Daily Archives: 6/29/2011

Recordings of High Frequency Beacons…

It’s been quite some time since I’ve hunted for any beacons, and I’ve never really payed much attention to HF pirate beacons. Typically these are solar powered beacons which are deployed somewhere in the deserts of the American Southwest, and charge during the day and transmit simple sequences of Morse characters once the sun goes down. While they are technically illegal, the amount of power they emit is so low that they could hardly be said to interfering with anything, and besides: they are almost certainly so cheap that if you took the trouble to direction find one down, the creator could simply erect another one the following week. In any case, I found this website which details some of the beacons you can find on HF:

High Frequency Beacon – HF Underground

Armed with the list, I decided to take my trust SDR-IQ and see if I could hear some of them tonight. With just a brief scan, I determined that I could hear three of them that are in the vicinity of 4.096Mhz. I made brief minute long recordings of them, and these are still in WAV format rather than putting them through an MP3 compressor which might remove the signal entirely.

Signal around 4.089Mhz, reportedly from Death Valley
“Dasher” signal around 4.0963Mhz, from Joshua Tree National Park
“Dasher” signal around 4.0966Mhz, from Mojave National Preserve

The Death Valley signal is easier to hear, the Dasher signals were fading in and out, but should still be reasonably legible. You should be able to tell the difference in speed between them.

Here’s a screendump of Spectravue spectrum display, centered around the two Dasher beacons:

Perhaps this isn’t too exciting, but it was fun to see if I could find these. I’ll try hunting down some more of these, as well as some more unusual signals from time to time.

Short wave listeners and hams: what’s the most unusual thing you’ve heard lately? Feel free to chime in below. Bonus points for things that other SWL’s can listen for.