WEBVTT - How Pagers Work 0:00:04.760 --> 0:00:12.600 With technology with tech Stuff from works dot com. Hey there, 0:00:12.640 --> 0:00:16.400 and welcome to tech Stuff. I am your host, Jonathan Strickland. 0:00:16.440 --> 0:00:19.479 I'm an executive producer at how Stuff Works. If you 0:00:19.480 --> 0:00:22.120 think my voice sounds a little odd, I'm coming down 0:00:22.200 --> 0:00:24.880 with a cold. But as I record this, this is 0:00:24.880 --> 0:00:27.880 the last episode of tech Stuff. I'm recording in the 0:00:27.960 --> 0:00:32.440 year seventeen, although you are hearing it in the year eighteen, 0:00:32.960 --> 0:00:35.519 So you're listening to me from the past, unless you're 0:00:35.520 --> 0:00:38.600 in the chat room at twitch dot tv slash slash 0:00:38.600 --> 0:00:40.960 tech Stuff, in which case you're actually watching me record 0:00:41.000 --> 0:00:44.360 it right now, So you're hearing a episode seventeen, in 0:00:44.360 --> 0:00:47.400 which case, uh, we traveled to the future. That's how 0:00:47.440 --> 0:00:50.800 time works. And speaking of time, you know, I've I've 0:00:50.800 --> 0:00:54.880 covered some cutting edge technologies recently and talked about blockchain, 0:00:55.320 --> 0:00:57.680 which will be an episode coming up soon. That's all 0:00:57.720 --> 0:01:01.240 about the technology of the future. Well, I want to 0:01:01.280 --> 0:01:03.560 talk about the technology of the past today and talk 0:01:03.720 --> 0:01:09.080 about pagers or beepers. Uh, something that's classic, right, the 0:01:09.160 --> 0:01:12.119 humble pager. The beeper This is the device that gives 0:01:12.120 --> 0:01:14.920 you an alert to an incoming message, so as you 0:01:14.920 --> 0:01:17.480 can dash out of a theater in dramatic fashion to 0:01:17.520 --> 0:01:20.000 make an important phone call on a pay phone outside. 0:01:20.840 --> 0:01:23.520 Oh yeah, there used to be pay phones too. So 0:01:23.720 --> 0:01:26.119 where did pagers come from and how do they work? 0:01:26.520 --> 0:01:28.760 So that's our focus of our show today. So to start, 0:01:29.200 --> 0:01:31.520 we're gonna take a trip all the way back to 0:01:31.680 --> 0:01:35.840 nineteen twenty one, which was a tumultuous year. Socialism and 0:01:35.880 --> 0:01:40.200 communism were sweeping Eastern Europe and parts of Asia. Russia 0:01:40.319 --> 0:01:43.559 was expanding its borders and invading various nations to claim 0:01:43.600 --> 0:01:46.600 them for its own. Northern Ireland got its own parliament 0:01:46.760 --> 0:01:50.240 in nine. Adolf Hitler would become the fearer of the 0:01:50.320 --> 0:01:54.280 Nazi Party in nineteen twenty one, and the first White 0:01:54.320 --> 0:01:58.000 Castle Hamburger joint opened in Wichita, Kansas in nineteen twenty one, 0:01:58.080 --> 0:02:01.440 spelling doom for us all. But also in that year, 0:02:01.680 --> 0:02:05.400 the Detroit Police Force implemented what is generally agreed upon 0:02:05.600 --> 0:02:10.200 as the precursor to pagers, and that system was actually 0:02:10.240 --> 0:02:14.120 a one way radio communication system, which when you boil 0:02:14.200 --> 0:02:18.160 a pager down, that's what your typical pager is. By 0:02:18.160 --> 0:02:20.959 the way, don't boil down pagers, it will ruin them. 0:02:21.000 --> 0:02:23.880 But a pager ultimately is a receiver that's at one 0:02:24.000 --> 0:02:27.120 end of a radio communications system. Let's get back to 0:02:27.200 --> 0:02:30.600 those Detroit police. So it's the nineteen twenties and the 0:02:30.680 --> 0:02:34.320 United States was dealing with some pretty serious crime. This 0:02:34.560 --> 0:02:38.679 was an era of bank robberies and bootlegging. Prohibition, that's 0:02:38.720 --> 0:02:41.960 the era that made alcohol illegal in the United States 0:02:42.200 --> 0:02:45.040 began in nineteen twenty and it would remain in effect 0:02:45.120 --> 0:02:49.920 until December nineteen thirty three. The constitutional amendment that outlawed 0:02:49.960 --> 0:02:52.880 the production, sale, and consumption of alcohol in the United 0:02:52.919 --> 0:02:58.480 States created enormous opportunity for criminals because people love their hooch, 0:02:58.960 --> 0:03:04.600 and so it became incredibly profitable to smuggle alcohol. Gangsters 0:03:04.600 --> 0:03:08.520 made a fortune off of bootlegging and other illegal activities, 0:03:08.560 --> 0:03:11.840 and the police were largely unprepared to deal with this 0:03:11.919 --> 0:03:15.760 problem in the major metropolitan areas. This was before two 0:03:15.800 --> 0:03:18.760 way radios were small enough to fit into police cruisers, 0:03:19.120 --> 0:03:21.000 and so there was no easy way to send out 0:03:21.000 --> 0:03:23.359 a message among a police force to have them close 0:03:23.480 --> 0:03:27.680 in on the bad guys. But three Detroit police officers, 0:03:28.200 --> 0:03:33.600 Kenneth our Cox, Walter Vogler, and Bernard Fitzgerald, had an idea. 0:03:34.120 --> 0:03:37.840 They experimented by putting radio sets in the back seats 0:03:37.920 --> 0:03:42.320 of their model t Ford police patrol cars, and yeah, 0:03:42.360 --> 0:03:44.960 it took up pretty much the whole seat. The radio 0:03:45.040 --> 0:03:47.880 sets weren't special in any way, and though they could 0:03:47.920 --> 0:03:51.280 pick up a signal, they weren't terribly consistent. They also 0:03:51.360 --> 0:03:54.480 didn't operate on a special bandwidth, which meant police back 0:03:54.480 --> 0:03:57.520 at HQ, but have to broadcast on a normal channel, 0:03:57.600 --> 0:04:00.320 which could be picked up by anyone with a radio set. 0:04:00.680 --> 0:04:02.880 So if you wanted to listen in on police radio, 0:04:02.960 --> 0:04:06.160 which again was just a one way communication from headquarters 0:04:06.200 --> 0:04:09.680 to a few cruisers that had radio sets, you could 0:04:09.680 --> 0:04:12.480 do it. In fact, in order to operate, the Detroit 0:04:12.520 --> 0:04:17.240 Police Force had to register their police radio station as 0:04:17.240 --> 0:04:21.400 an entertainment station and they would play recorded music whenever 0:04:21.440 --> 0:04:24.560 they weren't reading off lists of stolen vehicles or other 0:04:24.600 --> 0:04:28.760 criminal information. And the call sign for this radio station 0:04:29.240 --> 0:04:34.600 was ko P COP. Pretty cute, right, all that's true? 0:04:35.040 --> 0:04:39.400 By nine Kenneth Cox, one of those three police officers, 0:04:39.600 --> 0:04:43.400 and an engineering student named Robert L. Bats built a 0:04:43.520 --> 0:04:47.839 radio set specifically for a vehicle. It was stable, it 0:04:47.920 --> 0:04:50.719 had its own antenna, and the antenna could attached to 0:04:50.720 --> 0:04:53.960 the car, and the Detroit Police Force began to install 0:04:54.080 --> 0:04:57.320 those kinds of systems into cruisers for real. In n 0:04:58.760 --> 0:05:02.600 the Detroit Police for became the first law enforcement agency 0:05:02.640 --> 0:05:06.200 to dispatch police cars by radio. Other cities would soon 0:05:06.360 --> 0:05:09.360 follow that lead, and it might be a good idea 0:05:09.400 --> 0:05:12.760 to have a brief refresher on how radio communication works. 0:05:13.279 --> 0:05:16.520 With one way communication, you're working with a transmitter and 0:05:16.600 --> 0:05:19.480 a receiver. We'll look at both of these components. Will 0:05:19.520 --> 0:05:22.440 start with the transmitter first, you need a power supply. 0:05:22.880 --> 0:05:26.520 Next along the chain of components is a device called 0:05:26.560 --> 0:05:30.839 an oscillator, which creates an alternating current at a particular frequency. 0:05:31.360 --> 0:05:34.640 And typically you'd use the oscillator to create a sign wave. 0:05:35.080 --> 0:05:38.000 This would serve as your basic radio signal, also known 0:05:38.040 --> 0:05:41.719 as the carrier signal. But here's a problem. That signal 0:05:41.800 --> 0:05:44.560 carries no information. You could send it out, but it 0:05:44.560 --> 0:05:48.680 would just be blank. It would be nothing to send 0:05:48.760 --> 0:05:51.839 information along such a signal. You have to modify the 0:05:51.920 --> 0:05:54.800 signal in some way, and with radio as you do 0:05:54.880 --> 0:05:58.480 this with a modulator. Modulators affect the sign waves sent 0:05:58.560 --> 0:06:02.279 by radio signals in some fundamental way. There are two 0:06:02.320 --> 0:06:06.279 main approaches to doing this. There's amplitude modulation or a 0:06:06.560 --> 0:06:11.440 M That involves increasing or decreasing the amplitude or intensity 0:06:11.520 --> 0:06:13.479 of the sign waves. So if you draw a sign 0:06:13.520 --> 0:06:17.400 wave out going from left to right, the height of 0:06:17.440 --> 0:06:20.720 the peaks and the depth of the troughs, that's your amplitude. 0:06:21.160 --> 0:06:23.440 So if you make them taller and you make the 0:06:23.480 --> 0:06:27.840 troughs deeper, you're increasing the amplitude of that wave. Then 0:06:27.880 --> 0:06:31.919 there's frequency modulation or FM, which involves changing the frequency 0:06:31.920 --> 0:06:36.279 of a radio wave. So that involves decreasing the wave 0:06:36.400 --> 0:06:40.200 length now so that you have more of these waves 0:06:40.240 --> 0:06:43.920 pass a given point within a second. That's your frequency. 0:06:44.000 --> 0:06:47.160 So if you think again about this is a time function. 0:06:47.400 --> 0:06:51.560 You've got this form of a wave. It passes through 0:06:51.600 --> 0:06:54.760 a point. Let's say that it's fast enough where a 0:06:54.839 --> 0:06:58.680 thousand of them pass a point a specific point in 0:06:58.760 --> 0:07:02.880 space every second. That's a thousand hurts. That's one thousand 0:07:03.320 --> 0:07:08.039 wavelengths per second. If you were to decrease that, you know, 0:07:08.160 --> 0:07:12.440 decrease the length of the waves, they're still traveling at 0:07:12.440 --> 0:07:16.040 the same speed, but now there's they're squished, right, you 0:07:16.040 --> 0:07:18.600 get more waves in per second. Now it might be 0:07:18.720 --> 0:07:22.440 five thousand or five thousand hurts. It's five thousand wavelengths 0:07:22.440 --> 0:07:26.640 per second. So next you would typically have an amplifier 0:07:26.920 --> 0:07:29.840 and that would take this signal and create an amplified 0:07:30.000 --> 0:07:32.600 version of it, which then gets sent to an antenna, 0:07:32.760 --> 0:07:37.080 a transmittle emitter antenna. The antenna essentially converts this electrical 0:07:37.160 --> 0:07:40.360 signal into radio waves, which propagate out from the antenna 0:07:40.400 --> 0:07:44.960 into the surrounding environment. The amplifier and antenna determine how 0:07:45.080 --> 0:07:49.240 far the signal will carry, So when you hear about 0:07:49.240 --> 0:07:51.800 transmitters and how powerful they are, you're really thinking about 0:07:52.000 --> 0:07:56.280 what's the amplification. Uh And some radio broadcast towers have 0:07:56.440 --> 0:07:59.640 much greater amplification than others, which is why you can 0:07:59.640 --> 0:08:03.560 pick them up further away than the their their counterparts. 0:08:04.280 --> 0:08:07.320 Now on the receiver side, you have a very similar 0:08:07.360 --> 0:08:10.720 series of components. First, we'll start with the receiver's antenna. 0:08:10.760 --> 0:08:13.760 We're gonna go from where the signal comes in and 0:08:13.800 --> 0:08:18.200 work our way inward. So the antenna captures the radio waves, 0:08:18.320 --> 0:08:20.680 or rather we could say the radio waves induce an 0:08:20.680 --> 0:08:24.920 alternating current to flow through the antenna that goes to 0:08:24.960 --> 0:08:28.160 an amplifier, which detects this electrical signal and boosts it 0:08:28.280 --> 0:08:31.360 so that a detector can separate the relevant information from 0:08:31.360 --> 0:08:34.960 the base carrier sign wave. In audio radios, you also 0:08:35.000 --> 0:08:38.040 have a couple of other elements, like a tuner, because 0:08:38.400 --> 0:08:40.839 there are lots of different frequencies you can broadcast at, 0:08:40.880 --> 0:08:43.480 so a tuner allows you to tune into that band 0:08:43.520 --> 0:08:47.280 of frequencies um and it ignores everything else, so that 0:08:47.400 --> 0:08:51.320 way you can just concentrate on the radio station you 0:08:51.360 --> 0:08:53.880 want to hear. Otherwise you would get all radio stations 0:08:53.920 --> 0:08:56.760 all the time, and that would be annoying. You also 0:08:56.800 --> 0:09:00.720 have an audio amplifier, typically in your regular sumer radio. 0:09:00.920 --> 0:09:02.920 That I mean you have to otherwise you're not gonna 0:09:02.920 --> 0:09:05.439 hear anything that boosts the signal, so it's strong enough 0:09:05.440 --> 0:09:08.719 to make the speakers work. So essentially, what you're doing 0:09:08.760 --> 0:09:12.280 is you're taking some information, you transform that information into 0:09:12.320 --> 0:09:16.240 electrical signals. You use that to modify a carrier wave. 0:09:16.600 --> 0:09:19.079 You amplify that wave and send it out over in 0:09:19.160 --> 0:09:24.079 antenna to create radio signals. Those radio signals get picked 0:09:24.160 --> 0:09:28.000 up by a receiver's antenna and essentially revert that receiver 0:09:28.160 --> 0:09:31.640 reverses this process. Now, I mentioned that Detroit started using 0:09:31.679 --> 0:09:34.480 this one way radio communication, which at the time depended 0:09:34.559 --> 0:09:39.400 upon amplitude modulation radio signals am back in nine in 0:09:39.440 --> 0:09:44.400 an official capacity, but a year earlier, a young boy 0:09:44.440 --> 0:09:47.360 who would become incredibly important in the development of multiple 0:09:47.360 --> 0:09:51.960 wireless technologies first became fascinated with radio. That boy's name 0:09:51.960 --> 0:09:55.640 was al Gross. He was nine years old in nineteen seven, 0:09:55.800 --> 0:09:59.320 and he was on a steamship traveling across the Great Lakes, 0:09:59.480 --> 0:10:01.320 and he got to tour the ship and he got 0:10:01.360 --> 0:10:02.839 up to the radio room and he thought it was 0:10:02.880 --> 0:10:06.120 absolutely fascinating. He could hear the wireless being operated on there. 0:10:06.640 --> 0:10:10.120 And the operator brought Al Gross into the room and 0:10:10.160 --> 0:10:13.600 explained what the equipment was and and Gross was completely 0:10:13.600 --> 0:10:17.880 blown away. Eleven years later, Al Gross develops a prototype 0:10:17.920 --> 0:10:21.400 of a two way radio communications device, and Gross gave 0:10:21.440 --> 0:10:25.720 the gadget an interesting name. He called it the Walkey Talkie. 0:10:26.760 --> 0:10:29.360 His invention brought him to the attention of the United 0:10:29.400 --> 0:10:33.679 States Office of Strategic Services, which would eventually evolve into 0:10:33.760 --> 0:10:38.760 the Central Intelligence Agency, and Gross was recruited to develop 0:10:38.840 --> 0:10:42.480 this technology for military use, specifically creating a way for 0:10:42.600 --> 0:10:47.000 covert communication between aircraft and troops while the troops were 0:10:47.040 --> 0:10:50.560 behind enemy lines during World War Two. After the war, 0:10:51.040 --> 0:10:54.960 Gross built his own business called Gross Electronics Incorporated and 0:10:55.000 --> 0:10:59.120 filed a dozen patents relating to wireless communication, a lot 0:10:59.120 --> 0:11:01.240 of which would end up being really important over the 0:11:01.280 --> 0:11:04.840 following decades, including one that described the circuitry needed for 0:11:04.920 --> 0:11:08.480 a personal paging system. And this would be in nineteen nine. 0:11:09.120 --> 0:11:11.559 A year earlier, by the way, he had actually pioneered 0:11:11.600 --> 0:11:15.200 citizens band radio or CB radio, So you radio fans 0:11:15.200 --> 0:11:19.040 out there should really raise a glass to Mr Al Gross. Now. 0:11:19.080 --> 0:11:22.720 Gross's breakthrough in nineteen nine was adapting his walkie talkie 0:11:22.760 --> 0:11:27.880 technology for cordless remote telephonic signaling, and essentially his system 0:11:27.960 --> 0:11:32.400 used radios to alert doctors for specific messages. Hospitals have 0:11:32.480 --> 0:11:35.840 been relying on intercom systems with speakers wired up throughout 0:11:35.880 --> 0:11:38.760 the building. You might be familiar with the classic line 0:11:38.920 --> 0:11:43.160 paging Dr Howard, Dr Fine, Dr Howard. If you are 0:11:43.760 --> 0:11:45.680 be sure to shout out to me what that's from, 0:11:45.720 --> 0:11:49.200 because I'm always happy to meet another cultured individual. The 0:11:49.240 --> 0:11:51.760 intercom system was a bit intrusive, and it meant that 0:11:51.840 --> 0:11:54.480 doctors frequently had to listen for messages that they really 0:11:54.480 --> 0:11:56.760 didn't need to worry about because it wasn't for them. 0:11:57.280 --> 0:12:02.400 Gross's solution was these pages. The they weren't called pagers yet. 0:12:02.760 --> 0:12:06.440 The gadgets had what M i T calls discriminating circuitry, 0:12:06.679 --> 0:12:09.320 which just means the circuits could detect a specific signal 0:12:09.400 --> 0:12:12.000 so that the owner of the pager would only get 0:12:12.040 --> 0:12:16.120 alerts intended for that person. And that's an important distinction. 0:12:16.600 --> 0:12:19.200 A commercial radio is just a dumb receiver, so you 0:12:19.240 --> 0:12:21.600 can tune it to a specific band of frequencies, but 0:12:21.679 --> 0:12:24.120 you're getting the same signal as everyone else that's also 0:12:24.200 --> 0:12:26.400 tuned to that band. If you want to send a 0:12:26.440 --> 0:12:29.360 message to a specific person, you need to have some 0:12:29.400 --> 0:12:32.400 way to indicate to that person's radio device that there's 0:12:32.440 --> 0:12:35.000 a personal message for them and have that device ignore 0:12:35.040 --> 0:12:38.160 anything that wasn't intended for its owner. So how does 0:12:38.160 --> 0:12:41.000 it do that? Well, we'll cover it in just a second, 0:12:41.320 --> 0:12:51.600 but first let's take a quick break to thank our sponsor. Okay, 0:12:51.640 --> 0:12:54.040 So how do you make sure a pager knows which 0:12:54.080 --> 0:12:56.880 signal is meant or hit? Well. One way to do 0:12:56.920 --> 0:12:59.079 that is to create a system in which every pager 0:12:59.200 --> 0:13:02.600 unit within a service has a specific set of audio 0:13:02.720 --> 0:13:07.479 tones associated with it. Early pages used a two tone system. 0:13:07.520 --> 0:13:10.440 Typically you describe them as an A tone and a 0:13:10.520 --> 0:13:13.920 B tone. And these tones would be anywhere from three 0:13:13.960 --> 0:13:16.840 hurts to three thousand hurts, and frequency which is within 0:13:16.880 --> 0:13:21.040 the range of human hearing, which averages out to hurt hurts, 0:13:21.080 --> 0:13:24.120 although you start to lose those higher ranges as you 0:13:24.160 --> 0:13:27.640 get older. The two tones would also last a specific 0:13:27.679 --> 0:13:30.400 amount of time each, and the combination of the tone's 0:13:30.480 --> 0:13:33.800 frequency and duration would be enough to create unique call 0:13:33.880 --> 0:13:38.320 signs for each pager. The approach did have some limitations, however, Namely, 0:13:38.320 --> 0:13:40.440 it limited how many pages could be connected to a 0:13:40.480 --> 0:13:43.520 single system. Early pages topped out at fewer than a 0:13:43.600 --> 0:13:46.640 thousand units per systems, somewhere in the realm of eight 0:13:46.679 --> 0:13:49.319 hundred and fifty or so, which works fine. If the 0:13:49.360 --> 0:13:51.920 pages are meant for a specific place like a hospital 0:13:52.120 --> 0:13:55.160 or even a restaurant, you're never going to need more 0:13:55.280 --> 0:13:58.720 than that. But if you wanted a general consumer pager, 0:13:59.000 --> 0:14:00.679 that was not going to cut it. You max out 0:14:00.679 --> 0:14:03.280 your customer base if fewer than one thousand, and if 0:14:03.280 --> 0:14:05.600 you wanted to grow, you'd have to implement news systems 0:14:05.600 --> 0:14:08.720 and administer them all at the same time using different 0:14:08.800 --> 0:14:12.400 radio frequencies. It would just become a nightmare. Later, pager 0:14:12.480 --> 0:14:15.640 manufacturers would switch to a five six tone system, which 0:14:15.679 --> 0:14:18.880 meant that the identification code would consist of either five 0:14:19.080 --> 0:14:22.160 or six audio tones that increase the potential number of 0:14:22.160 --> 0:14:24.760 pages on the single system dramatically to more than a 0:14:24.840 --> 0:14:28.600 hundred thousand up to a million. As for the messages, 0:14:29.320 --> 0:14:32.840 those also varied. The early pagers were really just one 0:14:32.840 --> 0:14:36.240 way radios, similar to what Detroit had been using decades earlier. 0:14:36.400 --> 0:14:38.760 Al Gross's invention was meant for doctors to wear in 0:14:38.800 --> 0:14:42.080 their clothing. An operator would work a central switchboard and 0:14:42.120 --> 0:14:44.160 when a request would come in for a specific doctor, 0:14:44.680 --> 0:14:47.760 the operator would activate the circuit for that doctors specific 0:14:47.800 --> 0:14:51.040 pager frequency. Though it's send a signal that the doctor's 0:14:51.040 --> 0:14:52.920 pager would pick up, and the pager would make some 0:14:52.960 --> 0:14:55.960 sort of audible alert also known as a noise to 0:14:56.080 --> 0:14:58.160 let the doctor know, Hey, you need to listen to me. 0:14:58.840 --> 0:15:00.520 The doctor would hold up the pag or to their 0:15:00.560 --> 0:15:03.800 ear and listen as a voice clear as a day, 0:15:03.840 --> 0:15:06.000 if a day were you know, a little fuzzy, with 0:15:06.080 --> 0:15:09.120 some feedback, and it would say something like dr fine, 0:15:09.160 --> 0:15:13.000 please report to the ICU. The technology didn't really catch 0:15:13.040 --> 0:15:16.520 on outside of a few narrow uses. The Jewish Hospital 0:15:16.520 --> 0:15:18.760 in New York City saw the value, but according to 0:15:18.760 --> 0:15:21.520 al Gross, he encountered a lot of reluctance among other 0:15:21.600 --> 0:15:24.880 doctors who seemed to hate the idea, and they didn't 0:15:24.880 --> 0:15:27.600 really care for the fact that someone could get ahold 0:15:27.600 --> 0:15:30.200 of them at any time, like when they're playing golf, 0:15:30.280 --> 0:15:32.960 for example. That was al Gross's joke, by the way, 0:15:33.040 --> 0:15:36.480 not mine. And so while his idea was demonstrably useful, 0:15:36.600 --> 0:15:38.360 it was still ahead of its time, and he he 0:15:38.400 --> 0:15:41.400 couldn't get any of the big electronics companies really interested 0:15:41.560 --> 0:15:45.600 in it at first either. But in ninety a company 0:15:45.640 --> 0:15:49.640 called to L answer Phone. Yeah, that's a fun one 0:15:49.680 --> 0:15:51.640 to read off and then say, wait, how do I 0:15:51.720 --> 0:15:54.520 say this out loud? To L answer Phone operate a 0:15:54.560 --> 0:15:58.400 paging service for doctors in New York. It was not automated, 0:15:59.080 --> 0:16:01.960 generally speaking. The way the paging service worked was that 0:16:02.560 --> 0:16:05.160 you would call a number. Let's say it's a patient 0:16:05.160 --> 0:16:08.120 and a doctor, because it was almost exclusively used by doctors. 0:16:08.560 --> 0:16:11.600 A patient calls a doctor's number, the doctor fails to 0:16:11.600 --> 0:16:14.240 pick up the phone. The call, after a certain number 0:16:14.240 --> 0:16:16.760 of rings, relays to a messaging service where a human 0:16:16.800 --> 0:16:19.760 being listens to the message takes it down for the doctor. 0:16:20.240 --> 0:16:23.680 If the call is urgent. The messaging service then makes 0:16:23.680 --> 0:16:25.720 a note that this needs to be broadcast to the 0:16:25.800 --> 0:16:30.680 doctor's pager using a three digit code number unique to 0:16:30.800 --> 0:16:34.400 that doctor. Once an hour, the doctor is expected to 0:16:34.400 --> 0:16:36.960 turn on their receiver and listen into a series of 0:16:37.000 --> 0:16:40.880 three digit codes. If the doctor's own code is among them, 0:16:41.360 --> 0:16:43.640 the doctor is to call into the messaging service to 0:16:43.640 --> 0:16:46.360 find out what's going on, and once the doctor checks in, 0:16:46.440 --> 0:16:49.800 the messaging service removes the doctor's code from the broadcast. 0:16:50.360 --> 0:16:52.720 So this pager did not alert you when you got 0:16:52.720 --> 0:16:55.720 a new message. Instead, you actually had to turn it 0:16:55.800 --> 0:16:58.640 on actively and listen in to find out if you 0:16:58.720 --> 0:17:02.400 had any messages. The codes themselves were recorded on sixteen 0:17:02.440 --> 0:17:05.920 millimeter film, and that film was then encased in plastic 0:17:06.040 --> 0:17:09.080 sticks which could be hung on a looped belt of 0:17:09.119 --> 0:17:12.120 a transmitting machine. So this belt would just rotate through 0:17:12.280 --> 0:17:14.880 and these little plastic sticks with film in them would 0:17:14.920 --> 0:17:17.840 get scanned by a reader and that would pick up 0:17:18.080 --> 0:17:21.760 what the code was for that particular piece of film. 0:17:21.800 --> 0:17:25.440 It would then broadcast that information out uh in its 0:17:25.600 --> 0:17:29.600 actual broadcast. That broadcast gets repeated every single minute for 0:17:29.680 --> 0:17:32.199 an hour. After a doctor called in, you would just 0:17:32.200 --> 0:17:34.840 remove that doctor's stick from the belt and it would 0:17:34.920 --> 0:17:37.920 then remove that three digit number from the broadcast, which 0:17:38.000 --> 0:17:41.040 seems pretty wild to me. It's kind of an interesting concept. 0:17:42.040 --> 0:17:44.719 Doctors would actually pay to be included on this service. 0:17:44.760 --> 0:17:48.000 It cost about twelve dollars a month back in the 0:17:48.280 --> 0:17:51.800 nineteen fifties, and the range on the broadcast tower was 0:17:51.920 --> 0:17:55.160 twenty five miles twenty five mile radius around the tower. 0:17:55.680 --> 0:17:58.840 Oh and we still weren't calling them pagers, even though 0:17:58.880 --> 0:18:01.840 they worked on what was referred to as a paging service. 0:18:01.920 --> 0:18:04.080 So they called the service a paging one. But the 0:18:04.200 --> 0:18:07.560 devices we're still just kind of radios. They weren't called pagers. 0:18:07.960 --> 0:18:11.560 It wasn't until a decade after Gross's attempts, so we're 0:18:11.560 --> 0:18:15.080 talking nineteen fifty nine, that we finally get the word pager. 0:18:15.960 --> 0:18:19.399 That word was coined by a little company called Motorola. 0:18:19.680 --> 0:18:23.560 The original Motorola pager was a personal radio communications device. 0:18:23.640 --> 0:18:27.440 It could transmit radio messages to pager owners. This one 0:18:27.480 --> 0:18:30.600 got a bit more traction than Gross's approach. Also, by 0:18:30.600 --> 0:18:33.720 this time, some of the patents Gross had filed were expiring. 0:18:34.040 --> 0:18:38.080 Now that's what happens with patents. When you file a patent, 0:18:38.200 --> 0:18:41.440 you have exclusive rights to that particular implementation of ideas 0:18:41.480 --> 0:18:45.199 for the duration of the patent. In return, you submit 0:18:45.240 --> 0:18:49.520 documentation describing those ideas, and that documentation is publicly available 0:18:49.520 --> 0:18:51.760 through the patent office. So if anyone wants to use 0:18:51.800 --> 0:18:54.680 your implementation, they can see how you did it, more 0:18:54.760 --> 0:18:57.320 or less, but they're supposed to come to you and 0:18:57.359 --> 0:19:01.239 negotiate a license or otherwise purchased the Latin or they 0:19:01.240 --> 0:19:03.520 can just bide their time and wait until the patent 0:19:03.520 --> 0:19:07.280 has expired, and then they can use that same implementation, 0:19:07.720 --> 0:19:10.040 because at that point it's a fair game, which is 0:19:10.080 --> 0:19:12.399 more or less what Motorola was able to do, and 0:19:12.440 --> 0:19:15.879 it wasn't necessarily malicious. Gross's ideas were great, but the 0:19:15.880 --> 0:19:18.520 world just wasn't really ready for it yet, and the 0:19:18.520 --> 0:19:21.040 technology Gross used was a bit bulkier than the tech 0:19:21.080 --> 0:19:25.120 available a decade later. Motorola's approach, well very similar to Grosses, 0:19:25.200 --> 0:19:29.520 was more practical by ninety nine. Even so, the pagers 0:19:29.560 --> 0:19:32.360 Motorola offered weren't exactly like the ones we'd see later on, 0:19:32.600 --> 0:19:36.360 it did evolve over time. In nineteen sixty an inventor 0:19:36.480 --> 0:19:40.200 named John Francis Mitchell developed the first pager of this style, 0:19:40.240 --> 0:19:44.800 to use transistors. See earlier pages were actually using vacuum tubes, 0:19:44.840 --> 0:19:47.919 which made the pages larger, heavier, and it meant they 0:19:47.920 --> 0:19:49.879 could heat up if they were used a lot, although 0:19:50.000 --> 0:19:53.160 the nature of pages meant that that rarely ever happened. 0:19:53.840 --> 0:19:57.119 Mitchell was able to make a pager using transistors instead 0:19:57.160 --> 0:19:59.679 of vacuum tubes, and he was a chief engineer a 0:19:59.720 --> 0:20:02.080 motor Ela and would eventually rise to the rank of 0:20:02.160 --> 0:20:05.639 president and CEO of the company. He'd also play an 0:20:05.680 --> 0:20:09.080 instrumental part in developing the technology that made cell phones possible. 0:20:09.800 --> 0:20:13.400 Bell System the Telephone company offered a paging service as 0:20:13.400 --> 0:20:16.520 early as nineteen sixty two using a gadget they called 0:20:16.800 --> 0:20:21.040 the bell Boy, which is just so adorable. It contained 0:20:21.040 --> 0:20:24.960 three receivers. Each receiver was tuned to a different frequency, 0:20:25.320 --> 0:20:28.520 so the pager would only activate if all three receivers 0:20:28.560 --> 0:20:31.359 picked up a signal simultaneously. You had to send three 0:20:31.400 --> 0:20:34.920 signals of those three frequencies for the pager to react. 0:20:35.480 --> 0:20:37.439 This would also cause the Bellboy to make a noise, 0:20:37.640 --> 0:20:40.320 which would alert the owner to a call that they 0:20:40.320 --> 0:20:42.600 needed to call into a central messaging service in order 0:20:42.600 --> 0:20:45.360 to get their relevant message. So again, I didn't tell 0:20:45.359 --> 0:20:47.720 you what the message was, but rather that you had 0:20:47.760 --> 0:20:49.840 received a message and you needed to call into your 0:20:49.840 --> 0:20:53.439 answering service to find out what that was. In nineteen 0:20:53.520 --> 0:20:57.879 sixty four, Motorola introduced the page boy. Now, originally this 0:20:58.000 --> 0:21:00.720 was a tone pager, which meant it would only send 0:21:00.720 --> 0:21:03.359 a tone to the targeted device, and the tone would 0:21:03.359 --> 0:21:06.560 indicate whatever your specific course of action should be, such 0:21:06.600 --> 0:21:09.560 as call the home office or get your took us 0:21:09.560 --> 0:21:12.600 to the emergency room as soon as possible. Within a 0:21:12.600 --> 0:21:16.920 couple of years, Motorola began offering tone and voice page boys, 0:21:16.920 --> 0:21:20.400 which could play either a tone or an actual voice message. Now, 0:21:20.400 --> 0:21:23.480 clearly voice messages can relay more information than just when 0:21:23.480 --> 0:21:26.600 you hear this noise, do this thing. But in any case, 0:21:26.640 --> 0:21:30.040 these technologies all involved broadcasting a message out into the environment. 0:21:30.200 --> 0:21:33.600 And when the Motoroles moved to make Pages a consumer product, 0:21:34.119 --> 0:21:38.359 the man explained to customers, Okay, this product works, but 0:21:38.480 --> 0:21:41.000 only if you live with an X number of miles 0:21:41.040 --> 0:21:44.960 of this broadcast tower, because the alternative meant broadcasting the 0:21:44.960 --> 0:21:48.320 same message across numerous towers, because you never know where 0:21:48.320 --> 0:21:51.680 you're intended recipient might be. The pages in those days 0:21:51.720 --> 0:21:54.520 were all one way receivers, so again they gave no 0:21:54.600 --> 0:21:58.800 information back to their system. There was no nationwide paging 0:21:58.840 --> 0:22:02.120 system set up yet, so they're all local area, one 0:22:02.160 --> 0:22:06.080 way communication devices. Now, this makes it a great time 0:22:06.119 --> 0:22:09.040 to address a cliche about pagers that was prevalent in 0:22:09.080 --> 0:22:12.080 the eighties and nineties and up to today really, and 0:22:12.119 --> 0:22:14.399 that was that the only people who carried pages around 0:22:14.400 --> 0:22:18.439 were doctors and drug dealers. Why drug dealers because they 0:22:18.440 --> 0:22:20.840 could get a message from someone who wanted to buy drugs, 0:22:20.920 --> 0:22:23.760 but the drug dealer would never be tracked because pages 0:22:23.800 --> 0:22:26.760 are just dumb receivers. They couldn't reveal information about the 0:22:26.800 --> 0:22:30.080 drug dealers whereabouts. I gave the dealer the ability to 0:22:30.119 --> 0:22:33.040 receive messages, decide which ones to respond to, and keep 0:22:33.080 --> 0:22:37.680 everything below the radar. But these messages also for the 0:22:37.720 --> 0:22:42.080 most part, were unencrypted, which meant was possible to intercept 0:22:42.160 --> 0:22:46.280 these messages and hear them unencrypted and understand exactly what 0:22:46.400 --> 0:22:48.399 was being sent to them. So you also had to 0:22:48.440 --> 0:22:51.679 be sneaky about you know what the messages content actually was. 0:22:52.640 --> 0:22:55.359 Now I also need to point out that eventually there 0:22:55.400 --> 0:22:58.240 would be two way pagers on the market, and those 0:22:58.240 --> 0:23:01.440