WEBVTT - TechStuff By the Numbers (Stations) 0:00:04.400 --> 0:00:07.800 Welcome to Tech Stuff, a production from I Heart Radio. 0:00:12.200 --> 0:00:15.160 Hey there, and welcome to tech Stuff. I'm your host, 0:00:15.280 --> 0:00:18.400 Jonathan Strickland. I'm an executive producer with I Heart Radio 0:00:18.520 --> 0:00:24.560 and I love all things tech And recently Amazon canceled 0:00:24.720 --> 0:00:28.320 their television series truth Seekers, which I thought of as 0:00:28.720 --> 0:00:31.800 sort of a cross between Shaun of the Dead and 0:00:32.040 --> 0:00:36.000 The X Files. So in the series, a cable technician 0:00:36.200 --> 0:00:40.600 named Gus played by Nick Frost, is obsessed with ghost 0:00:40.720 --> 0:00:44.320 hunting and he gradually indoctrinates his new partner, who says 0:00:44.360 --> 0:00:50.279 his name is Elton John. He's played by Sampson Keo. Anyway, 0:00:50.400 --> 0:00:53.360 it's it's a cute show. It's a little odd in tone. 0:00:53.680 --> 0:00:56.320 And the part that really applies to this episode, however, 0:00:57.160 --> 0:01:00.360 is that one of the things that Gus fixates on 0:01:00.640 --> 0:01:04.640 in the early episodes is a radio frequency playing a 0:01:04.760 --> 0:01:09.120 numbers station. It's based off of an actual historical number 0:01:09.200 --> 0:01:13.640 station that folks call the Lincolnshire Poacher. And here's what 0:01:13.800 --> 0:01:33.360 it sounds like, gree nine seven one five green nine 0:01:33.800 --> 0:01:42.959 seven one hive green nine seven one hive. So that's 0:01:43.280 --> 0:01:46.039 a real thing, or it was a real thing, and 0:01:46.280 --> 0:01:49.920 it's not the only such station out there. There have 0:01:49.960 --> 0:01:54.560 been lots of numbers stations over the years, some using 0:01:54.720 --> 0:01:58.360 different jingles to signal an incoming series of numbers. Some 0:01:58.480 --> 0:02:02.200 of them have male voices, some use female voices, some 0:02:02.800 --> 0:02:06.360 use children's voices. Some of them are in morse code, 0:02:07.000 --> 0:02:10.760 some have people reciting not just numbers but letters and 0:02:11.360 --> 0:02:15.079 code signals. A lot of them are super creepy, which 0:02:15.280 --> 0:02:19.200 makes them really ideal for a show about paranormal investigation. 0:02:19.840 --> 0:02:24.120 But while the supernatural stuff is fanciful nonsense, the numbers 0:02:24.240 --> 0:02:27.919 stations are actually anchored in our real world. And while 0:02:28.000 --> 0:02:32.080 tech Stuff did do an episode about numbers stations many 0:02:32.600 --> 0:02:35.240 many years ago, I thought it would be good to 0:02:35.320 --> 0:02:37.960 use numbers stations as a way to talk about not 0:02:38.080 --> 0:02:42.600 just what they are, but also about short wave radio communications, 0:02:42.919 --> 0:02:46.399 the physics of radio in general, and the process of 0:02:46.960 --> 0:02:51.760 ciphering and encrypting information. So this is really gonna be 0:02:52.240 --> 0:02:56.320 a big overview, catch all kind of podcast. So let's 0:02:56.320 --> 0:03:00.680 start off with radio itself. Radio wave are part of 0:03:00.720 --> 0:03:05.160 the electromagnetic spectrum. Uh. They are there along with stuff 0:03:05.200 --> 0:03:10.440 like microwaves, visible light, X rays, and gamma rays. All 0:03:10.480 --> 0:03:14.640 of this is part of one big spectrum of electromagnetic radiation. 0:03:14.680 --> 0:03:17.559 You could actually think of it all as different flavors 0:03:17.600 --> 0:03:21.040 of light if you like. It's just that the slice 0:03:21.560 --> 0:03:24.440 of light that we can see is a very small 0:03:24.560 --> 0:03:29.240 slice of the overall spectrum. Now, specifically, radio waves are 0:03:29.360 --> 0:03:34.720 in the long wavelength part of that spectrum. Electromagnetic radiation 0:03:34.960 --> 0:03:37.920 moves in waves all at the speed of light, because hey, 0:03:38.000 --> 0:03:41.160 really it is just light, just different flavors of it. 0:03:41.600 --> 0:03:44.960 But those flavors of light do have different wavelengths, which 0:03:45.000 --> 0:03:47.960 also means they have different frequencies. So what does that 0:03:48.120 --> 0:03:53.320 mean exactly, Well, let's start with wavelengths. Imagine a nice 0:03:53.320 --> 0:03:58.840 smooth wavy line the distance between two consecutive crests on 0:03:58.960 --> 0:04:02.440 that wave, so the very peaks at the top parts 0:04:02.520 --> 0:04:05.720 of our curve. In other words, that would be one 0:04:05.840 --> 0:04:10.440 wave length from one crest to the next. A frequency 0:04:10.520 --> 0:04:13.440 just refers to the number of times a given cycle 0:04:13.840 --> 0:04:17.479 happens within a given amount of time, and we frequently 0:04:17.600 --> 0:04:22.480 use one second as the time unit, and with electromagnetic radiation, 0:04:22.640 --> 0:04:25.880 we talked about how many full wavelengths of a given 0:04:25.920 --> 0:04:31.440 signal pass a specific point in space within one second. 0:04:32.120 --> 0:04:35.560 We also use the unit hurts to describe this relationship. 0:04:35.839 --> 0:04:40.360 A one Hurts frequency would have one cycle or one 0:04:40.480 --> 0:04:44.240 wavelength per second passing you know this given point in 0:04:44.279 --> 0:04:49.359 one second, a giga Hurts frequency has a billion cycles 0:04:49.400 --> 0:04:54.599 per second. Now, all electromagnetic radiation is traveling at the 0:04:54.640 --> 0:04:58.360 same speed, which is around three thousand kilometers per second 0:04:58.400 --> 0:05:02.320 in a vacuum. Because the speed actually changes depending upon 0:05:02.440 --> 0:05:06.840 the medium through which the radiation is traveling, that happens 0:05:06.880 --> 0:05:10.120 to be the speed limit of the universe. Nothing goes 0:05:10.360 --> 0:05:14.480 faster than that, So the energy is traveling at that speed, 0:05:14.800 --> 0:05:18.000 but the frequency is dependent not just on speed but 0:05:18.160 --> 0:05:21.680 how long those waves are. In fact, because we know 0:05:21.920 --> 0:05:25.680 all these waves are traveling at that same speed, we 0:05:25.720 --> 0:05:29.320 can figure out the wavelength if we know the frequency, 0:05:29.400 --> 0:05:34.520 and vice versa. So the formula is wavelength equals the 0:05:34.600 --> 0:05:40.560 speed of light divided by the waves frequency. Alternatively, frequency 0:05:40.839 --> 0:05:44.440 is equal to the speed of light divided by the wavelength. 0:05:44.720 --> 0:05:48.000 So as long as we know either the frequency or 0:05:48.040 --> 0:05:50.880 the wavelength, we can figure out the other one. Because 0:05:50.920 --> 0:05:53.919 the speed of light is a constant, it's not a variable. 0:05:54.440 --> 0:05:58.760 On the longest wavelength side of the spectrum are radio waves, 0:05:58.760 --> 0:06:01.719 which can measure more and a hundred meters in length, 0:06:02.160 --> 0:06:05.520 so a radio wave with a wavelength of one meters 0:06:05.560 --> 0:06:08.720 would have a frequency of about three mega hurts, meaning 0:06:08.760 --> 0:06:12.720 about three million wavelengths would pass a given point in 0:06:12.760 --> 0:06:16.320 a second, and each wavelength is measuring one hundred meters 0:06:16.400 --> 0:06:20.359 between those crests. Again, the speed of the signal is 0:06:20.400 --> 0:06:23.320 still the speed of light. But let's say we get 0:06:23.360 --> 0:06:25.960 to the other end of the spectrum, towards the very 0:06:26.080 --> 0:06:30.240 very very tiny wavelengths on the electro magnetic spectrum. And 0:06:30.279 --> 0:06:34.719 when I say tiny, I mean really tiny. Gamma radiation, 0:06:34.920 --> 0:06:38.480 which represents the smallest of the waves that we know about, 0:06:38.839 --> 0:06:42.359 are less than one hundred pico meters in length, and 0:06:42.400 --> 0:06:46.360 a pico meter is one trillionth of a meter, so 0:06:46.400 --> 0:06:50.480 this is actually smaller than the nanoscale. The frequency started 0:06:50.480 --> 0:06:53.920 out at around ten to the power of nineteen hurts 0:06:54.080 --> 0:07:00.480 or ten quintillion hurts. Now, I've talked about electro magnetic 0:07:00.560 --> 0:07:03.200 radiation in terms of waves, but we also know that 0:07:03.279 --> 0:07:06.800 it behaves as both a wave and a particle. There 0:07:06.839 --> 0:07:09.200 are a lot of experiments that have shown this, and 0:07:09.279 --> 0:07:11.960 they're fascinating. But I don't want to get too far 0:07:12.040 --> 0:07:14.800 off track. Some of you out there might be screaming 0:07:15.240 --> 0:07:19.160 too late now, so we should also mention photons, the 0:07:19.200 --> 0:07:23.960 particles of light. A photons energy is directly proportional to 0:07:24.160 --> 0:07:30.160 the electromagnetic frequency of that wave. It's also inversely proportional 0:07:30.480 --> 0:07:34.720 to the wave length, So gamma rays pack a huge 0:07:34.840 --> 0:07:39.920 energetic wallop, while radio waves, by comparison, are whims. So 0:07:40.080 --> 0:07:43.720 let's get back to the radio spectrum. In particular. We 0:07:43.840 --> 0:07:47.200 know that radio waves have the longest wavelengths in the 0:07:47.240 --> 0:07:51.120 electromagnetic spectrum, which means they also have the lowest frequencies 0:07:51.560 --> 0:07:56.480 and the lowest amount of photonic energy. Generally speaking, we 0:07:56.560 --> 0:08:01.520 group electromagnetic frequencies ranging from thirty hurts or thirty wavelengths 0:08:01.560 --> 0:08:05.040 per second up to three hundred giga hurts or three 0:08:05.120 --> 0:08:09.680 hundred billion wavelengths per second. Obviously this is a really 0:08:09.760 --> 0:08:13.960 big range, but all of that are radio frequencies. Now, 0:08:14.000 --> 0:08:18.520 different countries divvy up this spectrum of frequencies for different uses, 0:08:18.840 --> 0:08:23.040 some of which depend upon the capabilities of those frequencies. So, 0:08:23.080 --> 0:08:26.720 for example, if you're looking at around thirty hurts, this 0:08:26.800 --> 0:08:31.760 is the extremely low frequency or e l F ELF range. 0:08:32.440 --> 0:08:34.320 You know, I used to play in ELF range in 0:08:34.400 --> 0:08:37.920 Dungeons and Dragons. Wait don't think of something else. So 0:08:37.960 --> 0:08:41.480 these wavelengths are really long and they are good at 0:08:41.520 --> 0:08:44.280 penetrating stuff like deep water, so it can be used 0:08:44.280 --> 0:08:49.280 for very basic communications with submarines. A M radio would 0:08:49.320 --> 0:08:52.959 be up in the medium frequency range for radio frequencies, 0:08:53.000 --> 0:08:57.080 and also the medium wavelength range. Just above that are 0:08:57.160 --> 0:09:01.280 the high frequency short wave radio hands, which are what 0:09:01.320 --> 0:09:04.080 we're really going to talk about a lot today. These 0:09:04.120 --> 0:09:08.400 have a wavelength between ten and one and frequencies that 0:09:08.440 --> 0:09:12.720 are between three and thirty mega hurts. Radio waves in 0:09:12.720 --> 0:09:16.160 this band of frequencies have some really useful properties, and 0:09:16.240 --> 0:09:19.640 one of those is the broadcast range, as in how 0:09:19.760 --> 0:09:24.000 far these radio waves can travel. So higher frequency radio 0:09:24.080 --> 0:09:28.199 bands can essentially only travel by line of sight, so 0:09:28.440 --> 0:09:30.920 there is a limited range to them. If you've ever 0:09:30.960 --> 0:09:34.760 listened to an FM radio station, because FM frequencies are 0:09:34.800 --> 0:09:38.800 in a band called very high frequency or VHF, then 0:09:38.920 --> 0:09:41.200 you might have had the experience of the station starting 0:09:41.200 --> 0:09:43.600 to give out as you travel away from the source. 0:09:44.320 --> 0:09:48.199 Depending upon the power of the broadcasting station, you typically 0:09:48.280 --> 0:09:51.200 have a range of around thirty to forty miles or 0:09:51.280 --> 0:09:54.960 fifty to sixty kilometers, but radio waves that are a 0:09:54.960 --> 0:09:58.280 bit longer can travel further thanks to a layer in 0:09:58.360 --> 0:10:03.280 Earth's atmosphere called the ionosphere. Higher frequencies can move right 0:10:03.360 --> 0:10:05.720 through the ionosphere. They just punch right through and go 0:10:05.760 --> 0:10:11.440 out into space, but lower frequencies, those having the longer wavelengths, 0:10:11.960 --> 0:10:14.640 aren't able to do that, so they actually bounce off 0:10:14.760 --> 0:10:18.199 the layer and come back down to Earth. By reflecting 0:10:18.200 --> 0:10:21.600 back down to Earth, these radio waves could travel much 0:10:21.600 --> 0:10:24.440 further than they would just by line of sight. Now, 0:10:24.480 --> 0:10:28.040 as the name suggests, the ionosphere is a layer of 0:10:28.080 --> 0:10:32.720 our atmosphere that is host to ionized particles. Ionization is 0:10:32.760 --> 0:10:36.160 the process by which an atom becomes charged either with 0:10:36.240 --> 0:10:40.080 a positive charge meaning it has lost electrons electrons are 0:10:40.160 --> 0:10:43.599 the negatively charged particles. So then you've got an imbalance. 0:10:43.679 --> 0:10:47.280 You have more protons with the atom than you have electrons, 0:10:47.400 --> 0:10:51.120 and thus you have an overall positive charge, or it 0:10:51.160 --> 0:10:54.600 could become negatively charged, meaning that an atom has taken 0:10:54.600 --> 0:10:59.000 on more electrons. Now, this makes that layer of Earth's 0:10:59.040 --> 0:11:04.160 atmosphere a electrically conductive. It happens because our atmosphere is 0:11:04.240 --> 0:11:07.440 hit by ultra violet light from the Sun and it 0:11:07.520 --> 0:11:10.240 hits the atoms in this layer of the atmosphere it 0:11:10.360 --> 0:11:14.120 energizes those atoms, and when the atoms get really energetic, 0:11:14.480 --> 0:11:18.880 the electrons move further out from the nucleus and they 0:11:18.880 --> 0:11:23.000 can actually peel off if they have enough energy. Now 0:11:23.040 --> 0:11:25.880 you've got free electrons, and those free electrons are either 0:11:25.960 --> 0:11:28.960 reflecting radio waves if they have a long enough wavelength, 0:11:29.360 --> 0:11:31.839 or they can actually absorb them or otherwise allow them 0:11:31.880 --> 0:11:36.640 to pass through for shorter wavelengths. This works in both directions. 0:11:36.640 --> 0:11:39.120 By the way, not just radio waves coming from Earth, 0:11:39.480 --> 0:11:42.160 but also radio waves that are coming in from space, 0:11:42.200 --> 0:11:45.319 because lots of stuff out there generates radio waves. I'm 0:11:45.320 --> 0:11:48.920 not talking about aliens. I'm talking about like solar activity 0:11:48.920 --> 0:11:52.599 and stuff like that. Now, the activity of the ionosphere 0:11:52.760 --> 0:11:56.400 changes throughout a day over any given spot on Earth. 0:11:56.920 --> 0:11:59.560 So during the daytime, that part of the Earth is 0:11:59.600 --> 0:12:03.040 facing the Sun, so the atmosphere overhead is being hit 0:12:03.080 --> 0:12:06.640 with a lot more ultra violet radiation, and thus the 0:12:06.720 --> 0:12:10.400 lower part of the ionosphere, the part that's closer to us, 0:12:11.040 --> 0:12:14.360 ends up getting more crowded with ions. Now that means 0:12:14.440 --> 0:12:17.520 that longer radio waves are going to hit the ionosphere 0:12:17.559 --> 0:12:21.360 at a lower altitude and then reflect off. But at nighttime, 0:12:21.679 --> 0:12:24.080 the sun is on the other side of the planet. 0:12:24.480 --> 0:12:27.840 So the lower part of the ionosphere kind of calms 0:12:27.880 --> 0:12:30.240 down a bit, and now the longer radio waves will 0:12:30.280 --> 0:12:34.160 actually travel at a further altitude. They'll go higher up 0:12:34.240 --> 0:12:37.960 before they hit the ionosphere and reflect back down. That 0:12:38.040 --> 0:12:40.959 also means that you can actually pick up longer wavelength 0:12:41.040 --> 0:12:46.040 radio signals from further away at nighttime because there's this 0:12:46.080 --> 0:12:49.800 different angle that allows the waves to reflect and travel 0:12:49.880 --> 0:12:53.800 even further. Now, the history of radio, as in the 0:12:53.920 --> 0:12:57.560 technology that we use to leverage radio waves, this gets 0:12:57.640 --> 0:13:00.880 complicated because we call the technology this same terms as 0:13:00.880 --> 0:13:06.559 we call the the scientific phenomena that is interoperating with 0:13:06.640 --> 0:13:09.959 the technology. But we'll we'll carry on. So the tech 0:13:10.679 --> 0:13:14.600 radio has a very long and complicated history, and it's 0:13:14.640 --> 0:13:19.440 full of some really serious drama. I mean not just 0:13:20.080 --> 0:13:24.200 radio dramas like soap oparas, I mean like drama drama. 0:13:24.320 --> 0:13:27.760 Just get a couple of radio enthusiasts talking about Tesla 0:13:27.880 --> 0:13:32.080 and Marconi or Armstrong and DeForest and see how things 0:13:32.160 --> 0:13:35.120 go if you want some entertainment. But we'll just cut 0:13:35.120 --> 0:13:37.320 to the chase and say that by World War One, 0:13:38.000 --> 0:13:40.880 people were figuring out potential uses for radio waves like 0:13:40.960 --> 0:13:44.760 being able to send communications quickly across large areas if 0:13:45.080 --> 0:13:48.320 you know you're trying to coordinate numerous groups of soldiers 0:13:48.360 --> 0:13:52.440 in different theaters of combat. For example, communicating by radio 0:13:52.800 --> 0:13:57.880 involves generating a carrier wave signal at a specific frequency 0:13:58.080 --> 0:14:01.240 and then modulating it so, in other word, changing that 0:14:01.360 --> 0:14:04.520 signal in some way in order for it to carry information. 0:14:04.920 --> 0:14:08.840 A steady signal gives you no real useful information other 0:14:08.920 --> 0:14:13.280 than someone or something is generating this signal. But by 0:14:13.320 --> 0:14:17.880 creating a way to encode and decode information by altering 0:14:17.920 --> 0:14:20.440 that signal, do you have a way to send more 0:14:20.480 --> 0:14:25.080 complex information. A M radio modulates a carrier signal by 0:14:25.160 --> 0:14:29.120 changing the amplitude of the wavelength, and this requires a 0:14:29.120 --> 0:14:32.120 good deal of power, and the long wavelengths mean you 0:14:32.200 --> 0:14:36.040 need big radio towers to beam out these signals. FM 0:14:36.160 --> 0:14:41.720 radio modulates signals through frequency modulation, altering the frequency of 0:14:41.760 --> 0:14:45.040 the signal slightly. And radio stations, like the kind we 0:14:45.160 --> 0:14:50.160 tune into for entertainment purposes, these are fixed frequencies right 0:14:50.280 --> 0:14:52.720 like If they weren't, you would never be able to 0:14:52.800 --> 0:14:56.080 tune into your favorite radio station because you wouldn't know 0:14:56.120 --> 0:14:58.960 what frequency to go to. So this means they can't 0:14:59.000 --> 0:15:03.360 take advantage of the changes in the ionosphere. They're always 0:15:03.360 --> 0:15:07.760 stuck transmitting at a set frequency, whether conditions are good 0:15:07.800 --> 0:15:12.600 for long range transmission or not. Shortwave radio operators have 0:15:12.720 --> 0:15:16.760 a little more flexibility. They're working with a specific series 0:15:16.800 --> 0:15:20.560 of frequencies in the high frequency range of the RF spectrum, 0:15:20.840 --> 0:15:23.480 but they can swap from one of those sets of 0:15:23.480 --> 0:15:27.600 frequencies to another and thus take advantage of atmospheric conditions. 0:15:27.640 --> 0:15:30.360 So early in the day you might use one set 0:15:30.800 --> 0:15:33.640 of frequencies that are available to you, and late at 0:15:33.720 --> 0:15:37.520 night you might use a different set, because the actual 0:15:37.680 --> 0:15:42.520 radio waves will travel at different distances as the day changes. 0:15:43.200 --> 0:15:46.600 But there's another aspect to communicating during wartime, which is 0:15:46.640 --> 0:15:49.840 that generally speaking, you don't want the people who are 0:15:49.880 --> 0:15:52.200 fighting on the other side of the war to know 0:15:52.320 --> 0:15:54.720 what the heck you're talking about, so you have to 0:15:54.720 --> 0:15:57.240 come up with some means of of you skating the 0:15:57.320 --> 0:16:01.080 meaning of your message. This is particularly important with radio 0:16:01.280 --> 0:16:04.400 for a very obvious reason. See, there are a lot 0:16:04.400 --> 0:16:07.000 of different ways to send secret messages, and some of 0:16:07.000 --> 0:16:09.800 them are more secure than others. If you and I 0:16:09.960 --> 0:16:13.880 are the only ones who know about a black glassy rock, 0:16:14.040 --> 0:16:16.520 near a trina field, you know, a rock that has 0:16:16.560 --> 0:16:20.000 no business being there, And I hide a message under 0:16:20.040 --> 0:16:22.640 that rock for you, there's a decent chance that you'll 0:16:22.680 --> 0:16:25.480 get to the message before anyone else does. I might 0:16:25.520 --> 0:16:28.280 not even need to encode the message at all, because 0:16:28.680 --> 0:16:30.840 no one else even knows that there's a rock there. 0:16:31.440 --> 0:16:34.120 If I were to send you a message through the mail, well, 0:16:34.320 --> 0:16:38.400 now there's a few points where someone could intercept that message, right, 0:16:38.760 --> 0:16:41.800 I mean, perhaps the batties check my mailbox. They see 0:16:41.840 --> 0:16:44.560 that I've put the little mail flag up, so they 0:16:44.600 --> 0:16:46.560 come and check it and they steal the message before 0:16:46.560 --> 0:16:49.880 I can even go anywhere. Or maybe they keep checking 0:16:49.920 --> 0:16:52.960 your mailbox on the other side, looking at incoming mail, 0:16:53.400 --> 0:16:56.760 and they grab my message when it arrives at your mailbox. 0:16:57.080 --> 0:17:01.040 Or maybe they're super tricksy and they've infiltrated the postal 0:17:01.120 --> 0:17:04.080 service and Cliff the mailman is secretly a dirty old 0:17:04.119 --> 0:17:09.800 spy always suspected it. Well. Radio communications are out in 0:17:09.840 --> 0:17:13.480 the open. Anyone with a receiver that has an antenna 0:17:13.520 --> 0:17:17.080 that can tune into whichever frequency is being used can 0:17:17.119 --> 0:17:20.480 actually listen in on that frequency, So you have no 0:17:20.600 --> 0:17:23.679 control over who can hear what you're sending out. So 0:17:23.760 --> 0:17:26.439 if you're sending something out in secret, you have to 0:17:26.640 --> 0:17:29.040 encode it in some way that makes it hard or 0:17:29.040 --> 0:17:32.639 impossible to determine what is being communicated. Now, when we 0:17:32.720 --> 0:17:36.320 come back, will talk about how this sometimes involves making 0:17:36.520 --> 0:17:41.159 creepy radio broadcasts. But first, let's take a quick break. 0:17:48.760 --> 0:17:52.200 Let's say you want to create your own radio station. 0:17:52.560 --> 0:17:55.400 You've put up a transmission tower, you figured out your 0:17:55.400 --> 0:17:59.040 power needs to generate the signal necessary to claim a 0:17:59.160 --> 0:18:03.119 subsection the r F spectrum set aside for broadcasts, and 0:18:03.119 --> 0:18:06.080 you're ready to go right. Well, no, now if you 0:18:06.080 --> 0:18:09.480 don't want to get shut down and find or worse. 0:18:09.880 --> 0:18:12.719 In order to make sure the spectrum isn't just a 0:18:12.800 --> 0:18:16.280 free for all, which would make communication difficult at least, 0:18:16.880 --> 0:18:21.679 governments have designated specific bands of frequencies for specific uses. 0:18:22.280 --> 0:18:25.479 See if multiple transmitters were trying to use the exact 0:18:25.560 --> 0:18:29.280 same frequency, everything would get garbled. You would have tons 0:18:29.359 --> 0:18:32.879 of interference. If you've ever used a pair of walkie talkies, 0:18:33.280 --> 0:18:36.119 you probably know that it's standard for folks to say 0:18:36.320 --> 0:18:40.600 over when they're done talking, because the walkie talkies switched 0:18:40.640 --> 0:18:45.080 between transmitter and receiver mode and without the over you 0:18:45.160 --> 0:18:47.800 might have both parties trying to talk at the same time, 0:18:48.160 --> 0:18:51.240 and no one can hear anything because you're both holding 0:18:51.240 --> 0:18:54.440 down the transmit button. Well, when you think about all 0:18:54.480 --> 0:18:59.600 the radio, television, cellular, WiFi, and other signals zooming around 0:18:59.600 --> 0:19:02.000 out there, all of which are part of the RF spectrum, 0:19:02.320 --> 0:19:04.240 you quickly realize that you've got to make up some 0:19:04.359 --> 0:19:07.040 rules or else no one would ever know who they're 0:19:07.080 --> 0:19:10.800 talking to. Now, way back in eighteen sixty five, the 0:19:10.880 --> 0:19:15.520 International Telegraph Union came into formation, and in nineteen thirty 0:19:15.560 --> 0:19:19.639 four it changed its name to the International Telecommunication Union, 0:19:19.920 --> 0:19:22.840 and it's part of the United Nations today, and one 0:19:22.840 --> 0:19:26.280 of its jobs is to designate specific slices of the 0:19:26.440 --> 0:19:31.080 RF spectrum for specific uses to allow for seamless operations 0:19:31.119 --> 0:19:34.240 between the world. That way, the radio is made by 0:19:34.240 --> 0:19:36.960 a company in Japan will work in places like the 0:19:37.040 --> 0:19:40.840 US because the frequencies that we've set aside for terrestrial 0:19:41.000 --> 0:19:44.439 radio stations are the same, assuming that both US and 0:19:44.520 --> 0:19:48.040 Japan are following the suggestions from the i t U. Now, 0:19:48.080 --> 0:19:51.919 it's up to the governments of various countries to enforce 0:19:52.000 --> 0:19:55.679 these rules. In the United States, radio stations have to 0:19:55.760 --> 0:19:59.360 obtain a license from the Federal Communications Commission to get 0:19:59.359 --> 0:20:03.359 a permission to broadcast on specific frequencies within the A, 0:20:03.640 --> 0:20:07.560 M or FM bands of the RF spectrum. There are 0:20:07.600 --> 0:20:11.520 other frequencies reserved for amateur radio operators, but if you 0:20:11.600 --> 0:20:15.000 want to operate your own amateur station, you have to 0:20:15.040 --> 0:20:17.600 get a license from the f c C, and passing 0:20:17.600 --> 0:20:20.280 a test is part of that process. Now, if you 0:20:20.320 --> 0:20:23.560 just want to listen to radio, that's different. You don't 0:20:23.600 --> 0:20:26.159 need a license. In that case, you could have a 0:20:26.200 --> 0:20:29.679 short wave radio set and as long as you're not transmitting, 0:20:29.720 --> 0:20:33.399 you're just listening, no licenses needed. But to transmit, you 0:20:33.520 --> 0:20:36.480 gotta get permission first, and the f c C will 0:20:36.520 --> 0:20:41.400 even assign a call signed to you. Number stations are different. 0:20:41.840 --> 0:20:44.639 With commercial radio stations, you can do some research to 0:20:44.640 --> 0:20:49.119 see who owns and operates that station, but with numbers stations, 0:20:49.480 --> 0:20:53.199 there's a distinct lack of information. This puts them in 0:20:53.240 --> 0:20:57.119 the realm of pirate radio stations. These are stations that 0:20:57.200 --> 0:21:00.880 have no identifying information associated with them and they are 0:21:00.920 --> 0:21:05.680 operating without being registered with the FCC or similar agency 0:21:05.720 --> 0:21:09.639 in other countries. Now that doesn't mean that these agencies 0:21:09.680 --> 0:21:13.080 like the f c C don't know about them. There 0:21:13.200 --> 0:21:17.600 is a look the other way situation in which one 0:21:17.640 --> 0:21:20.000 part of the government is using stuff that the other 0:21:20.040 --> 0:21:23.560 parts just don't need to worry about. You know, by 0:21:23.560 --> 0:21:27.399 the way, if you're wondering if people operate pirate radio stations, 0:21:27.480 --> 0:21:31.440 they sometimes do. But there are ways to triangulate signals 0:21:31.560 --> 0:21:35.320 and determine where those signals are coming from. So if 0:21:35.359 --> 0:21:40.440 someone is broadcasting without permission on a specific frequency, it's 0:21:40.480 --> 0:21:43.040 typically just a matter of time before the Feds come 0:21:43.080 --> 0:21:46.080 in and shut things down. Now, you could hop onto 0:21:46.080 --> 0:21:50.680 other frequencies, but unless your audience knows where to tune in, 0:21:51.240 --> 0:21:54.080 you would likely be talking to no one or at 0:21:54.160 --> 0:21:57.160 least very few people. So, since we know that it's 0:21:57.160 --> 0:22:00.760 possible to figure out where a radio signal ridge and eates, 0:22:00.800 --> 0:22:04.320 and since numbers stations can remain in operation for years 0:22:04.440 --> 0:22:08.160 or decades, we have to draw the conclusion that these 0:22:08.240 --> 0:22:13.120 numbers stations have some sort of sanction from governments, otherwise 0:22:13.160 --> 0:22:16.200 they would get shut down. Now, some sources say that 0:22:16.320 --> 0:22:20.320 numbers stations, these radio frequencies that are sending out seemingly 0:22:20.359 --> 0:22:24.680 nonsensical information, got their start in World War One. Others 0:22:24.800 --> 0:22:27.919 say it was actually closer to World War Two, and 0:22:27.960 --> 0:22:31.760 I tend to suspect that the latter is more accurate. 0:22:32.359 --> 0:22:35.280 Radio was important in World War One, but it was 0:22:35.359 --> 0:22:39.280 also still pretty early on in the evolution of the technology. 0:22:39.800 --> 0:22:42.280 But at some time around World War One and World 0:22:42.320 --> 0:22:45.159 War Two, someone got an idea, and that idea was 0:22:45.480 --> 0:22:49.800 to establish a transmission on a particular signal or sometimes 0:22:49.800 --> 0:22:52.000 a series of signals that would change throughout the day 0:22:52.000 --> 0:22:55.680 to take advantage of the ionosphere and the differences and 0:22:55.840 --> 0:22:59.840 signal propagation, and the signal would broadcast encoded and for 0:23:00.040 --> 0:23:03.720 vation presumably two spies. So let's say you're running a 0:23:03.760 --> 0:23:09.240 top secret spy organization like the m I six. Now, granted, 0:23:09.480 --> 0:23:13.119 you're spending a lot of time dealing with the fact 0:23:13.160 --> 0:23:16.120 that your top spy has a habit of introducing himself 0:23:16.200 --> 0:23:19.320 to any one in hearing range and then drinking his 0:23:19.359 --> 0:23:21.720 way across the world. But you've got a lot of 0:23:21.760 --> 0:23:26.119 other more responsible spy types out there too, and you 0:23:26.200 --> 0:23:29.520 might occasionally need to send them orders. But if your 0:23:29.560 --> 0:23:34.120 operative is halfway across the world, deep in enemy territory 0:23:34.320 --> 0:23:38.040 and you can't rely on normal communication channels, you might 0:23:38.080 --> 0:23:41.639 want to send a coded message by shortwave radio. This 0:23:41.720 --> 0:23:44.880 has a huge advantage and that the radio signal goes 0:23:44.920 --> 0:23:48.080 out everywhere, so you know that your enemies will be 0:23:48.119 --> 0:23:50.960 able to detect the signal, but they won't know what 0:23:51.040 --> 0:23:54.919 the message was or who it was actually for. If 0:23:54.960 --> 0:23:57.920 you were to call your operative, it's possible someone could 0:23:57.960 --> 0:24:01.879 detect the call and trace it to the recipient the spy, 0:24:01.960 --> 0:24:05.159 and thus compromising them. So sending out a message via 0:24:05.320 --> 0:24:08.800 radio means you give no information about who is supposed 0:24:08.840 --> 0:24:12.919 to receive that message. The operative nose to tune into 0:24:13.040 --> 0:24:17.359 a specific radio frequency at a specific time. This is 0:24:17.400 --> 0:24:20.080 something that you have to work out beforehand, obviously, as 0:24:20.080 --> 0:24:22.199 most of us aren't aware of what's going on with 0:24:22.320 --> 0:24:25.120 radio waves all around us, or we'd have a lot 0:24:25.119 --> 0:24:29.080 of trouble concentrating on anything. You might set up a 0:24:29.119 --> 0:24:32.879 regular broadcast session using different frequencies throughout the day, depending 0:24:32.960 --> 0:24:36.639 upon whichever one works best. And maybe some days you 0:24:36.640 --> 0:24:39.280 have nothing to report, so you might even send out 0:24:39.320 --> 0:24:41.560 a code for that, or it might just be gibberish. 0:24:41.800 --> 0:24:44.600 But other days you need to alert your operative to 0:24:44.880 --> 0:24:48.119 return home, or step it up and place a bigger 0:24:48.160 --> 0:24:51.840 bet in baccarat or whatever it may be. So these numbers. 0:24:51.880 --> 0:24:55.440 Stations typically have some sort of indicator at the top 0:24:55.440 --> 0:24:58.560 of the hour. The Lincoln Share Poacher, which we played 0:24:58.600 --> 0:25:01.520 at the beginning of this episode, is an example of that. 0:25:01.520 --> 0:25:05.400 That little tune marked the beginning of a transmission, followed 0:25:05.440 --> 0:25:09.679 by the actual message. The message would be a sequence 0:25:09.800 --> 0:25:14.560 of some sort, typically numbers, sometimes letters. The voice might 0:25:14.560 --> 0:25:16.679 be a recording, or it might be read live on 0:25:16.760 --> 0:25:19.000 the air. It could be a man, a woman, or 0:25:19.040 --> 0:25:21.359 a child's voice. You might pick up a short wave 0:25:21.400 --> 0:25:24.359 signal with someone counting in another language. But what do 0:25:24.440 --> 0:25:27.679 those codes actually mean? Well, that's the real question, and 0:25:27.760 --> 0:25:30.320 that's one that's kind of impossible for us to answer 0:25:30.440 --> 0:25:34.600 because the coded messages use an approach that is unbreakable 0:25:34.960 --> 0:25:38.800 assuming you don't get hold of the secret. So this 0:25:39.000 --> 0:25:44.520