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Today in Science History

Which Dry Battery for You?

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

Light Waves to Logic Optical Computing

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

AEC: A Brief Overview and Historical Context

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

Empower RF 8 kW, X-Band Pulsed HPA

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

The Fraudulent Technician - A Minority

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

Unexplored Electron Gap

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

Werbel 10-Way Splitter for DC-7.2 GHz

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

Hugo Gernsback: A Biography

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

CostQuest Gerrymanders for BEAD Biddable Locations

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

RCA: A Brief Overview and Historical Context

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

IEEE '69 International Convention & Exhibition

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

The Gas that Makes You Laugh

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

Crosley Radios: A Brief Overview and Historical Context

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

Novel GaN Transistors and HPAs for LEO & GEO Satellites

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

Allen DuMont: A Biography

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

News Briefs: Spherics

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

World's Most Powerful Sound Laser

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

Powel Crosley, Jr.: A Biography

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

Measuring & Mitigating EMI at IC Inputs

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

The Space Race

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

Many Thanks to Anatech Electronics for Long-Time Support!

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

Electronics-Themed Comics

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

Iridium Pushes Boundaries with 3GPP Acceptance

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

Capitol Radio Engineering Institute

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

Engineering & Tech Headlines <Archives>

• Solar Cycle 25 Producing Record High Sunspot Numbers

34% Huawei Revenue Hike for 1st Half Year

• Layoff Survival Guide for These Tough Times

• Rumors of Samsung Acquiring Nokia Fly

Supply Chain Sustainability's Future

Clear Road for FM Stereo

Clear Road for FM Stereo, July 1961 Radio-Electronics - RF CafeThe early 1960s was an era of significant change for the realm of in-home entertainment. Television was transitioning to color, radio was transitioning from AM to FM, and FM radio was transitioning from monaural to stereo. Print media was beginning to include more color in its pages. The human sense organs and brain were being called upon to process much more information from sources other than real-world experience. For many people, seeing the world's natural and manmade features in color was an amazing revelation, and our household was one of last in the neighborhood to get a color TV. My introduction to stereophonic music does not have as much of a stark place in memory. Prior to high school, my radio listening was AM station WNAV...

International Geophysical Year (IGY)

International Geophysical Year (IGY) (ChatGPT-generated content) - RF CafeThe International Geophysical Year (IGY) was an extraordinary scientific endeavor, representing a global cooperative effort to study Earth's physical properties and atmosphere. Spanning from July 1, 1957, to December 31, 1958, the IGY was timed to coincide with a period of maximum solar activity, a factor which was thought to significantly influence Earth's environment. The project brought together scientists from 67 countries, transcending Cold War tensions, with the goal of advancing our understanding of the Earth and space sciences. This extensive treatise delves into the various aspects of this monumental event, including the research conducted, the countries involved, key figures, industrial partnerships, the science of rockets and satellite...

1000x Faster Plasmonic Resonator Computer Chips

1000x Faster Computer Chips With Plasmonic Resonators - RF Cafe"Physicists present a nanometer-sized light antenna with electrically modulated surface properties - a breakthrough that could pave the way for faster computer chips. Advances in plasmonic resonators could lead to computer chips that are up to 1000 times faster, thanks to collaborative efforts between German and Danish universities. These teams have successfully modulated light antennas electrically and integrated quantum mechanics into classical physics models, promising profound technological impacts. Today's computers reach their physical limits when it comes to speed. Semiconductor components usually operate at a maximum usable frequency of a few gigahertz..."

The Loudness Control

The Loudness Control, December 1963 Electronics World - RF CafeRaise your hand if your old stereo system had a "Loudness" control, but you never really knew what it did - other than change the loudness (my hand is up). Author Rudolph Jacobs addresses the subject in a technical manner - Fletcher-Munson curves and all - in this 1963 edition of Electronics World magazine. In a nutshell, in case you don't feel like reading the entire article, Loudness compensates for the difference in perceived sound intensity level across the audio frequency spectrum as the reference level is varied. That is to say, it maintains the same perceived listening level across the audio spectrum whether you have the volume control turned way down, way up, or in the middle - a sort of volume-dependent equalizer.

Blog: Grid Simulators Are Smart Power Sources

Axiom Test Equipment Blog: Grid Simulators Are Smart Power Sources - RF CafeTranscat | Axiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post entitled "Grid Simulators Are Smart Power Sources" that covers how to pick the right grid simulator that best fits the needs of your project requirements. Choosing a grid simulator for an application is a matter of understanding available functions and key operating parameters, such as voltage, current, power, and output frequency. Grid simulators supply AC and DC electrical power under the many conditions exhibited on an electrical power grid and can accurately measure bidirectional power from DUTs or loads capable of generating power. A regenerative grid simulator can manage fully four-quadrant electrical power while returning a high percentage of power to the grid...

Electronics-Themed Comics

Electronics-Themed Comics, February 1969 Electronics World - RF CafeThe tech-themed comic that appeared on page 59 of the February 1969 issue of Electronics World magazine is consistent with the prevailing theme of the era where wives and girlfriends were fairly oblivious to the meaning of technical endeavors of their husbands and boyfriends, respectively (or not necessarily). The other comic from that edition is reflective of the times as well, when a television was considered to be one of the essentials of modern life. Carrying one's essentials wrapped up in a cloth and tied to the end of a wooden pole represented the stereotypical kid running away from home. I was a pretty rotten kid, but I don't remember ever running away from home - probably because I knew that my parents knew that I knew...

Semiconductors Sit for Their Portraits

Semiconductors Sit for Their Portraits, November 1962 Radio-Electronics - RF CafeThis could be one of those quizzes where common items are shown close-up so they do not look familiar, and the reader's job is to figure out what he's seeing. The montage of micrographs of antimony, cadmium sulfide, germanium etched in argon, and germanium etched in hydrogen, appeared in a 1962 issue of Radio-Electronics magazine. All are elements / compounds currently (at the time and now) being researched and used in semiconductors. Knowledge of semiconductor physics has multiplied exponentially in the succeeding six decades (hard to believe that much time has passed). The Massachusetts Institute of Technology's (MIT) Lincoln Laboratory did the work shown here...

Using Transistors as Negative-Resistance Devices

Using Transistors as Negative-Resistance Devices, June 1969 Electronics World - RF CafeLike most people familiar with electronics, when negative resistance semiconductors are mentioned, I immediately think of tunnel diodes. Negative resistance is the characteristic where in increase in voltage across the p-n junctions results an a decreased current. Although the tunnel diode was invented by by Leo Esaki (Sony) in 1957, it is not mentioned anywhere in this 1969 article. Instead author Wesley Vincent (Motorola) describes the theoretical operation of 4-layer (3 junction) semiconductors and how they can be biased to mimic true negative resistance devices. Given that one of the most common applications of tunnel diodes is to construct relaxation oscillators, knowing which configurations of standard BJTs can act like...

Silk & Graphene Spin up Electronics

Silk & Graphene Spin up the Future of Electronics - RF Cafe"Researchers have developed a method to create a two-dimensional silk protein layer on graphene, enhancing its potential in microelectronics, particularly for wearable and implantable health sensors and memory transistors in computing. This innovation offers a nontoxic, water-based, and biocompatible system, potentially revolutionizing silk's application in luxury materials and high-tech industries. The research opens pathways for further advancements in silk-integrated circuits and sustainable electronic solutions. After thousands of years as a highly valuable commodity, silk continues to surprise. Now it may help usher in a whole new direction for microelectronics and computing..."

DJC - The Radio Voice of Germany

DJC - The Radio Voice of Germany, February 1935 Short Wave Craft - RF CafeThis 1935 article found in Short Wave Craft magazine quotes the DJC radio station engineer as saying that they transmitted with only 5 kW into the farm of directional antenna arrays, and that it was sufficient to provide what was evidently very high quality reception to many remote regions of the world. Adolph Hitler had become "Führer und Reichskanzler" the year before, with plans already in the works to dominate the world. Troops invaded Poland on September 1, 1939, officially beginning WWII. DJC's global reach was used extensively for propaganda during the war...

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...

How to Target RFCafe.com for Your Google Ads

Google AdSense - it makes good sense - <em>RF Cafe</em>One aspect of advertising on the RF Cafe website I have not covered is using Google AdSense. The reason is that I never took the time to explore how - or even whether it is possible - to target a specific website for displaying your banner ads. A couple display opportunities have always been provided for Google Ads to display, but the vast majority of advertising on RF Cafe is done via private advertisers. That is, companies deal with me directly and I handle inserting their banner ads into the html page code that randomly selects and displays them. My advertising scheme is what the industry refers to as a "Tenancy Campaign," whereby a flat price per month is paid regardless of number of impressions or clicks. It is the simplest format and has seemed to work well for many companies. With nearly 4 million pageviews per year for RFCafe.com, the average impression rate per banner ad is about 225,000k per year (in eight locations on each page, with >17k pages)...

Engineering & Science Crossword Puzzle for March 8

Engineering & Science Crossword Puzzle March 8, 2020 - RF CafeAs with my hundreds of previous science and engineering-themed crossword puzzles, this one for March 8, 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.

Radio-Electronics Monthly Review

Radio-Electronics Monthly Review, April 1946, Radio-Craft - RF CafeBelieve it or not, many countries did - and some still do - charge people wanting to receive over-the-air (not cable or satellite) commercial radio and/or television programming a wireless license fee for the privilege. Yes, this is for receiving, not transmitting, signals. If you dared to tune in a BBC program without a license, a fee could be expected upon detection (pun intended). The Monthly Review feature in this 1946 issue of Radio-Craft magazine reported an increase in cost to the equivalent of $29 in 2021 money (per the BLS Inflation Calculator). Also highlighted was a method for printing radio circuits made with conductive inks on ceramic sheets - known today as thick-film printing. An announcement of the U.S. War Department's 18,000-tube ENIAC electronic calculating device was made as well. The electronics field was moving quickly...

Electronic Puzzle Square

Electronic Puzzle Square, July 1945 Radio & Television News - RF CafeDue to the era in which this "Electronic Puzzle Square" appeared (1945), I made a couple edits to help prevent misinterpretation. For instance the "mfd." in question 5 is microfarad (μF) in today's units standard. Question 4 originally had an upper case "E," which was a typo since it should have been a lower case "e," as in the base of the natural logarithm. When working Q7, leave the input and output terminals open when calculating the equivalent resistance; it's not like doing a "Pi" to "Tee" attenuator conversion. Q11 originally had "logE" where it should have been just "e." Q9 is a piece of cake. Question 15 assumes you know the resistance per foot of #25 B&S (AWG) copper wire, which you can find here (hint: it's 32.4 Ω/1000 ft)...

Sally, the Service Maid: The Case of the Dual Volume Control

Sally, the Service Maid: The Case of the Dual Volume Control, August 1944, Radio-Craft - RF CafeBy 1944, the U.S. and its Allied partners were occupied full-time beating back the forces of Communism, Fascism, Socialism, and many other 'isms.' A vast majority of active service members were men who were either training on domestic soil or fighting on foreign soil. That left sisters, mothers, and grandmothers to conduct a lot of the business and work production jobs that historically had been the near sole purview of men. Rosie the Riveter was a very familiar symbol of that new paradigm, while less known and celebrated were the women who handled building and servicing electronics products. I have posted many articles that appeared in magazines ...

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...

Robot Makes Radios

Robot Makes Radios, September 1947 Radio-Craft - RF CafeBritish engineer John Sargrove was to the production of radios what Henry Ford was to automobiles. At the time this "Robot Makes Radios" article appeared in a 1947 issue of Radio-Craft magazine, Sargrove had recently put his Electronic Circuit Making Equipment (ECME) fully automated assembly line into operation. Applying knowledge from two decades of developing methods of crating inductors, capacitors, resistors, and interconnecting conductors using controlled deposition of various materials on flat substrates, he was able to build 2-tube AC/DC radios at a rate of up to three per minute, with only two ECME operators - one at the input and one at the output. The only manual assembly required was the installation of a potentiometer-switch, a transformer, speaker...

Stable Microwave Oscillators

Stable Microwave Oscillators, July 1966 QST - RF CafeLong before digital communications was widely adopted, there was a great need for stable frequency-determining devices / systems. That is to say, low bit error rates (BER) for digital communications are not the sole motivation for oscillators with low short-term and long-term stability and low levels of jitter. One obvious need for precise frequency control is radar, in order for accurate ranging (the second "R" in radar) and in the case of Doppler systems, for accurate radial velocity reporting and clutter cancellation. Those capabilities existed long before digital systems came online. Aside from radar, precise frequency was needed in order to reduce guard band width between assigned channel assignments, thereby enabling more broadcast stations (commercial and military) to coexist in an allotted frequency band...

Keying the Crystal Oscillator

Keying the Crystal Oscillator, May 1941 QST - RF CafeThere is still a lot of vintage ham radio equipment in use both by the original owners and by newcomers who buy the equipment at Hamfests and on eBay. User's manuals are hard to come by, since they often were separated from the original gear a long time ago. Knowing how to operate, repair, and align everything properly is still necessary, especially as the airwaves get ever more crowded and the FCC gets more serious about prosecuting violators. Old editions of QST are the perfect resource for locating such information. This article covers some of the basics of oscillators - tritet types in particular - used for CW keying. The tritet oscillator gets is name from having been designed originally to efficiently generate third and fourth harmonics, per James Lamb's June 1933 QST article "A More Stable Crystal Oscillator of High Harmonic Output." ARRL members can download the article...

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...

Radio Training Association of America Advertisement

In God We Trust: All Others Pay Cash - RF CafeWhenever I see advertisements for electronics training courses, I think of the line in "Duel in the Snow, or, Red Ryder Nails the Cleveland Street Kid," where it mentions how during the Great Depression years the magazines were filled with ads "promising successful careers repairing radios." That story, which ultimately became the book and movie "A Christmas Story," was contained in Gene Shepherd's book In God We Trust: All Others Pay Cash. Jean Shepherd was a radio announcer and story teller who first read "A Christmas Story," on his WOR (New York City) show in 1970. You can listen to a 1974 broadcast in the YouTube video embedded below. This reading is slightly different than the one given to me by a guy who actually recorded it on tape...

Ziff-Davis Electronic Laboratories

Ziff-Davis Electronic Laboratories, January 1940 Radio News - RF CafeJudging by some of the letters written to magazines by their readers, obtaining parts referenced in many construction articles proved difficult or impossible to procure. Ziff-Davis, a major publisher in 1940 as well as today, ran this notice in a 1940 issue of its Radio News magazine offering advice as to how one might go about getting everything needed. Unlike nowadays where nearly every available source worldwide can be found on the World Wide Web, back then searching could be - and too often was - a long, slow process. Just finding a phone number or mailing address for a potential supplier presented a major obstacle to anyone without a collection of catalogs and magazines - or at least knowing someone who did. Imagine needing ten non-standard parts and having to write letters to manufacturers and/or distributors trying to located critical component...

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...

Operation Telephone 1965

Operation Telephone 1965, September 1961 Popular Electronics - RF CafeCall forwarding, call waiting, call holding, speed dialing, conference calling, all of these features are taken for granted with mobile phone and VOIP phone service and are included in the base service package. It will cost you extra if you subscribe to a local legacy POTS (Plain Old Telephone Service) provider. What is standard now was considered ground-breaking technology in the early1960s when this article appeared in Popular Electronics magazine. When phone calls were processed via human operators manipulating patch cords and then electromechanical relays, it was enough to simply place a successful call and not be interrupted or disconnected. Once transistorized circuits entered the scene, much more was possible, and phone system engineers were quick to exploit the technology. Sophisticated decision making requires both logical circuits and a form of memory. Logic could be provided using hard-wired diode steering...

How to Select RF Chokes

How to Select R.F. Chokes, May 1966 Electronics World - RF CafeWirewound inductors (as most are) can be mysterious entities even when you are familiar with their many interdependent physical and electrical properties. Because of interwinding capacitance and a sometimes (when a large number of turns are involved) rather significant series resistance, the equivalent circuit model gets quite complex - literally in a mathematical sense. If you have the luxury of staying far away from the self-resonant frequency (SRF) of the coil, your component will behave very much like an ideal inductor, that is, XL = 2πfL. This 1966 Electronics World magazine article delves into what causes inductors to act like parallel and/or series resonant tank circuits, how to avoid the inconvenience of unwanted resonances, and how to exploit resonances in your favor. You'll also learn (if you don't already know) the distinction between a "choke" and an inductor...

Engineering & Science Crossword Puzzle for March 24

RF Cafe Engineering & Science Crossword Puzzle March 24, 2019Since 2000, I have been creating custom technology-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. A database of thousands of words has been built up over the years and contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, 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...

Hams on the Alaska Highway

Hams on the Alaska Highway, April 1945 QST - RF CafeEven though my fingers stop working when exposed to temperatures below freezing, I love the northern climate - four full seasons, snow, iced-over lakes, migrating birds, fiery autumns, cool summers, the whole experience. Having the option of not participating in the cold outdoor environs is what makes it good. However, the U.S. Army Signal Corps guys pulling duty in Alaska during World War II did not have that luxury. As told by radio engineer Major Colvin in this story from a 1945 edition of ARRL's QST magazine, winter life in Alaska at -40° was a real challenge. It was a world where Prestone antifreeze froze, the sun shone only a few hours a day, vehicles had to be left running 24/7 or risk not being able to be re-started, and mile-long treks between buildings was common. There were no snowmobiles. The success of the communications station...

Carl & Jerry: The Snow Machine

Carl & Jerry: The Snow Machine, December 1960 Popular Electronics - RF CafeWe are moving into the colder days of the year in the northern hemisphere. The normal high temperature here in Erie, Pennsylvania is around 49°F (35° today with snow on the ground for the last three days). It is the time of year that causes those less appreciative of cold weather to conjure up memories of warm summer days with green leaves on tree branches and colorful flowers in the garden. For those of you like me who actually prefer the cooler weather, this Carl & Jerry story about making snow by blasting clouds with ultrasonic energy just adds to my appreciation of the onset of winter and visions of a white Christmas. To date there has been no major, efficient progress in the field of snowmaking or rainmaking (other than seeding clouds with silver iodide). Ski resorts still need sub-freezing weather...

Sparks on Ice: Radio in the Arctic

Sparks on Ice: Radio in the Arctic, December 1945 Flying Aces - Airplanes and RocketsThe old adage about pioneers taking the arrows is true in many realms - not just the exploration and settling of the wild west. This story entitled "Sparks on Ice" recounting the trials and tribulations of the troops who installed and debugged the first arctic directional beacons appeared in a 1945 issue of Flying Age magazine. "Sparks" (or "Sparky") was an endearing nickname given to early radio operators who used spark gap transmitters to send out their Morse code messages. It stuck around for many years after better transmitter systems were developed - although it is not very often heard today. The most interesting part of Mark Weaver's article is a discussion of the many atmospheric phenomena that affect radio waves of various wavelengths. A lot of smart people - enlisted, commissioned, and civilian - sacrificed mightily...

Tube Testers for Speedy Checking

Tube Testers for Speedy Checking, October 1955 Radio & Television News - RF CafeIt's a pretty good bet that most RF Cafe visitors are not overly interested in vacuum tube testers. Today they are collectors' items with some actually still being used for maintaining vintage electronics gear; however, in the days before semiconductor components they were the life blood of service men. Because tubes (aka "valves" in other parts of the world) are by nature one of the most vulnerable parts of any product in which they are used, often the first step in troubleshooting a radio, television, record player, etc., was to test suspected tubes for sub par performance. As mentioned often in Mac's Radio Service Shop stories, customers balked at service centers charging for their expertise but didn't mind as much paying for replaced components. That meant mark-ups on vacuum tubes comprised...

The Amazing Transistor

The Amazing Transistor, April 1952 Radio & Television News - RF CafeLess than half a decade had passed when Radio & Television News editor Oliver Reed wrote this piece extolling the virtues of the transistor and how "it may well revolutionize the entire electronics industry." If you have followed a lot of my postings from the vintage electronics magazines here on RF Cafe, you are well aware that there was a lot of resistance to and doubt about the future of semiconductors. Naysayers had the same kind of reaction to the advent of the horseless carriage (automobile) and locomotive, relativity and quantum mechanics, and even curative medicines. Point contact transistors were still largely in use, but were costly compared to the relative simplicity and low cost of junction transistors once the manufacturing details were worked out - which, as we now know, happened very rapidly. By 1965 the process was so refined that Gordon Moore...

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...

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...

Engineering & Science Crossword Puzzle for September 29

Engineering & Science Crossword Puzzle September 29, 2019 - RF CafeFor two decades, I have been creating custom engineering- and science-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. This September 29, 2019, puzzle uses a database of thousands of words which I have built up over the years and contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure ...

Bridge Circuit Quiz

Bridge Circuit Quiz, December 1966 Popular Electronics - RF CafeI found this Bridge Circuit Quiz in my stack of vintage Popular Electronics magazines. Your challenge here is to decide what the main function of each type of bridge circuit is. Most bridge circuits are designed such that a component of unknown value is inserted into one of its four branches, and then one or more variable components of known values are adjusted to balance the bridge and thereby create a minimum (null) between opposite (circuit-wise) nodes. Admittedly, I did not fare well, but it is because I do not recall having the names associated with many of these bridge circuits. Of course nearly everyone is familiar with the Wheatstone, Kelvin, and Wien bridges. Hyperlinks...

USAF Entrance Test

USAF Entrance Test from 1973 Popular Mechanics - RF CafeA few days ago, I was perusing an April 1973 edition of Popular Mechanics magazine, when I ran across the following full-page ad with a U.S. Air Force enlistment aptitude test. Take the test, and if you get the same answers as the geniuses that created the ad, you're a shoe-in for a great career in the USAF! Uncle Sam wants you, bay-bee. I did the first two tests and got what they got for answers. Then I took the third test - the one with the little folded house - and was shocked at what I found. You take the three tests, and see if you think something is amiss with the last one. Look way down at the bottom of the page for my conclusion...

Hazel TV Episode "Stop Rockin' Our Reception"

Hazel TV Episode "Stop Rockin' Our Reception" - RF Cafe Video for EngineersQST reader George P. Orphan, KG4DXJ, wrote in the February 2020 issue's "Letters from Our Members" column about an episode of the old "Hazel" television show entitled, "Stop Rockin' Our Reception," where interference on the Baxters' TV set was blamed on the "shortwave set" operated by a teenager, Bruce, who had recently moved in down the street. George Baxter, the household's impulsive lawyer father, was convinced enough that Bruce, a friend of his son, Harold, was responsible that he paid a visit to the boy's house and spoke to his father about it. Bruce politely informs Mr. B that unless his television was was manufactured before 1950, it was unlikely that his operations on the 10-meter band would be causing the interference, but it fell on deaf ears. Shortly thereafter, a power company investigator was seen walking around the front yard with a box bearing a loop antenna on the top of it. At the request of Bruce's father...

Radio Sextant Tracks Moon

Radio Sextant Tracks Moon, May 1959 Electronics World - RF CafeAccording to Wikipedia, The Navy's USS Compass Island was one of two ships, the other being USS Observation Island, converted and classified as navigational research test vessels under the Polaris Missile system budget. As reported here, the newfangled radio sextant tracks the position of the sun or moon to provide location accuracy much better than the best traditional compass. Remember that in 1959 there was no satellite navigation, and in the middle of the ocean land-based transmitters were useless as radio bearing references. Inertial navigation systems could not hold their calibrations in the harsh physical environment of stormy seas. This radio sextant system is fine as long as the sun and/or moon is high enough in the sky to have antenna pointing access to one or...

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...

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