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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...

Balloons Raise Shortwave Antenna

Balloons Raise Shortwave Antenna, April 1935 Short Wave Craft - RF CafeAntennas have been deployed in difficult environments using many ingenious methods over the years both by professionals and amateurs. The process typically involves first propelling a lightweight string or wire across and/or up to a supporting structure (a tower, tree, building, whatever) and then using that lead line to draw the antenna and its accompanying coaxial or twin lead cable into its final position. Sometimes simply tying a line to a rock and tossing it over a tree branch does the trick, but usually deployment requires a more powerful launch such as a a bow and arrow or even a model rocket. Many years ago R/C Modeler magazine reported on a large radio controlled airplane (Senior Telemaster) that towed a lead line across a wide gulch...

Within Earshot of the Editor

Within Earshot of the Editor - FCC Interference Law, August 1938 Radio News - RF CafeThe August 1958 issue of Radio News marked the merging of All-Wave Radio with Radio News, both founded by Hugo Gernsback. Radio News began publication in July 1919 (actually titled Radio Amateur News for the first year) and All-Wave Radio debuted in September 1936. "All-wave" radio referred to a class of radios popular at the time which could tune in most of the worldwide commercial broadcast stations, spurring the accompanying "short wave listening" craze. This instance of the monthly "Within Earshot of the Editor" column received a lot of attention because it fired a shot across the bow of the ARRL for not sufficiently lobbying the FCC for the electromagnetic spectrum access rights currently enjoyed and the serious threat of loss. Many people subsequently accused Radio News of attempting to torpedo the ARRL and replace it with another organization of Ham operators...

Mac's Radio Service Shop: The Time Is Now

Mac's Radio Service Shop: The Time Is Now, March 1958 Radio News - RF CafeUnlike many electronics enthusiasts including hobbyists, salesmen, servicemen, and commercial and domestic users, Mac McGregor was an early-on believer of the ultimate replacement of vacuum tubes by transistors. Only a decade old and not yet adopted by a lot of manufacturers (to their ultimate demise in some cases), transistors were fighting a major battle to gain acceptance and trust by the public. Not only were transistors still more expensive than an equivalent vacuum tube, but the reliability was not as good - most times due to designers not properly accounting for their special needs for protection against voltage extremes. Once the price of transistorized products fell into parity with their predecessors, consumers quickly adopted the products because of the markedly smaller sizes and lower power consumption...

Sparton Selectronne Receivers Models 1068 and 1068X

Sparton Selectronne Receivers Models 1068 and 1068X, December 1937 Radio-Craft - RF CafeWell shazam, I found a radio service datasheet that had been missed. This one for the Sparton Selectronne Model 1068 brings the grand total to 220 that have been scanned and posted here on RF Cafe. They appeared in various formats in Radio-Craft, Radio News, and Radio & Television News magazines. It was in the 1930s that pushbutton tuning appeared in most radio sets, both tabletop and floor-sitting console models. Those mechanical pushbutton tuner mechanisms were pretty impressive. The Selectronne also sported a popular visual tuning indicator called the Viso-Glo tube. It was not...

Hugo Gernsback on Radio Astronomy

Radio Astronomy, March 1953 Radio-Electronics - RF CafeHugo Gernsback wrote this editorial about the state of the art of radio astronomy in a 1953 issue of his Radio-Electronics magazine. He cites Dr. Jansky's discovery of radio frequency signals emanating from the center of our Milky Way galaxy, and the subsequent work done by radio astronomers in the interim. Little did Gernsback know that a mere decade later later, Bell Telephone Labs engineers Dr. Wilson and Dr. Penzias would serendipitously discover, using the company's "sugar-scoop" antenna, the ubiquitous cosmic microwave background radiation (CMBR) believed to be a signature of the "Big Bang" era. He predicted that, as is true for most realms of theoretical research, much collateral technology would be created as a result. Ultra low noise, cryogenically cooled receivers are an obvious example...

Waveguide Theory and Application (NEETS)

Waveguide Theory and Application (NEETS), Module 11 - RF CafeThat portion of the electromagnetic spectrum which falls between 1000 megahertz and 100,000 megahertz is referred to as the Microwave region. Before discussing the principles and applications of microwave frequencies, the meaning of the term microwave as it is used in this module must be established. On the surface, the definition of a microwave would appear to be simple because, in electronics, the prefix "micro" normally means a millionth part of a unit. Micro also means small, which is a relative term, and it is used in that sense in this module. Microwave is a term loosely applied to identify electromagnetic waves above 1000 megahertz in frequency because of the short physical wavelengths of these frequencies. Short wavelength energy offers distinct advantages in many applications...

RF Cascade Workbook

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

Micro-Modules

Micro-Modules, September 1958 Radio & TV News - RF Cafe"Micro" as applied to electronics is relative, depending on which decade you reference. In the 1940s, a micro-size electronic assembly might have included "peanut" vacuum tubes and even some sort of printed circuit board. That was a huge step down in size from standard size tubes with point-to-point wiring between tube sockets and solder lugs on switches, potentiometers, variable capacitors, etc. Fixed value leaded resistors, capacitors, and inductors, and transformer wires connected to those lugs as well as to many terminal strips installed specifically for making connections. Once transistors came on the scene in the 1950s, a new round of miniaturization took place based on not just a significantly smaller size of solid state transistors and diodes, but their lower voltage and current requirements meant ancillary components could be made smaller as well due to lower voltage...

Bell Telephone Laboratories Advertisement - Crystal Timekeeping

Bell Telephone Laboratories Advertisement - Crystal Timekeeping, January 1946 Radio News - RF CafeI don't know about you, but I really miss the hard-wired POTS (Plain Ordinary Telephone System) days of remote communications. Unless the conversation was with an overseas telco system, there was never a noticeable delay where both parties were constantly either 'stepping' on each other's words or having to consciously wait before speaking to make sure the other guy has finished. Whether it be cellphone-to-cellphone or cellphone-to-VoIP, nearly every conversation is annoying. Sometimes when one party is on the POTS line with either a cell or Internet connection it can go well, but if you want a hassle-free conversation (assuming the person you're talking to is not a PiTA), you need a hard-wired connection on both ends. People loved to hate Bell Telephone back in the day...

How Much Current Is Fatal?

How Much Current Is Fatal?, January 1972 Popular Electronics - RF CafeThose of us who have been working for a long time around electricity with exposed circuit components are well aware that as little as one-tenth of an ampere (1/10 A) can produce a lethal reaction, particularly if the current path runs through the heart (i.e., hand-to-hand). Some of us (moi) have even experienced a pretty significant jolt from a high voltage vacuum tube power supply and/or from a 480 volt, three-phase supply to an industrial motor. Fortunately, the worst damage done was to my ego and a feeling of utter stupidity for allowing the occurrence to happen. If you are new to the concept of electrocution, you might be inclined to wonder why, when the chart below shows certain current levels with corresponding effects, would I mention exposure to high voltages? The answer is that various current paths through your body...

Science Celebrity Theme Crossword Puzzle for December 12th

Science Celebrity Theme Crossword Puzzle for December 12th, 2021 - RF CafeThis Science Celebrity themed crossword puzzle for December 12th contains no fewer than 18 names of notable scientists and engineers (marked with an asterisk *) known famously to folks like you who visit RF Cafe. It took quite a while to design. Elsewise, only clues and words which are directly to RF, microwave, and wireless engineering, optics, mathematics, chemistry, physics, and other science 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...

Thanksgiving Day Crossword Puzzle

Thanksgiving Day Crossword Puzzle - RF CafeThis week's RF Cafe crossword puzzle contains the usual assortment of engineering and science related words and clues, but there are also a few specific words commemorating our Thanksgiving Day holiday (indicated by a asterisk *) that is celebrated each year on the fourth Thursday of November. Macy's 90th Thanksgiving Day Parade occurs on the morning of November 24th and follows a route along Central Park West and 6th Avenue. Interestingly, the parade was cancelled during the World War II years of 1942, 1943, and...

Magnetism - Its History

Electricity - Basic Navy Training Courses, NAVPERS 10622, Chapter 11 - Magnetism - RF CafeAn ancient legend tells us that nearly 5,000 years ago an Emperor of China had a small statue of a man mounted on his chariot. This statue was pivoted at the base and one outstretched arm always pointed to the south. In those ancient times, this action must have seemed truly miraculous - probably the Emperor used his statue more to impress his subjects than he did to find his way. This legend is the first report of man's use of a black or lead-colored stone called magnetite. About the time of Christ, magnetite was rediscovered by a Grecian shepherd. He noticed that the iron of his staff was attracted to certain stones. But for nearly another 1,000 years, no particular use was made of this discovery...

RCA Radio - Cost Reduction

RCA Radio - Cost Reduction, March 1946, Radio-Craft - RF CafeIf you have seen many of the articles I post from vintage electronics magazines, you know I often compare prices from the magazine's era to today's prices. The online Inflation Calculator from the Bureau of Labor Statistics (BLS) is as good as any, so it is used. This RCA advertisement in a 1946 issue of Radio-Craft magazine boasts of how drastically the cost of vacuum tubes has come down since 1923. It claims a $9 tube in 1923 costs a mere 80¢ in 1946; that is about 1/11th of the original price. Prior to around 1965, inflation was very low, so the inflation-adjusted price for the $9.00 tube would be $9.80 in 1946 - a full 23 years later (a 9% increase, per the BLS). Therefore, the 80¢ price is an even better deal. Let us compare that to what a $9 item 23 years ago (1998) from today (2021) would cost now. Per the BLS Inflation Calculator, it would take $15.06 in 2021...

RF Cascade Workbook

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

Mac's Service Shop: Zenith's 1973 Color Line

Mac's Service Shop: Zenith's 1973 Color Line, March 1973 Popular Electronics - RF CafeThose of us who have been around for six or more decades have lived through two evolutions of video display types - raster scanned cathode ray tubes (CRTs) and digitally pixelated light-emitting diode (LED) and liquid crystal (LCD) displays. Unlike with the latter display types that improved in color depth, picture resolution and display size, the former had effectively a fixed resolution of horizontal lines (525 vertical steps - only 484 visible, actually, due to blanking). That meant for CRTs, designers needed to find ways to make images appear in-focus while also looking continuous on larger screens. Doing so involved cleverly adjusting the size and spacing of fluorescent color dots on the picture tube face while also using special metal masks between the electron gun and the tube. A lot of research that included panels of people rendering opinions...

All Channel Antenna Corporation

All Channel Antenna Corp., April 1954 Radio & Televsion News - RF CafePhased vertical stacks of two or more antennas were fairly common in the television realm - especially once color broadcasts became more dominant in the 1950s. Up to 3 dB per additional antenna is possible, but due to various non-ideal physical parameters (summed phase angle, imperfect antenna geometry, etc.), realized gain is typically in the 2.5 to 2.8 dB range. Higher signal to noise ratios were needed to guarantee good color separation with the National Television System Committee (NTSC) and stereo channel audio separation with the advent of Multichannel Television Sound (MTS). As you might expect, companies appeared claiming to have invented physics-defying antennas that "outperform all present antennas." This particular "Super 60" model from All Channel Antenna Corporation further claims to outperform antennas that use a mechanical rotator (see my Alliance U-100 Tenna-Rotor) by virtue of its 9-position electronic phase switching...

Patent Information for the Inventor

Patent Information for the Inventor Part 1, July 1962 Electronics World - RF CafeNot having ever applied for a patent, I do not know how much of what appeared in this "Patent Information for the Inventor" article from a 1962 issue of Electronics World magazine is still valid. The fundamentals are probably about the same. One thing that has changed since this article was written is the name change in 1975 from the U.S. Patent Office to the U.S. Patent and Trademark Office (USPTO), which occurred when ownership was passed from the Department of the Interior (1849-1925) to the Department of Commerce (1975-present). The schedule of fees has grown to a very complex table of definitions and requirements for various types of patents and services. A Basic Filing Fee runs $320 for big businesses, $160 for smaller concerns ("Small Entity"), and $80 for individuals with no more than four current patents ("Micro Entity). That compares to $25 in 1962 ($220 in 2021 money per BLS). July 31, 1790, the first U.S. patent was issued to Samuel Hopkins for an improvement "...in the making of Pot ash and Pearl ash by a new Apparatus and Process...

A Logic Named Joe

A Logic Named Joe - The Internet Foretold? - RF Cafe SmorgasbordSomebody get Al Gore on the phone - preferably using Skype. It appears that maybe he did not invent the Internet after all. Sci-fi writer William F. Jenkins, who went by the pen name "Murray Leinster," wrote a short story entitled A Logic Named Joe, that appeared in March 1946 issue of Astounding Science Fiction. In the story, an amazingly prescient description of the modern Internet is laid out. The works is copyrighted so I will not replicate the entire thing here, but these are a few excerpts that sound a lot like Mr. Leinster was in cahoots with DARPA during the development*. Before I forget, thanks to RF Cafe visitor Terry W. for sending the link. My comments look like...

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...

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...

Carl and Jerry: Tunnel Stomping

Carl and Jerry: Tunnel Stomping, March 1962 Popular Electronics - RF CafeA year has passed since I last posted a Carl and Jerry high-tech saga. John T. Frye created the duo of teenage sleuths in 1954 for the very first issue of Popular Electronics magazine. More than 100 adventures carried Carl and Jerry from high school through college. Their practical jokes, crime solving, and mystery investigations incorporated microphones, timers, cameras, Ham radio, transformers, metal detectors, remote controllers, home brew circuits, photodetectors, and a host of other gadgets that could be pulled from a stash of parts in Carl's or Jerry's basement workshop, or borrowed from a friend. In this story, Carl and Jerry, now students at Parvoo University in Indiana, have an unexpected confrontation with a radio operator while exploring a campus...

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...

The MOSFET

The MOSFET, May 1973 Popular Electronics - RF CafeThe metal-oxide-semiconductor field-effect transistor (MOSFET) was patented in its present form by Bell Labs in 1959, following the original patent by inventor Julius Edgar Lilienfeld, in 1925. It had only been on the open market for designers to use for a bit over a decade when this article appeared in Popular Electronics. Adolph Mangieri wrote a number of articles for the magazine in the early 1970s introducing readers to the many new types of semiconductor devices coming out of research laboratories and into the commercial marketplace; e.g., "Understanding the Junction Field Effect Transistor." MOSFET's are nowadays the primary building...

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...

Mac's Radio Service Shop: Cabinet Crisis

Mac's Radio Service Shop: Cabinet Crisis, March 1955 Radio & Televsion News - RF CafePlastic is one of those materials that seems like it has been around since the dawn of time - like metal. There was an Iron Age in the 1,000 BC timeframe (depends on location), but the Plastic Age - not that there officially was one - did not begin in the commercial world until World War II. If you note in older photos and films, there was not much, if any, in the way of objects made of plastic before the 1940s. In fact, the formulation and production of some types of plastic like Plexiglas and polycarbonates was considered a matter of national security for a while both for Allied and Axis powers. Bomber and fighter aircraft windshields were made of the material. After the war, use of plastics for industrial and consumer products exploded due to the much easier manufacturing of product enclosures, knobs, and parts with complex shapes. Lighter weight, lower cost, easy application of color, and in some cases greater robustness made plastic very popular with consumers. Plastic does have its drawbacks compared to the wood, metal, and phenolic materials previously used for radios, TVs, and phonographs, and Barney experienced one of them...

Bell Telephone Labs - Electrical Pipeline

Bell Telephone Laboratories - Electrical Pipeline, July 1946 Radio-Craft - RF Cafe"Electrical Pipeline" is as apt a layman's description for waveguide as "electrical hose" is for coaxial cable. What would be a good commoner's name for twin lead? "Ladder Line" and "Window Line" are descriptive of the type with open regions between supports, but neither relates to a water analogy that would be familiar to Joe Six-Pack. I'm open to suggestions. Module 11 of the Navy Electricity and Electronics Training Series (NEETS), entitled "Microwave Principles," does a very nice job introducing and explaining how waveguide works. It discusses rectangular, elliptical, and circular waveguide. Bell Telephone Laboratories, which was responsible for some of the most profound and world-shaping innovations of the 20th Century, pioneered the use of waveguide in commercial telecommunications systems...

Standardized Wiring Diagram & Schematic Symbols

Standardized Wiring Diagram & Schematic Symbols, April 1955 Popular Electronics - RF CafeElectronics symbols for schematics and wiring diagrams have remained amazingly consistent for the last hundred years, although obviously many new ones have been added. You can see from this set of standardized wiring diagram and schematic symbols from a 1955 edition of Popular Electronics what I mean. Even symbols for newly introduced devices tend not to change. There are some variations such as whether or not to draw a circle around a transistor or how many lightning bolt lines to use with photon emitters and detectors, but that's about it. The digital world adopted IEEE Standard 91-1984 for logic and microprocessors, although you will still occasionally see variants in symbols, especially in early digital circuit schematics. The ARRL publishes its own version of standardized electrical schematic symbols, but even the ARRL Handbook, in which the symbols are printed, does not strictly conform to its own standards.

How to Solder

How to Solder, April 1955 Popular Electronics - RF CafeProper soldering is almost as much of an art form as it is a technical skill. Having been through numerous soldering classes in my career, starting with electrical vocational courses in high school, then again in USAF technical school, and other times while working as a technician and engineer, I always exercise care in making solder joints. Proper preparation - including both tinning of mating surfaces and a means to prevent the joint members from moving during cool-down - is of utmost importance for assuring a nice, smooth, shiny joint with just the right amount of solder. Lead-free solders do not tend to produce the level of shininess as do the good old 60-40 type tin-lead solders, but you can still make a nice looking joint. This might be more information than you want to know about me, but I even strive for perfection in solder joints in copper pipes and fittings used in plumbing work...

RF Cafe Quiz #55: Conquer Radio Frequency

RF Cafe Quiz #55: Conquer Radio FrequencyThis quiz is based on the information presented in Conquer Radio Frequency, by Francesco Fornetti. See my review for the online version. This material, which includes a full-color textbook and over 12 hours of video tutorials (in mp4 format on enclosed DVD-R), provides a comprehensive guide for the RF and Microwave engineering student or junior professional. It allows the reader to achieve a good understanding of the foundation theory and concepts behind high frequency circuits as well illustrating the most common design and simulation techniques for passive and active RF circuits. A preview of the textbook, a comprehensive description of the content of the video tutorials and sample video tutorials are available on the Explore RF website.

Holzsworth
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