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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...

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...

Electronics IQ Quiz

Electronics IQ Quiz, May 1967 Popular Electronics - RF CafeUnlike those IQ tests conceived of and administered by Ph.D. college professors with pulsating veins in their foreheads, this "Electronics IQ Quiz," created by Popular Electronics quizmaster Robert Balin, is a true measure of your real-world acumen. Here are a couple hints to assist quiz takers not familiar with last century electronics. You need to have knowledge of the NTSC-mandated broadcast television channel bandwidth for figure A, but you might be able to guess it by process of elimination. For figure E, consider the bandwidth limits in terms of dB, not MHz. Kinks in the characteristic curves of the tube alluded to in figure D betray its number (extra hint: it's not a diode or a triode). Good luck...

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 Radio Service Shop: What's Right with the Service Business

Mac's Radio Service Shop: What's Right with the Service Business, May 1955 Radio & Television News - RF CafeAll types of sales and repair services get accused of ineptness of skill which requires more time than necessary, overcharging for parts and/or labor, underhandedness in faking problems and selling unnecessary replacement parts, improper customer interfacing, sloppiness in appearance and/or work environment, failure to arrive on time for appointments, etc. Some of the most often cited these days are auto mechanics, cellphone repairers, home improvement contractors, lawn care, and builders. Up until about a decade ago when cellphone repair began to dominate over computer repair, the latter was a big source of complaints. In the 1950s and 60s, it was TV and radio repairmen who took a lot of abuse not just from their customers, but from large, organized electronic service conglomerates and were abetted by mostly ignorant media outlets looking for a good story ...

TVI and the "Dallas Plan"

TVI and the "Dallas Plan", May 1952 Radio & Television News - RF CafeAmateur radio operators have been blamed for a lot of radio frequency interference (RFI) and television interference (TVI) over the years, with some being justified and a lot being unjustified. The surest sign that a Ham set is interfering with your entertainment box is when you actually hear voice or a series of dits and dahs. However, when the interference is a steady or waver buzzing sound or scratchy intermittent hash, chances are greater that the interference is coming from a noisy motor in a vacuum cleaner, a kitchen blender, a power tool, or an arcing power line transformer / cracked insulator. The American Radio Relay League (ARRL) has jumped through burning hoops (figuratively) to educate licensed operators on how to avoid complaints by assuring gear is functioning properly, and educating the public about the likelihood that the problems they experience are not coming from the guy down the street with big antennas in the yard but from the next-door neighbor's swimming pool filter pump...

Crystals for CB & Ham Communication

Crystals for CB & Ham Communication, March 1973 Popular Electronics - RF CafeAccording to author R.R. Freeland, manufacturing processes for radio-quality manmade crystals saw major improvements toward the end of World War II. At the time, the process was highly manual-intensive, as can be seen in this really nicely done 1940s video titled "Crystals Go to War." Prior to the use of crystals as frequency-determining devices, inductor-capacitor (LC) tank circuits were the dominant configuration. There were actually other frequency-determining schemes like spark gaps and even vibrating mechanical reeds. As you might guess, anything less than...

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!

Do You Know Your Bipolar Transistors? Part 3

Do You Know Your Bipolar Transistors? (Part 3), October 1973 Popular Electronics - RF CafeMr. Lothar Stern, of Motorola Semi, published a 3-part series on transistor theory in Popular Electronics magazine in 1973. This is part 3. Part 1 introduced the basics of the bipolar transistor, and Part 2 addressed transistor circuit configurations - common emitter, common gate, common collector, Darlington, differential - as well as presenting gain equations and delving a bit into the physical construction of the semiconductor elements. Finally, the author talks about the newest processes in use at the time and what was available for low power and high power RF applications. In 1973, high power semiconductors were just pushing past the 100 MHz barrier. GaAs and GaN were still in university and corporate laboratories being prepared for the amazing devices...

Carl & Jerry: Ultrasonic Sound Waves

Carl & Jerry: Ultrasonic Sound Waves, July 1955 Popular Electronics - RF CafeAside from the storyline, one notable aspect of this installment of "Carl & Jerry" is one of the illustrations used in it. Jeff Duntemann (K7JPD), himself a sci-fi and technical book author, wrote a piece on the evolution of John T. Frye's Carl & Jerry series in Popular Electronics, and in it he commented on the changes in drawing styles and character appearances over the many years that Frye inked his illustrations. I read Duntemann's article a while ago, but remembered the picture of Norma and Carl's dog Roscoe when I saw it again just now. The format obviously departs from the vast majority of Frye's typical works due to its distinctly cartoonish look. As for the plot of the story...

Engineering & Science Crossword Puzzle for February 2

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

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...

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...

1 to the 4th Power Amplification in Star Trek Redux

1 to the 4th Power Amplification in Star Trek Episode - RF CafeA few years ago I posted a note about a technical faux pas on an episode of Star Trek titled "Court Martial," where Captain Kirk makes a comment ordering the ship's auditory sensors to be boosted "on the order of 1 to the 4th power," (14) in order to pick up heart beats. RF Cafe visitor Sam M. just sent me a note offering a possible - and plausible - explanation for the gaff. If you are a devoted Trekkie looking for a response to your apostate friends when confronted over the scene, read on...

RCA Graphechon Tube

RCA Graphechon Tube ad in the July 8, 1950 Saturday Evening Post - RF CafeEver heard of the revolutionary Graphechon Tube, by RCA? Neither had I, until I saw it mentioned in an ad for RCA televisions in a 1950 edition of The Saturday Evening Post. My curiosity was piqued enough to do some research. First, here is the text of the ad: "Scientists at RCA Laboratories work with split-seconds of time too infinitesimal for most of us to imagine. Their new electron tube, the Graphechon, makes it possible. For instance, in atomic research, a burst of nuclear energy may flare up and vanish in as little as a hundred-millionth of a second. The Graphechon tube oscillograph, taking the pattern of this burst from an electronic circuit, "remembers" what happened - and re-creates it in a slow motion image which can last for a minute and a half. Scientists may then observe the pattern...

Sentinel Model 217-P Portable Radio Set Radio Service Data Sheet

Sentinel Model 217-P Portable Radio Set Radio Service Data Sheet, August 1940 Radio-Craft - RF CafeMany months have passed since I last posted one of the Radio Service Data Sheets for vintage radio sets. This one for the Sentinel Model 217-P portable appeared in the August 1940 issue of Radio-Craft magazine. Hobbyists and professional electronics service shops relied on these back in the day because obtaining the information from manufacturers could be difficult or even impossible. Some companies would not provide service information for alignment and troubleshooting to businesses that were not officially endorsed to do so. That left some of the smaller shops and most do-it-yourselfers without a means to work on sets. Once places like SAMS Photofacts came along with information packets that could be purchased ...

Introduction to Amplifiers: Coupling

NEETS Module 8 - Introduction to Amplifiers: Coupling - RF CafeNotice that the output (collector) of Q1 is connected directly to the input (base) of Q2. The network of R4, R5, and R6 is a voltage divider used to provide the bias and operating voltages for Q1 and Q2. The entire circuit provides two stages of amplification. Direct coupling has several disadvantages, however. The major problem is the power supply requirements for direct-coupled amplifiers. Each succeeding stage requires a higher voltage. The load and voltage divider resistors use a large amount of power and the biasing can become very complicated. In addition, it is difficult to match the impedance from stage to stage with direct coupling. The direct-coupled amplifier is not very efficient and the losses increase as the number of stages increase...

Burning out Your Circuits Without Really Trying

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

Microwave Principles: Directional Couplers

Microwave Principles: Directional Couplers (NEETS) - RF CafeThe discussion of waveguides, up to this point, has been concerned only with the transfer of energy from one point to another. Many waveguide devices have been developed, however, that modify the energy in some fashion during transit. Some devices do nothing more than change the direction of the energy. Others have been designed to change the basic characteristics or power level of the electromagnetic energy. This section will explain the basic operating principles of some of the more common waveguide devices, such as Directional Couplers, Cavity Resonators, and Hybrid Junctions. The directional coupler is a device that provides a method of sampling energy from within a waveguide for measurement or use in another circuit. Most couplers sample energy traveling in one direction only. However, directional couplers can be constructed that sample energy in both directions...

Engineering & Science Crossword Puzzle March 22

Engineering & Science Crossword Puzzle March 22, 2020 - RF CafeThis March 22, 2020, tech-themed crossword puzzle contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have personally built over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you...

Vintage Heathkit CR-1 Crystal Receiver Kit

Vintage Heathkit CR-1 Crystal Receiver Kit - RF Cafe Cool ProductThis vintage Heathkit CR-1 Crystal Receiver kit is one the latest unbuilt Heathkit kits which appeared on eBay, and can still be found there occasionally both in kit form and fully built sets. I have been saving the images in order to preserve the history. The constantly growing list is at the lower right. A PDF version of the Heathkit CR-1 Crystal Receiver Manual can be found here, but I captured the pages (below) in case it disappears someday. Note the information included on the operation of detectors and oscillators. The copyright on the manual is 1956, and it appears in the 1958 Heathkit catalog for $7.95 ($75.10 in 2021 money per the BLS). From the catalog page: "This crystal radio is just the ticket for construction by young people interested in radio or electronics - yet it is definitely not a toy. Employs high-quality standard components throughout. It is even usable as an AM tuner in high fidelity applications. Covering from 540 to 1600 kc...

Espresso Engineering Workbook™ for Excel

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

$15 Federal License Fee for Telephone Users?

$15 Federal License Fee for Telephone Users?, November 15, 1965 Electronics Magazine - RF CafeIf you have read as many vintage electronics magazines as I have, one thing that is obvious is how many of the same issues that plagued the field since the middle of the last century are still with us today - only in a much worse way by now. Government meddling, regulation and taxation are amongst the top offenders. Both the electric power industry and the communications industry have been hit hard, and huge costs to consumers is the result. Itemized bills from the utility companies do not give the full picture of what a large percentage of your monthly premiums go to feed the government beast. You might see some line items for taxes, surcharges, contributions and user fees, but those being paid for you by the providers (i.e., absorbed in the base charge) are hidden. One of the more recent, highly publicized example...

The FM Radio Boom

FM Radio Boom, August 1947 Radio-Craft - RF CafeHugo Gernsback is not necessarily a household name in 2020, but in the early to middle 20th century, he was fairly well known in both the hard science and science fiction realms. He was a prolific author of books and magazines in both areas, applying his profound knowledge of technology and his ability to foretell the futures of many aspects of communications, mechanics, electronics, and marketing and societal behavior to the aforementioned. If you are a regular RF Cafe visitor, you have seen very many articles written by Hugo Gernsback reproduced. This particular work of prognostication appeared in a 1947 issue of his Radio-Craft magazine. It presciently claimed that a post-war boom in consumer buying after half a decade of sacrifice of creature comforts for the good of the country and world would feed a significant adoption of FM radio over...

Mathematical Puzzles, 1981 Old Farmer's Almanac

Mathematical Puzzles, 1981 Old Farmer's Almanac - RF CafeEach autumn I used to anxiously await the appearance of the newest edition of The Old Farmer's Almanac on the store shelf, and such was the case with this 1981 issue. It is not that I was/am an avid farmer, just that I enjoy reading the anecdotes, tales, and interesting historical tidbits included amongst the pages along with tables of high and low tides, moon and sun rising and setting times, astronomical events, and weather patterns expected for the year that lay ahead. Most of all, I liked working the puzzles and riddles. Over the years the difficulty levels gradually got lower and lower (aka dumbed down), to the point where for the last decade or so I have not even bothered buying the OFA. Now it is full of numbnut stuff...

432-Mc. Solar Patrol

432-Mc. Solar Patrol, August 1967 QST - RF CafeNASA (and its predecessor NACA), and private and public operators have been monitoring solar events in the optical realm for many decades while attempting to correlate terrestrial phenomena with it. Auroral light displays in the extreme polar regions have long been known to be caused by solar flare and coronal mass ejections (CME). With the advent of radio, the electrical nature of the upper atmosphere became evident when static (AM) and long range propagation affected long range communications. Extreme CME activity eventually was associated with behavior of the electrical power grid; indeed, massive blackouts and brownouts are to blame for many. Last but not least came concern for sun-sourced electrons regarding satellites. More than one 'bird' has been smoked by the sun's ejecta. In 1967 when this article appeared in QST magazine, scientists were still in the early stages of measuring and understanding the effects of solar activity on the sun. The Geophysical Year...

Hams in Combat -One Life to Give

Hams in Combat - One Life to Give, July 1944 QST - RF CafeQST did a regular series of articles titled "Hams in Combat" during World War II. This story is unique in nature in that it tells of a newspaperman-turned-soldier who, in the story writer's mind, would have been the most suited for the job of author. It tells a far different story of the South Pacific than we were treated to in weekly episodes of McHale's Navy! "Had this story been written by the man who should have written it - Capt. William H. Graham, W9BNC - it would have been one of the greatest "Hams in Combat" yarns ever told in these pages. But Bill Graham never got around to writing his story. He was too intensely occupied with the living of it - too keenly aware of the new paragraph... Note the letter I received from Capt. Graham's great grandson.

Hobnobbing with Harbaugh - The Store

Hobnobbing with Harbaugh - The Store, June 1962 Popular Electronics - RF Cafe"My husband wants a selenimum rectalfire, a silicode capasitator, and a 16 bome appleflyer." That is the caption of one of the "Hobnobbing with Harbaugh," comics that appeared in the June 1962 edition of Popular Electronics magazine.  Dave Harbaugh's "Hobnobbing with Harbaugh" was a monthly feature for a couple years that dealt with stereotypical (pun intended) behavior of technophiles and their often unwilling, often unwitting wives, girlfriends, kids, parents, workmates, and neighbors.

Designing a Low-Distortion 12-Watt Amplifier

Designing a Low-Distortion 12-Watt Amplifier, August 1958 Radio-Electronics - RF CafeWebsite visitor Daniel O. wrote to request that I post this "Designing a Low-Distortion 12-Watt Amplifier" article from the August 1958 issue of Radio-Electronics magazine, which of course I was glad to do. It is nice to know there is still some interest in building vacuum tube circuits, just to keep the knowledge alive. When reading through the vintage magazines in search of good articles, I typically do not include ones like this not because I don't think they are worthy of posting, but because they are narrowly focused and would not be of interest to a wide number of people. If you run across an article which appears in the table of contents of one of the hundreds of old magazines I have posted, let me know and I'll be glad to do the same for you...

Amateur Radio Crossword Puzzle for June 14

Amateur Radio Crossword Puzzle for June 14, 2020 - RF CafeEach 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. In this crossword for June 14th 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 Lamarr or the Bikini Atoll, respectively. Enjoy!

Radio Theme Crossword Puzzle for May 9th

Radio Theme Crossword Puzzle for May 9th, 2021 - RF CafeThis Radio Theme Crossword Puzzle for May 9th has many words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. Also, it contains at least six (6) instances of this puzzle's theme word. 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!

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