Digital HF: The world without infrastructure

[HOME]| [BACK]

What if, tomorrow, some great catastrophe hit? What if, the wires holding the internet together like a spider's web were cut? What if, half the world could not communicate with the other. What if Voice communications were similarly disrupted? Hrm... So you haven't heard of ham radio? You haven't heard of HF skip? You haven't heard of CW?

Please try to understand that our technology right now depends on a particular set of infrastructure (ie: wires, satellites, etc.) which increase the distance between us and the world. If the internet and telephone systems were wiped out, the only communication possible (around the world, point to point) would be HF communications.. and considering the sun spot cycle we're in right now, CW (Morse Code).

So why have we abandoned the very basic functions necessary for global communications for more fragile means? Some people say fidelity... I don't know... really... I don't. Either way I don't like it. The only way HF communications would fail would be in massive global atmospheric (ionospheric) catastrophies... ie: increased sunspot burts etc.... either way, we'd be dead.. so it wouldn't matter if we could still talk to eachother!

The atmosphere is the backbone with HF... not a cable or satellite, which could be "disabled".

here's a digital signal from Halifax, Nova Scotia, Canada (I live in Philadelphia, I was using an HF rig, with a simple dipole - wire - hanging out the window more or less 12 ft long.) No satelites or special equiptment was used... just the FAX... which before used on telephone lines, it was used by radios! :)

I finally get a signal... but haven't tuned it in yet.

Good signal! Finally! I see something!

Dead straight on (I have a hard time keeping things straight! So this is cool!!!!! ;))!


1

Check it, well, not exactly outer space but it's close.

From Halifax, Nova Scotia's (Canada) WEFAX transmitter. 6.495 MHz USB Mode

I found this program for the mac called Multimode. I hooked up my short-wave receiver to it, and was able to receive these images. Sorry for the poor picture quality, but all I have is a piece of wire hanging out my window! Cool non-the-less!!!! :) I LOVE RADIO!!!

The first image was a screw up. I was "diving in" to the software... getting pissed no less... luckily brad was here when I started receiving a signal (ie: I was not going crazy!) ... made him wait before the cigi... still feel bad for that... that's what you get for dating a geek! :-P

The second was cooler. (of course after brad left... shit works when people aren't around to see it.) In the middle of the image, i realised that I was seeing the image off a few dozen pixels. Moved it to the left a bit. The blank spot in the lower section was a constant signal... probably a reset.

If you also notice, the image gets clearer as time progresses. The entire Image took about 1/2 hour to get. The ionosphere decided to get a little friendlier to me! :) All the random darkened horizontal lines are noise from different stuff, ie: static. I completely lost a previous image due to one of my neighbors turning out something that caused a lot of interference.

The darkened grey areas are where i turned on the greyscale smoothing on the software receiver. No good, i turned it back off. I decided to greyscale it with the GIMP.

The last (third) image is the best one so far. I am going to probably buy this program, it rocks!! But alas it's not open source... hrm... do I see a project coming along?

WHO NEEDS THE INTERNET WHEN YOU HAVE RADIO! :-P

There's other stuff i want to try and receive, now that I have this piece of software... Slow-scan TV, HellsFeld, PSK31 (which i've done on linux really well already, you can't hardly tell it's a signal, but comes in banging on the machine), Packet (bleh), Radio Teletype (YAY!!hehehe) and SITOR/PACTOR etc.

2 Remember back in the day when I hooked up the radio to my comptuer, and picked up that station from Mexico... that was only text. I have never been able to get much else working on the linux box. So it wasn't till I received an email from this mailing list i forgot I was on (in portuguese... so I couldn't really understand it too much) that I thought... "hey I haven't tried some software for the Mac... it'll probably work really well." I hooked the radio in and boom! :) The problem I'm having with the radio stuff, is that I have to get accustomed to hearing, and identifying the sounds. Different speeds, modes, conditions, and just plain bad tuning, has to get distinguished from "noise" (IE: tv's, blow dryers, etc.), and each of the valid signals are, in and of themselves, not only distinct, but similar (sounds wierd...keep reading) For example, morse code always sounds "the same." But different speeds, conditions etc, makes it ultimately sound different... but there's something in there a general "feel" or "gut feeling" that makes you say: "Oh, that's morse code." Yesterday I had problems with the fax stuff, cause I didn't realise that between each fax transmission, they were switching back to "Radio Teletype (AKA: RTTY)" it's in the old movies all the time (ticker tapes, and rat-tat-tat'ing in the background - acutally 1010 WINS, and 1060 KYW has a fake background track of what the machines sound like; I guess they do it for show; it's not used anymore obviously with the internet.) Anyways, I was trying to get a FAX when they had switched to RTTY. The point is, had I known what each mode sounded like, I would have instantly known to switch to RTTY to pick up the written stuff.

emrecio@gmail.com