The magic of AM waves

Entry Filed under: Hardware

May 30th, 2008

Loads of streaming electrons, oscillating on one frequency, and jumping up and down in amplitude to be broadcasted on a really wide area and get received by an AM radio - what's not to like? The shear simplicity of AM radio is just astonishing and it's ability to jump up off the ionosphere and reach much farther than it usually should is only a bonus.

Inspired by the Conet project, I found an old AM/LW Russian transistor radio that was lying around, attached 3 AA bateries to it (yes, TO it, because the battery leads inside it were corroded really badly), and got cracking!

It's interesting to see, uhm... hear that AM radio broadcasters still play radio talk shows, educational stories and radio dramas, even though probably very few people listen to them. In comparison FM stations are usually crammed with music, and nothing else. (which is pure crap, in my opinion, since local stations can and should do more than just broadcast music)

What's even more interesting is that I found some weird stations on both AM and LW bandwidths that emmit morse code signals. I placed the transistors near a 80m long wire that's hanging from my window over to my neighbors window, and maybe that's why I picked up more stations than usual.

One broadcaster was present on the ~620KHz frequency and was sending out ".- .-. -.." ("ARD" in Morse code) and the second one was present on ~300KHz and was sending out a long beep, followed by ".--. ...-" ("PV" in Morse code) and then a long beep again. I have absolotely no idea what these stations do or what they may be used for, so I'll just keep on checking.

Be sure to check out the "Conet" project that I mentioned earlier! You can download the whole CD pack for free, and if you are a radio nut, you will enjoy hearing all sorts of different number stations (most likely used by spies on foreign territory) which give out a warm "cold war" feeling

Attached: A quick walkthrough from the 600-1600KHz bandwidth, and the recordings of the weird stations that I caught.

Scan 620khz 300khz

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