µB
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A gray world of dread

Note that some old radios have the option to change the band between FM, MW, SW and LW. Check your attic for those late 80s / early 90s ghetto blasters. That's a cheap alternative to pro SW radios; you'll have less options, but browsing the bands feels much the same, so you'll get an idea of it.

Awol, SW has a pretty decent range. The whole point of number stations is that field agents can get their briefings from afar, after all. But yeah, there are american number stations. Here's a list with UTC schedules of active stations:
http://www.spynumbers.com/profiles/enigma.html

m0d
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Wow, being referenced before even joining a community. Awesome. smile

Interesting effect as well is multipath propogation. Signals go out from the antenna in almost all directions, and it has the possibility of arriving at the recieving station at slightly different times depending on which route around the planet it took. You get an interesting phazer effect because of this as signals arriving out of phase with others cancel out part of the signal. It's actually one of the big problems on shortwave.

akira^8GB
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New York City

I heard about all this recently in a security conventiion and  I thought it was both scary and super cool.
Thanks for the reference links! I'm interested in this one time pad thing though. Any more info?

dexter
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southampton, uk
akira^8GB wrote:

I heard about all this recently in a security conventiion and  I thought it was both scary and super cool.
Thanks for the reference links! I'm interested in this one time pad thing though. Any more info?

http://en.wikipedia.org/wiki/One-time_pad#Example
^ Here is a great explanation of how they work.
http://www.fourmilab.ch/onetime/otpjs.html
^ here is a fun little generator of one time pads

Jacko
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Adelaide, Australia

Whats the power output of these said stations? are we talking Killowatts?

If so i'd say even my untuned roll of wire should be able to pick something up!

Also what emission mode do they use? just regular AM or do they venture into sideband?

m0d
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They vary but can bein the KW levels. They are typically AM, but the one I have heard have been on SSB piggybacking on a broadcast station's AM carrier, though, therefore decodable with an AM radio.

I'd also like to point out that there are also a couple of broadcast AM stations with /modulated/ carrierwaves which contain what appears to be a bitstream. Very low bitrate, and very odd indeed. One of them is carrying what appears to be a atomic clock time sync code.

Last edited by m0d (Jan 13, 2010 12:00 am)

m0d
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Also if anyone out there has SWL equipment, i'd be happy to give a go at sending you some signals smile

vblank
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Central Pennsyltucky

Hey!  I missed this whole thread! Yeah, I've been doing the radio thing since my first Atari. (Thats how I learned electronics)
I've caught a lot of Cuban numbers in the 7000khz am range. VERY high power. Of more interest to me are the pirate stations. You can usually catch them around 6925khz around holiday weekends. Also on usb there's some pretty bizarre image transmissions around there.

There was a numbers station comp album out about 2 years ago. Everyone on it used #'s samples in their pieces. I'll try to dig it up.