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Today in Science History

Taming Transients

Taming Transients, July 1963 Electronics World - RF CafeDealing with the problem of lightning strikes was of concern long before electronic equipment needed to be protected from its effects. Fires that were the result of lightning have always been a problem in nature, but they were really catastrophic to civilization once cities crowded with close-quartered wooden buildings became the norm. Benjamin Franklin observed that when the many lightning-induced fires of Philadelphia were sparked (pun intended), it was almost always the tallest structures in the area that were hit. Those fire often spread to neighboring buildings and burned down entire city blocks. It was a devastating and frequency...

Next-Gen Electronics Fail at Lower Temps

How Next-Gen Electronics Fail at Lower Temperatures - RF Cafe"By observing spintronic magnetic tunnel junctions in real-time, researchers found these devices fail at unexpectedly low temperatures, offering valuable insights for improving future electronic designs. Next-Generation Electronics Degradation A new study led by researchers at the University of Minnesota Twin Cities is providing new insights into how next-generation electronics, including memory components in computers, breakdown or degrade over time. Understanding the reasons for degradation could help improve efficiency of data storage solutions. The research is published in ACS Nano, a peer-reviewed scientific journal and is featured on the cover..."

Arthur C. Clarke: A Biography

Arthur C. Clarke: A Biography - RF CafeArthur C. Clarke's writings and contributions to science are vast and influential, intertwining his imaginative narratives with profound scientific concepts. Clarke is credited with proposing the idea of geostationary satellites in a paper he published in the October 1945 issue of Wireless World magazine. Titled "Extra-Terrestrial Relays: Can Rocket Stations Give Worldwide Radio Coverage?," he described the concept of using a network of geostationary satellites to provide global radio coverage. Geostationary satellites are satellites that orbit the Earth at the same rate as the Earth rotates, so they appear to stay in the same place in the sky relative to a fixed point on the Earth's surface. This makes them ideal for telecommunications and broadcasting, as they can provide constant coverage of a particular area without the need for multiple satellites or complicated ground infrastructure...

What's Your EQ?

What's Your EQ?, July 1961 Radio-Electronics - RF CafeHere we go with three new "What's Your EQ?" challenges from the July 1961 issue of Radio-Electronics magazine. Readers submit the problems, which typically involve creating a circuit to perform a specified function, or determining how a given circuit works. The first of these is more of a puzzle, since the author shows you how to go about arriving at the answer. Since incandescent light bulbs are not overly familiar to a lot of people these days, it might be to the advantage of pre-Millennials who grew up using them and are acquainted with their properties. The second is an old-fashioned Black Box challenge that some readers will solve without much...

HAPS Aircraft for Stratospheric Comms

SoftBank Trials HAPS Aircraft for Stratospheric Communications - RF Cafe"Japanese operator SoftBank announced that the Sunglaider, its large-scale solar-powered uncrewed aircraft system (UAS) designed for High Altitude Platform Station (HAPS) stratospheric telecommunications, was utilized in a field trial conducted by AeroVironment and the U.S. DoD in New Mexico, the U.S. During the trial, carried out in early August, Sunglider succeeded in achieving stratospheric flight, the Japanese operator said. With a wingspan of 78 meters and the capability to carry payloads weighing up to 75kg, the Sunglider is larger than other publicly announced HAPS UAS..."

Electronics Diagram Quiz

Electronics Diagram Quiz, August 1966 Popular Electronics - RF CafeMonday (any day, for that matter) is a good day for Carl and Jerry stories, Mac's Electronics Service Shop sagas, Hobnobbing with Harbaugh, electronics-themed comics, electronics quizzes, and other forms of nerd entertainment. Here is another of Robert P. Balin's great challenges titled, "Diagram Quiz," this one from a 1966 issue of Popular Electronics magazine. Most RF Cafe visitors will easily identify eight or nine of the ten diagrams. Relatively few will be familiar with the Rieke diagram (hint: power amplifier designers will know about it). The Biasing diagram is a bit misnamed IMHO, and could cause confusion...

Anatech Has 3 New Filter Models for October

Anatech Electronics - 3 New Filter Models for October 2024 - RF CafeAnatech Electronics offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Three new ceramic bandpass filters have been announced for October 2024 - a 2275 MHz center frequency filter with a bandwidth of 250 MHz, a 2275 MHz center frequency filter with a bandwidth of 250 MHz, and a 6245 MHz center frequency filter with a bandwidth of 360 MHz. Custom RF power filter and directional couplers designs can be designed and produced with required connector types when a standard cannot be found, or the requirements are such that a custom approach is necessary.

The Operational Amplifier

The Operational Amplifier, July 1963 Electronics World - RF CafeWhen you read this 1963 Electronics World magazine article's title, I doubt you immediately assumed it would be about a vacuum tube circuit, or even one that uses discrete transistors to implement the circuit. Rather you most likely though it would be about an integrated circuit (IC). Operational amplifiers (opamp) are building blocks characterized (ideally) by their infinite input impedance, zero output impedance, infinite open-loop bandwidth and gain, zero input offset voltage, amongst other defined parameters. The first commercially produced integrated circuit (IC) opamp came to market in 1964 via Fairchild Semiconductor (the µA702, brainchild of Bob Widlar)...

The Nickel-Cadmium (NiCad) Battery

Nickel-Cadmium (NiCad) Battery (ChatGPT-generated content) - RF CafeNickel-cadmium (NiCad) batteries have a long and significant history in energy storage, with their invention attributed to Swedish engineer Waldemar Jungner in 1899. Jungner's work laid the foundation for an electrochemical power source based on nickel oxide hydroxide and cadmium, leading to the development of the rechargeable NiCad battery. It was a pioneering breakthrough because it represented one of the earliest forms of rechargeable energy storage systems. This battery technology found widespread use in various industries due to its robust performance and ability to be recharged multiple times. At its core, the chemistry of NiCad batteries involves the reaction between cadmium (the negative electrode) and nickel oxide hydroxide (the positive electrode), with potassium hydroxide as the electrolyte. During...

Electronics-Themed Comics

Electronics-Themed Comics, September 1969 Electronics World - RF CafeThese two tech-themed comics from the September 1969 issue of Electronics World magazine are pretty good. I especially like the one where the guy's wife entered his printed circuit board layout in an art contest. PCBs were just starting to gain momentum in production electronics as they replaced the old point-to-point wiring method. Also popular in that era was high fidelity stereo equipment. Owning a system with speakers that operated from 1 Hz through 30 to 40 kHz was major evidence of an audiophile's technical savvy, even though the human ear con only detect frequencies in the 30 Hz to 20 kHz range. Dogs can hear frequencies up into the 45 kHz range. Porpoises can hear up to 150 kHz. A ferret can hear from 16 Hz...

NextGen Thermal Performance Testing

Next Generation Thermal Performance Testing - RF CafeTotalTemp Technologies offers advanced and innovative methods for meeting and optimizing your thermal testing requirements. We specialize in benchtop thermal testing because small batches are typically the most cost-effective approach. We offer heat transfer by conduction with thermal platforms, forced convection as in traditional temperature chambers, combined systems, and thermal vacuum for Space Simulation. Thermal testing of Traveling Wave Tube Amplifiers and other devices with dramatically uneven power dissipation can easily be achieved with a dual zone thermal platform. Managing the heat produced by the electron gun side allows for the RF outputs side to be tested at various required temperatures. The Dual Zone Thermal Platforms allows the user to maintain safe controlling...

Engineering & Tech Headlines <Archives>

• Ham Radio Serving Southeast U.S. Recovery Efforts

• Radio "A Godsend for So Many" in Helene's Aftermath

• Estate Planning for Hams

• Intel's Woes Damaging U.S. Chip Indpendence

• Is Gen-Z Low Car Ownership a Threat to Radio? (they can't afford cars due to massive inflation - not because they don't want a car)

AMRAD: A Brief Overview and Historical Context

AMRAD: A Brief Overview and Historical Context - RF CafeAmrad, American Radio & Research Corporation, was based in Medford Hillside, Massachusetts and was founded in 1915 with funds from J. Pierpont Morgan. The company's first manager, Harold James Power, was an amateur radio enthusiast and built a research laboratory. In 1916, Amrad made its first broadcast to J. Pierpont Morgan Jr., who was aboard the ocean liner "Philadelphia." Amrad received orders for military radio equipment during World War I, but discontinued these orders after the war ended. To keep the company afloat, Amrad produced items such as electric egg beaters and cigar lighters. In 1919, Amrad was awarded a contract to make 400 SE1420 receivers, and it began advertising components for amateur radio enthusiasts...

Which Dry Battery for You?

Which Dry Battery for You?, June 1963 Radio-Electronics - RF CafeThis "Which Dry Battery for You" article is a follow-on from the previous month's "Dry Cell Battery Types" in Radio-Electronics magazine. It was a time long before the dominance of rechargeable lithium batteries. In 1963, battery-powered devices were nowhere near as widespread and diverse as they are nowadays. Hand tools like drills, saws, routers, planers, and screwdrivers got their power either from a wall outlet or the user's arm and hand muscles. Lawn mowers, grass and hedge trimmers, chain saws, and snow blowers were powered mostly by gasoline, although some models plugged into the wall. Those devices which did use batteries most often had no built-in...

Light Waves to Logic Optical Computing

Light Waves to Logic Optical Computing - RF Cafe"Researchers have developed a new architecture for optical computing called diffraction casting, offering power-efficient processing by using light waves. This method promises better integration and flexibility for high-performance computing tasks and could be used in fields like AI and machine learning. As artificial intelligence and other complex applications demand ever more powerful and energy-intensive computers, optical computing emerges as a promising solution to enhance speed and power efficiency. However, its practical application has faced numerous challenges..."

AEC: A Brief Overview and Historical Context

Atomic Energy Commission, AEC: A Brief Overview and Historical Context (ChatGPT-generated content) - RF CafeThe Atomic Energy Commission (AEC) was established in 1946 as a result of the Atomic Energy Act, signed into law by President Harry S. Truman. This legislative decision marked the United States' formal entry into managing and controlling atomic energy, a rapidly advancing field that had been essential in concluding World War II through the development and use of nuclear weapons. The AEC was conceived to handle not only military applications of atomic energy but also to develop peaceful uses, such as energy production, medical research, and industrial applications. The creation of the AEC emerged from the Manhattan Project, the secret wartime effort to develop atomic bombs. The Manhattan Project brought together prominent scientists like J. Robert Oppenheimer, Enrico Fermi, and Niels Bohr. After the war, however, the question arose...

Empower RF 8 kW, X-Band Pulsed HPA

Empower RF Systems Model 2221, 8 kW, X-Band Pulsed HPA - RF CafeEmpower RF Systems, the technology leading provider of high-performance RF amplifiers, is proud to announce the launch of the Model 2221 X-Band Pulsed High Power Amplifier. The Empower RF 2221 amplifier operates in the 9-10 GHz X-band, delivering an impressive 8000 W peak output power with long and short pulse widths. Its applications encompass radar systems, electronic warfare, HPM research, and electromagnetics effects testing. With a rugged, modular design, the 2221 offers a reliable, high-performance solution for applications demanding significant X-band power. Key Features and Specifications The model 2221 amplifier operates in the 9-10 GHz X-band frequency range, delivering an impressive 8 kW of peak pulsed output power...

The Fraudulent Technician - A Minority

The Fraudulent Technician - A Minority, May 1964 Electronics World - RF CafeAlthough not in the title as it used to be, this 1964 Electronics World magazine piece by John T. Frye is a "Mac's Service Shop" story. If Mac and Barney are the stars of the saga, then it can be none other. The story is about how the misdeeds of a few dishonest operators can taint the reputation of an entire industry - nothing new there. Barney is telling Mac about a "sting" ploy pulled by a consumer protection group whereby TV sets with a specific easy-to-troubleshoot problem introduced to see how repair technicians from a suspect company would bill the service. I'll not spoil the ending for you; however, a comment mentioned that $10 would have been a reasonable price for a house call that included the fix. According to the BLS's inflation calculator, $10 in 1964 was the equivalent of about $102 in 2024...

Unexplored Electron Gap

Unexplored Electron Gap, March 1962 Radio-Electronics - RF CafeEver the futurist, in 1962 Radio-Electronics magazine editor Hugo Gernsback was making the case for occupying millimeter- and submillimeter-wave bands. In fact, he first proposed the concept back in 1959. He refers to it as "gap between the infrared (IR) and radio regions." IR is generally understood to include wavelengths from around 750 nm (400 THz) to 1 mm (300 GHz). Gernsback cites work done by Professor Gwyn O. Jones, of Queen Mary College of the University of London, with the claim that among other advantages of millimeter-wave (mm-wave) is an ability to penetrate certain wavelength "windows" in the atmosphere where lower frequencies do not propagate efficiently, more "channels" of communications can be accommodated, smaller antennas could be used, and narrower focused transmission beams possible...

Werbel 10-Way Splitter for DC-7.2 GHz

Werbel Microwave 10-Way Resistive Power Splitter for DC to 7.2 GHz - RF CafeWerbel Microwave's WMRD10-7.2-S is a 10-way resistive splitter that covers up to 7.2 GHz with ultra-wide bandwidth. This unique design accomplishes extremely flat frequency response in a small radial package. Our unique design approach provides higher than expected isolation between outputs at far ports than would be achieved in a typical star topology. It has applications in markets such as CATV, test and measurement, and military radio. Its small size makes it easy to integrate into compact systems. Designed, assembled, and tested in the USA.

Hugo Gernsback: A Biography

Hugo Gernsback: A Biography - RF CafeHugo Gernsback, often heralded as the "Father of Science Fiction," was an extraordinary figure whose influence extended beyond the realm of speculative literature into the world of electronics, radio communication, and futurism. His life, inventions, and publications shaped not only popular science but also the practical development of radio and electronics, making him a pivotal figure in early 20th-century technological advancements. Gernsback was born Hugo Gernsbacher on August 16, 1884, in Luxembourg City, Luxembourg, to a wealthy family. His father, Moritz Gernsbacher, was a winemaker and merchant, while his mother, Bertha, came from a prominent local family. Hugo had several siblings, though details of his early family life remain somewhat obscure. From a young age, Hugo showed a strong interest in science and technology, particularly in electricity and wireless communication. He attended local schools in Luxembourg and later pursued formal education at the Technikum in Bingen, Germany...

CostQuest Gerrymanders for BEAD Biddable Locations

CostQuest Gerrymanders for BEAD Biddable Locations - RF CafeThese government programs take forever to implement, then a major portion of the money gets wasted in bureaucracies, payoffs, and misappropriations (e.g., 8 EV charging stations after spending $7.5B). "If you know CostQuest at all you probably think of it as the company that the FCC hired to clean up and refine its national broadband map. But the company is also working with state broadband offices on their Broadband Equity, Access and Deployment (BEAD) programs. To give a little background, CostQuest works with the FCC on its national broadband map. But it was also hired, separately, by the National Telecommunications and Information Administration (NTIA) to work with states..."

RCA: A Brief Overview and Historical Context

Radio Corporation of America (RCA): A Brief Overview and Historical Context - RF CafeThe Radio Corporation of America (RCA) holds a significant place in the history of American technology and business. Founded in 1919, RCA was initially created as a government-sanctioned monopoly to manage the United States' growing interest in wireless communication. During its peak, RCA was a dominant player across multiple industries, including consumer electronics, communications, broadcasting, and defense technology. Its influence extended through radio, television, radar, semiconductors, and beyond. The inception of RCA was rooted in the growing importance of wireless communication during and after World War I. The company was established by General Electric (GE), which was pressured by the U.S. government to create a new entity that would ensure...

IEEE '69 International Convention & Exhibition

IEEE '69 International Convention & Exhibition Advertisement, January 1969 Electronics World - RF CafeWhen this was originally posted it was the beginning of the IEEE's 2007 Microwave Theory and Techniques Society's (MTT-S) International Microwave Symposium (IMS) in Honolulu, Hawaii. This advertisement from the January 1969 issue of Electronics World magazine promoted Institute of Electrical and Electronics Engineers (IEEE) annual symposium. Per the MTT.org website, the very first IMS show was held in 1995, in Orlando, Florida. The 1969 IEEE International Convention & Exhibition, which was not specifically a microwave electronics theme, was held in the New York Coliseum, located in New York City...

The Gas that Makes You Laugh

The Gas that Makes You Laugh, June 1949 Popular Science - RF CafeIf you have been wanting access to nitrous oxide (N2O), aka laughing gas, in order to "encourage" someone to divulge subconscious (or intentionally suppressed) information, but don't want to pay the high cost of storage bottles and refilling, then here are instructions in a 1949 issue of Popular Science magazine for brewing some on your own. Purchase of N2O is legal, and is used, among other things, as an engine supercharger which is injected into the intake manifold. I had a friend back in the 1970s with such a system installed on his 1968 Camaro that had a 454 cu. in. big block in it. It could easily pop the front wheels off the ground. Dentists and doctors still use it as an anesthetic, food products like whipped cream...

Crosley Radios: A Brief Overview and Historical Context

Crosley Radios: A History - RF CafeThe evolution of Crosley radio products is a fascinating journey through the golden age of radio, a period marked by significant technological advancements and changing consumer preferences. Powel Crosley Jr.'s genius lay in his ability to combine affordability with cutting-edge features, making his radios highly desirable for the average American household. Crosley Radio Corporation's products evolved rapidly, reflecting the company's commitment to innovation and its response to market demands. Crosley's radio journey began in 1921 when he created the Harko, an affordable crystal set that was small and compact enough to sit on a tabletop. Early radios at the time were relatively... 

Novel GaN Transistors and HPAs for LEO & GEO Satellites

Novel GaN Transistors and HPAs for LEO & GEO Satellites - RF CafeIt is amazing how some substrate layouts look exactly like a block diagram of circuit they represent. "With increasing data rates in mobile communications, the need for more powerful high-frequency electronics is growing. This is particularly true for satellite-based global communication networks, which must function reliably and securely in all weather conditions and at any location. In the ESA Magellan project, researchers at Fraunhofer IAF, together with UMS and TESAT, are therefore developing novel efficient GaN transistors and high-power amplifiers for LEO and GEO communication satellites to provide high..."

Allen DuMont: A Biography

Dr. Allen B. DuMont: A Biography - RF CafeAllen B. DuMont, a pivotal figure in the early days of television and electronics, was born on January 29, 1901, in Brooklyn, New York. His contributions to the advancement of television technology, particularly through his work on cathode-ray tubes, and the founding of the DuMont Television Network, left a lasting mark on the broadcasting industry. DuMont's early years were marked by adversity. As a young boy, he contracted polio, which left him bedridden for several months. Despite the physical limitations imposed by the disease, DuMont's intellectual curiosity flourished, and he turned to reading and tinkering with electronics to occupy his time. This early exposure to electrical engineering would shape his future. DuMont's passion for electronics was evident from an early age. By the time he was a teenager, he had built his own radio receiver. He attended Rensselaer Polytechnic Institute (RPI)...

News Briefs: Spherics

News Briefs: Spherics, July 1961 Radio-Electronics - RF CafeEver heard of "sferics?" That's a new word in my technical lexicon as of right now. Sferics (aka spherics), is a contraction, derived from "atmospheric" phenomena, specifically referring to the electromagnetic signals generated by natural events in the atmosphere, such as lightning discharges. Over time, its use has become specialized in the field of meteorology, physics, and certain branches of electrical engineering, where it is used to describe specific types of electromagnetic emissions. It was mentioned in this "News Briefs" column in a 1961 issue of Radio Electronics magazine. Also in the news was the decreasing conductivity of the atmosphere due to low sunspot activity. Ham DX'ers love sunspots since by charging the upper atmosphere, it facilitates long distance communications. Japanese color TV sets were deemed "impressive." Much more...

World's Most Powerful Sound Laser

World's Most Powerful Sound Laser - RF Cafe"Recent advancements in phonon laser technology, which utilizes sound waves rather than light, show promising new applications in medical imaging and deep-sea exploration. A novel technique enhances these lasers by stabilizing and strengthening the sound waves, allowing for more precise and powerful outputs. This development not only improves existing uses in medical and underwater applications but also extends potential uses to material science and quantum computing. Scientists in China have made a significant leap in developing lasers that use sound waves instead of light. These 'phonon lasers' hold promise for advancements in medical..."

Powel Crosley, Jr.: A Biography

Powel Crosley, Jr.: A Biology - RF CafePowel Crosley Jr., an American inventor, entrepreneur, and industrialist, was born on September 18, 1886, in Cincinnati, Ohio. He became one of the most prolific figures in American industry, with contributions spanning from radios to cars, and from kitchen appliances to television broadcasting. His innovative spirit, coupled with a keen business sense, enabled him to leave an indelible mark on American consumer culture during the first half of the 20th century. Crosley's early years were shaped by a supportive, middle-class family. His father, Powel Crosley Sr., was a successful attorney, which afforded young Powel and his siblings a comfortable upbringing. Crosley was drawn to mechanical and electrical engineering from an early age, demonstrating an innate talent for tinkering. As a boy, he built his own working model of a car...

Measuring & Mitigating EMI at IC Inputs

Measuring and Mitigating EMI Disturbances at IC Inputs - RF Cafe"In these modern times, electronic systems are usually operating within an electromagnetic-interference (EMI) environment that contains many other electronic systems. These systems need to exist and fully operate undisturbed while meeting electromagnetic compatibility (EMC). EMC requirements are separated into two main parts: Electromagnetic immunity - a system must not be disturbed by any other systems. The electromagnetic interference in a system can't disturb any other system. Then, if immunity and emission requirements are individually met, the electronic product, such as an integrated circuit (IC), may be marketed from an EMC point of view. Measurement methods for EMI and electromagnetic emission (EME) are fully described for ICs in the IEC62132-4 (immunity) and IEC61967-4 (emission)..."

The Space Race

Space Race (ChatGPT-generated content) - RF CafeThe Space Race was one of the most significant geopolitical and scientific competitions of the 20th century, driven by the rivalry between the United States and the Soviet Union during the Cold War. It spanned from the late 1940s through the 1970s, with a focus on achieving superiority in space exploration, a domain viewed as critical not only for scientific advancement but also for military and strategic dominance. Rooted in rocket technology developed during World War II, the Space Race transformed the world's understanding of science and technology, culminating in the most dramatic achievement: the landing of humans on the Moon in 1969. This treatise explores the key milestones, the countries and key players involved, technological developments, the interplay between military...

The Tube Family Tree, Part 1

The Tube Family Tree, Part 1, May 1963 Popular Electronics - RF CafeFor some inexplicable reason I went backwards on this three-part Tube Family Tree series that appeared in Popular Electronics. Author Louis Garner, Jr., starts out with the early history of vacuum tubes, beginning with Thomas Edison's incandescent light bulb and then quickly progresses to Lee de Forest's Audion amplifier tube, and on through the evolution of multi-grid vacuum tubes that are specially designed for low noise receiver front ends, high power transmitters, voltage and current regulators, video cameras, pulse forming networks, traveling wave tubes, and many other types. There is quite a bit of information and history contained in these three installments that will do a very nice job of introducing you to the wonder... Here you can read Part 1, Part 2 and Part 3

Origin of "HAM" for Amateur Radio Operators

Origin of the Name "HAM" for Amateur Radio Operators - RF CafeThis story was posted sometime around 2009. Since that time, research has been conducted by members of the Harvard Wireless Club regarding the veracity of the claim. RF Cafe visitor Fred Hopengarten, Esq. (K1VR), wrote to apprise me of the situation. It concludes as follows: "Back in 1999, the late K3UOC, who received his Ed.D. from the Harvard Graduate School of Education and was very active with our club, wrote: Note: This legend has been published and told by word-of-mouth countless times over the past 90 years. Unfortunately, it isn't so. HWC members researched this story, even obtaining the copy of the Congressional Record for the date in question. We could find no record of Mr. Hyman appearing before congress. We have to admit, though, it's a very entertaining story!"

Recent Developments in Electronics

Recent Developments in Electronics, January 1960 Electronics World - RF CafeThis "Recent Developments in Electronics" from a 1960 issue of Electronics World had a lot of antenna news that included a retarded surface wave antenna with high gain and low silhouette for use in airborne early warning radar as well as ground based and shipboard radar, a pair of 60-foot tropospheric scatter antennas that are specially mounted at opposite ends of a 180-mile long section of the Gulf of Mexico, and a 104-foot-long rotating 50-ton radar antenna used for the SAGE early warning system. Also reported was Westinghouse Electric's airborne Stratovision for broadcasting educational television programming to rural areas out of reach of existing towers...

Color Television Systems

Color Television Systems, January 1951 Radio-Electronics - RF CafeIt's probably a safe bet that most people, even at the dawn of color television, knew of the competition which occurred for the adoption of three different methods of implementation. Two of them - line-sequential by Color Television, Inc. (CTI), and dot-sequential by Radio Corporation of America (RCA) - were fully electronic while the third system by the Columbia Broadcast System (CBS) used a kludge of a spinning color wheel placed in front of a black and white display. The CBS field-sequential design used a synchronization component of the composite transmitted signal to position the correct color screen (red, yellow, or blue) in front of the screen as the electron gun scanned the CRT - analogous to how World War I airplane machine guns were synchronized with the engine to fire between propeller blades. Of course an out-of-synch scenario in the color wheel was not as serious as with the machine gun. The worst that could happen with the TV is a false color picture whereas with the machine gun your biplane instantly became a glider. Although I poke some fun at the CBS solution...

Burning out Your Circuits Without Really Trying

Burning out Your Circuits Without Really Trying, May 1970 Popular Electronics - RF CafeAcrylic wall-to-wall carpeting really came into vogue in the late 1960s to early 1970s - just in time for the arrival of miniaturized microelectronics (is that redundant or just superfluous?). Gate widths were being shrunken rapidly as the birth of the Moore's Law era was in its infancy (born in a 1965 paper written by Intel engineer and co-founder Gordon Moore). The result was copious quantities of electronic gadgets being zapped when the unsuspecting user would walk across the Van de Graaff generator in the form of floor covering and reach for a dial or switch. A couple thousand volts could easily build up on a body clad in lime green polyester pants (remember the era), then fzzzzt, there goes the clock radio or AM/FM tuner. Vacuum tube circuits from a decade earlier ...

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers" Smith chart design. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. My graphic has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. I only make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way to help support RF Cafe. Thanks...

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 225,000 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. If you need your company news to be seen, RF Cafe is the place to be...

Whap - You're X-Rayed

Whap - You're X-Rayed, July 1969 Electronics World - RF CafeIf you think science-challenged politicians grandstanding in the media to gain - ostensibly, but unfortunately likely - favor with their constituents is a new phenomenon, take a look at this. On almost a daily basis these days we have elected doofuses pretending to be experts in physics, climatology, chemistry, medicine, economics, and other realms of learned science, when all they are really are mouthpieces for special interest lobbyists whose clients have lots of money for elections. At the risk of being too repetitive, I have to point out the brilliant congressman from Georgia who thought that the...

Sweden Electronics Market

Sweden Electronics Market, December 27, 1965 Electronics Magazine - RF CafeThis is the electronics market prediction for Sweden, 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. Among Sweden's modern-day most recognizable electronics and related manufacturers are Ericsson, Saab Group and Electrolux, in existence in one form or another since 1965. Automotive company Volvo is also among the largest manufacturers there, although not specifically of electronics. A number of contemporary resources are available for obtaining reports (at a cost) on the electronics industry in almost every country on Earth. Among them are "Consumer Electronics in Sweden, August 2019" and "Electronics Industry in Sweden June 2019..."

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, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

AM/FM Under Siege

AM/FM Under Siege - RF CafeThe electromagnetic world sure is a noisy place and it is getting worse all the time - in every region of the spectrum. Intentional radiation is not so much of a problem because it usually falls within well-defined limits and is predictable, but sloppy engineering and, honestly, ignorance, has made life harder for just about everyone. Listeners to broadcast radio in both the AM and FM bands have really taken a hit. AM has always been prone to interference by its very nature, so anyone listening expects the occasional pop or hiss from atmospheric phenomena or a light switch being flipped on or off. Have someone in the house run a blender or drill and you can forget hearing anything until the task is completed. It comes with the territory, so to speak. FM was and is largely immune to most forms of interference, but lately I have been noticing it coming from some of the most unusual places. For as long as I can remember, I have preferred to have a radio on in the background whilst whiling away at work and at play...

Report on the Soviet Earth Satellite

Report on the Soviet Earth Satellite, February 1958 Radio & TV News - RF CafeInterestingly, the February 1958 article in Radio & TV News magazine entitled "Report on the Soviet Earth Satellite" never mentions the craft's name - "Sputnik 1," or "Простейший Спутник-1," which in English is "Elementary Satellite 1." Sputnik 1 was, in case your history is a bit fuzzy, the world's first successful artificial communications satellite. Launched by the Union of Soviet Socialist Republics (USSR) on October 4, 1957, Sputnik 1 remained operational for about three weeks in low Earth orbit (284 miles average), during which time radio receiving stations across the globe anxious tuned in hoping to hear the 20.005 MHz and 40.002 MHz pulses that alternately repeated continuously in an alternating manner - the first FSK (frequency-shift keying) from space. Ruskie engineers made the signal frequencies and periods as stable as possible in order to enable careful frequency and timing...

RF Cafe Quiz #7: Radar Fundamentals

RF Cafe Quiz #7: Radar Fundamentals - RF CafeAll RF Cafe quizzes would make perfect fodder in employment interviews for technicians or engineers - particularly those who are fresh out of school or are relatively new to the work world. Come to think of it, they would make equally excellent study material for the same persons who are going to be interviewed for a job. This particular quiz challenges your knowledge of radar fundamentals. Do you know what a "radar mile" is? Bon chance.

New Crystron Lapel Radio

New! Crystron Lapel Radio, April 1947 Radio-Craft - RF CafeAdmittedly, with all the reading I have done of vintage electronics magazines, news of this Crystron (crystal-electron) vacuum tube device invented by Mr. Mohammed Ulysses Fips, as reported in the April 1947 issue of Radio Craft magazine, evaded my attention. The article came only a couple months after publication of the 40th anniversary edition that celebrated Dr. Lee de Forest's invention of the Audion tube. According to Mr. Fips, his Crystron one-upped the Audion by virtue of its containing a small amount of radio isotope which obviated the need for the traditional "B-battery" concept also developed by de Forest to supply a high voltage for driving the output stage circuit. While not capable of powering a concert hall audio speaker system, it did make possible use of a small speaker as a nearby personal listening device rather than requiring headphones or earbuds. Without divulging the most critical and closely-held details of the Crystron as the U.S. Patent Office...

Engineering & Science Crossword Puzzle for April 12

Engineering & Science Crossword Puzzle April 12, 2020 - RF CafeWorking crossword puzzles can be contagious. This April 12, 2020, tech-themed crossword puzzle may even go viral - the second in a series. It contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have personally built over nearly two decades. That includes the cause for our planet's current dilemma. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia...

Engineering & Science Crossword Puzzle for February 2

Engineering & Science Crossword Puzzle February 2, 2020 - RF CafeAs with my hundreds of previous science and engineering-themed crossword puzzles, this one for February 2, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you...

Are Radio Symbols Wrong?

Are Radio Symbols Wrong?, March 1944 Radio-Craft - RF CafeDo you remember back in the 1980s when adoption of the IEEE-type logic schematic symbols* got a big push? It proposed a logical approach (pun intended) to building any type of combinational logic or sequential logic devices based on strict rules of construction. Curved lines are nowhere in sight. Interestingly, the same type of schematic symbol "simplification" was proposed in the 1940s. The motivation for removing curved lines was to prevent draftsmen from needing to use a compass or special drawing template rather than using only a straight edge. Vacuum tube outlines, light bulbs, inductors, etc., required more time to pencil in. In 1944, this article entitled "Are Radio Symbols Wrong?" appeared in Radio-Craft magazine...

Predicting the Future of Radio Communications

Predicting the Future of Radio Communications, June 1951 Radio-Electronics - RF CafeSyzygy is a great word for a Scrabble game. If you use it on a Triple Word Score (TWS) space where the "Z" sits on a Double Letter Score (DLS) space, it will net you 105 points. About the only way to do better is to use all 7 letters on a TWS play, where you earn 50 bonus points added to your word score (I've done it twice in the last year). Syzygy is an astronomical term referring to an alignment of three or more celestial bodies - not necessarily in exact alignment, but within a few degrees. Astrologers (not to be confused with astronomers) have since their knuckles no longer dragged on the ground exploited such scenarios to predict various events both good and bad. That was even before they knew those "wandering" orbs (planet means "wanderer") were different than the (seemingly) stationary points of light. Until Galileo turned his rudimentary telescope on the planets, the only celestial objects with a discernable disk shape were the sun and moon, and possibly the earth. But I digress. It was long thought that the vector sum of gravitational influences was responsible for certain phenomena on our planet, including weather, tides, and earthquakes...

Ode on a Power Supply?

Electronics Poetry - "Power Supply", September 1942 QST - RF CafeOde on a Power Supply? Well, maybe not really an ode, but this poem entitled, "Power Supply," written by Eileen V. Corridan, appeared in the September 1942 edition of the ARRL's QST magazine. It is really quite entertaining and instructive! It applies to the original tube-based circuit as well as to modern solid state versions. I somehow get the feeling that this poem will now be republished in many places...

New Antenna to Multiply Field

New Antenna to Multiply Field, January 1938 Radio-Craft - RF CafeAmateur radio enthusiasts are very familiar with burying ground radials below the surface (or sometimes just laid on top) in order to increase antenna efficiency by affecting impedance and, more importantly, the radiation pattern. Long distance (DX) operators generally prefer low launch angles over high angle "cloud warmers." Pittsburgh's KDKA, the country's first commercial broadcast radio station, built what would have been the mother of all ground radial arrays for its time - 360 (one every degree), 700-foot copper wires (8 AWG), for a total of a quarter million feet! It was laid using a farm tractor drawing a non-motorized trench cutter that looks like it came straight from the John Deere factory. It also implemented a new type of passive vertical suppressor element array...

RF Cafe Engineering Crossword Puzzle w/Weekly Headlines: January 21

RF Cafe Engineering Crossword Puzzle w/Weekly Headlines January 21, 2018At least 10 clues with an asterisk (*) in this technology-themed crossword puzzle are pulled from this past week's (1/15 - 1/19) "Tech Industry Headlines" column on the RF Cafe homepage (see the Headline Archives page for help). For the sake of all the avid cruciverbalists amongst us, each week I create a new technology-themed crossword puzzle using only words from my custom-created related to engineering, science, mathematics, chemistry, physics, astronomy, etc. Enjoy!...

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, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Bell Telephone Laboratories 10th Anniversary Transistor

Bell Telephone Laboratories 10th Anniversary Transistor, June 1958 Radio & Television News - RF CafeThis Bell Telephone Laboratories (aka Bell Labs) advertisement appearing on the inside back cover of the 1958 issue of Radio & TV News magazine celebrated the 10th anniversary of their announcement of the world's first point contact transfer resistance (transresistance) semiconductor device  - aka the transistor. John Bardeen, William Shockley and Walter Brattain recorded the monumental event in a lab notebook on December 23, 1947 - a nice Christmas present for the world! The trio's invention was not like the robust bipolar transistors used today, or even ten years later in 1958. Rather than employing point-contact "cat's whisker" metallic probes for making the emitter and collector contacts with the germanium PN base substrate, commercially viable bipolar transistors use a doping element diffused into the purified crystal substrate to effect the emitter, base, and collector regions on a single crystal (with gold contact pads for attaching external leads)...

The Conical Monopole Antenna

The Conical Monopole Antenna, November 1966 QST - RF CafeIt is important to concentrate your transmitter power into the proper beam if you wish to deliver the best signal to the other fellow's receiving antenna. This has logically led to the popularity of the Yagi beam antenna on the higher-frequency amateur bands. A beam antenna for the 80-meter band should have a 140-foot reflector and a 77-foot boom on a 250-foot tower. This makes the beam antenna impractical for the 80-meter band, and even for 40-meter operation a full-size Yagi is a forbidding structure to the neighbor's narrow-minded view - even a well-trained XYL might view such a monster beam with alarm. There is no easy solution to the need for a good DX antenna at low frequency, but the conical monopole antenna may be of interest to the more eager radio amateur as a more practical solution. The conical monopole antenna is a base-fed vertical antenna that has an omni-directional pattern in azimuth but with an elevation...

"Ravin" - an Electronics-Themed Poem

Electronics Poetry - "Ravin", September 1942 QST - RF CafeThis is yet another example of humorous - and clever - poetry written by Hams from back in the 1940s... November 1942, to be exact. It appeared in the ARRL magazine QST. As alluded to in the title, "Ravin," it is a play on Edgar Allen Poe's famous "The Raven" poem. A few other electronic-themed poems are listed on the page as well, discovered in QST and in Popular Electronics. Enjoy...

Choosing Your Crossovers

Choosing Your Crossovers, October 1957 Radio & TV News - RF CafeAudio crossover networks have the same fundamental mission as RF multiplexer filters in radio systems, which is to separate and steer specific bands of frequencies into two or more signal paths. While simple in concept, implementation in hardware can be a major challenge depending on requirements for channel separation, feedthrough, phase and group delay, amplitude equalization, distortion, and other factors. This article discusses some of the decisions used by crossover network designers when considering where to make band breaks, while leaving actual circuit design rules to other authors. I built a set of custom speakers many moons ago and went through the frustrating process of deciding where to place the breaks and which speakers to use...

Editorial Comment on Grounding, March 9th "The Wireless World"

Editorial Comment, 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 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...

Panoramic Reception

Panoramic Reception, March 1945 QST - RF Cafe"Technically, panoramic reception is defined as the simultaneous visual reception of a multiplicity of radio signals over a broad band of frequencies. In addition, panoramic reception provides an indication of the frequency, type and strength of signals picked up by the receiver. Deflections or 'peaks' appearing as inverted 'V's on the screen of a cathode-ray tube." It is the kind of display that radar operators at Pearl Harbor were using when they mistook wave of incoming Japanese bombers a squadron of B-17s from the mainland. The panoramic receiver is not a wartime development, experimental models having been produced just prior to the outbreak of war. However, the many uses to which it has been put have demonstrated that the panoramic idea, particularly in the form of adaptors which may be connected to any receiver, is going to be very important...

Hams in Combat: A Lady of Mercy

Hams in Combat: A Lady of Mercy, July 1944 QST - RF CafeThis is another installment of the "Hams in Combat" series that the ARRL's QST magazine ran during WWII. I enjoy vicariously waxing nostalgic of a time before I was born, at time when there was still honor, courage, selflessness, and pride of country. During World War II, it was an ingrained part of most citizens, whether or not they happened to be serving in the military. Our modern day troops still have it, but sadly fewer and fewer people see their own country as any place special in the world. Many don't believe it ever was. Sure, as General William Tecumseh Sherman famously said, "War is hell," but then again so is witnessing the tearing apart of your country from forces within...

Yet More Tech-Centric Jokes

Yet More Tech-Centric Jokes - RF CafeTake a break from the drudgery with some of these tech-centric jokes, song parodies, anecdotes and assorted humor that has been collected from friends & from websites across the Internet. This humor is light-hearted and sometimes slightly offensive to the easily-offended, so you are forewarned. I have taken care to censor out "humor" with reproductive function innuendo and hateful tirades, so it is all workplace-safe. I have also tried to warn of any links that will result in audio clips so you can take appropriate precautions. As usual, there is no easy way to determine the true origin of any of these jokes. Unless otherwise noted, that prolific author "Anon" is the progenitor...

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, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Copper Mountain Technologies (VNA) - RF Cafe
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Noisecom

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