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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...

Simulating a CBS Color Signal

Simulating a CBS Color Signal, September 1951 Radio & Television News - RF CafeFor some reason the "too clever by half" saying (but not in an insulting way) comes to mind when reading this article about color TV from a 1951 issue of Radio & Television News magazine. The color television industry was still searching for an acceptable standard broadcast format when this was written, and the electromechanical contraption was not considered too elaborate considering the original color TV schemes were all a conglomeration of whirling colored wheels, light sources, and photodetectors coupled with accommodating timing and intensity signals. Because there was not agreement on what the final commercial broadcast signal format would look like, there was not a lot of motivation for test equipment makers to invest time and money into providing gear for research and development laboratories. Do you remember the ads for the screen that installed on the front of a TV set to convert black and white (B&W) to color...

I Married a Hobby

I Married a Hobby, August 1948 QST - RF CafeMrs. Helen McKee knew exactly what she was signing up for when she agreed to marry Mr. McKee. After all, she met and got familiar with the guy over the air during some rag chewing sessions. This story is a humorous (and true) account of what life can be like for the spouses of enthusiastic Ham radio operators. We all hope for such an understanding 'significant other.' Melanie has certainly endured and supported a lot of my pastime endeavors over the past 32 years. It's a short read, so take a break and put a smile on your face...

RCA Numitron Readout

RCA Numitron Readout, March 1970 Popular Electronics - RF CafeRCA's Numitron was their answer to the Nixie tube (manufactured by Burroughs Corporation). It was a simpler 7-segment incandescent display (DR2010) that, with all lines energized, formed the number 8. It worked off of +3.5 to +5 volts, with each element requiring 24 mA of current. The number 8 drew 192 mA of current and dissipated 0.672 W at 3.5 volts and a whopping 0.96 W at 5 volts! RCA marketed a BCD*-to-7-segment display driver (the CD2501E). The Numitron was pitched as a sensible alternative to the 7-segment LED display, but with an element size of 0.35" wide by 0.6" high, there was no real advantage over the LEDs, which were just entering the electronics market in 1970. Numitrons do have a certain nostalgic 'cool' factor, though. It is interesting to note that the author's last name, Wood, is the same as that of Frank Wood, who was issued...

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...

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 ...

Antenna Applications in Two-Way Radio Systems

Antenna Applications in Two-Way Radio Systems, December 1957 Radio & TV News - RF CafeIn spite of the proliferation of cellphones and near ubiquitous communications, there are still many applications that require private 2-way communications systems. Emergency services like police, fire, and ambulance; amateur radio, vehicular dispatch for utilities, delivery and repair services; and anywhere that cellular service is not either available or extremely reliable, cannot rely on cellphones for mission critical needs. There are a lot of legacy 2-way radio system antennas and associated towers still being used and many new installations in place. Word has it that use of Citizen Band (CB) radio is on the rise amongst not just truck drivers but everyday drivers and base station operators - largely for the anonymity factor...

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...

Junction Diode Amplifier Bell Telephone Laboratories Ad

Junction Diode Amplifier Bell Telephone Laboratories Ad, November 1958 Radio News - RF CafeRudolf Engelbrecht, an alum of Oregon state University, was inducted into the institution's Engineering Hall of Fame in 1998. As evidenced in this full-page advertisement in a 1958 issue of Radio & TV News magazine, Mr. Engelbrecht's work was instrumental in advancing the state of the art in communications electronics while an engineer at Bell Labs. Here, he is show with the four-stage junction diode amplifier developed for military applications. It exploited the variable capacitance nature of a varactor type diode to effect amplification in the UHF and microwave bands. Engelbrecht went on to work at Radio Corporation of America (RCA) later in his career. BTW, if you are wondering what other kind of diode might there be other than a "junction" diode ...

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...

Physics & Science Theme Crossword Puzzle for August 1st

Physics & Science Theme Crossword Puzzle for August 1st, 2021 - RF CafeThis Physics & Science Theme crossword puzzle for August 1st, 2021, 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!

Spectral Domain Simulation Vitally Important When Designing Complex Systems

Why Using Spectral Domain Simulation is Vitally Important When Designing Complex RF, Microwave, and Wireless Systems (by Ed TRoy) - RF CafeEd Troy, owner of Aerospace Consulting, was kind enough to offer a few of his articles for posting on RF Cafe. With more than 30 years in the electronics communications design field, Ed has a lot of valuable knowledge to impart to us mortals ;-) This third paper demonstrates why using a highly capable software simulator for system design work is essential because of its ability to predict and facilitate mitigation of system-generated problems prior to building and testing the prototype. Case in point are spurious spectral components generated by the local oscillator and SSB to PM conversion created in a frequency doubler circuit. This paper was adapted from an example circuit provided in Keysight (formerly Agilent) Genesys Spectrasys. Spectrasys is a spectral domain block diagram simulator that allows the user to construct a system model and quickly determine the system performance. Whether you are involved...

RF Cafe Quiz #48: Introduction to Infrared and Electro-Optical Systems

RF Cafe Quiz #48: Introduction to Infrared and Electro-Optical Systems - RF CafeThis quiz is based on the information presented in "Introduction to Infrared and Electro-Optical Systems," by Ronald G. Driggers and Melvin H. Friedman. All RF Cafe Quizzes make great fodder for employment interviews for technicians or engineers - particularly those who are fresh out of school or are relatively new to the work world. Come to think of it, they would make equally excellent study material for the same persons who are going to be interviewed for a job.

Special Information on Radio, TV, Radar and Nucleonics

After Class: Special Information on Radio, TV, Radar and Nucleonics, November 1957 Popular Electronics - RF CafeBy 1957, betatrons, cyclotrons, cosmotrons, synchrocyclotron, bevatrons, and other forms of "trons" had the physics world all agog with anticipation of the next big discovery. Quarks were still a decade away from being discovered and something as exotic as the Higgs boson (aka god particle) hadn't entered anyone's mind. The news media was agog with reports of the world possibly coming to the end as a result of those experiments sparking a nuclear reaction chain that would cause the whole world to explode. Today, the news media is no smarter, because nowadays they fret over the Large Hadron Collider (LHC) generating a black hole that will implode the whole world ...

Ulano Masking Films - Rubylith

Ulano Masking Films, December 27, 1965 Electronics Magazine - RF CafeRaise your hand if you're old enough to remember doing printed circuit board layout using Rubylith tape. My hand is up. Back in the early 1980s, I did prototype PCB designs in an engineering development lab at Westinghouse Electric's Oceanic Division. Most of it was for analog and RF substrates that would be photographically reduced in size for use with bare integrated circuit die and surface mount passive components (Rs, Ls, and Cs), upon which I would later epoxy-mount those components and wire-bond everything using 1-mil gold wire. However, there were projects where full-size leaded components were used on a through-hole PCB that used not only the Rubylith tapes but also sheets with special electronics shapes for solder pads around the holes for components leads, ground and power planes, board-edge connectors...

Antenna Principles - Directional Arrays for 300 MHz and Higher

Antenna Principles, April 1947 Radio-Craft - RF CafeThis installment of the multi-month series of articles on antenna principles covers directional arrays for 300 MHz and higher. Keep in mind that in 1947 when this appeared in Radio-Craft magazine, wavelengths of a meter or less were considered to be at the upper end of the operational range. Parabolic reflector antennas were the domain primarily of ground-based installations due to the physical size and weight being prohibitive in airborne platforms, and even then they were rarely used at the time. Most ground and airborne installations were composed of dipole antennas with various configurations of reflector and director elements for desired gain and directivity characteristics. Special applications like for direction finding and longer wavelength radio communications used loop and long wire antennas, respectively. Highly directive dipole...

Mac's Service Shop: Servicing "Too-New" Sets

Mac's Service Shop: Servicing "Too-New" Sets, April 1957 Radio & TV News - RF CafeListen to the RF Cafe Podcast. At the time this Mac's Service Shop episode appeared in a 1957 issue of Radio & TV News magazine, electronics technicians were beginning to see a lot of transistorized radios, televisions, record players, and tape recorders showing up in place of the very familiar vacuum tube models. It was a whole new ballgame. To complicate matters, biasing, interstage coupling, and tuning circuits were in many ways different requiring re-learning what a "typical" circuit looked like, and the introduction of printed circuit boards in place of point-to-point wiring made changing components more difficult. Delaminating metal traces was easy to do on early PCBs when using the big, high thermal inertia soldering irons required for larger and more heat-tolerant components. Author John T. Frye used these Mac's Service Shop stories...

Fundamental Crystal Control for Ultra-High Frequencies

Fundamental Crystal Control for Ultra-High Frequencies, April 1932 QST - RFCafeYou always need to pay careful attention to "breakthrough" type articles when they appear in April issues, since many magazines have a tradition of burying an "April Fools' Day" item without notice. This April 1932 issue of QST magazine seems to be legitimate. The term "lycopodium pattern" aroused my suspicion, but it turns out to refer to a pattern of vibration that resembles the needle orientation of certain pines and cedars. As radio frequencies continued to increase during the early years of "wireless" development, the use of quartz crystals as a stable reference source ran into a physical limitation because as crystal slices reached a certain thinness, overtone and subharmonics appeared that caused problems in circuits. A new mineral called tourmaline saved the day. With an elasticity much greater than quartz, tourmaline is able to vibrate at higher fundamental frequencies for a given thickness...

Why Key Clicks?

Why Key Clicks?, October 1966 QST - RF CafeWaveform shaping is essential in today's crowded communications spectrum. Spectral masks are precisely defined in order to prevent "spreading" beyond the allocated frequency ranges at defined power levels. Whenever anything other than a continuous sinewave is being broadcast, there is spectral content generated in addition to the fundamental frequency. A Fourier transform of the waveform reveals which frequencies at what power levels comprise the waveform. The CW signal used by Morse code operators is a pure sinewave (or nearly so), but there is a spectral problem with it every time the signal turns on or off because of the square-ish edges involved during switching. RC networks are used in the transmitter circuits to tame the edges so that they do not turn on and off so quickly and in doing so reduce the extraneous frequency content. Author George Grammer argues that even though the signal could theoretically be made "clickless" (aka "chirpless"), there is an auditory benefit to the clicks or chirps that aids operators listening to high speed code transmissions...

Fundamentals of Solid-State Receivers

Fundamentals of Solid-State Receivers, February 1972 Popular Electronics - RF CafeRF, IF and baseband amplifiers; RF, IF, and baseband filters; fixed and tunable local oscillators, single- and double-balanced mixers, attenuators, envelope detectors and phase detectors, directional couplers, power combiners and dividers, et cetera, are all component types used for receiver systems regardless of whether vacuum tubes or transistors comprise the active parts. In 1972 when this article appeared in Popular Electronics magazine, people were beginning to get comfortable with the idea of transistorized products replacing the familiar tube. Instant-on televisions and radios were...

The Radar Man

The Radar Man, October 1960 Popular Electronics - RF CafeNow here is a profound ode to one of the most noble of technician genres ever to tweak a receiver front end or to change out a transmitter magnetron - The Radar Man!! It appeared in a 1960 issue of Popular Electronics magazine. Some of you know that I worked on airport surveillance and precision approach radar in the USAF, so my bias is established. Hmmm... now that I read the poem more carefully, I realize that it is not complimentary at all. It must have been one of those jealous TACAN or satellite communications technicians that wrote it! 

How's Your Radio Geography?

  How's Your Radio Geography? August 25, 1945 Saturday Evening Post - RF CafeWith a cover date of August 25, 1945, this issue of The Saturday Evening Post obviously went to print some time prior to the dropping of the two nuclear bombs on Japan that ended World War II. Victory in Japan Day (V-J Day), was August 14, 1945. There is no hint inside the magazine that the end of the war was nigh. There were, however, plenty of ads by companies touting their contributions to the war, and even some ads, particularly food ads, anticipating the end of rationing. Within this edition is also a short quiz entitled, "How's Your Radio Knowledge?" The author, Captain James F. C. Hyde, Jr., challenges readers to identify the locations of radio stations just by looking at their call signs. As is done today, most stations attempt to get call signs that are relevant to their location...

Subminiature Magnetic Amplifiers

Subminiature Magnetic Amplifiers, December 1957 Radio & TV News - RF CafeMagnetic amplifiers (aka "mag amps") use a property of saturated core inductors (saturable reactors) to obtain signal amplification via a transformer-type plus diode-assisted voltage multiplication. Magnetic amplifiers were preferred over vacuum tube amplifiers in some circuits because they do not require a high bias voltage, are generally smaller in size, are quite robust and are practically immune to microphonics. Their biggest limitation is bandwidth. The high number of turns in the core provides a lot of interwinding capacitance so the self-resonant frequency is in the low megahertz range. Additionally, the need for the magnetic amplifier reactor to operate in a saturated condition further imposed a limit on the frequency response. Even today, there are some critical applications that exploit the fool-proof and ultra high reliability nature of the magnetic amplifier. This article goes into the details of operation both as amplifiers and as bistable multivibrators...

Mac's Service Shop: Safety in Medical Electronics

Mac's Service Shop: Safety in Medical Electronics, July 1969 Electronics World - RF CafeIt should come as no surprise that in the pre-safety-ground era which included the 1960s that electrical shocks of patients in hospitals was not uncommon. If the jolt came intentionally from a cardiac defibrillator, then it would be a good thing. However, these shocks, which were the subject of a Time magazine story in the April 18th, 1969 issue cited by Mac's technician, Barney, were being administered unintentionally by patient monitoring and ancillary life-sustaining equipment. Per the article, no Underwriter's Laboratory (UL) certification was required for hospital equipment. Maybe it was felt that it wouldn't be so bad if someone got zapped in the hospital since there would be a doctor on-hand to resuscitate the zapee. Since that time medical equipment has been required to undergo stringent safety conformance requirements that makes electrocution virtually impossible. Now, if we could just keep doctors from cutting off the wrong limb or removing the wrong organ...

Carl & Jerry: Two Tough Customers

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

An Amateur Application of Modern Filter Design

An Amateur Application of Modern Filter Design, July 1966 QST - RF CafeThe term "modern" in the title of any book or article never has set right with me because it is utterly ambiguous about the era to which "modern" refers. Sure, it sounds good at the time, but when applied to this 1966 QST article, "modern" should be replaced with "four-decade-old." However, in this case the content is still relevant even thought it was written so long ago (or else I would not be reproducing it here). It may well have been most people's first exposure to elliptical (Cauer) filters. As you might expect, the rigorous, headache-inducing mathematics is omitted, but the article does give an example of implementing an audio frequency bandpass filter by cascading a lowpass filter and a highpass filter. If you are familiar with filter design, you know that because of phasing and inband impedance mismatch issues you cannot simply butt the two together to yield an equivalent bandpass filter. In fact, the author found it necessary to insert a 13 dB attenuator between them in order to get acceptable performance...

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...

X-Rays from TV Sets - Are They Harmful?

X-Rays from TV Sets - Are They Harmful?, November 1958 Radio News - RF CafeMost of us are likely familiar with the ongoing debate over whether radiation from cellphones, Wi-Fi routers and laptop computers, cell towers, smart meters, and other such modern gadgetry is harmful to humans. It is not ionizing radiation like nuclear decay, but there are heating effects that can cause damage under the right conditions. One week news breaks from the latest organization shocking the public with proof of tissue cell damage to brain, hand, face, eyeball, and groin tissue (from laptops). The next week brings a counter report refuting apocalyptic claims of previous studies... then the cycle repeats. Early in the age of ubiquitous wireless devices, those seeking to mitigate worries of radiation argued - somewhat correctly - that enough time had not yet passed to collect statistically meaningful data. If significant harm could be proven right away, dismissing the empirical results...

UJT Monocycle Multivibrator

UJT Monocycle Multivibrator, April 1969 Electronics World - RF CafeMonostable multivibrator, one-shot multivibrator, monocycle multivibrator - it's a matter of semantics, although the circuit designer doesn''t necessarily think so. The distinction, evidently, is that this monocycle multivibrator uses a positive-going pulse as a trigger and the output in its rest (stable) state is a digital "0" (low). A mere 2 mA of current flows since all the unijunction transistors (UJTs) are turned off. A UJT, to refresh your memory, is not used as a linear amplifier because of its regenerative, negative resistance operating region that causes it to effectively lock into a fully on or fully off conduction state until an external stimulus causes...

Antennas-Themed Crossword Puzzle for September 6th

Antennas-Themed Crossword Puzzle for September 6th, 2020 - RF CafeSeptember 6th's custom Antennas themed crossword puzzle contains only only words from my custom-created lexicon related to engineering, science, mathematics, chemistry, physics, astronomy, etc. (1,000s of them). Clues with an asterisk (*) are specifically antenna-related. 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, find someone or something in the otherwise excluded list directly related to this puzzle's technology theme, such as Hedy Lamarr or the Bikini Atoll, respectively. The technically inclined cruciverbalists amongst us will appreciate the effort.

Transmission Lines

Transmission Lines, June 1956 Radio & Television News - RF CafeLots of RF transmission cable parameter charts are available on the Internet, but what sets this one apart is that is has entries for some of the popular 300 Ω twin-lead cables of the rooftop television antenna era. It appeared in a 1956 issue of Radio & Television News magazine. Mentioned in the article is the reason most TV lead-in cable was colored brown was to help keep the sun's ultraviolet rays from penetrating and deteriorating the plastic. Author Robert Gary claims silver coloring was also used to reflect the UV, but I don't recall ever seeing silver twin-lead - maybe it was a regional thing like for in the southwest. At the time, μμfd (micro-microfarad) was commonly used rather than pF (picofarad). He also mentions the G-Line transmission cable used by many of the...

Exodus Advanced Communications Best in Class RF Amplifier SSPAs - RF Cafe
RF Cascade Workbook 2018 by RF Cafe

Werbel Microwave (power dividers, couplers)

Copper Mountain Technologies (VNA) - RF Cafe