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Radio Corporation of America Radiograms

Radio Corporation of America Radiograms, June 1947 Popular Science - RF CafeLong distance radio communications made significant advances during World War II. It had to. With as widespread and intense as fighting was, war rooms needed as much and as accurate information as possible from land, sea, and air forces. Satellite systems were more than a decade away when this news item on RCA Radiograms appeared in a 1947 issue of Popular Science magazine. While improved transmitters, receivers, and antennas were extremely important, perhaps the most significant factor in achieving reliable, predictable long distance communications was a better understanding of the Earth's upper atmosphere and how it affected the transmission of electromagnetic waves. No direct measurements of ionospheric heights and conduction levels had been made at the time, so it was a combination of theoretical and operational experience that determined parameters necessary for success. After the war, when some strategic secrets were divulged to the public, businesses and even private citizens were able to enjoy the newfound benefits. Many of the companies that helped develop the wartime technology were able to exploit that effort afterward...

The Coming Boom in Rare Earths

The Coming Boom in Rare Earths - RF Cafe"It would be an overstatement to say that the modern world runs on rare-earth elements. But as overstatements go, that one has more than a grain of truth. Because of their unique luminescent, electrochemical, and magnetocrystalline properties, rare-earth elements are essential to some of the most important and fastest-growing tech-based industries. They're used in the phosphors that make white-light and other LEDs possible, and they're in compounds used to purify key semiconductor materials such as silicon carbide and gallium nitride, to indicate just a couple of their scores of applications in technology. Perhaps most importantly, though, they're essential components of the permanent magnets used in the motors of most electric vehicles and many appliances, and also in the generators in most wind turbines. As much as 90 percent of processed rare-earth elements come from China, a supply-chain dependence that spooks Western executives and, especially, defense officials. That critical importance of rare-earths in so many tech industries is of mounting concern in many Western countries. As much as 90 percent of processed rare-earth elements come from China, a supply-chain dependence that spooks Western executives and, especially, defense officials. Rare earths are vital to countless military applications, including night-vision goggles, laser-targeting..."

Grounding & Line Fluxuations

Editorial Comment: Grounding & Line Fluxuations, March 9th The Wireless World Article - RF CafeAs radio equipment builders and operators, we still battle two fundamental issues that have been around since the beginning of time (well, from Marconi's time, anyway) - grounding and power supply fluxuations. Both topics are addressed briefly here in this editorial column from a 1932 The Wireless World magazine. Back in the day, grounding was referred to as "earthing," and was/is essential to optimal wireless and wired performance. Line voltage "fluxuations" (fluctuations) are generally much less severe today than in the 1930s thanks to better transformers, automated monitoring and adjusting of line voltages, and better distribution designs. The worst type of power line fluxuation - a lightning-induced surge - has been greatly reduced thanks to superior engineering, primarily by the simple running of a grounded neutral "static" wire running at the top of all the lines below it on utility poles and transmission towers...

1st Complete Memristor-Based Bayesian Neural Network Implementation

1st Complete Memristor-Based Bayesian Neural Network Implementation - RF CafeConsidering medical-diagnosis and other safety-critical, sensory-processing applications that require accurate decisions based on a small amount of noisy input data, the study notes that while Bayesian neural networks excel at such tasks because they provide predictive uncertainty assessment, their probabilistic nature requires increased use of energy and computation. The increase is caused by the fact that implementing the networks in hardware requires a random number generator to store the probability distributions, i.e. synaptic weights. "Our paper presents, for the first time, a complete hardware implementation of a Bayesian neural network utilizing the intrinsic variability of memristors to store these probability distributions," said Elisa Vianello, CEA-Leti chief scientist. "We exploited the intrinsic variability of memristors to store these probability distributions, instead of using random number generators." A team comprising CEA-Leti, CEA-List and two CNRS laboratories...

Hughes Aircraft Company Space Engineering

Hughes Aircraft Company Space Engineering, October 18, 1965 Electronics Magazine - RF CafeHughes Aerospace has many openings for qualified design engineers in Culver City, California. High power airborne transmitters, low noise receivers using parametric amplifiers, solid state maser component development, radar processing systems, crystal oscillators, telemetering, and high efficiency spaceborne power supplies are among the kinds of specialties needed by Hughes to support military and civilian projects. If you have been looking for just such an opportunity, then the wait is finally over... provided you happened to see this advertisement in Electronics magazine back in the fall of 1965. Quiz question: What is the difference between a geosynchronous orbit and a geostationary orbit?

Flying Hoop Explodes Mines by Magnetism

"Flying Hoop" Explodes Mines by Magnetism, May 1943 Popular Mechanics - RF CafeBeginning in the early days of World War II, Hitler's navy was laying mines in the water that were triggered by the magnetic field surrounding the metallic hulls of military and merchant ships. They usually floated just below the surface or even lay on the sea floor near shallow ports so as to avoid visual sighting, and then would detonate when ships passed overhead. It was like laying a spring leg trap on the ground and covering it with leaves. The ship's crew would never see it coming. The magnetic mines were as deadly and menacing as any U−Boat. The problem was so dire that by January 8, 1940, British engineers and flight crews had successfully designed and implemented a system for detonating the magnetic mines using a Vickers Wellington bomber fitted with a 51' diameter electromagnetic coil under its belly, powered by a Ford V−8 engine. The system was called Directional Wireless Installation (DWI). Because the war in Europe was still in progress, not much detail could be obtained or printed in 1943 when this news bit appeared in Popular Mechanics magazine...

Kenyon Transformer Holiday Message

Kenyon Transformer Holiday Message, January 1941 QST - RF CafeThe Christmas holiday season is here officially now that Thanksgiving is over. When deciding which articles from vintage electronic magazines to post, I always try to pick a few that pertain to specific holidays, like Christmas, Independence Day (aka 4th of July), Halloween, etc. Many companies ran magazine advertisements - often full-page - in QST, Radio News, Electronics World, etc. Here is one by the Kenton Transformer Company, of New York, New York. It alludes to the military buildup that America was conducting in anticipation of being drawn into the battles which had been going on for two years already in Europe, North Africa, and the South Pacific. That it appeared in the very issue of QST that was being delivered just about the time Japanese attacked Pearl Harbor on December 7th of that very year is the epitome of irony (or prognostication). Now, I'm not trying to start anything here, but the name Kenyon is probably pronounced the same as for a person who comes from the country of Kenya (i.e., Kenyan). I also noted the company's address is 840 Barry Street. Have you heard of Barry Soetoro? I'm just say'n...

How Memristors Help Machines Think at Different Timescales

How Memristors Help Machines Think at Different Timescales - RF CafeUh-oh, memristor−denier Tim H. will be triggered by this! "In the latest episode of Brains and Machines, EE Times regular Dr. Sunny Bains talks to Professor Melika Payvand, who designs neural systems from the circuit-level up at the Institute of Neuroinformatics in Zurich. You'll find out the role that memristors are playing in the systems she designs, why neural circuits need to operate at different timescales, and why copying some features of biological dendrites could add computational power to silicon brains. Discussion follows with Dr. Giulia D'Angelo from the Italian Institute of Technology and Professor Ralph Etienne-Cummings from Johns Hopkins University. Welcome to Brains and Machines, a deep dive into neuromorphic engineering and biologically inspired technology. In this episode, EE Times regular Sunny Bains talks to Professor Melika Payvand, who designs neural systems from the circuit-level up at the Institute of Neuroinformatics in Zurich. You'll find out the role that memristors are playing in the systems she designs..."

Wayne-George Corporation Advertisement

Wayne-George Corporation Advertisement, February 28, 1964 Electronics Magazine - RF CafeAdmittedly, the only thing I remember about Gray Code (aka reflected binary) from college courses is that successive count values change only one bit per increment, saving power in some digital circuits. The power savings comes from the fact that, especially for CMOS circuits, current only flows during the transition of a state change from "0" to "1" or from "1" to "0." Shaft position encoders were and still are a primary application of Gray Code switching. If the encoder output digital code is going to be used in a binary computation system, then there is an advantage in generating a direct binary ("natural") count that does not require a Gray-Code-to-Binary conversion circuit (or software routine). When the Wayne-George Corporation introduced its paradigm-changing "Natural Code Non-Ambiguous Optical Encoder" in 1964, those conversion circuits were probably not simple, compact, inexpensive semiconductor IC's, but more likely vacuum tube behemoths. Even if IC's were used, the conversion circuit would have been comprised of quad packs of AND's, OR's, NAND's, and NOR's, not even a single application...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000 or so symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing. Check them out!

How to Smell Your TV Troubles

How to Smell Your TV Troubles, January 1965 Popular Mechanics - RF CafeAlthough I have never experienced it myself, I have it on good authority (Mac MacGregor) that the odor which emanates from a burned up selenium rectifier is very foul. Those were the first form of "tubeless" rectifiers. Legend has it that TV and radio repairmen could sometimes smell the burnt up rectifier in a high voltage circuit upon walking into a house on a service call. My own troubleshooting methodology for anything electrical - circuit board, motor, even cables and connections - consists of a careful visual and smell test. Unless very high current is involved, there usually is not a failure betraying hint of either type on today's low power products. Often when the ballast of an old commercial fluorescent light fixture fails, it sends out a nasty hot tar smell. A couple times a year back in elementary, junior high, and high school (1960s-1970s) that odor would permeate the classroom and hallway. Although this article from a 1965 issue of Popular Mechanics magazine specifically refers to TVs, the same principle goes for any malfunctioning electronic device. I remembered and found the Peanuts comic shown in the thumbnail where Snoopy declares regarding the suitability of his dinner, "The eye can be deceived, but the nose knows." That is pretty much universally true...

Axiom Test Equipment 2024 Calendar - "Test Equipment Museum"

Axiom Test Equipment 2024 Calendar - "Test Equipment Museum" - RF Cafe Cool ProductContinuing its tradition of creating wall calendars with a test equipment theme, Axiom Test Equipment just announced the availability of their year 2024 "Test Equipment Museum" calendar. In the past, Axiom's calendars juxtaposed an unrelated topic with various types of test equipment to result in a clever melding of the two. The 2022 "Top Hits" calendar used historic rock music bands. "Traveling Through Time," in 2023, references notable historical eras. This "Test Equipment Museum" calendar presents both a modern piece of test equipment next to a vintage version of the same type. For example the month of January has both a circa 1948 Associated Research Hypot Junior 412 instrument and a modern Associated Research 7804 Hypot model. That represents more than half a century technology evolution by the same company. Both were/are used to test the ability of electronic assemblies to withstand high voltage potentials without breaking down. Another example of a company's extensive history with the same product type is the April page with a 1964 era HP 851A Spectrum Analyzer and a modern Keysight N9020B Spectrum Analyzer. Axiom really reached back for the June exhibit by showing a 1920s-30s B-Battery Eliminator RT−40 high voltage direct current power supply. "B" batteries had a nominal output at 45 volts...

TYPIT Special Typewriter Symbols

TYPIT Special Typewriter Symbols, January 10, 1964 Electronics Magazine - RF CafeIf you are typing on your computer or phone (which is actually more of a computer than a phone) and you need to create a character other than the standard keyboard set, most programs provide a means to access extended characters either with a menu selection or an ability to enter ASCII extended character set codes into the source code. At most, it takes a couple additional keystrokes (assuming you know how to do it). Back in the days of typewriters, the task was nowhere near as easy. Some manufacturers of typewriters had the replaceable balls for allowing a variety of typefaces and fonts, often including one with special science and engineering characters. Those required the typist to reserve space on the page for the characters, swap out the ball, then go back and fill in the blanks. It was tedious and error-prone. There is often a noticeable shift in the character baseline compared to all the rest in the line. The Mechanical Enterprises company produced an add-on gadget called the TYPIT that needed to be attached to the typewriter and allowed interchangeable character die to be quickly inserted and removed as the need required. More than a thousand characters were available...

Secrets of the Prague Astronomical Clock

Secrets of the Prague Astronomical Clock - RF CafeYou have to admire the mechanical and artistic mastery of these ancient relics. Designing mechanisms around complex physical and mathematical principles required multiple forms of genius. This one does not present planet positions, which was difficult prior to Copernicus' heliocentric solar system model. Replicating retrograde motion of inner planets is quite involved based on the previous geocentric model. "The Prague Astronomical Clock is one of the city's most popular landmarks (YouTube). It is well over 600 years old and is one of the oldest functional astronomical clocks in the world. Like other astronomical clocks, the famous Prague example is effectively a specially designed mechanism to display astronomical information. Many, like the Orloj, tend to show the relative positions of the Sun, Moon, Zodiac constellations and, sometimes, other planets. The astronomical clock in Prague, otherwise known as The Orloj, does all this, and much more. It tells the time, provides the date, shows astronomical and zodiacal information, and, best of all, provides some theatre for its viewers on the hour, every hour."

France Joins the Space Age Club

France Joins the Space Age Club, December 13, 1965 Electronics Magazine - RF CafeFrance's A-1 (aka "Astérix") satellite launch in November of 1965 made it the sixth country to place a satellite in orbit - behind Russia, USA, the UK, Canada, and Italy, respectively. Astérix's primary mission was to test the booster rocket, and verify the ground tracking networks. Onboard were a radar transponder, a tracking beacon, and a telemetry transmitter. Due to a presumed damaged antenna, received signals from the beacon were very weak and only lasted for two days. Although initially France relied on U.S. contractors for much of its hardware (mechanical and electronic), it endeavored to develop and produce the majority of the required technology in-country. Note that the commemorative postage stamp issued by Ecuador uses the same picture of the Diamant-A rocket booster that is in this December 1965 Electronics magazine article...

RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Death-Ray Chamber Tests Atom Effects

Death-Ray Chamber Tests Atom Effects, January 1953 Popular Mechanics - RF CafeNearly everyone has seen photos and/or videos of the Operation Crossroads nuclear weapons tests at the Bikini Atoll from shortly after the end of World War II. Upon the ships were penned various species of animals - goats, pigs, rats, guinea pigs, etc. - along with radiation and mechanical measurement equipment. The goal was to determine exposure levels to nuclear and electromagnetic radiation, as well as to severed physical forces. That was for both the ship and its "crew." A Fat Man type fission bomb was detonated underwater (90-foot depth), as opposed to the air drop type. Many sources provide details of the entire operation, including the findings. Given the extreme complexity and risks involved in using bombs, laboratory facilities were constructed to simulate exposure from bombs. This "Death-Ray Chamber Tests Atom Effects" story from a 1953 issue of Popular Mechanics magazine describes one method used by the Naval Medical Research Institute...

Belgium Electronics Market

Belgium Electronics Market, December 27, 1965 Electronics Magazine - RF CafeThis is the electronics market prediction for Belgium, circa 1966. It was part of a comprehensive assessment by the editors of Electronics magazine of the state of commercial, military, and consumer electronics at the end of 1965. Military systems for NATO and television sets were a big part of the picture. Unless you can find a news story on the state of the industry, detailed reports must be purchased from research companies like Statista. Their website has a lot of charts on Belgium's current electronics market showing revenue in the consumer electronics segment amounts of US$2,995M in 2023. Reports for other countries - Japan, the UK, France, Russia, and more - are also provided...

Celebrating Field Engineers: The Unsung Heroes of Innovation

Celebrating Field Engineers: The Unsung Heroes of Innovation - RF Cafe"Field engineers help implement, deploy, and maintain technology in the field, driving innovation in areas primarily unseen. The world doesn't fix itself. Doesn't set itself up. It hardly ever changes - not until a field engineer shows up. Day, night, cold or hot, these unsung heroes of engineering will answer the call not just because they get paid, but because they love the job. What's not to love. While most engineers hardly leave their offices, field engineers rarely spend any time in one. They're the individuals who bridge the gap between theory and reality, ensuring that technologies are seamlessly integrated into our daily lives. It's with this that we delve into the narrative of celebrating field engineers and unravel the pivotal role they play in the ever-changing world of innovation and progress. Field engineers are the problem solvers, the troubleshooters, and the architects of the seemingly impossible. They're the ones outside of the limelight who ensure those technologies keep functioning behind the scenes..."

Over Mountains on 5 Meters!

Over Mountains on 5 Meters!, January 1935 Short Wave Craft - RF CafeThe 5-meter band (56-64 MHz) allocated to U.S. amateur radio operations in the 1930s was reallocated in 1946 to television broadcasting. However, Hams still are permitted to operate on 6-meter (50-54 MHz) and 2-meter (144-146 MHz) bands on either side of 5 meters. Therefore, this 1935 Short Wave Craft magazine article on non-line-of-sight communications within mountainous regions will still be of interest, even if only from a historical perspective. There is an interesting comment made about feeding a vertical 1/4-wave antenna from the top rather than from the bottom (with the entire structure located 50' above the ground). No explanation is offered as to the reason...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features...

Channel Master 6515 "Super Fringe" Radio

Channel Master Model 6515 "Super Fringe" Radio, October 1960 Electronics World - RF CafeA lot of people from the era of rooftop television antennas were/are familiar with the name Channel Master. Many of their antennas included an integrated FM radio antenna. Very few were likely aware that Channel Master also made radios. I don't think they ever made televisions. The fact is, companies like Channel Master did not design and manufacture their own radios and televisions; instead, they paid to have custom versions of existing products branded with their names. Sears, Roebuck's Silvertone line, Montgomery Ward's Airline products, Western Auto's Truetone line, and others are examples. This Channel Master Model 6515 "Super Fringe" transistor radio was made by Sanyo. 1960, when this ad appeared in Electronics World magazine, was the transition period between vacuum tubes and transistors. It was not uncommon to find two or more identical radios bearing different company logos. Channel Master Model 6515 "Super Fringe" radios can be found in eBay for around $30...

DJC - The Radio Voice of Germany

DJC - The Radio Voice of Germany, February 1935 Short Wave Craft - RF CafeThis 1935 article found in Short Wave Craft magazine quotes the Reichs-Rundfunk Gesellschaft (Zeesen) station engineer as saying that they transmitted with only 5 kW into the farm of directional antenna arrays, and that it was sufficient to provide what was evidently very high quality reception to many remote regions of the world. Adolph Hitler had become "Führer und Reichskanzler" the year before, with plans already in the works to dominate the world. Troops invaded Poland on September 1, 1939, officially beginning the Second World War. DJC's global reach was used extensively for propaganda during the war. "On the Shortwaves" website has a digitized audio file of the 78 rpm greetings record that German shortwave radio station JDC would send to American listeners upon request...

How Much Power Is Enough When Selecting an AC Supply

Axiom Test Equipment Blog: How Much Power Is Enough When Selecting an AC Supply - RF CafeAxiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post that covers how to find the right AC Power Supply with enough output power for each component, device, and system during testing. While precisely controlled AC electricity may not be needed when testing DUTs powered by DC power, an AC supply can help simulate real-world operating conditions. For certain DUTs, such as electric motors, a well-controlled AC power supply can mimic the conditions in which the DUT will operate, including power supply line fluctuations, peaks, and surges. AC power supplies can be compared by electrical capabilities, such as maximum root-mean-square (RMS) voltage, maximum RMS current, maximum frequency, and maximum power in volts-amperes (VA) at a given frequency. They can also be considered by physical attributes, such as the size and weight needed to fit an application. This is a glimpse of several AC power supplies having sufficient output power for feeding a wide range of DUTs...

1957 Auto Radios: Ford

1957 Auto Radios: Ford, July 1957 Radio & TV News - RF Cafe1957 was part of the heyday of the newfound radio-in-your-car craze, and the public was voraciously consuming all the high tech equipment it could afford. Rock and Roll music was on every teenager's mind and many guys for the first time were able to have their own wheels and were outfitting them with sound systems that could blast the latest works of Buddy Holley, Chuck Berry, Elvis Presley, and Fats Domino. Those machines were the first babe magnets used for cruising the strip on Saturday nights. Radio stations were popping up all over the country, enabling cross-country travel with non-stop music, news, and variety show entertainment. Ford and Chevrolet were not going to miss an opportunity, so they delved into the high end mobile radio manufacturing business. As the quality of broadcasts increased, noise caused by automobile ignition systems bubbled to the top of issues affecting listening pleasure, including the distance over which a broadcast could be received. This 1957 Radio & TV News article describes Ford's efforts to please their customers' demands...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated in all locations on the page! RF Cafe typically receives 8,000-15,000 visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 17,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. Your Banner Ads are displayed on average 280,000 times per year! New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be...

Electronics Theme Crossword for December 3rd

Electronics Theme Crossword Puzzle for December 3rd, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for December 3rd contains words and clues which pertain exclusively to the subjects of electronics, science, physics, mechanics, engineering, power distribution, astronomy, chemistry, etc. If you do see names of people or places, they are intimately related to the aforementioned areas of study. As always, you will find no references to numbnut movie stars or fashion designers. Need more crossword RF Cafe puzzles? A list at the bottom of the page links to hundreds of them dating back to the year 2000. Enjoy...

Espresso Engineering Workbook™ for Excel - 12.2.2023

RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeThe newest release of RF Cafe's spreadsheet (Excel) based engineering and science calculator is now available - Espresso Engineering Workbook™. Among other additions, it now has a Butterworth Lowpass Filter Calculator that does not just gain, but also phase and group delay! Since 2002, the original Calculator Workbook has been available as a free download. Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is also provided at no cost, compliments of my generous sponsors. The original calculators are included, but with a vastly expanded and improved user interface. Error-trapped user input cells help prevent entry of invalid values. An extensive use of Visual Basic for Applications (VBA) functions now do most of the heavy lifting with calculations, and facilitates a wide user-selectable choice of units for voltage, frequency, speed, temperature, power, wavelength, weight, etc. In fact, a full page of units conversion calculators is included. A particularly handy feature is the ability to specify the the number of significant digits to display. Drop-down menus are provided for convenience. Now that a more expandable basis has been created, I have been adding new calculators on a regular basis...

Wanted: 50,000 Engineers

Wanted: 50,000 Engineers, January 1953 Popular Mechanics - RF Cafe"Right now America is crying for engineers - 50,000 of them." That is the tag line from the "Wanted: 50,000 Engineers" article in the January 1953 issue of Popular Mechanics magazine. The Korean War was winding down (ended in July), inflation was low (0.7%, compared to 6-7% the last couple years, and 13% in Carter years) and many technological breakthroughs generated a huge demand for engineers to design products and systems to exploit and improve upon the knowledge. Here is an apt statement from the article: "Just what is engineering? It has been called the art that makes pure science useful." Magazines of the era were chock full of features like this as well as advertisements attracting men - and sometimes women - to tech schools, universities, industry, military, and government through promises of great pay and prestige. Tests in physics, aviation, and geology are included here to help the reader determine whether he is engineer material. In truth, they are about as useful as the "Draw Me" type ads for artist schools...

Anatech November 2023 Newsletter

Anatech Electronics November 2023 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his November 2023 newsletter that, along with timely news items, features his short op−ed entitled "If Extraterrestrial Life is out There, We're Closer to Finding It." In it, Sam discusses the current state of the worldwide search for alien intelligent life. SETI has been around for as long as I remember - established November 11, 1984. That means SETI and related efforts have been at it for four decades, with no qualifying signals having ever been identified (which is not to say might have been received but not recognized). That is just a blip in time on a universal scale, so it is no reason to demur the effort. Astronomical equipment in all wavelengths - radio, microwave, mm-wave, infrared, visible, ultraviolet, x-ray - is advancing in sensitivity and speed at an extreme rate. Keep in mind that prior to the Hubbell Space Telescope, there was still a debate as to whether the entire sky, if examined closely enough, would be filled with celestial objects. Now, telescopes operating outside the optical range with fine resolution are detecting stars and galaxies hiding behind regions of interstellar gas that blocks light in the red-to-blue visual spectrum. A civilization would need to have been emitting electromagnetic signals for much longer a time than the 150 years or so of those originating from the Earth in order for the probability of something intercepting our position in the universe with enough power to detect...

6 Routes to Noninductive Tuned Circuitry

Six Possible Routes to Noninductive Tuned Circuitry, November 15, 1965 Electronics Magazine - RF CafeI remember in one of my circuits classes in college when the gyrator was introduced, and I thought it was an ingenious invention. The gyrator circuit, implemented with an opamp and a couple resistors and capacitors, changed its measured impedance type from that of a capacitance to that of an inductance. That is, its impedance represents an R + jX Ω format. Frequency limits are imposed by a combination of the self-resonant frequencies of the resistors and capacitors as well as the GBWP of the opamp, and power handling is primarily limited by the opamp's voltage and current capabilities. You might ask why, with all those constraints on its use you would even want to use a gyrator circuit? The answer is that within its limitations, the gyrator often represents a less expensive and more compact version of a physical inductor. This is particularly true with ICs where, unless it is a MMIC operating in the tens of gigahertz region, there is no space available on the die for a printed metallic inductor with enough inductance to be useful. Any inductors would need to be mounted off-chip on the PCB with I/O pins interfacing to the IC. Gyrators...

China High Orbit Internet Satellite Constellation Coming

China High Orbit Internet Satellite Constellation Coming - RF Cafe"China announced it has completed the initial set-up of its first high-orbit satellite communication network, which is expected to provide a swift satellite internet service within its borders and in several belt and road nations. The Chinese project could be an alternative to SpaceX's Starlink, according to a Beijing-based communications expert. China Aerospace Science and Technology Corporation, the parent company of the satellite operator, said the network would provide internet service for industries ranging from aviation and navigation to emergency services and energy, state news agency Xinhua reported on Monday. The network includes high-throughput satellites ChinaSat 16, 19 and 26. According to the network operator, the satellites cover China as well as parts of Russia, Southeast Asia, Mongolia, India, and the Indian and Pacific Oceans - encompassing much of the area included in the Belt and Road Initiative, Beijing's strategy to boost infrastructure links and connectivity across Asia, Africa and Europe..."

Your Radio Training and the Defense Program

Your Radio Training and the Defense Program, December 1940 January 1941 National Radio News - RF CafeThe National Radio Institute (NRI) was one of the first country-wide organizations to offer formal electronics training both as classroom and as self-study courses. Magazines were filled with offers to train men in what was an exciting new career field. The drums of war were beating in the background in Europe and the South Pacific by December 1940 when this article appeared in National Radio News, and the U.S. military was gearing up for what was sure to be an eventuality. Three months earlier, the Tripartite Pact united Japan, Italy and Germany to formalize the Axis Powers, and Hitler's forces had invaded Western Europe. The push was on to train a large number of engineers and technicians to handle communications and control systems for Army and Navy forces. It is always interesting to read pieces penned at the time events were unfolding, rather than after having been filtered through the worldview of subsequent authors...

RF & Electronics Symbols for Visio

RF Electronics Wireless Analog Block Diagrams Symbols Shapes for Visio - RF CafeWith more than 1000 custom-built symbols, this has got to be the most comprehensive set of Visio Symbols available for RF, analog, and digital system and schematic drawings! Every object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Symbols are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing. The file format is XML so everything plays nicely with Visio 2013 and later...

Channel Master Contact Cleaner

Channel Master Contact Cleaner, October 1960 Electronics World - RF CafeAsk anyone who has ever asked me to fix something electrical or electronic and they will tell you my motto on such things, born of extensive experience, is that the vast majority of the problems are caused by poor electrical contacts of one form or another. The culprit can be a dirty or broken connector, a cold or broken solder joint, a dirty potentiometer (contact between wiper and resistor), etc. I have repaired everything from ceiling lights, to car starters, to kitchen appliances, to large screen TVs simply by finding and repairing connections. When possible, I always do a final cleaning with isopropyl alcohol and then spray with a silicon contact protector. This Contact Shield product from Channel Master would be a good choice. I can honestly say I cannot think of a single instance where the restored connection failed again. Of course sometimes it is not that simple, but enough that my initial approach to troubleshooting - unless a broken or burnt component is immediately apparent - is to unplug and inspect connectors (then plug-unplug-plug to wipe contacts clean), flip switches on-off a few times while applying various directional forces (left-right, up-down, twisting), tugging on wires, etc. People's eyes light up in amazement when a sophisticated piece of equipment starts working after doing so. Then, I me

Rigol DHO1000 Oscilloscope - RF Cafe

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Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024


    Kirt Blattenberger,


RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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