Re: Numbers Stations
Avalanche, Mon Jun 12 2006, 11:25PM

Fascinating stuff. Would this kind of station be a pirate station? How did you find out the name of the station, is there some kind of database somewhere?

Sorry for the noobish questions, ham radio is something that has always fascinated me yet I have never 'got into' it. I went to a hamfest yesterday, so that only fuelled my desire to get into ham radio, but I never know where to start properly.

Edit: I suppose if that signal comes from Cyprus, I should be able to recieve it quite strongly here in the UK... I'll have a go sometime, I just went into the attic and found an old shortwave radio that tunes from 6 to 18Mhz. I guess it's a start

Re: Numbers Stations
Chris Russell, Mon Jun 12 2006, 11:59PM

I suppose it is sort of a pirate station. They are not licensed or registered, or even really acknowledged to exist. I'm sure the FCC or any other authorities aren't about to shut them down, though.

At any rate, the name of this station is informal. The listeners have named it because of the tune it uses. There isn't any official name, of course, because officially, it doesn't exist.

I should note that I received these sound clips at 2200 hours UTC, on 6959kHz, on USB (upper sideband). This was the last transmission of the day for this particular station. You can find the complete schedule here: , which I found to be accurate. The Lincolnshire Poacher transmits on three different frequencies at once, so you may want to check all three if you can. I had a "louder" signal on 10426 and 11545kHz, but both were subject to more noise and fading, and were thus less readable. Good luck!

Re: Numbers Stations
Michael W., Tue Jun 13 2006, 12:36AM

I think it said my phone number.......

Re: Numbers Stations
Chris Russell, Tue Jun 13 2006, 01:11AM

Here's another one from a different station, on 6840kHz. Presumed to be originating from Israel, for their Mossad intelligence agency. Recorded in USB mode at 0100 UTC.
]1150161093_1_FT11318_e10__mossad.mp3[/file]

Re: Numbers Stations
Avalanche, Tue Jun 13 2006, 12:35PM

I've been having a go, but I'm not having much luck really, just picking up loads of interference and strong foreign stations. Lack of digital tuning makes it quite difficult as well.

I was wondering, what kind of antenna is required? My quick setup is 10 meters of wire wound spaciously onto a long piece of 10mm dowel, placed indoors, and I've earthed the radio to a pipe. I guess the whole setup just isn't up to scratch.

Re: Numbers Stations
Dave Marshall, Tue Jun 13 2006, 12:52PM

Ideally a tuner and dipole antenna would be used. In your case, just stretching the wire out instead of winding it around a form would probably help. By winding it, you introduce alot of inductance, which drastically reduces the effective bandwidth of the antenna.

Stringing the wire out a window to a nearby tree or other support, and adding a variable inductor of some sort to the base of the antenna would probably give you the best bang for the buck.

Alternately you could google for a simple L tuner design that would probably require a 9 position switch, an air variable capacitor, and a homemade inductor.

Whether you just use a loading inductor in the antenna, or build a tuner, you just tune the antenna for the loudest noise/signal, at which point you can assume the impedance of the antenna, and the feedpoint impedance of the radio are pretty close to the same. This will drastically improve the effectiveness of any receiver.

I happen to have an extra tuner, receiver, and computer. I'm thinking about setting up something to record the broadcasts on a specific frequency for several days in a row. It might be interesting to see if anyone on the forum can break the code.

Dave

Re: Numbers Stations
Avalanche, Tue Jun 13 2006, 08:25PM

Thanks for the tips. I've found a schematic for an ATU but first I might just try the inductor.

Anyway, at 2000UTC I received the Lincolnshire Poacher on 9251Khz My setup is now a cheap pocket shortwave radio, with the 10M piece of wire stretched out between two rooms and clipped onto the radio's built in antenna. The signal was so weak I thought at one point I was just imagining it, but when the tune came on I knew I had it. Had to use headphones though.

I'll have another go tomorrow, hopefully with an improved setup.

Re: Numbers Stations
Chris Russell, Wed Jun 14 2006, 01:32AM

Excellent news! That tune really seals the deal, leaves no doubt as to what you're hearing. Any chance of an audio capture from your next attempt?

I should note that all my attempts so far have just used a 20M hamstick, no tuner. Obviously I would get much better results if I had a longwire antenna handy.

Re: Numbers Stations
Penguin7471, Wed Jun 14 2006, 05:15AM

Recently I got an old shortwave radio from a friend who had it collecting dust. Actually its got alot of pretty lights and signal meters, lucky I found it before it saw the bin.

Anyway it has a range from 2.5 to 18MHz. I set up a 50m antenna looping from tree to tree outside in the backyard. It is almost impossible to tune for anything because the entire range is completely swamped out by the gazillion chinese stations. EVERY single spot on the dial.

I never knew about numbers stations. Fascinating though.. I'll try and have a listen somenight.

Re: Numbers Stations
rev, Wed Jun 14 2006, 04:48PM

number stations have been around for many years. the one that got some conspiracy attention several years ago was a cuban number station (in spanish). the mysterious nature of number stations can realy bring out the inner pariniod in some peeps ecpecialy if it's coming from cuba.

i did some noise reduction on the first sample listed. i'll do the others latter for comparison.

note the seemingly random tones that are present during the numbers and music. not sure if that a fluke of some intence noise reduction or part of the transmision. due note that it begins prior to the speach, between each phrase and not present during the pause between numbers and music.

also chris. would you dcc me your full un edited recording so that i may play with it?

thought i'd ad a pic of the analysis of the removed noise.

it's only a 12khz 16bit mp3 so there is not much info/data to get a good clean-up with as it's clearly seen in the pic.






] 1150303715_112_FT11318_noise_reduced_poacher.mp3[/ file]

Re: Numbers Stations
Chris Russell, Thu Jun 15 2006, 11:31PM

Yet another update. Last night I was able to capture the Cuban "Atencion" station that Rev mentioned above. Note the terrible sound quality. I did have the volume a tad too high, but the vast majority of the distortion was already present. The signal was loud, as it is aimed at the United States, but the distortion makes it a little tough to copy all the code groups. Current speculation is that the code groups are actually "phoned in" to the transmitter, as evidenced by a "click" which you can hear at the end of each transmission. This is supposedly the sound of a phone hanging up. I included it in the second clip, just for fun. Listen carefully, and you'll hear "finale... finale... click."

Time, date, mode, and freqency are included in the file name.
] 1150414305_1_FT11318_v2a__20060615__0706z__9153khz __am__short_sample.mp3[/file]
] 1150414305_1_FT11318_v2a__20060615__0745z__9153khz __usb__finale_and_click.mp3[/file]

Re: Numbers Stations
joshua_, Fri Jun 16 2006, 03:19AM

Hmm, I can hear almost all of the Spanish code groups quite well...

Transcribed:

[incomplete] Tres, [?], Siete
{Tres|Seis}, Nueve, Cinco, Tres, Cinco
Siete, Cinco, Uno, Cuatro, Cinco
Nueve, Uno, Ocho, Ocho, Uno
Cinco, Uno, Ocho, Siete, Ocho
[?], Cinco, Siete, Ocho, Uno/Cero
Cero, Ocho, Tres, [?], Ocho
Siete, Cinco [?], Ocho, Tres, Tres
Ocho, Cero, Siete, Cinco, Cero
Cuatro, Cinco, Tres, [?], Cinco
[?], Cinco, Uno, Cuatro, Cinco
Uno, Nueve, Tres, Seis, Nueve
Siete, Ocho, Ocho, Uno, Seis[?]

I transcribed this making the assumption that there were only numbers. On IRC, rev posited that there could've been the letter F ("Efe", pronounced like the English "F. A."). If there was an F, I would've likely interpreted it as either tres or seis; often in Spanish, trailing syllables will be lost ("Efe" -> Ef[e] "Ayf-uh"), so the long (english) A sound would'be been most likely to come from tr[e]s or s[e]is.

Re: Numbers Stations
Banana Man, Sun Apr 15 2007, 08:54AM

Very strange and somehow concerning hearing that. It brings back memories from when I was a kid and used to play with a ham radio. I found this one particular station that had a womans voice reading off numbers for hours. When I go home to Hollywood, FL on leave maybe I'll fire up that old radio and see if they're still transmitting. Has anybody ever tried to decypher these codes?

Re: Numbers Stations
GreySoul, Sun Apr 15 2007, 10:35PM

Numbers stations are so varied it's hard to say they serve a single purpose.

I've been listening to these stations since the early 90s and I've heard so many theories that it makes my head hurt thinking about it.

I tend towards the Occam's Razor school of thought on this, that it's either drug smugglers or people pranking the radio community.

Drug smugglers would be more likely to use commercially available amature radio equipment than the military. The Governments of the world are far too sophisticated in their technology to bother with anything that could be intercepted by civilians.

These stations couldn't be stationary within the US without the knowledge of their purpose by the FCC. Triangulation technologies exists that could pinpoint the transmission to within inches in a second, so hiding it would be nearly impossible if anyone really wanted to find the broadcast location.

I like the idea that it's just bored kids with modified CB radios that have been perpetrating these pranks since the 70s just to mess with HAMs. before I had my lisence, back when I was like 12, 13, doing stuff like that was a near daily pursuit.... if I could have made a mobile numbers station... oh man, I'd still be running it today.

-Doug

Re: Numbers Stations
Chris Russell, Mon Apr 16 2007, 02:19PM

There are a lot of theories on what numbers stations are, but facts are relatively scarce on the subject, because nobody is talking. As you said, there are a lot of different kinds of numbers stations, so it may very well be that different stations serve different purposes.

The one I linked to above, the Lincolnshire Poacher, is copyable all around the world on a regular basis, even in adverse propagation conditions, which would seem to indicate that the transmitter is using far more power than an amateur station or modified CB is capable of. Additionally, direction finding techniques have been used to determine the transmitter's exact location -- a Royal Air Force base on the island of Cyprus. Clearly there is some level of participation by the UK's military. Similar stories hold true for other numbers stations -- several of the so-called Mossad stations originate from Israel's embassies around the world.

The Governments of the world are far too sophisticated in their technology to bother with anything that could be intercepted by civilians.

Hide in plain sight. One time pad encryption is still 100% unbreakable when properly employed. There's no reason to care if anyone else can hear it, as there's no way that anyone other than the recipient will ever know what the message says. Broadcasting it where anyone can pick it up also makes it hard for anyone listening in to determine who might be receiving it. Anyone with a radio is a suspect. The government of Iran feels strongly enough about the Lincolnshire Poacher that they use an array of megawatt-range jamming stations to try to prevent reception inside their own country.

These stations couldn't be stationary within the US without the knowledge of their purpose by the FCC. Triangulation technologies exists that could pinpoint the transmission to within inches in a second, so hiding it would be nearly impossible if anyone really wanted to find the broadcast location.

The FCC's official stance is "no comment." They do not discuss numbers stations originating in the US, period. Some years back, they famously denied some FOIA requests for information about numbers stations, claiming an exemption for "national security information concerning the national defense or foreign policy properly classified under an executive order." As I pointed out above, many people have used direction finding to pinpoint transmitters, and they almost invariably end up at military installations, embassies, or private facilities with security personnel. To the best of my knowledge there has never been an incident of a regularly received numbers station being exposed as a prank.

I like the idea that it's just bored kids with modified CB radios that have been perpetrating these pranks since the 70s just to mess with HAMs. before I had my lisence, back when I was like 12, 13, doing stuff like that was a near daily pursuit.... if I could have made a mobile numbers station... oh man, I'd still be running it today.

It's tempting to think that way, but a cursory examination of some of the evidence does indeed point to powerful folks with deep pockets being involved. Look at the Lincolnshire Poacher, or her sister station, Cherry Ripe. There's no easy or cheap way to modify a CB to put out a perfectly clean SSB signal that peaks well into the tens of kilowatts. There's no easy or cheap way to modify a CB to put out three such signals on non-harmonically related frequencies at the same time. And, how many bored kids would have the patience to transmit several 45 minute messages on a rotating frequency schedule, 12 times a day, 7 days a week, for 30 years?

Other stations are shoddier, and don't follow their schedules very well. Some have terrible signal quality. Others just have an amateurish feel to them. I could buy those as being pranks, or drug smugglers. Some of them, though, are very mysterious indeed.

Re: Numbers Stations
GreySoul, Tue Apr 17 2007, 04:39AM

I learn something new every time i stop in here... those Iranian jamming stations are ...just a bit paranoid...maybe? maybe not.

I also wonder if a FOIA has been submitted recently concerning the numbers stations.

As for the long term stationary high power stations those could be some deeper conspiracy....but down here in New Mexico i remember picking up sometimes over a dozen numbers stations a night, mostly in Spanish, that I always figured were drug smugglers of drugs or people.

...been a while since I read it, but weren't numbers stations explained as one time pad cyphers in Cryptonomicon?

-doug

Re: Numbers Stations
Chris Russell, Tue Apr 17 2007, 07:55PM

Maybe the whole point of the Lincolnshire Poacher is to make Iran spend resources to block it. After all, if those megawatt transmitters are busy jamming, they can't be used to broadcast propaganda.

A FOIA request could be worthwhile, but I don't suppose the FCC will have changed its mind about the matter. Last I heard, the UK Ministry of Defense was still pulling articles about numbers stations from publication. Seems like they feel it's still important enough to protect.

I've never had much luck with the low-power Spanish numbers stations. I wouldn't be surprised if they were from people moving drugs or people or both across the US/Mexico border. I can easily pick up the Cuban numbers station, as its antenna is aimed pretty much right at me. Signal strengths of S9+20dB are not uncommon.

Haven't read Cryptonomicon, but a one time pad cipher is a logical assumption. Some of the less professional stations, though, could just be using a simple code, since OTP encryption relies on synchronized pads which could get lost or otherwise rendered useless. It might be interesting to do some analysis on those stations, and see if any weak points can be found.

Re: Numbers Stations
Banana Man, Fri Apr 20 2007, 10:44AM

In order for these to be so common there must be a reason for them or a standard of some sort. The thing I dont get is why would any government still use manual code when you can just load crypto into your radio and chat away. Encryption is very secure, common, and easy to come by. If you dont want it jammed you can use ECCM freq hopping to communicate into places like Iran. When it's so easy to use normal communications, why would anybody use PlainText codes? The only thing I can think of at the moment is that it is either government or corporate targeting individuals with low resources.

Re: Numbers Stations
Dave Marshall, Fri Apr 20 2007, 08:41PM

As was said above, triangulation and Doppler Direction Finding is pretty easy. The USAF has aircraft that can do it in a matter of minutes across huge chunks of the RF spectrum. Hell, a bunch of curious ham operators could do it in a few hours.

With a numbers station, you don't have to worry if someone knows where the transmitters are, because they'll never be able to find where the receiver is. The transmitters are in embassies and other secured locations, and they don't really care if people know that they exist, because theres no way to determine a purpose or a target for the broadcasts.

There is some seriously covert black hat stuff that goes on in the political and military world. People buried deep under cover for years at a time in foreign countries. Now if someone gets suspicious and goes snooping through said operative's home or work place and finds a crypto capable HF or satellite transceiver, thats like a giant neon light calling attention. A $50 Grundig shortwave radio isn't nearly as likely to arouse suspicion.

Also, encrypted radio traffic SOUNDS encrypted. You can hear it with a standard radio, (unless you're using spread spectrum/frequency hopping) you just can't understand it. An encrypted radio signal originating in a residential area is likely to raise a red flag. If they need only receive, theres no risk of detection.

Frequency hopping/spread spectrum technology is decent for avoiding jammers, but is still quite detectable if you've got a broadband receiver or something similar to a 'frequency counter'. I've got one frequency counter that can lock onto my HF radio running at 5w on any frequency (1.8-440Mhz) from 100m with just a little rubber ducky antenna. With a larger wire antenna on each end, I have no doubt it could easily have a range of half a mile or more before other sources overwhelmed it. Using a more sophisticated sort of frequency counter, it would be possible to not only detect that a spread spectrum signal was there, but to determine the pattern it uses to determine its next frequency, thus rendering it insecure.

Dave

Re: Numbers Stations
Banana Man, Mon Aug 06 2007, 03:02AM

I checked up with my grandfather (into HAM enough to have a 70' antenna in his yard) When he was in the navy he lost his security clearance for a while and was almost jailed because someone thought he was a spy for Cuba. He was investigating numbers stations coming out of Cuba and recording all their transmissions. He tells me he never had the chance to decode any of it but there were a lot of numbers stations and they've been around for a while.

Edit:
Today I realized the obvious source of information made by people all around the world. Look up "numbers stations" in wikipedia.org
There is a lot of information about them here and half of it is probably true