what Freemen says is that when the grain goes in the pit and is sealed with a clay cap, the clay blocks out moisture, air and light. Moisture is still available at the sides and bottom of the pit, of course, especially as they are in green Hampshire.

The grain touching the sides of the pit sucks the moisture out of the soil at the edges, and uses it to attempt to germinate. The germination process sucks up oxygen and releases carbon dioxide, effectively clearing the chamber of oxygen. At that point, as Neil puts it, “Time stops.” Nothing can grow, nothing changes. The grain cache keeps for at least a year, perhaps two years, and provided a very handy safety backup for hard working iron age farmers. And some very basic appropriate tech for modern armchair survivalists to ponder.

Farm Hack

farm hack

Farm Hack is an innovative blog that synthesizes high tech and low tech in the service of growing food and community. The blog is run by the National Young Farmers Coalition. While geared towards agriculture, many of the posts will be of interest to backyard gardeners. Recent subjects include a project to develop an infrared camera to monitor plant health, smartphone tools for farmers and open source appropriate technology resources. It’s exactly this kind of innovation that gives me great hope for the future.

Thanks to Tommy Berbas for the tip.