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Today in Science History

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...

Many Thanks to Anatech Electronics for Long-Time Support!

Anatech Electronics logo - RF CafeAnatech Electronics (AEI) manufactures and supplies RF and microwave filters for military and commercial communication systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter and cable assembly products are published in our website database for ease of procurement. Custom RF filters designs are used when a standard cannot be found, or the requirements dictate a custom approach for your military and commercial communications needs. Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please visit Anatech today to see how they can help your project succeed. 

Electronics-Themed Comics

Electronics-Themed Comics, July 1961 Radio-Electronics - RF CafeYay, Friday is here at last! To help you wind down the week, take a gander at these four electronics-themed comics which appeared in a 1961 issue of Radio-Electronics magazine. The one on page 106 is my favorite. It reminds me of an old Bugs Bunny cartoon from back in the 1970s, where a freeway was going to built over his rabbit hole (warren), and Bugs thwarted all efforts by construction crews from violating his humble abode (see "No Parking Hare"). There was another similar episode where skyscrapers were built around his hole, but I cannot find it. The page 95 comic reflects the public's fascination with rocket flights in an era when the first satellites were being launched, and manned spaceflight filled the imaginations of young and old. By coincidence, today's (October 4th) RF Cafe header logo features the Sputnik launch...

Iridium Pushes Boundaries with 3GPP Acceptance

Iridium Pushes Boundaries with 3GPP Acceptance - RF Cafe"Iridium Communications Inc., a leader in global voice and data satellite communications, has taken a significant step forward in its mission to enhance connectivity. The 3rd Generation Partnership Project (3GPP) has officially accepted Iridium's request to expand the functionality of Narrowband Internet of Things (NB-IoT) for Non-Terrestrial Networks (NTN) into the Work Plan for 3GPP Release 19. This marks a pivotal moment for Iridium's upcoming service, Iridium NTN Direct?, which aims to provide unprecedented access to satellite services via standard chipsets. What is Iridium NTN Direct?...

Capitol Radio Engineering Institute

Capitol Radio Engineering Institute Program Advertisement, May 1964 Electronics World - RF CafeThe Space Race was at its peak in 1964 when this advertisement by the Capitol Radio Engineering Institute (CREI) Program in Space Electronics appeared in Electronics World magazine. Although it all began in 1957 with the International Geophysical Year, the heat was turned up that year when the USSR successfully launched Sputnik 1, the world's first artificial satellite. President John F. Kennedy made his famous speech before the U.S. Congress in 1961, where he said in part, "This nation should commit itself to achieving the goal, before the decade is out, of landing a man on the moon and returning him safely to the earth." A huge push was made by colleges...

Electronic Analogy Quiz

Electronic Analogy Quiz, November 1961 Popular Electronics - RF CafeIt is common in electronics courses for an analogy to be drawn between electrical and mechanical phenomena. In fact, a lot of circuit analysis methods and equations apply directly to mechanics, and vice versa. An LC (inductor-capacitor) oscillating tank circuit is akin to a spring and dashpot. Resistance of a wire is likened to skin friction of water flowing through a hose. Who among us can forget those lessons? This Electronic Analogy Quiz from the November 1961 edition of Popular Electronics presents a challenge both because some not-so-familiar examples of analogies are offered, and because some are a real stretch. Therefore, don't feel too bad if you don't get a few. That's my way of saying that I didn't get all of them right ;-)...

Sperry Gyroscope Company - The Klystron

Sperry Gyroscope Company - The Klystron, April 1945, Radio-Craft - RF CafeKlystron is a household word these days - literally - since every microwave oven contains one. Do you know who registered the trade name originally? Per this advertisement from a 1945 edition of Radio-Craft magazine, Sperry Gyroscope Company did. It was actually scientists at Stanford University (Russell and Sigurd Varian) who developed the klystron tube, financed by Sperry as part of its blind aircraft landing system. In an act of magnanimity that would never be considered in today's competitive markets, Sperry issued the following statement: "From now on, the name Klystron belongs to the public, and may be used by anyone as the designation for velocity-modulated tubes of any manufacture." Right decent of them.

Two-Wire Three-Way Switching Circuit

Two-Wire Three-Way Switching Circuit, July 1966 Popular Electronics - RF CafeI have to laugh a bit when seeing this article on how to wire up a set of 3-way switches "[i]f you only have a two-wire cable to work with." There have been many times when I needed to wire a set of 3-way switches and only had 2-wire Romex cable on-hand. The simple solution is to simply run two pieces of 2-wire cable and only use one wire from the second piece. A 250' roll of 14-3 w/ground costs about $79 at the hardware store. A 250' roll of 14-2 w/ground costs about $45. For short runs, the additional cost of using two pieces of 14-2 compared to a single piece of 14-3 is diddly. However, if you want...

Crystal Photocell Circuits

Crystal Photocell Circuits, January 1957 Radio & Television News - RF CafeElectronics hobbyists are always anxious to hear the announcement of a new device that is forecast to revolutionize the tech world. In the late 1950s something as relatively tame as a crystal photocell satisfied that urge. This 1957 article in Radio & Television News magazine is a prime example. Today it takes something like a negative refractive index metamaterial to invoke the same sense of awe and wonder. Those were simpler times, but then again even today's beginners in the world of electronics circuit designing and building have to start somewhere, and these types of circuits are as good as any place...

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...

Inertial Guidance Directs Planes and Missiles

Inertial Guidance Directs Planes and Missiles, December 1958 Radio-Electronics - RF CafeWerner von Braun and his team of rocket scientists are credited with developing the first useful inertial stabilization platforms for ballistic missiles. The infamous and formidable V2 rocket wreaked terror upon the heads of Londoners during the latter days of World War II. It served to keep the rocket in a fixed orientation during the boost phase of the flight, but did not serve any active targeting function. Inertial navigation systems, on the other hand, are used to provide both accurate positional and attitude information for the pilot (if the platform has one) and to steer the platform (vehicle) to a predetermined destination. Inertial navigation systems are therefore much more complex. Early inertial navigation systems relied on physical spinning gyroscopes mounted within a series of nearly frictionless gimbals to maintain a fixed reference position in space. Contactless encoders about the rotation axes of the gimbals sent positional information to a computer, which then performed necessary calculations and sent formatted data to visual flight instruments...

Carl and Jerry: El Torero Electronico

Carl and Jerry: El Torero Electronico, April 1960 Popular Electronics - RF Cafe"So if I can work out a really efficient way of changing part of this wasted noise into electrical energy, it can be charging batteries and taking some of the load off the plane's generating plant." That passage, from the April 1960 Carl and Jerry adventure story, reads like a modern day energy harvesting project. Each month Popular Electronics included an electronics saga that normally included some high tech sleuthing by the teenagers a la the Hardy Boys. This is a particular favorite of mine because it involves a radio controlled airplane model. BTW, according to the Google translator, the title of this story is "The Electronic Bull."

Broadcasting - As I Imagined It...

Broadcasting - As I Imagined I..., February 1939 Radio-Craft - RF CafeDr. Lee DeForest might have had something like National Public Radio (est. 1970) in mind when he penned this article in 1933. In it, the famous vacuum tube amplifier inventor lamented and criticized the commercialization of broadcasts because of all the paid product announcements (aka commercials) that had been steadily increasing over the years. He also was critical of the "hit-or-miss, higgeldy-piggeldy mélange program basis" of programing; i.e., the same station playing a mix of jazz, opera, swing, syndicated story-telling, etc. The good doctor did not elaborate on where funding for such dedicated, uncorrupted broadcasts would originate if not from paying advertisers, and I do not recall ever reading about a DeForest Radio Network paid for by his vast fortune. I don't like commercials any more than the next person, but a company deserves time to pitch its products and/or services if it helps deliver a source of entertainment to you that...

Curiosa in Radio

Curiosa in Radio, June 1935 Radio-Craft - RF CafeI usually try to post something a little less serious and technical on Fridays to help everyone wind down from the long week just passed. It could be a Carl & Jerry or a Mac's Radio Service Shop story, an electronics quiz, or even something I found out on the Internet. This time it is a "believe-it-or-not" type feature entitled "Curiosa in Radio," about radio manufacturing, operating, and infrastructure. One factoid claims "Only 1.1% of set manufacturers in business in 1924 are building sets today." It could due to being in the middle of the Depression Era so almost nobody was making / buying radios, but more likely it reflects the reality of the many people who jumped into the fledgling radio industry early on and then could not gain market share. Enjoy.

How Intermodulation Distortion (IMD) Results from Nonlinearity

Intermodulation Distortion, February 1960 Electronics World - RF CafeAudio distortion is most often expressed as total harmonic distortion (THD) as opposed to intermodulation distortion (IMD). As the name suggests, THD is a measure of harmonic power content relative to the fundamental frequency (a single tone) from which harmonics are created. IMD on the other hand, is generated from the nonlinear mixing of two or more tones, with the products being non-harmonically related to the original tones. The author's discussion of audio frequency IMD applies equally to radio frequency IMD. Intentionally generated harmonic components can enhance sound quality due to being consonant, whereas IM products create dissonant tones not directly related to the originals...

Editorial Comment: 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 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...

Bell Telephone Laboratories - Miniaturization

Bell Telephone Laboratories - Miniaturization, November 1949 Radio-Electronics - RF CafeWhen many people hear the name of Bell Telephone Company, the first thing they think of is the court-directed breakup of Bell System into what became known as "Baby Bells" after being sued for monopolistic policies. What is too often forgotten - or more likely never realized - is the immense role Bell played in the building of America into an industrial and technology giant. Vintage magazines like this 1949 issue of Radio-Electronics as well as many other types including The Saturday Evening Post, Popular Mechanics, Family Circle, and many other publications commonly found in homes, contained full-page advertisements by Bell Telephone Laboratories promoting their work and reminding subscribers of how their hard-earned money was being invested on improvements. Along with the Interstate Highway System, America's robust, dependable, and high quality personal communications...

The Day Before Christmas

The Day Before Christmas, December 1958 Radio-Electronics - RF CafeThe December 1958 (my 1st Christmas) issue of Radio-Electronics magazine featured a clever take-off of the famous children's story "Twas the Night Before Christmas," by Clement Clarke Moore (originally titled A Visit from St. Nicholas). "The Day Before Christmas," by Jack Darr, might contain some terms not familiar to a more contemporary crowd. For instance, how many even know that "Gunsmoke" was a Prime Time television shown from the 1950's, and is not just a forbidden word in today's public schools (since it contains the word "gun")? How about an antenna on the roof, or a telephone with a "dial" on it? Most people don't even carry paper "pelf" around anymore. If you're under 30 years old and run across an unfamiliar word or phase, simply speak it into your smartphone and Siri (or some variant) will be glad to look it up for you ;-) ...

$5.00 for Best Short Wave Kink

$5.00 for Best Short Wave Kink, May 1935 Short Wave Craft - RF CafeIf you need a cheap, quick lightning arrestor for your antenna or just about any type of wired system, this idea from Mr. Burgess Brownson looks like a good idea. He used an automotive spare plug. Voltage breakover points can be set by varying the spark gap distance. The old vacuum tube transmitters and receivers had a better of chance of surviving a lightning strike because the components were able to handle much more of a shock than our modern semiconductor sets with miniature, closely spaced components. Still, the spark plug setup is better than nothing, if for no other reason than to protect the shelter. it should suffice. This and many more "kinks" are offered in this 1935 issue of Short Wave Craft magazine...

Science Theme Crossword Puzzle for January 24th

Science Theme Crossword Puzzle for January 24th, 2021 - RF CafeThis Science Theme crossword puzzle for January 24th contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Radio Theme Crossword Puzzle for July 4th 

Radio Theme Crossword Puzzle for July 4th, 2021 - RF CafeThis Radio Theme Crossword Puzzle for July 4th has a few words paying homage to what remains of the freedoms and promises of America, along with words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Carl & Jerry: Two Tough Customers

Carl & Jerry: Two Tough Customers, June 1960 Popular Electronics - RF CafeHmmm... this is the first time recall either of Carl's or Jerry's father, at least where either was present in the story. Their mothers are mentioned on occasion for providing sandwiches or uttering words of caution when embarking on a sleuthing mission. In this episode entitled "Two Tough Customers," creator and author John T. Frye have the techno-teens set out on an adventure to shop for a good deal on a fundamentally sound car - which they would own in a partnership set up by their fathers. As you would expect if you are an ardent C&J follower, their effort includes inspecting not just the mechanical integrity but also the electrical system health. Frye always used his stories as the basis for a lesson on some technical aspect of everyday life. The boys broke teenage car owners into three groups: Hot-Rodders, Show-Offs, and Mechs. They seemed to assign one trait or the other, but not a combination thereof. Personally, I was a bit of all three with my first car - a 1969 Camaro SS. While reading, see if you notice what I did about the battery measurement...

POPULAR ELEComics - Comics with an Electronics Theme

POPULAR ELEComics - Comics with an Electronics Theme, January 1968 Popular Electronics - RF CafeAlways a good way to end a busy week, here is a collection of electronics-themed comics that appeared in a 1967 issue of Popular Electronics magazine. A few of the artists you will recognize if you are a regular reader. Some drawing styles are immediately identifiable, such as those by Dave Harbaugh (of "Hobnobbing with Harbaugh" fame). Others, at least to me, are not quite so familiar. Frank Tabor, George White, Stan Fine, and JAS (I'm sure I know those initials, but can't place them) are amongst the others. I have to admit to not really knowing what the gag is in the comic with the guy in his pajamas. The party guy is cutting a wire to his ear buds ...

How the J-K Flip-Flops

How the J-K Flip-Flops, January 1969 Radio-Electronics - RF CafeAn alternate title for this article that appeared in a 1969 issue of Radio-Electronics magazine could have been, "How to Build a J-K Flip-Flop." Author Leonard Geisler takes the reader through a step-by-step assembly of a functional J-K flip-flop using a collection of 1- 2- and 3-input NAND gates. The 1-input NAND, in case you are wondering, is used as an inverter. The piece reads like an in-depth first-semester electrical engineering technician course textbook. In the process of building the J-K, an R-S (reset/set) flip-flop is described. Nowhere does Geisler offer an explanation of from where the "J" and the "K" input labels come. According to electrical engineer Sourav Bhattacharya blog, it was Dr. Eldred Nelson of Hughes Aircraft who first coined the term J-K flip-flop...

Who is Liable?

Who is Liable?, February 1953 Radio-Electronics - RF CafeMost of us probably never give much thought to how vulnerable we could be in a lawsuit related to our professional activities - until it's too late. That is particularly true if you are not directly involved in the sales or service business. Even when it is reasonable to believe that there is no way a jury or judge could find you liable for a charge levied against you, the skill of a talented lawyer and/or whims and prejudices of judges and/or jurors can doom you. Although a bit dated, the legal cases cited in this Radio-Electronics article give a little insight into why you would do well to give some thought to what the consequences of your actions and/or statements might invite if someone decides you have offended him or her. Remember that settled legal cases are regarded as precedence...

RF Cafe Engineering & Science Crossword Puzzle March 25

RF Cafe Engineering & Science Crossword Puzzle March 25, 2018Each week, for the sake of all avid cruciverbalists amongst us, I create a new technology-themed crossword puzzle using only words from my custom-created lexicon related to engineering, science, mathematics, chemistry, physics, astronomy, etc. You will never find among the words names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You might, however, see someone or something in the exclusion list who or that is directly related to this puzzle's theme, such as Hedy Lamar or the Bikini Atoll, respectively...

Smellevision Now Here!

Smellevision Now Here!, June 1951 Radio-Electronics - RF CafeWe all know that for the most part television stinks. Back in 1951 when this article appeared in Radio-Electronics magazine, the technology was very new and it was considered a miracle not to be wasted on inane programming. Newscasts actually presented news and not opinion, movies and sitcoms cast the nuclear family, law enforcement, the military, religion, and patriotism in a positive light rather than as the purveyors of evil in the world. By the end of the 1960s to early 1970s a lot of that had changed. Political and social agendas weaseled their way into nearly all programming to the extent that terms like "boob tube" and even, yes, "smellivision," became common monikers for television. The form of smellivision presented in this article was granted patent (US2540144A) protection in 1951 under the title, Television with scent effects..."

Crossovers, Electrical or Electronic?

Crossovers, Electrical or Electronic?, March 1969 Radio-Electronics - RF CafeMaybe it is because I recently rebuilt a set of stereo speakers that this article on frequency crossover circuits seemed appropriate for posting. Crossovers networks are essentially an audio version of a an RF multiplexer filter. The speakers were just some cheap jobs from an old system where one had a split in the 8" bass speaker cone. I wanted to keep the enclosures since they match the receiver and turntable and replace just the speakers themselves. The so-called crossover circuit consisted of a series capacitor in one line of each of the midrange and tweeter speakers. Good quality stereo speakers and a good crossover circuit would have cost a couple hundred dollars - well beyond my budget, so I opted for some just-above-low-end car speakers...

Engineering & Science Crossword Puzzle for June 23

Engineering & Science Crossword Puzzle June 23, 2019 - RF CafeSince 2000, I have been creating custom engineering- and science-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. A database of thousands of words has been built up over the years and contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc. 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 ...

Electronic Crosswords, April 1960 Electronics World

Electronic Crosswords, April 1960 Electronics World - RF CafeJohn Gill published many electronics-themed crossword puzzles in Electronics World magazine in the 1950s and 1960s. Unlike the weekly RF Cafe engineering crossword puzzles, some of the words used herein are not directly related to science, engineering, mathematics, etc. You will find the level of difficulty much less than that of a Sunday edition New York Times crossword, but there are some challenging clues, particularly given the era that it was created. Bon chance...

Crystal Finishing

Crystal Finishing, November 1944 Radio News - RF CafeWith a last name like Blattenberger and an unusually spelled first (Kirt), I learned a long time ago not to poke fun at anybody's name, but surely the parents of Dr. Hal F. Fruth had a sense of humor when assigning their little bundle of joy in such a manner (HalF Truth?). Maybe I assume too much. Anyway, the good doctor published in this issue of Radio News magazine a very extensive treatise on the art and science of mass producing radio frequency crystals at a time when the country - and free world - was in urgent need of them. He notes that, "Prior to Pearl Harbor Day, the world production of these plates and bars could be counted by the thousands. The present production rate has skyrocketed more than one hundred fold so that the present production rate is nearly 30,000,000 units per year...

Bell Telephone Laboratories Lens Antenna

Bell Telephone Laboratories Lens Antenna, May 1946, Radio-Craft - RF CafeAt first look this antenna from Bell Telephone Laboratories appears to be a phased array, but in fact it is a "lens" that uses reflecting metal fins to direct incoming and outgoing radio waves into a narrow beam. This is a new approach to the standard method of using a curved (usually parabolic) reflective dish with a feedhorn. No detail is given about how, if at all, the phases of the received signals are phase-adjusted at the point they converge on the back-side waveguide feed. It is sort of akin to the Osgood optical lens used in lighthouses. Shortly after the end of World War II, Bell Telephone Labs began a major effort to interconnect the entire country with microwave relay stations to enhance efficiency and reliability of long distance telephone calls...

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+ 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...

Receiving U.S. Satellite Signals

Receiving U.S. Satellite Signals, March 1958 Radio News - RF CafeIn 1958, most people were not accustomed to seeing the now-familiar maps plotting the sinusoidal courses of satellites across the face of the earth. It had only been in October of the previous year that any object other than the moon was in orbit around our home planet - that was U.S.S.R.'s Sputnik. Just as people of all ages and all backgrounds enthusiastically joined in the newfangled phenomenon of aeroplanes after the Wright Brothers flew their fragile craft at Kitty Hawk, electronics communications and scientists worldwide hopped aboard the satellite train (so to speak). This article from a 1958 issue of Radio & TV News magazine provided insight into the construction and flight characteristics of early U.S. satellites, and offered advice on how to participate in the ongoing International Geophysical Year (IGY) research effort by tuning in and reporting your signal reception characteristics. Activity was not just the domain of operators with sophisticated equipment...

How to Derive -40°F = -40°C

How to Derive -40°F = -40°C - RF Cafe UniversitySome of what you and I consider common knowledge is largely unrealized by most people. Call me a geek, but I take pleasure in pointing out to people that the Fahrenheit and Centigrade scales are equal at -40°, and I especially enjoy working out the simple proof for them. Most people appreciated the effort and are amazed, claiming to have never seen that before. When I read the following in Smithsonian magazine, "Winter temperatures here, some 250 miles northeast of St. Petersburg, sometimes plunge to minus 40 degrees Fahrenheit," I wondered whether the author knew that -40°F = -40°C. Maybe he just didn't want to confuse his readers by omitting the redundant superfluous 'F' or 'C,' and it couldn't be 'K' because there are no negative Kelvin degrees. It could also be that he knew but figured most people do not...

Innovative Power Products Cool Chip Thermal Dissipation
Innovative Power Products Cool Chip Thermal Dissipation - RF Cafe

Anatech Electronics RF Microwave Filters - RF Cafe

Werbel Microwave (power dividers, couplers)