Shortwave

shortwave

Catching signals from others is how we started communicating as human beings. It all started, of course, with our vocal cords. Then we moved to smoke signals for long-distance communication. At some point, we discovered radio waves and are still using them for contact. This article will describe how you can tune in using and an SDR dongle. Fedora Linux My journey I got interested in radio communication as a hobby when I was a kid, while my local club, LZ2KRS, was still a thing. I was so excited to be able to listen and communicate with people worldwide. It opened a whole new world for me. I was living in a communist country back then and this was a way to escape just for a bit. It also taught me about ethics and technology. Year after year my hobby grew and now, in the Internet era with all the cool devices you can use, it’s getting even more exciting. So I want to show you how to do it with Fedora Linux and a hardware dongle. What is Ham Radio Amateur Radio (ham radio) is a popular hobby and service that brings people, electronics, and communication together. People use ham radio to talk across town, worldwide, or even into space, without the Internet or cell phones. What’s SWLing? To broadcast with your ham radio or SDR system, you need to obtain a license from a governmental body. But to intercept signals and listen to the open communication between two amateur radio stations, you don’t need one. The term SWLing comes from the abbreviation of Short Wave Listener, where you listen to stations communicating in the shortwave bands between 3 and 30 MHz. This can be used for long-distance communication using the , a layer of the Earth’s atmosphere. ionosphere To get started, you don’t need a license. Still, I recommend getting yourself an SWL sign to identify yourself in a listening contest. These are competitions for categories like who will discover the most connections in a month or who can listen to contacts from each country in the world. How to get an SWL Sign? There are two options: Contact your national radio club and ask them to issue one for you. I got my Czech one, OK1-36568, after a few weeks. Join the community and request a sign there. Short Wave Amateur Radio Listening You will get more information and help from either of these locations if you get stuck in some fashion! QSL Cards You can also use your sign to send QSL cards via post or electronically. This is a great way to communicate with people worldwide and make friends. Per Wikipedia, A QSL card is a written confirmation of either a two-way radio communication between two amateur radio or citizens band stations; a one-way reception of a signal from an AM radio, FM radio, television, or shortwave broadcasting station; or the reception of a two-way radio communication by a third party listener (in our case). A typical QSL card is the same size and made from the same material as a regular postcard; most are sent through snail mail. Replace the radio receiver with your Fedora Linux The focal point of the ham radio hobby is the radio transmitter/receiver. Most of the time, enthusiasts build their radio from scratch, but this differs from what I will write about here. SDR A software-defined radio (SDR) system is a radio communication system that uses software for the modulation and demodulation of radio signals. In other words, a piece of hardware and software replaces a radio transmitter/receiver. This helps you discover more in a way you are familiar with – a User Interface with built-in functions instead of the limited interface of a radio receiver. My explanation oversimplifies things, so if you want to go deep and read more about SDR, here is an excellent start. SDR Set Up under Fedora Linux Choosing the proper hardware If you search the Internet for an SDR dongle, you’ll find many ideas depending on your budget. In this tutorial, I’ll work with the one I have, which works well under Fedora 37. A note: The dongle covers frequencies from 25MHz to 1750MHz, which doesn’t cover the Short Wave bands. You would need an additional device to listen to them. This is included in the package I linked above. Some other hardware providers offer all-in-one products. Check if the dongle is visible Before installing anything, detect whether Fedora Linux recognizes your USB dongle. I hope you didn’t buy a fake one :-). Use the following command to list the USB devices on your system. lsusb One of the output lines (in the case of Nooelec) should be Realtek Semiconductor Corp. RTL2838 DVB-T Now proceed by installing the software you need Fedora offers a set of tools and drivers packaged as a group. Even though you would not use all the components in this package from the beginning, I recommend installing it. You’ll have more software to play with. sudo dnf group install 'Electronic Lab' I advise you to explore what’s in the group by running this command: sudo dnf group info 'Electronic Lab' Now check if you have everything set up correctly by running: rtl_test You should see something like this: Do not forget to kill this process because the device will be busy and cannot be used in the next step. A simple Ctrl + c works. Gqrx You have the dongle already in your device’s USB port and all the software you need to get started. Now it’s time to intercept your first signal. Start the program called . Don’t be alarmed by the strange interface. You’ll get used to it. Gqrx Configure the I/O Device Screen From the “Device” Dropdown, select the ‘ .’ RealtekRTL2838.. Leave the rest untouched for the moment. If you don’t see your device there, click the “ ” button at the bottom of the screen. Device Scan When your device is selected, click “OK,” and the dialogue will close. Configure the frequency screen Before you start intercepting signals, ensure there is something out there that proves everything works correctly. Since the dongle covers the FM radio band as well, do this: Locate your favorite radio station’s frequency. Mine is 105MHZ Set it in the Frequency field Select WFM (stereo) in the “Mode” dropdown. If you don’t do this, you will hear a sound. not Play And now, you need to start the reception by clicking the “play button” in your main menu. You will see the frequency visualized like this: If you hear a sound, everything will move to the next step. Check if everything is set up correctly if you don't hear anything. You may ask a question in the comments for this article; I can direct you to the proper forum to solve this. Feel free to play with some more FM broadcasts. You have the antenna for it in your pack. Let’s go Short Wave In the case of the Nooelec, you need to add one more device to the USB dongle and turn it on. Instructions on how to do that are included in the package you receive. In short, you plug the “Up Converter” into your USB dongle and make sure the switch is in the “convert” position. Some videos are available on how to do it if you get stuck. You will need an antenna and a good location Now things get trickier. If you live in an area where you don’t see an open space out your window or other buildings surrounding your building, you might have trouble catching a Short Wave radio amateur signal. Let’s try this to see if it works Try to be in the open. I usually listen from my terrace, which could be better but works under particular conditions. You would need a long wire to act as your antenna apart from the hardware. Try the antenna with the hardware initially – the telescoping one from , but it will catch only powerful signals. Nooelec Let’s go back to Gqrx Now with the converter, you need to make some changes to your device screen: Please note the – for the . This is required for the Up Converter to work. 125Mhz LNB LO field Tune your frequency to 14.100 Mhz and make sure your Mode is (standing for ) because this is this band’s main demodulation option. USB Upper sideband Then go to your screen, use the zoom slider, and set it to see about . In our case, you should have between 14.05 to 14.15 Mhz on your screen. FFT Settings 100 kHz Also, click the “ ” to see the information about the SW bands you are exploring. Enable Band Plan Then hit the play button and explore the space between 14.0 and 14.3 Mhz to get any amateur radio transmission. When intercepting a transmission, adjust your settings to improve your listening experience. It’s a journey that you have already started. Most probably, you will hear something like this: “CQ CQ CQ this is ..(followed by the radio license number spelled with the ). ham radio phonetic alphabet Listen very carefully, and by the call sign, you can determine the location of the radio amateurs’ country. You can visit the to learn more about them and even send them a QSL card confirming their connection. QRZCQ website . Keep the momentum going Now you have some tools and ideas for starting Short Wave Listening. This is the first step of an incredible and exciting journey you can have together with your Fedora Linux OS. You will discover the pleasure of , reading more about , how to be a part of a listening competition, and what mean. building your antenna for the specific band how the ionosphere helps those Q-codes This article was initially published in Fedora Magazine

Mastering Shortwave Listening (SWL) with Fedora Linux and Software Defined Radio

The Radio Amateur's Hand Book, by A. Frederick Collins is part of . You can jump to any chapter in this book here: . Chapter XI: Short wave Regenerative Receiving Sets HackerNoon’s Book Blog Post series [LINK TO TABLE OF LINK] XI. SHORT WAVE REGENERATIVE RECEIVING SETS A short wave receiving set is one that will receive a range of wave lengths of from 150 to 600 meters while the distance over which the waves can be received as well as the intensity of the sounds reproduced by the headphones depends on: (1) whether it is a regenerative set and (2) whether it is provided with amplifying tubes. High-grade regenerative sets designed especially for receiving amateur sending stations that must use a short wave length are built on the regenerative principle just like those described in the last chapter and further amplification can be had by the use of amplifier tubes as explained in , but the new feature of these sets is the use of the variocoupler and one or more variometers. These tuning devices can be connected up in different ways and are very popular with amateurs at the present time. Chapter IX Differing from the ordinary loose coupler the variometer has no movable contacts while the variometer is provided with taps so that you can connect it up for the wave length you want to receive. All you have to do is to tune the oscillation circuits to each other is to turn the rotor, which is the secondary coil, around in the stator, as the primary coil is called in order to get a very fine variation of the wave length. It is this construction that makes sharp tuning with these sets possible, by which is meant that all wave lengths are tuned out except the one which the receiving set is tuned for. A Short Wave Regenerative Receiver--With One Variometer and Three Variable Condensers.--This set also includes a variocoupler and a grid coil. The way that the parts are connected together makes it a simple and at the same time a very efficient regenerative receiver for short waves. While this set can be used without shielding the parts from each other the best results are had when shields are used. The parts you need for this set include: (1) one variocoupler; (2) one .001 microfarad variable condenser; (3) one .0005 microfarad variable condenser; (4) one .0007 microfarad variable condenser; (5) one 2 megohm grid leak; (6) one vacuum tube detector; (7) one 6 volt A battery; (8) one 6 ohm, 1-1/2 ampere rheostat; (9) one 200 ohm potentiometer; (10) one 22-1/2 volt B battery; (11) one .001 microfarad fixed condenser, (12) one pair of 2,000 ohm headphones, and (13) a variometer. The Variocoupler.--A variocoupler consists of a primary coil wound on the outside of a tube of insulating material and to certain turns of this taps are connected so that you can fix the wave length which your aerial system is to receive from the shortest wave; i.e., 150 meters on up by steps to the longest wave, i.e., 600 meters, which is the range of most amateur variocouplers that are sold in the open market. This is the part of the variocoupler that is called the stator. The secondary coil is wound on the section of a ball mounted on a shaft and this is swung in bearings on the stator so that it can turn in it. This part of the variocoupler is called the rotor and is arranged so that it can be mounted on a panel and adjusted by means of a knob or a dial. A diagram of a variocoupler is shown at A in Fig. 53, and the coupler itself at B. There are various makes and modifications of variocouplers on the market but all of them are about the same price which is $6.00 or $8.00. The Variometer.--This device is quite like the variocoupler, but with these differences: (1) the rotor turns in the stator, which is also the section of a ball, and (2) one end of the primary is connected with one end of the secondary coil. To be really efficient a variometer must have a small resistance and a large inductance as well as a small dielectric loss. To secure the first two of these factors the wire should be formed of a number of fine, pure copper wires each of which is insulated and the whole strand then covered with silk. This kind of wire is the best that has yet been devised for the purpose and is sold under the trade name of litzendraht. A new type of variometer has what is known as a basket weave, or wavy wound stator and rotor. There is no wood, insulating compound or other dielectric materials in large enough quantities to absorb the weak currents that flow between them, hence weaker sounds can be heard when this kind of a variometer is used. With it you can tune sharply to waves under 200 meters in length and up to and including wave lengths of 360 meters. When amateur stations of small power are sending on these short waves this style of variometer keeps the electric oscillations at their greatest strength and, hence, the reproduced sounds will be of maximum intensity. A wiring diagram of a variometer is shown at A in Fig. 54 and a basketball variometer is shown complete at B. Connecting Up the Parts.--To hook-up the set connect the leading-in wire to one end of the primary coil, or stator, of the variocoupler and solder a wire to one of the taps that gives the longest wave length you want to receive. Connect the other end of this wire with one post of a .001 microfarad variable condenser and connect the other post with the ground as shown in Fig. 55. Now connect one end of the secondary coil, or rotor, to one post of a .0007 mfd. variable condenser, the other post of this to one end of the grid coil and the other end of this with the remaining end of the rotor of the variocoupler. Next connect one post of the .0007 mfd. condenser with one of the terminals of the detector filament; then connect the other post of this condenser with one post of the .0005 mfd. variable condenser and the other post of this with the grid of the detector, then shunt the megohm grid leak around the latter condenser. This done connect the other terminal of the filament to one post of the rheostat, the other post of this to the - or negative electrode of the 6 volt A battery and the + or positive electrode of the latter to the other terminal of the filament. Shunt the potentiometer around the A battery and connect the sliding contact with the - or zinc pole of the B battery and the + or carbon pole with one terminal of the headphone; connect the other terminal to one of the posts of the variometer and the other post of the variometer to the plate of the detector. Finally shunt a .001 mfd. fixed condenser around the headphones. If you want to amplify the current with a vacuum tube amplifier connect in the terminals of the amplifier circuit shown at A in Figs. 44 or 45 at the point where they are connected with the secondary coil of the loose coupled tuning coil, in those diagrams with the binding posts of Fig. 55 where the phones are usually connected in. Short Wave Regenerative Receiver. With Two Variometers and Two Variable Condensers.--This type of regenerative receptor is very popular with amateurs who are using high-grade short-wave sets. When you connect up this receptor you must keep the various parts well separated. Screw the variocoupler to the middle of the base board or panel, and secure the variometers on either side of it so that the distance between them will be 9 or 10 inches. By so placing them the coupling will be the same on both sides and besides you can shield them from each other easier. For the shield use a sheet of copper on the back of the panel and place a sheet of copper between the parts, or better, enclose the variometers and detector and amplifying tubes if you use the latter in sheet copper boxes. When you set up the variometers place them so that their stators are at right angles to each other for otherwise the magnetic lines of force set up by the coils of each one will be mutually inductive and this will make the headphones or loud speaker howl. Whatever tendency the receptor has to howl with this arrangement can be overcome by putting in a grid leak of the right resistance and adjusting the condenser. The Parts and How to Connect Them Up.--For this set you require: (1) one variocoupler; (2) two variometers; (3) one .001 microfarad variable condenser; (4) one .0005 microfarad variable condenser; (5) one 2 megohm grid leak resistance; (6) one vacuum tube detector; (7) one 6 volt A battery; (8) one 200 ohm potentiometer; (9) one 22-1/2 volt B battery; (10) one .001 microfarad fixed condenser, and (11) one pair of 2,000 ohm headphones. To wire up the set begin by connecting the leading-in wire to the fixed end of the primary coil, or stator, of the variocoupler, as shown in Fig. 56, and connect one post of the .001 mfd. variable condenser to the stator by soldering a short length of wire to the tap of the latter that gives the longest wave you want to receive. Now connect one end of the secondary coil, or rotor, of the variocoupler with one post of the .0005 mfd. variable condenser and the other part to the grid of the detector tube. Connect the other end of the rotor of the variocoupler to one of the posts of the first variometer and the other post of this to one of the terminals of the detector filament. Connect this filament terminal with the - or negative electrode of the A battery and the + or positive electrode of this with one post of the rheostat and lead a wire from the other post to the free terminal of the filament. This done shunt the potential around the A battery and connect the sliding contact to the - or zinc pole of the B battery and the + or carbon pole of this to one terminal of the headphones, while the other terminal of this leads to one of the posts of the second variometer, the other post of which is connected to the plate of the detector tube. If you want to add an amplifier tube then connect it to the posts instead of the headphones as described in the foregoing set. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Collins, A. Frederick. 2002. The Radio Amateur's Hand Book. Urbana, Illinois: Project Gutenberg. Retrieved April 2022, from https://www.gutenberg.org/files/6934/6934-h/6934-h.htm#chap11 This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever.  You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

What’s Up with Short Wave Regenerative Receiving Sets?

For more than 45 years the Shortwave radio spectrum has been used by the worlds intelligence agencies to transmit secret messages. These messages are transmitted by hundreds of “Numbers Stations”. Shortwave Numbers Stations are a perfect method of anonymous, one way communication. Spies located anywhere in the world can be communicated to by their masters via small, locally available, and unmodified Shortwave receivers. The encryption system used by Numbers Stations, known as a “one time pad” is unbreakable. Combine this with the fact that it is almost impossible to track down the message recipients once they are inserted into the enemy country, it becomes clear just how powerful the Numbers Station system is. These stations use very rigid schedules, and transmit in many different languages, employing male and female voices repeating strings of numbers or phonetic letters day and night, all year round. The voices are of varying pitches and intonation; there is even a German station that transmitted a female child’s voice! ‘The Swedish Rhapsody’ One might think that these espionage activities should have wound down considerably since the official “end of the Cold War”, but nothing could be further from the truth. Numbers Stations, and by inference, spies, are as busy as ever, with many new and bizarre stations appearing since the fall of the Berlin wall. Why is it that in over 45 years, the phenomenon of Numbers Stations has gone almost totally unreported? What are the agencies behind the Numbers Stations, and why are the eastern European stations still on the air? Why did the Czech republic operate a Numbers Station 24 hours a day? How is it that Numbers Stations are allowed to interfere with essential radio services like air traffic control and shipping without having to answer to anybody? Why did the “Swedish Rhapsody” Numbers Station use a small girls voice? These are just some of the questions that remain unanswered. Detail of a voice generator from the cover of the 5th disc of The Conet Project: Recordings of Shortwave Numbers Stations TCP/1111 Now Irdial-Discs is releasing , a special edition of the legendary and first ever comprehensive collection of Numbers Stations recordings to be made public, now augmented and updated with The Conet Project: Recordings of Shortwave Numbers Stations / 1111 a new 5th CDs worth of previously unreleased recordings, all 176 Songs, 5 Hours, 51 Minutes, available for the first time on iTunes . is an important historical reference work for research into this hitherto unreported and unknown field of espionage. Many of the stations on the CD have ceased operations, and can no longer be heard. The latest package consists of the 4 original Conet Project CDs containing 150 recordings of Numbers Stations spanning the twenty years up to the release of the original set in 1997, an 80 page, perfect bound booklet, 4 post cards, plus a new of , and a new 8 page booklet accompanying the 5th CD. The Conet Project 5th CD 26 previously unreleased recordings of bizarre ‘Noise Stations’ An Anecdote… In 1997, the time of the first pressing of , we really had no idea about how it would be received or how best to get it into the public view. We took every opportunity to try and expose it to the public, including the contact below. The Conet Project: Recordings of Shortwave Numbers Stations Around the corner from THESE Records (who were distributing The Conet Project) in Lambeth Road London, is the , who were running an exhibition entitled which is Imperial War Museum The Secret War “the UK’s only permanent exhibition devoted to UK espionage”. Naturally, we imagined that the Imperial War Museum might like to stock some ‘SOR’ copies of , as it dovetails nicely into the exhibition. All we would have to do is , and they should be sold on the idea. The Conet Project show it to them ‘SOR’ means ‘Sale Or Return’ — this is how it works. We deliver a box of seven or fourteen copies of TCP, they put them on display in their shop. If they sell, they pay us, if they do not sell, they return the copies to us at our expense. There is no money up front, no security deposit, no account needed; we trust them to pay us, and there is no risk to them . whatsoever We delivered a sample copy to them with a letter about TCP. You can imagine how we laughed when we received this reply from The Imperial War Museum Shop: Now, the paranoid would say that someone made a phone call and nixed The Conet Project being stocked. The cynical would say, “they just didn’t get it”, and others will say, “It is just as stated”. Either way, it struck us as that something as germane to a comprehensive espionage exhibition as TCP is, an exhibition featuring amongst other things, , short wave radios, spy equipment of all sorts etc. would be dismissed in this very odd way. rather bizarre ENIGMA machines One listen to should have been enough to convince them to stock it. The idea of The Conet Project seems very dry on the surface, but the fact of it is very different. Once you listen to it, it is instantly clear that The Conet Project is the polar opposite of a remote and inaccessible, ‘specialised’ release. The Conet Project Which of the above three reasons do think stopped them from stocking TCP? you Your guess is as good as ours. 000–000

The Conet Project: Recordings of Shortwave Numbers Stations

United States v. Apple INC Court Filing, retrieved on March 21, 2024 is part of . You can jump to any part in this filing . This part is 14 of 25. HackerNoon’s Legal PDF Series here B. Smartphone Hardware 151. A smartphone’s hardware includes the frame and screen. Higher performing smartphones are typically constructed from better materials like glass and metal instead of plastic, manufactured to higher standards that make them more durable (e.g., water and dust proof), and have higher quality displays. 152. A smartphone’s hardware also includes the semiconductor chipsets that run the smartphone: central processing of software instructions, graphics, video, display, memory, data storage, and connection to wireless networks. Chipsets that offer superior performance—faster processing and network connections, better graphics, more storage—are costly. As a result, smartphone manufacturers typically include them only in more expensive performance smartphones. 153. Smartphone hardware includes other important components like cameras, and position and motion sensors. Performance smartphones typically have higher quality cameras, better battery life, wireless charging, and advanced biometrics such as face scanning. 154. Smartphones also contain several types of antennas that allow the phone to communicate with other smartphones, accessories, or other devices using standard communication protocols such as Wi-Fi, Bluetooth, and Near-Field Communications (NFC). a. Wi-Fi is a wireless networking technology that uses radio waves to provide wireless high-speed Internet access through mobile devices, computers, printers, and other equipment. “Wi-Fi,” in particular, refers to IEEE 802.11 standards that define the protocols that enable communications with current Wi-Fi-enabled wireless devices such as wireless routers and access points. b. Bluetooth is a wireless standard that allows smartphones to use shortwave radios to communicate with accessories like headphones and smartwatches. An industrywide Bluetooth standard specifies technological requirements to ensure that all Bluetooth devices can recognize and interact with each other. A typical Bluetooth signal has a range of about 30 feet. c. Near Field Communication (NFC) allows smartphones to interact with NFCenabled devices like a credit card terminal at a coffee shop. NFC relies on shortrange wireless technologies, including radio signals, to communicate and share information. To operate, two NFC-enabled devices must typically be within four centimeters or less of one another. 155. Three device manufacturers, Apple, Samsung, and Google, account for approximately 94 percent of all smartphones by revenue in the United States. Apple and Samsung alone account for approximately 90 percent of all smartphone revenues in the United States. 156. Cloud-based technologies are run using hardware and software in remote computing centers (“the cloud”) rather than by hardware and software on a smartphone. The user experiences the technology on the phone but the complex computing that generates the rich experience and that executes the user’s commands happens in the cloud. Thus, cloud apps can deliver rich experiences on smartphones with less capable hardware than iPhones currently contain. Continue Reading . Here About HackerNoon Legal PDF Series: We bring you the most important technical and insightful public domain court case filings. This court case retrieved on March 21, 2024, from is part of the public domain. The court-created documents are works of the federal government, and under copyright law, are automatically placed in the public domain and may be shared without legal restriction. justice.gov

The Guarded Dominance of Apple, Samsung, and Google in the Smartphone Market

Authors: (1) Maggie D. Bailey, Colorado School of Mines and National Renewable Energy Lab; (2) Douglas Nychka, Colorado School of Mines; (3) Manajit Sengupta, National Renewable Energy Lab; (4) Aron Habte, National Renewable Energy Lab; (5) Yu Xie, National Renewable Energy Lab; (6) Soutir Bandyopadhyay, Colorado School of Mines. Table of Links Abstract and Intro Data Bayesian Hierarchical Model (BHM) Solar Radiation Example Results Conclusion Appendix A: Simulation Study Appendix B: Regridding Coefficient Estimates References 2 Data 2.1 National Solar Radiation Database 2.2 Climate Model Database Climate model data is sourced from the North American CORDEX (NA-CORDEX) data archive, containing RCM output forced by various global climate models (GCMs) (McGinnis and Mearns (2021)). The NA-CORDEX data archive contains many common climate variables, including surface downwelling shortwave radiation, at daily scales and sub-daily for some variables. Note that surface downwelling shortwave radiation is recorded as rsds in NA-CORDEX but is equivalent to GHI and measured in the same units. Therefore, it will be referred to as “GHI” throughout this article. The archive includes ERA-Interim driven runs generally covering 1979-2014. GCM driven runs cover both historical periods (1949-2005) and future years (2006- 2100) for various climate path scenarios and a model domain covering all of the conterminous United States as well as most of Alaska, Canada, Mexico, and the Caribbean. The data chosen for this study will later be used in statistical downscaling operations for solar radiation for future years and RCMs for this study are chosen with this long-term goal in mind. The output chosen for this study are three ERA-Interim driven RCMs: Weather Research & Forecasting Model (WRF), Canadian Regional Climate Model 4 (CanRCM4), and the fifth generation Canadian Regional Climate Model from the University of Quebec at Montreal (CRCM5-UQAM). These RCMs have desirable representative concentration pathways (RCPs) and grid resolution for future GCM driven runs. This paper is under CC 4.0 license. available on arxiv

Exploring Data Sources for Solar Radiation Studies

The old-school phone whistling is back! Well, almost, but this audio below isn’t that far off. https://securityinnovation.hubs.vidyard.com/watch/5b3Yk8ga9noiqKJ2rTNnSS?embedable=true On July 13th, we discovered an interesting vulnerability. A particular webpage was tracking digital radio chatter and it would display a running log of what its station was hearing. This is a handy tool if you’re into this sort of thing; after all, it’s great to know if your calls are being heard or if there are ongoing conversations that you might want to join. This tool captured whatever it was hearing and inserted it into the webpage. Send a message and a few seconds later it would show up there. If the message included HTML, well that would end up on the webpage too. Classic HTML Injection. To deliver an attack like this, you don’t really need the internet at all -you just need a long piece of wire. In our Attacks Over the Air series, in February 2023, we discussed the wireless issues presented by a basketball scoreboard with a controller that operates at 913 MHz. In this post, we’ll move way, way down in frequency, down into the shortwave radio band. This attack works at 7.078 and 14.078 MHz. So how does this work? published There are many interesting digital signals down here, and JS8 is one of them. JS8 is a popular keyboard-to-keyboard chatting tool for amateur radio. It absolutely excels at enabling direct conversations over long distances and through very poor link conditions. JS8 is itself based on FT8, an extremely popular tool for making simple contacts between stations that can hear each other. Night and day, FT8 and JS8 are continually in use. barely Several weird things happen to signals down in the shortwave band. It’s such a low frequency that at 100 miles above us, the E and F layers of Earth’s ionosphere begin to reflect the radio signal back down to the ground again. The signals bounce between the Earth and the ground several times, like skipping a stone off water. It allows us to hear commercial AM stations on the other side of the planet at night. During the day, this bounce works at higher frequencies too, enabling communication over vast distances. My backyard transmitter and the website’s station are 674 miles apart. One bounce covers that distance easily. JS8 messages are constructed in ASCII text, all uppercase characters. Most messages are sent to wide groups, such as Skywarn, JS8Chess, or, to reference everyone, simply ALLCALL. Following this, the message can be just about anything. First we build out HTML payload in the editor. We must legally provide our amateur radio callsign for identification (a step that will be ignored by a real attacker) and in the end our final message looks like this: So how do you attack a website with a shortwave signal? We are now ready to transmit. The JS8 software converts this text to binary, adds forward error correction, and modulates the result using Gaussian Frequency Shift Keying, (GFSK). The final product audibly sounds like strange whistling noises. If we open the sound using Audacity, and open a spectrogram, it looks like this: KJ7YLS: @TEST  <DIV STYLE="WIDTH: 500PX;HEIGHT:100PX;COLOR:RED;">HTML INJECTION!</DIV> Taking a closer look, you can see the GFSK modulation slowly transitioning from one frequency to another. It also holds at each frequency for a specific length of time. There are eight different frequencies in use here and thus each symbol has eight distinct states. As a result, each symbol can carry three bits at a time. This is illustrated with some labels: We can then send the whistling noise into the microphone of a radio transmitter. Like most amateur and military signals, the audio is delivered using upper-sideband modulation, which is a section of an AM broadcast type of signal. JS8 messages are standardized at several frequencies, and our target listens at 7.078 MHz and 14.078 MHz. We tune the radio to either frequency and send the audio using 20 watts of power into a 16-AWG wire about 30 feet in the air. The signal radiates out into the air, bounces off the ionosphere, and their antenna receives it. Their JS8 software reverses the process and pulls out the ASCII message. It’s at this point that we see the problem. The website (link withheld in this article out of respect to its author) logs JS8 traffic. Under the hood, it’s powered by , a useful Python tool that talks directly to the API of the JS8 software. In the repository, the script grabs the JS8 messages and places them on the website. At time of writing, it contains the following lines of code at line 859: JS8Net monitor.py # Text
j['text']=j['stuff']['params']['TEXT']
key=str(j['stuff']['time'])
j['id']=':'.join([fmcall,tocall,key,str(j['freq'])])
traffic[key]=json.dumps(j) is the ASCII JS8 message pulled from , which pulls from the API of the JS8 software. After this step, the text in is placed onto the page using Javascript. These steps are fine. The issue occurs in the change in context because there is an assumption that the JS8 traffic, already fully processed by the JS8 software, is ready to go and will not affect the context of the webpage. This is the behavior that we can then exploit. j['stuff']['params']['TEXT'] collector.py traffic[key] From start to finish, our attack looks like this: https://securityinnovation.hubs.vidyard.com/watch/dEaxwfcKAopxUVnVeMQtbf?embedable=true A few minutes later, our message is logged on the website... The end result is mostly cosmetic. This is a public page, so there’s no session cookies to steal or controls to spoof. Stored XSS is a real possibility too, but after a frustrating morning sending many, many time-consuming payloads (each JS8 message takes several minutes to send) we couldn’t get working Javascript that would execute on the page. I suspect that the JS8net software accidentally blocked many of the key characters and words and our workarounds didn’t seem to fire. Nevertheless, Burp Suite came in handy here. The ionosphere was cooperative that particular day and bouncing signals pretty well. I knew from other tools that stations in other countries were hearing JS8 traffic from the U.S.. So my next payload was This URL points to a DNS and HTTP listener run by Burp Suite’s Collaborator tool, which we often use during penetration tests for finding out-of-band information leaks. This was no different. Within a few minutes, DNS and HTTP traffic was recorded by the Collaborator Server from users visiting the page in Chile. I also viewed the page to inspect the injection and was logged as well. KJ7YLS: @ALLCALL <img src="http://727k2w1hfoamqewpm7rpiocu0l6cu2ir.oastify.com" alt="@HB DN13"> This was about as far as I wanted to ethically go with the injection. I reported the issue to the website’s owner, Jeff, with suggestions on remediation. He got back to me the next day, saying: While I waited for the patch to go live, I reflected on a few lines from the JS8Net README: I work in security myself (I do R&D for a network security company in the Bay Area), but I'll have to admit that submitting JS via radio to hack a web site was totally off my radar. It's important to note that this part of the software is still very much in the development stage, and may have critical vulnerabilities that make exposing the exposed services to the open Internet a Very Bad Idea. While it certainly will work, it's intended for protected, internal LAN use at this time. Honestly this is an excellent warning in general, especially for projects that are in progress and have not been thoroughly tested. Vulnerabilities at this point are an “unknown unknown” but the author was primarily thinking about the exposed listeners and APIs in his software. However, we exploited a slightly different type of problem. The README warns that the service should be run inside a LAN and this would indeed protect others from HTML injections and defilement of the webpage. However, a payload with Collaborator payloads would leak the public IP address of anyone viewing the page within their private LAN as well, so that’s a little harder to address. In short, this is a radio signal attacking a webpage on the Internet. An attacker doesn’t need to fool around with VPNs, Tor, or botnets to try to hide their identity on the Internet. JS8 is so effective at extracting messages -24dB below the noise floor (the whistling literally cannot be audibly heard at this level) that very little power is needed to reach distant stations. One watt of transmission power, on good ionospheric conditions, can go coast-to-coast across the U.S.. An attacker could be anywhere in the world. A burst message is all that is needed, so direction-finding would also be difficult. I think that’s about as close to untraceable as you can get with something like this. Timeline: July 13: discovered the issue, reported to Jeff, applied to MITRE for a CVE July 14: Jeff responds. July 22: Jeff applies a patch to JS8Net on Github. July 25: The patch goes live on the website. Aug 18: the blog post is published.

Attacks Over The Air — Phreaking HTML Injection

বাতাসে আক্রমণ - এইচটিএমএল ইনজেকশন

Angriffe über Funk – Phreaking-HTML-Injection

Ataques por aire: inyección de Phreaking HTML

Attaques en direct — Phreaking HTML Injection

हवा से हमले - भयभीत करने वाला HTML इंजेक्शन

無線攻撃 - 異常な HTML インジェクション

공중파 공격 - HTML 인젝션을 위협하다

Ataques Over The Air — Phreaking HTML Injection

Havadan Saldırılar — Phreaking HTML Enjeksiyonu

Tấn công qua mạng — Phreaking HTML injection

空中攻击 — Phreaking HTML 注入

Studies in the Psychology of Sex, Volume 4 by Havelock Ellis is part of the HackerNoon Books Series. You can jump to any chapter in this book here . SMELL II SMELL II Rise of the Study of Olfaction—Cloquet—Zwaardemaker—The Theory of Smell—The Classification of Odors—The Special Characteristics of Olfactory Sensation in Man—Smell as the Sense of Imagination—Odors as Nervous Stimulants—Vasomotor and Muscular Effects—Odorous Substances as Drugs. During the eighteenth century a great impetus was given to the physiological and psychological study of the senses by the philosophical doctrines of Locke and the English school generally which then prevailed in Europe. These thinkers had emphasized the immense importance of the information derived through the senses in building up the intellect, so that the study of all the sensory channels assumed a significance which it had never possessed before. The olfactory sense fully shared in the impetus thus given to sensory investigation. At the beginning of the nineteenth century a distinguished French physician, Hippolyte Cloquet, a disciple of Cabanis, devoted himself more especially to this subject. After publishing in 1815 a preliminary work, he issued in 1821 his Osphrésiologie, ou Traité des odeurs, du sens et des organes de l'Olfaction, a complete monograph on the anatomy, physiology, psychology, and pathology of the olfactory organ and its functions, and a work that may still be consulted with profit, if indeed it can even yet be said to be at every point superseded. After Cloquet's time the study of the sense of smell seems to have fallen into some degree of discredit. For more than half a century no important progress was made in this field. Serious investigators seemed to have become shy of the primitive senses generally, and the subject of smell was mainly left to those interested in "curious" subjects. Many interesting observations were, however, incidentally made; thus Laycock, who was a pioneer in so many by-paths of psychology and anthropology, showed a special interest in the olfactory sense, and frequently touched on it in his Nervous Diseases of Women and elsewhere. The writer who more than any other has in recent years restored the study of the sense of smell from a by-path to its proper position as a highway for investigation is without doubt Professor Zwaardemaker, of Utrecht. The invention of his first olfactometer in 1888 and the appearance in 1895 of his great work Die Physiologie des Geruchs have served to give the physiology of the sense of smell an assured status and to open the way anew for much fruitful investigation, while a number of inquirers in many countries have had their attention directed to the elucidation of this sense. Notwithstanding, however, the amount of work which has been done in this field during recent years, it cannot be said that the body of assured conclusions so far reached is large. The most fundamental principles of olfactory physiology and psychology are still somewhat vague and uncertain. Although sensations of smell are numerous and varied, in this respect approaching the sensations of vision and hearing, smell still remains close to touch in the vagueness of its messages (while the most sensitive of the senses, remarks Passy, it is the least precise), the difficulty of classifying them, the impossibility of so controlling them as to found upon them any art. It seems better, therefore, not to attempt to force the present study of a special aspect of olfaction into any general scheme which may possibly not be really valid. The earliest and most general tendency in regard to the theory of smell was to regard it as a kind of chemical sense directly stimulated by minute particles of solid substance. A vibratory theory of smell, however, making it somewhat analogous to hearing, easily presents itself. When I first began the study of physiology in 1881, a speculation of this kind presented itself to my mind. Long before Philipp von Walther, a professor at Landshut, had put forward a dynamic theory of olfaction (Physiologie des Menschen, 1807-8, vol. ii, p. 278). "It is a purely dynamic operation of the odorous substance in the olfactory organ," he stated. Odor is conveyed by the air, he believed, in the same way as heat. It must be added that his reasons for this theory will not always bear examination. More recently a similar theory has been seriously put forward in various quarters. Sir William Ramsay tentatively suggested such a theory (Nature, vol. xxv, p. 187) in analogy with light and sound. Haycraft (Proceedings of the Royal Society of Edinburgh, 1883-87, and Brain, 1887-88), largely starting from Mendelieff's law of periodicity, similarly sought to bring smell into line with the higher senses, arguing that molecules with the same vibration have the same smell. Rutherford (Nature, August 11, 1892, p. 343), attaching importance to the evidence brought forward by von Brunn showing that the olfactory cells terminate in very delicate short hairs, also stated his belief that the different qualities of smell result from differences in the frequency and form of the vibrations initiated by the action of the chemical molecules on these olfactory cells, though he admitted that such a conception involved a very subtle conception of molecular vibration. Vaschide and Van Melle (Paris Academy of Sciences, December 26, 1899) have, again, argued that smell is produced by rays of short wave-lengths, analogous to light-rays, Röntgen rays, etc. Chemical action is however, a very important factor in the production of odors; this has been well shown by Ayrton (Nature, September 8, 1898). We seem to be forced in the direction of a chemico-vibratory theory, as pointed out by Southerden (Nature, March 26, 1903), the olfactory cells being directly stimulated, not by the ordinary vibrations of the molecules, but by the agitations accompanying chemical changes. The vibratory hypothesis of the action of odors has had some influence on the recent physiologists who have chiefly occupied themselves with olfaction. "It is probable," Zwaardemaker writes (L'Année Psychologique, 1898), "that aroma is a physico-chemical attribute of the molecules"; he points out that there is an intimate analogy between color and odor, and remarks that this analogy leads us to suppose in an aroma ether vibrations of which the period is determined by the structure of the molecule. Since the physiology of olfaction is yet so obscure it is not surprising that we have no thoroughly scientific classification of smells, notwithstanding various ambitious attempts to reach a classification. The classification adopted by Zwaardemaker is founded on the ancient scheme of Linnæus, and may here be reproduced:— I. Ethereal odors (chiefly esters; Rimmel's fruity series). II. Aromatic odors (terpenes, camphors, and the spicy, herbaceous, rosaceous, and almond series; the chemical types are well determined: cineol, eugenol, anethol, geraniol, benzaldehyde). III. The balsamic odors (chiefly aldehydes, Rimmel's jasmin, violet, and balsamic series, with the chemical types: terpineol, ionone, vanillin). IV. The ambrosiacal odors (ambergris and musk). V. The alliaceous odors, with the cacodylic group (asafœtida, ichthyol, etc.).VI. Empyreumatic odors. VII. Valerianaceous odors (Linnæus's Odores hircini, the capryl group, largely composed of sexual odors). VIII. Narcotic odors (Linnæus's Odores tetri). IX. Stenches. A valuable and interesting memoir, "Revue Générale sur les Sensations Olfactives," by J. Passy, the chief French authority on this subject, will be found in the second volume of L'Année Psychologique, 1895. In the fifth issue of the same year-book (for 1898) Zwaardemaker presents a full summary of his work and views, "Les Sensations Olfactives, leurs Combinaisons et leurs Compensations." A convenient, but less authoritative, summary of the facts of normal and pathological olfaction will be found in a little volume of the "Actualités Médicales" series by Dr. Collet, L'Odorat et ses Troubles, 1904. In a little book entitled Wegweiser zu einer Psychologie des Geruches (1894) Giessler has sought to outline a psychology of smell, but his sketch can only be regarded as tentative and provisional. At the outset, nevertheless, it seems desirable that we should at least have some conception of the special characteristics which mark the great and varied mass of sensations reaching the brain through the channel of the olfactory organ. The main special character of olfactory images seems to be conditioned by the fact that they are intermediate in character between those of touch or taste and those of sight or sound, that they have much of the vagueness of the first and something of the richness and variety of the second. Æsthetically, also, they occupy an intermediate position between the higher and the lower senses. They are, at the same time, less practically useful than either the lower or the higher senses. They furnish us with a great mass of what we may call by-sensations, which are of little practical use, but inevitably become intimately mixed with the experiences of life by association and thus acquire an emotional significance which is often very considerable. Their emotional force, it may well be, is connected with the fact that their anatomical seat is the most ancient part of the brain. They lie in a remote almost disused storehouse of our minds and show the fascination or the repulsiveness of all vague and remote things. It is for this reason that they are—to an extent that is remarkable when we consider that they are much more precise than touch sensations—subject to the influence of emotional associations. The very same odor may be at one moment highly pleasant, at the next moment highly unpleasant, in accordance with the emotional attitude resulting from its associations. Visual images have no such extreme flexibility; they are too definite to be so easily influenced. Our feelings about the beauty of a flower cannot oscillate so easily or so far as may our feelings about the agreeableness of its odor. Our olfactory experiences thus institute a more or less continuous series of by-sensations accompanying us through life, of no great practical significance, but of considerable emotional significance from their variety, their intimacy, their associational facility, their remote ancestral reverberations through our brains. [26] It is the existence of these characteristics—at once so vague and so specific, so useless and so intimate—which led various writers to describe the sense of smell as, above all others, the sense of imagination. No sense has so strong a power of suggestion, the power of calling up ancient memories with a wider and deeper emotional reverberation, while at the same time no sense furnishes impressions which so easily change emotional color and tone, in harmony with the recipient's general attitude. Odors are thus specially apt both to control the emotional life and to become its slaves. With the use of incense religions have utilized the imaginative and symbolical virtues of fragrance. All the legends of the saints have insisted on the odor of sanctity that exhales from the bodies of holy persons, especially at the moment of death. Under the conditions of civilization these primitive emotional associations of odor tend to be dispersed, but, on the other hand, the imaginative side of the olfactory sense becomes accentuated, and personal idiosyncrasies of all kinds tend to manifest themselves in the sphere of smell. Rousseau (in Emile, Bk. II) regarded smell as the sense of the imagination. So, also, at an earlier period, it was termed (according to Cloquet) by Cardano. Cloquet frequently insisted on the qualities of odors which cause them to appeal to the imagination; on their irregular and inconstant character; on their power of intoxicating the mind on some occasions; on the curious individual and racial preferences in the matter of odors. He remarked on the fact that the Persians employed asafœtida as a seasoning, while valerian was accounted a perfume in antiquity. (Cloquet, Osphrésiologie, pp. 28, 45, 71, 112.) It may be added, as a curious example familiar to most people of the dependence of the emotional tone of a smell on its associations, that, while the exhalations of other people's bodies are ordinarily disagreeable to us, such is not the case with our own; this is expressed in the crude and vigorous dictum of the Elizabethan poet, Marston, "Every man's dung smell sweet i' his own nose." There are doubtless many implications, moral as well as psychological, in that statement. The modern authorities on olfaction, Passy and Zwaardemaker, both alike insist on the same characteristics of the sense of smell: its extreme acuity and yet its vagueness. "We live in a world of odor," Zwaardemaker remarks (L'Année Psychologique, 1898, p. 203), "as we live in a world of light and of sound. But smell yields us no distinct ideas grouped in regular order, still less that are fixed in the memory as a grammatical discipline. Olfactory sensations awake vague and half-understood perceptions, which are accompanied by very strong emotion. The emotion dominates us, but the sensation which was the cause of it remains unperceived." Even in the same individual there are wide variations in the sensitiveness to odors at different times, more especially as regards faint odors; Passy (L'Année Psychologique, 1895, p. 387) brings forward some observations on this point. Maudsley noted the peculiarly suggestive power of odors; "there are certain smells," he remarked, "which never fail to bring back to me instantly and visibly scenes of my boyhood"; many of us could probably say the same. Another writer (E. Dillon, "A Neglected Sense," Nineteenth Century, April, 1894) remarks that "no sense has a stronger power of suggestion." Ribot has made an interesting investigation as to the prevalence and nature of the emotional memory of odors (Psychology of the Emotions, Chapter XI). By "emotional memory" is meant the spontaneous or voluntary revivability of the image, olfactory or other. (For the general question, see an article by F. Pillon, "La Mémoire Affective, son Importance Théorique et Pratique," Revue Philosophique, February, 1901; also Paulhan, "Sur la Mémoire Affective," Revue Philosophique, December, 1902 and January, 1903.) Ribot found that 40 per cent. of persons are unable to revive any such images of taste or smell; 48 per cent, could revive some; 12 per cent, declared themselves capable of reviving all, or nearly all, at pleasure. In some persons there is no necessary accompanying revival of visual or tactile representations, but in the majority the revived odor ultimately excites a corresponding visual image. The odors most frequently recalled were pinks, musk, violets, heliotrope, carbolic acid, the smell of the country, of grass, etc. Piéron (Revue Philosophique, December, 1902) has described the special power possessed by vague odors, in his own case, of evoking ancient impressions. Dr. J. N. Mackenzie (American Journal of the Medical Sciences, January, 1886) considers that civilization exerts an influence in heightening or encouraging the influence of olfaction as it affects our emotions and judgment, and that, in the same way, as we ascend the social scale the more readily our minds are influenced and perhaps perverted by impressions received through the sense of smell. Odors are powerful stimulants to the whole nervous system, causing, like other stimulants, an increase of energy which, if excessive or prolonged, leads to nervous exhaustion. Thus, it is well recognized in medicine that the aromatics containing volatile oils (such as anise, cinnamon, cardamoms, cloves, coriander, and peppermint) are antispasmodics and anæsthetics, and that they stimulate digestion, circulation, and the nervous system, in large doses producing depression. The carefully arranged plethysmographic experiments of Shields, at the Johns Hopkins University, have shown that olfactory sensations, by their action on the vasomotor system, cause an increase of blood in the brain and sometimes in addition stimulation of the heart; musk, wintergreen, wood violet, and especially heliotrope were found to act strongly in these ways. [27] Féré's experiments with the dynamometer and the ergograph have greatly contributed to illustrate the stimulating effects of odors. Thus, he found that smelling musk suffices to double muscular effort. With a number of odorous substances he has found that muscular work is temporarily heightened; when taste stimulation was added the increase of energy, notably when using lemon was "colossal." A kind of "sensorial intoxication" could be produced by the inhalation of odors and the whole system stimulated to greater activity; the visual acuity was increased, and electric and general excitability heightened. Such effects may be obtained in perfectly healthy persons, though both Shields and Féré have found that in highly nervous persons the effects are liable to be much greater. It is doubtless on this account that it is among civilized peoples that attention is chiefly directed to perfumes, and that under the conditions of modern life the interest in olfaction and its study has been revived. [28] It is the genuinely stimulant qualities of odorous substances which led to the widespread use of the more potent among them by ancient physicians, and has led a few modern physicians to employ them still. Thus, vanilla, according to Eloy, deserves to be much more frequently used therapeutically than it is, on account of its excitomotor properties; he states that its qualities as an excitant of sexual desire have long been recognized and that Fonssagrives used to prescribe it for sexual frigidity. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Havelock Ellis (2004). Studies in the Psychology of Sex, Volume 4. Urbana, Illinois: Project Gutenberg. Retrieved October 2022 https://www.gutenberg.org/cache/epub/13613/pg13613-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org, located at https://www.gutenberg.org/policy/license.html.

Physiological and Psychological study of the senses

The Radio Amateur's Hand Book, by A. Frederick Collins is part of . You can jump to any chapter in this book here: . Chapter XII - Intermediate and Long wave Regenerative Receiving Sets HackerNoon’s Book Blog Post series [LINK TO TABLE OF LINK] XII. INTERMEDIATE AND LONG-WAVE REGENERATIVE RECEIVING SETS All receiving sets that receive over a range of wave lengths of from 150 meters to 3,000 meters are called intermediate wave sets and all sets that receive wave lengths over a range of anything more than 3,000 meters are called long wave sets. The range of intermediate wave receptors is such that they will receive amateur, broadcasting, ship and shore Navy, commercial, Arlington's time and all other stations using spark telegraph damped waves or arc or vacuum tube telephone continuous waves but not continuous wave telegraph signals, unless these have been broken up into groups at the transmitting station. To receive continuous wave telegraph signals requires receiving sets of special kind and these will be described in the next chapter. Intermediate Wave Receiving Sets.--There are two chief schemes employed to increase the range of wave lengths that a set can receive and these are by using: (1) loading coils and shunt condensers, and (2) bank-wound coils and variable condensers. If you have a short-wave set and plan to receive intermediate waves with it then loading coils and fixed condensers shunted around them affords you the way to do it, but if you prefer to buy a new receptor then the better way is to get one with bank-wound coils and variable condensers; this latter way preserves the electrical balance of the oscillation circuits better, the electrical losses are less and the tuning easier and sharper. Intermediate Wave Set With Loading Coils.--For this intermediate wave set you can use either of the short-wave sets described in the foregoing chapter. For the loading coils use honeycomb coils, or other good compact inductance coils, as shown in and having a range of whatever wave length you wish to receive. The following table shows the range of wave length of the various sized coils when used with a variable condenser having a .001 microfarad capacitance, the approximate inductance of each coil in millihenries and prices at the present writing: Chapter X TABLE OF CHARACTERISTICS OF HONEYCOMB COILS These and other kinds of compact coils can be bought at electrical supply houses that sell wireless goods. If your aerial is not very high or long you can use loading coils, but to get anything like efficient results with them you must have an aerial of large capacitance and the only way to get this is to put up a high and long one with two or more parallel wires spaced a goodly distance apart. The Parts and How to Connect Them Up.--Get (1) two honeycomb or other coils of the greatest wave length you want to receive, for in order to properly balance the aerial, or primary oscillation circuit, and the closed, or secondary oscillation circuit, you have to tune them to the same wave length; (2) two .001 mfd. variable condensers, though fixed condensers will do, and (3) two small single-throw double-pole knife switches mounted on porcelain bases. To use the loading coils all you have to do is to connect one of them in the aerial above the primary coil of the loose coupler, or variocoupler as shown in the wiring diagram in Fig. 57, then shunt one of the condensers around it and connect one of the switches around this; this switch enables you to cut in or out the loading coil at will. Likewise connect the other loading coil in one side of the closed, or secondary circuit between the variable .0007 mfd. condenser and the secondary coil of the loose coupler or variocoupler as shown in Fig. 53. The other connections are exactly the same as shown in Figs. 44 and 45. An Intermediate Wave Set With Variocoupler Inductance Coils.--By using the coil wound on the rotor of the variocoupler as the tickler the coupling between the detector tube circuits and the aerial wire system increases as the set is tuned for greater wave lengths. This scheme makes the control of the regenerative circuit far more stable than it is where an ordinary loose coupled tuning coil is used. When the variocoupler is adjusted for receiving very long waves the rotor sets at right angles to the stator and, since when it is in this position there is no mutual induction between them, the tickler coil serves as a loading coil for the detector plate oscillation circuit. Inductance coils for short wave lengths are usually wound in single layers but bank-wound coils, as they are called are necessary to get compactness where long wave lengths are to be received. By winding inductance coils with two or more layers the highest inductance values can be obtained with the least resistance. A wiring diagram of a multipoint inductance coil is shown in Fig. 58. You can buy this intermediate wave set assembled and ready to use or get the parts and connect them up yourself. The Parts and How to Connect Them Up.--For this regenerative intermediate wave set get: (1) one 12 section triple bank-wound inductance coil, (2) one variometer, and (3) all the other parts shown in the diagram Fig. 58 except the variocoupler. First connect the free end of the condenser in the aerial to one of the terminals of the stator of the variocoupler; then connect the other terminal of the stator with one of the ends of the bank-wound inductance coil and connect the movable contact of this with the ground. Next connect a wire to the aerial between the variable condenser and the stator and connect this to one post of a .0005 microfarad fixed condenser, then connect the other post of this with the grid of the detector and shunt a 2 megohm grid leak around it. Connect a wire to the ground wire between the bank-wound inductance coil and the ground proper, i.e., the radiator or water pipe, connect the other end of this to the + electrode of the A battery and connect this end also to one of the terminals of the filament. This done connect the other terminal of the filament to one post of the rheostat and the other post of this to the - or negative side of the A battery. To the + electrode of the A battery connect the - or zinc pole of the B battery and connect the + or carbon pole of the latter with one post of the fixed .001 microfarad condenser. This done connect one terminal of the tickler coil which is on the rotor of the variometer to the plate of the detector and the other terminal of the tickler to the other post of the .001 condenser and around this shunt your headphones. Or if you want to use one or more amplifying tubes connect the circuit of the first one, see Fig. 45, to the posts on either side of the fixed condenser instead of the headphones. A Long Wave Receiving Set.--The vivid imagination of Jules Verne never conceived anything so fascinating as the reception of messages without wires sent out by stations half way round the world; and in these days of high power cableless stations on the five continents you can listen-in to the messages and hear what is being sent out by the Lyons, Paris and other French stations, by Great Britain, Italy, Germany and even far off Russia and Japan. A long wave set for receiving these stations must be able to tune to wave lengths up to 20,000 meters. Differing from the way in which the regenerative action of the short wave sets described in the preceding chapter is secured and which depends on a tickler coil and the coupling action of the detector in this long wave set, [Footnote: All of the short wave and intermediate wave receivers described, are connected up according to the wiring diagram used by the A. H. Grebe Company, Richmond Hill, Long Island, N. Y.] this action is obtained by the use of a tickler coil in the plate circuit which is inductively coupled to the grid circuit and this feeds back the necessary amount of current. This is a very good way to connect up the circuits for the reason that: (1) the wiring is simplified, and (2) it gives a single variable adjustment for the entire range of wave lengths the receptor is intended to cover. The Parts and How to Connect Them Up.--The two chief features as far as the parts are concerned of this long wave length receiving set are (1) the variable condensers, and (2) the tuning inductance coils. The variable condenser used in series with the aerial wire system has 26 plates and is equal to a capacitance of .0008 mfd. which is the normal aerial capacitance. The condenser used in the secondary coil circuit has 14 plates and this is equal to a capacitance of .0004 mfd. There are a number of inductance coils and these are arranged so that they can be connected in or cut out and combinations are thus formed which give a high efficiency and yet allow them to be compactly mounted. The inductance coils of the aerial wire system and those of the secondary coil circuit are practically alike. For wave lengths up to 2,200 meters bank litz-wound coils are used and these are wound up in 2, 4 and 6 banks in order to give the proper degree of coupling and inductance values. Where wave lengths of more than 2,200 meters are to be received coto-coils are used as these are the "last word" in inductance coil design, and are especially adapted for medium as well as long wave lengths. [Footnote: Can be had of the Coto Coil Co., Providence, R. I.] These various coils are cut in and out by means of two five-point switches which are provided with auxiliary levers and contactors for dead-ending the right amount of the coils. In cutting in coils for increased wave lengths, that is from 10,000 to 20,000 meters, all of the coils of the aerial are connected in series as well as all of the coils of the secondary circuit. The connections for a long wave receptor are shown in the wiring diagram in Fig. 59. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Collins, A. Frederick. 2002. The Radio Amateur's Hand Book. Urbana, Illinois: Project Gutenberg. Retrieved April 2022, from https://www.gutenberg.org/files/6934/6934-h/6934-h.htm#chap12 This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever.  You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

Intermediate and Long wave Regenerative Receiving Sets

Into Space

En el espacio

Dans l'espace

अंतरिक्ष में

宇宙へ

No espaço

Trong không gian

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Photo by on Mike U Unsplash Introduction In general, the radio is constructed by mechanical devices, electronic devices, magnets, etc. It receives audio signals emitted by broadcasting stations through converting electric wave signals. After the invention of the , the circuit and receiving performance of the radio had undergone revolutionary progress and improvement, that is . Later, with the development of technology, radios with transistors as the core gradually became popular. It's what we know as a transistor radio. vacuum tube vacuum tube radio Radios are still widely used for many functions. Here two main radios will be described in detail below. Vacuum Tube Radio The valve radio, also known as the , was a product of the early 20th century, and immediately became the new favorite of that era with the launch of the broadcasting station. vacuum tube radio By the late 1920s, vacuum tube radio equipment replaced the primitive on most merchant ships. spark-gap systems This new equipment could send and receive signals virtually worldwide, by using high frequency or "short-wave" bands. Tube technology allowed radio signals to be tuned with much greater precision than spark-gap. The basic design for tube radio was perfected by the 1930s and continued in use on merchant vessels into the 1980s. 1.1 Classification AM (Amplitude Modulation) Radio In the era when tube radios were popular, AM radios were mainstream products. Amplitude modulation wave modulates the high-frequency carrier with audio signal. Its waveform is symmetrical, the amplitude is the same as that of the modulated signal. The audio signal is obtained after a high-frequency component is filtered out. In addition, the frequency of the carrier signal (the frequency of the broadcasting station) is the carrier frequency. AM radios can receive medium-wave and short-wave broadcasts, and some can receive long-wave broadcasts. Since the mid-band frequency interval has been unified to 9KHz, its highest audio frequency is only 4KHz. So the sound quality is affected because of large electromagnetic interference. There are two main types of AM radios: and . direct-amplifier type external (self) differential type 1.Direct-amp radio, also called high-amp radio, its typical circuit structure is as follows: (High Amplifier)—Detection—Low Amplifier—Power Amplifier A circuit that uses a grid detector circuit and high-frequency positive feedback is called a regenerative radio, which can obtain higher sensitivity and amplitude selectivity. A regenerative radio with high amplifier and short wave can receive AM telegraph signals. Most of the old Japanese-made radios have such circuits. Direct-amp radios are prone to self-excitation of high-frequency signals, high-end and low-end gains are uneven, and regenerative radios without high-amplification have poor selectivity. In addition, the reed speakers with poor sound quality are generally used, so they are gradually replaced by superheterodyne radios. Simple regenerative radios mostly use reed speakers, which have high impedance (about 10K) and high sensitivity. It can be directly used as the load of the power amplifier tube, but the frequency range is only 350~3000Hz, so the sound quality is poor. Later regenerative radios applied moving coil speakers, and the sound quality was better. However, because of low impedance, an output transformer is required, and its primary impedance must match the load impedance of the power amplifier tube. Moving coil speakers are divided into permanent magnets, constant magnets and excitation. Among them, excitation horns are used in AC electronic tube radios, and their excitation coils can also be used as filter chokes. 2.Heterodyne Radio The heterodyne radio adopts a frequency conversion circuit. The signal is generated by its high-frequency oscillation circuit and the input signal has a certain frequency difference. After the two are mixed, a fixed intermediate frequency signal (455~465KHz) is generated. Some people call the oscillation frequency higher than the signal frequency a heterodyne type, and vice versa. Heterodyne plus intermediate frequency amplifier circuit is called superheterodyne. This type of circuit requires a single electron tube to oscillate, and later a multi-pole or composite tube dedicated to frequency conversion appears. The superheterodyne type is the most common circuit of commercial radios. It has an automatic volume control circuit and can add tuning instructions. The circuit principle will be described in detail later. The superheterodyne radio can obtain more stable and higher gain due to amplifying the fixed frequency. The disadvantage is that there is image frequency interference. The circuit structure of a typical superheterodyne radio is as follows: Frequency Conversion—Middle Amplification—Detection—Low Amplification—Power Amplification 3.Autodyne Frequency Conversion Radio Using ordinary pentodes for frequency conversion is only suitable for the mid-band, and the middle frequency is 175KHz. Due to the popularization of special frequency conversion tubes, it is rarely used now. FM (Frequency Modulation) Radio FM radio is a radio that transmits radio signals through the use of FM frequency modulation carrier. Due to the shorter wavelength, the signal transmitted is much better than that of the radio that uses the AM wavelength. However, due to the short wave, the transmission distance is relatively short. FM wave uses the audio signal to modulate the frequency of high-frequency carrier. Its advantages include strong anti-interference ability, high signal-to-noise ratio, good frequency bandwidth and sound quality, in addition, the audio frequency can reach 20Hz~15000Hz. Because the FM wave works in the ultra-high frequency band, it can accommodate many radio stations. With its linear propagation characteristics, the same frequency can be reused at a distance of hundreds of kilometers, which can effectively solve the problem of congestion of medium and short wave radio stations. Modern FM broadcasting is compatible with stereo and mono channels(in the early days of stereo broadcasting, two frequencies were used and two radios for reception). Some hobbyists are likely to use a simple super-regenerative circuit to receive FM broadcasts. Because it works in a self-oscillation state, the work is unstable and has strong super-noise. 1.2 Advantages and Disadvantages of Valve Radio Advantages of Valve Radio The valve tube circuit has a simple structure and good anti-overload performance. The characteristics of the power amplifier circuit of the tube radio are better than those of the transistor or integrated circuit power amplifier. The screen current of the Class A power amplifier circuit with an output transformer for output impedance matching has little change at zero signal and full signal. So the performance is stable, the distortion of the line work area is very small, and the harmonic content is very rich. The speakers used in valve radios are generally larger in diameter than those of transistor or integrated circuit radios. The IF circuit characteristics of tube radios are better than those of transistor or integrated circuit radios. Have collection value. Disadvantages of Valve Radio As for the shortcomings, valve tubes that are large in size and used as basic components, built-in accessories are also bulky, power consumption has also increased, the overall quality has become poor, inconvenient to carry, and poor seismic performance. In addition, it is very difficult to make FM stereo radio devices, because early tube radios can only receive shortwave and medium waves. These shortcomings eventually led to the replacement of tube radios by transistor radios. 1.3 German Vintage Valve Radio Models for Sale AEG Radio Blaupunkt German EMUD Graetz Vintage Radio Grundig Vintage Radio Hornyphon Vintage Radio Vintage Koerting Radio German Metz Vintage Radio Vintage Nordmende Radio Philips Vintage Radio Vintage Saba Radio Vintage Siemens Radio Telefunken Transistor Radio 2.1 Transistor Radio Overview The transistor radio is the second generation radio after the valve radio. Compared with vacuum tubes, transistors are small in size, light in weight, resistant to vibration, long in life, and low in power consumption. These kinds of radios can be made compact and have relatively stable performance. Therefore, after the advent of transistor radios, a large number of portable radios and pocket radios have emerged. They are very convenient for daily use. The Regency TR-1 was the first commercially manufactured transistor radio by developed by Texas Instruments and IDEA Inc., introduced in 1954. Transistor radios use transistors to process and amplify signals. Simple to use, it is a small transistor-based radio receiver. 2.2 Selection Matters To choose a good transistor radio, you must first understand four basic relationships: The larger the chassis volume, the better the sound quality. The larger the horn diameter, the better the sound quality. The larger the battery volume, the longer the relative service life of the battery. The longer the magnetic bar, the higher the sensitivity. Secondly, we should also pay attention to five points when selecting: The change after the power supply voltage is reduced should be small. When selecting, you can have listening trial, because the impact on a high-quality radio should not be significant. The distortion of the offset radio should be small. After finding a radio station, having the left and right adjustments, the distortion should be small. In addition, there should be no whistling sound, otherwise, the frequency characteristics of the intermediate frequency part are poor. The volume change should be small when turning the button. Human body induction has little influence. When a person's body is close to the radio, it will have a certain impact on the work of the radio. This situation is particularly obvious for shortwave. The noise should be small. Noise generally includes electrical noise and mechanical noise. Turn the radio to a place where there is no station, and turn on the volume to the maximum. At this time, the minimum sound is better. Listen to a program to check whether there are noises caused by resonance of certain components when the volume is loud. Finally, you should also pay attention to whether the tuning knobs and buttons are coordinated and effective, and whether the shell of the radio is damaged or not. 2.3 Transistor Radio Brands for Sale Edifier GAORUI HOME TEXTILE SONY Rolton HALFSUN Panda Soaiy Nintaus 3 Radio Further Development With the advent and development of integrated circuits, transistors have been replaced by integrated circuits, that is the third-generation radios invention, sometimes also known as semiconductor radios. After the radio uses integrated circuits, not only the size can be made smaller, but also the reliability is high. As the number of integrated circuit components is getting larger and larger, radios made with it have better performance and more functions. The integration of radios has become an inevitable trend. First published here.

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