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Today in Science History

Electronics-Themed Comics

Electronics-Themed Comics, January 1962 Radio-Electronics - RF CafeI have written before about the love-hate relationship a lot of the buying public had with television and radio repair shops and repairmen - similar to car owners and mechanics. Lots of jokes and skits (what today is termed a "meme") were created back in the heyday of in-home entertainment to make light of the situation. These four electronics-themed comics from a 1962 issue of Radio-Electronics magazine are typical examples. The one from page 111 alludes to an issue that would almost never be seen today on a TV, unless maybe the AC power supply was on the fritz. A composite analog broadcast signal contained vertical and horizontal sync[ronization] components which...

3D-Shield Electronics from ESD

3D-Shield Electronics from ESD"Electrostatic discharge (ESD) protection is a significant concern in the chemical and electronics industries. In electronics, ESD often causes integrated circuit failures due to rapid voltage and current discharges from charged objects, such as human fingers or tools. With the help of 3D printing techniques, researchers at Lawrence Livermore National Laboratory (LLNL) are 'packaging' electronics with printable elastomeric silicone foams to provide both mechanical and electrical protection of sensitive components. Without suitable protection, substantial equipment and component..."

TV and Radio Repair Featured in "Dragnet"

Television and Radio Repair Featured in "Dragnet" - RF Cafe Video for EngineersMr. Bob Davis, a seemingly endless source of little known and/or long forgotten historical radio and television technical trivia, apprised me of this short segment from the 1960s Dragnet television series, starring Sgt. Joe Friday. It features a guy, who turns out to be a ... well, I won't spoil it for you ... who proudly professes his thirty year career as a radio repairman. "...started back in the days of the old Crosleys, Atwater-Kents, Farnsworths. Those were real radios, well built, well designed. Nothing cheap about any of them. They didn't have transistors in those days, just tubes as big as light bulbs. That meant heavy chassis, heavy transformers, and we didn't fix them by simply slapping in a new part, either. We fixed the old parts. I wish...

Square-Corner UHF Reflector Beam Antenna

The Square-Corner Reflector Beam Antenna for Ultra High Frequencies, November 1940 QST - RF CafeA new word has been added to my personal lexicon: "sphenoidal." Author John Kraus used it to describe the wedge shape of a corner reflector. The Oxford Dictionary defines "sphenoid" thusly: "A compound bone that forms the base of the cranium, behind the eye and below the front part of the brain. It has two pairs of broad lateral "wings" and a number of other projections, and contains two air-filled sinuses." This "square corner" configuration - essentially a "V" shape, is shown to exhibit up to 10 dB of gain while being relatively (compared to a parabolic reflector) insensitive...

General Relativity

Spacetime Distortion General Relativity - RF CafeAlbert Einstein's general theory of relativity, published in 1915, fundamentally reshaped the way scientists understand gravity, space, and time. It extended his 1905 special theory of relativity, which described how the laws of physics are consistent for all observers in uniform motion and how light's speed is constant in a vacuum. However, the special theory did not address accelerating reference frames or gravitational forces. Einstein's general theory tackled these limitations by proposing that gravity is not a force in the traditional sense, but rather a curvature of spacetime caused by mass and energy. This profound insight would alter the course of 20th-century physics, influencing cosmology, black hole theory...

Memristor Analog Switching Neuromorphic Computing

Memristor Analog Switching Neuromorphic Computing - RF Cafe"The growing use of artificial intelligence (AI)-based models is placing greater demands on the electronics industry, as many of these models require significant storage space and computational power. Engineers worldwide have thus been trying to develop neuromorphic computing systems that could help meet these demands, many of which are based on memristors. Memristors are electronic components that regulate the flow of electrical current in circuits while also 'remembering' the amount of electrical charge that previously passed through them. These components could replicate the function of biological..."

Reflections on the News

Reflections on the News, February 1969 Electronics World - RF CafeReading through the news items in the vintage electronics magazines provides a mixture of important historical facts and figures along with some predictions on the future of the industry. Some of the predictions turn out to be amazingly accurate, even though in retrospect they might seem obvious. Take, for example, Sylvania VP Dr. Robert Castor's foresight about how, "the future growth of the semiconductor industry lies in a major switch from the production of individual components to solid-state subsystems that can be used as building blocks in electronic designs." "Well of course," you might be temped to say; however, at the time there were still significant hurdles to overcome related to material purity, wafer size, photolithography...

Many Thanks to Reactel for Their Long-Time Support!

Reactel Filters - RF CafeReactel has become one of the industry leaders in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity, and waveguide designs, as well as state of the art high performance suspended substrate models. Through a continuous process of research and development, they have established a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact Reactel today to see how they might help your project.

Electronics in 2012 AD

Electronics in 2012 AD, October 1962 Radio-Electronics - RF Cafe2012 came and went more than a decade ago. The date was 50 years in the future back in 1962 when Radio-Electronics magazine editor Hugo Gernsback asked industry leaders to cogitate on possibilities of the state of electronics in 2012. Let's see how they did. One guy predicted our communications would be in the 100 THz to 1,500 THz band, using 2 decimeter antennas. Nope. Another believed we would be communicating with aliens on a regular basis. A military dude partly hit the mark by predicting 2- and 3-year-olds would be sitting in front of "televideo screens" (cellphones) learning Esperanto and "other basic studies." Bell Labs believed most audiovisual material, along with commerce, would be done electronically; i.e., the World Wide Web. I'm not quite sure how to interpret the IT&T guy's prediction of replacing microwave space transmission with light wavelength waveguide transmission. Seems bassackward to me...

The Phone Scam Gram

The Phone Scam Gram - RF CafeHere is a unique approach to discouraging scam callers. A lot of scam calls are themselves AI, so can one AI detect and aviod another? "Gangster Granny! Meet Daisy: O2's new weapon against scammers. O2 has unveiled its new, unique weapon in its fight against scammers: Daisy, an AI-powered assistant designed to keep fraudsters talking and waste their time. As part of Virgin Media O2's 'Swerve the Scammers' campaign, Daisy's mission is to distract scammers with realistic, rambling conversations, helping protect potential victims while raising awareness about fraud. Her lifelike conversations, peppered with stories about family or hobbies like knitting, have kept fraudsters on the line for up to 40 minutes..."

Special Relativity

Special Relativity - RF Cafe

Albert Einstein's special theory of relativity, a milestone in physics, transformed our understanding of space, time, and energy (mass). The theory, published in 1905, stemmed from Einstein's efforts to resolve inconsistencies in classical physics, specifically between Newtonian mechanics and electromagnetism as formulated by James Clerk Maxwell. By reconceiving space and time as interconnected and relative to the observer's frame of reference, Einstein established a framework that had profound implications for science and technology. To understand how this groundbreaking idea emerged, one must consider...

Werbel 2-Way Splitter for 500 MHz to 26.5 GHz

Werbel Microwave 2-Way Power Splitter for 500 MHz to 26.5 GHz - RF CafeWerbel Microwave's Model WM2PD-0.5-26.5-S is a wideband 2-way in-line power splitter covering of 500 MHz to 26.5 GHz with excellent return loss, low insertion loss, and high isolation performance. With ultrawideband performance, amplitude balance is typically 0.24 dB and phase unbalance is typically 2.6°. Insertion loss is low for the bandwidth, coming in at a typical 1.2 dB above 3 dB splitting loss. Return loss 16 dB typical. Isolation 18 dB typical. The device is precision-assembled and tested in the USA...

RCA Institutes Career Opportunity

RCA Institutes Ad, June 1969 Electronics World - RF CafeIf you wanted a career as an electronics technician at the end of World War II, the world was your oyster - so to speak. Electronics and communications trade magazines and publications like Mechanix Illustrated and Popular Science ran a plethora of ads monthly that offered unlimited opportunity to men seeking a career servicing the burgeoning market of postwar technological marvels. Even though the enclosures were not yet being marked with "No user serviceable parts inside," that fact was most people were not qualified - nor did they want - to monkey with the guts of radios, televisions, and other household appliances... (I provide a simulation to show the true zener diode circuit output)...

Electronics-Themed Comics

Electronics-Themed Comics, February 1962 Radio-Electronics - RF CafeTake time out of your busy workday to look at these three electronics-themed comics from the February 1962 issue of Radio-Electronics.. The page 32 comic reminds me of sometime in the late 1970s while working as an electrician (prior to enlisting in the USAF) when I was doing side jobs, and a guy had me wire up a receptacle for his big 25" screen (CRT) which he had mounted in a wall, with the chassis sticking out the back. It was in an upstairs room in a Cape Cod style house with lots of room behind the wall. He was a "man cave" pioneer with a full suite of high quality audiovisual equipment - even a Betamax machine! The page 81 comic exhibits the irony that would have existed in the day if American-made electronics equipment had been promoted in Japan, which they probably were not. In 1962, Japanese...

No Video for Satellite Direct-to-Cell

No Video for Satellite Direct-to-Cell - RF CafeAdmittedly, I mostly posted this because of the drawing. "While direct-to-cell (D2C) satellite communications were a big topic at the recent Brooklyn 6G Summit, the technology is already here, well before 6G's anticipated 2030 arrival. Apple and Google already offer D2C emergency messaging, and Starlink, T-Mobile and others are anticipated to follow. D2C satellite communications will be well established when 6G arrives. The 3GPP froze a 5G specification for Non-Terrestrial Networks (NTN) in Release 17 in March 2022, which means that NTN-compatible chips and components should be available now or soon. SpaceX has reduced the cost..."

Electricity & Physiology

Electricity & Physiology, January 1971 Popular Electronics - RF CafeThe subtitle of this article from a 1971 issue of Popular Electronics magazine, "From Quackery to Speculation to Programmed People," could to some extent still be applicable even though the author evidently meant to put an end to the "quackery" and "speculation" part of it. Indeed, a lot of advancement has been made in the fields of electrostimulation of weak or/or paralyzed muscles, healing of certain types of soft and hard tissues, suppressing sporadic muscle twitching and epileptic seizures, and other malady diagnosis and relief. Specifically tuned microwave frequencies have proven useful in healing and symptom relief as well. As with most articles on medical procedures, I cringe at some...

Anatech Intros 3 Filter Models for November

Anatech Electronics Intros 3 New Filter Models for November 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 C-band cavity bandpass filter models have been added to the product line, including a 4994 MHz BPF with a 50 MHz bandwidth, a 4950 MHz BPF with a 10 MHz bandwidth, and a 5785 MHz BPF with a 100 MHz bandwidth. 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...

Engineering & Tech Headlines <Archives>

• 5G Is 42% of Fixed Wireless Access (FWA) in 2024

• Robert Dennard, DRAM Pioneer, Dies at 91

• TSMC's Energy Demand Drives Taiwan's Geopolitical Future

• Semiconductor Packaging Market on 5.6% CAGR 'Till 2028

• Altering Asteroid Trajectories with Nuclear X-Rays

Albert Einstein: A Short Biography

Albert Einstein: A Short Biography - RF CafeAlbert Einstein, one of the most renowned physicists in history, was born on March 14, 1879, in Ulm, in the Kingdom of Württemberg, part of the German Empire. His father, Hermann Einstein, was an engineer and salesman who ran an electrochemical factory, and his mother, Pauline Koch, managed the household and supported her son's education. Einstein had one sister, Maja, who was born in 1881 and with whom he had a lifelong close relationship. Einstein's extended family included several relatives who would play various roles in his life, both personally and professionally. His early family life was comfortable, though his parents moved frequently as they sought economic stability. Hermann Einstein's business ventures had varying success, and eventually, the family moved to Italy in 1894...

Rotary Stepping Switches

Rotary Stepping Switches - They're Everywhere, December 1967 Radio-Electronics - RF CafeHere is the second part of a series of articles about stepping switches appearing in 1967 issues of Radio-Electronics magazine. A standard (at the time) dial rotary phone was used as a familiar example in the part one. It delivers a single pulse for each number / letter set from 1, 2 (ABC), 3 (DEF), through 9 (WXY), 0 (Operator). On some phones, you can hear the clacking of the switch contacts as the spring-loaded dial rotates from the selected number back to home position. The stepping action as the result of dialing occurs at the telephone system switching and call routing equipment at central locations. There, stepping switches increment with each pulse received, and when the full number of pulse sets have arrived, the circuit is complete and the call put through to ring the phone...

2024 ARRL Field Day Results Published

2024 ARRL Field Day Results Published - RF Cafe"Results are published, and the numbers are in. They paint a picture of a very active 2024 ARRL Field Day. Nearly 1.3 million contacts were reported during the 24-hour event. That is up from 2023's 1.25 million contacts. That's likely indicative of the continued rise of Solar Cycle 25 leading up to the event, but more people also participated this year. Entries were received from all 85 ARRL and Radio Amateurs of Canada (RAC) sections, as well as from 27 different countries from outside the US and Canada. 'It is encouraging to see a rise in participation year to year,' said ARRL Contest Program Manager Paul Bourque, N1SFE. 'ARRL Field Day is amateur radio's premier event, and the hams turned out for it..."

Einstein Expounds on His New Theory

Einstein Expounds on His New Theory, 12/3/1919 The New York Times - RF CafeAfter searching for the first mention of Nikola Tesla in U.S. newspapers, I performed a similar search on Albert Einstein, again using editions available in the NewspaperArchive.com database. I was utterly surprised to find it in a 1919 issue of the The New York Times. His theory of Special Relativity was published in 1905 and his theory of General Relativity was published in 1915, so it took The NY Times four years to mention it. There is a reference to Dr. Einstein's' work on relativity in a 1915 edition of The Manitoban, from Winnipeg, Canada. The NY Times article is an actual interview with Albert Einstein, wherein at one point it is stated that there were perhaps only a dozen people in the world at that time who understood general relativity. Interestingly, Einstein uses the term "difform motion" to describe...

Exodus AMP2103P-LC, 0.5–3.2 GHz, 1 kW Pulse SSPA

Exodus AMP2103P-LC, 0.5–3.2 GHz, 1 kW Pulse SSPA - RF CafeExodus Advanced Communications, is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. We are pleased to announce the model AMP2103P-LC, dual-mode (CW & pulse) amplifier covering 800 to 3200 MHz. 1000 watt peak pulse power, or 500 watts CW. Ideal for automotive pulse/radar EMC-testing & commercial applications. Pulse widths to 560 μsec, duty cycle to 10%, 60 dB gain, and outstanding pulse fidelity. Monitoring parameters for forward/reflected power in watts and dBm, VSWR, voltage, current, and temperature, with unprecedented reliability and ruggedness in a compact 7U chassis...

Sally, the Service Maid

Sally, the Service Maid: The Case of the Silent Speaker, April 1944 Radio-Craft - RF CafeSally Mason was the soldering iron-wielding heroette (heroine sounds too much like the narcotic) of Nate Silverman's "Sally, the Service Maid" series that ran in Radio-Craft magazine during the years of World War II. As I noted in the previous episode, many of the nation's women were left behind to run their husband's, father's and/or son's electronics sales and repair businesses when they went off to save the world from aggressive Communists, Socialists, Maoists, Nazis, and other nasty types. Some of those ladies had already become very adept at troubleshooting, component replacement, and aligning radio and television sets, while some were left to learn at the School of Hard Knocks. Sally's father, Gus Mason...

Thanks to Crane Aerospace & Electronics for Their Support!

Crane Aerospace & Electronics - RF CafeCrane Aerospace & Electronics' products and services are organized into six integrated solutions: Cabin Systems, Electrical Power Solutions, Fluid Management Solutions, Landing Systems, Microwave Solutions, and Sensing Components & Systems. Our Microwave Solution designs and manufactures high-performance RF, IF and millimeter-wave components, subsystems and systems for commercial aviation, defense, and space including linear & log amplifiers, fixed & variable attenuators, circulators & isolators, power combiners & dividers, couplers, mixers, switches & matrices, oscillators & synthesizers.

Electronic Navigation in Flight

Electronic Navigation in Flight, August 1962 Radio-Electronics - RF CafeThe AN/MPN-13|14 mobile radar system I worked on while enlisted in the U.S. Air Force was designed and fielded around the time this Electronic Navigation in Flight article appeared in a 1962 issue of Radio-Electronics magazine. It had been upgraded a few times by 1979 when I was in Air Traffic Control Radar Repairman technical school at Keesler AFB, Mississippi; however, the original system did not featured a Doppler capability. The fully RF analog system could not provide air traffic controllers with speed data, but it did use physical mercury delay lines to provide a stationary target (ground, and to some degree, rain, clutter) cancellation by inverting and summing a real-time radar...

Why Color-TV Makers Worry

Anxiety Amid Affluence: Why Color-TV Makers Worry, December 27, 1965 Electronics Magazine - RF CafeDecisions, decisions, decisions. As the title states, color television manufacturers were, in 1965 when this Electronics magazine article was published, finding themselves between a rock and a hard place, as the saying goes, regarding a change from vacuum tubes to transistors. The buying public (aka consumers) had mixed emotions about the newfangled semiconductors based at least partly on bad information about transistors. Transistors had been designed in various circuits for a decade and a half and were gaining rapidly in performance and reliability. The price was coming down, but as reported here, still cost $5 to $10 apiece compared to a $1 vacuum tube. Company management needed to decide whether to delay implementing the new engineering and production methods required to deal with transistors...

The 1st Virtual Meeting Was in 1916

The 1st Virtual Meeting Was in 1916 - RF Cafe"At 8:30 p.m. on 16 May 1916, John J. Carty banged his gavel at the Engineering Societies Building in New York City to call to order a meeting of the American Institute of Electrical Engineers. This was no ordinary gathering. The AIEE had decided to conduct a live national meeting connecting more than 5,000 attendees in eight cities across four time zones. More than a century before Zoom made virtual meetings a pedestrian experience, telephone lines linked auditoriums from coast to coast. AIEE members and guests in Atlanta, Boston, Chicago, Denver, New York, Philadelphia, Salt Lake City, and San Francisco had telephone receivers at their seats so they could listen..."

Admiral "Aeroscope" Midget Sets Radio Service Data Sheet

Admiral "Aeroscope" Models 161-5L, 162-5L and 163-5L Midget Sets Radio Service Data Sheet, August 1939 Radio-Craft - RF CafeFor many years I have been scanning and posting Radio Service Data Sheets like this one featuring the Admiral "Aeroscope" 161-5L, 162-5L, and 163-5L Midget Set models which appeared in a 1939 issue of Radio-Craft magazine. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. Some websites offer to sell this information, but often what is shown here is enough to get an old radio working again since most times both schematics and alignment steps are included. I keep a running list of all data sheets to facilitate a search...

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...

Receiver Noise from Antenna to Detector

Receiver Noise from Antenna to Detector, August 1965 Electronics World - RF CafeHere from a 1965 issue of Electronics World magazine is a really nice write-up on electrical noise, both how it originates and how it affects receiver systems. Although vacuum tubes were still the predominant active amplification components in 1965 (the date of this article), semiconductors were already solidly ensconced in the signal detector role. I have to confess to learning a new term that I probably should be familiar with: Equivalent-Noise-Sideband-Input, or ENSI. It appears also in Reference Data for Engineers: Radio, Electronics, Computer, and Communications. Interestingly, this is the first time in a long time I have seen noise referred to as "grass;" the drawings make it clear why the moniker was created. We were taught to use "grass" in USAF radar tech school and used it in common parlance...

"-Tron" Teasers - An Electronic Quiz

"-Tron" Teasers - An Electronic Quiz, October 1963 Electronics World - RF CafeThyratrons, klystrons, and magnetrons I've heard of, but trochotrons, charactrons, tonotrons I ain't heard of. That made this quiz more of a learning exercise for me than a test of any sort of knowledge possessed. Heck, I thought an 'ignitron' was a pejorative term for a really dumb techie wannabe. In all there are 17 types of '-tron' devices given for which to match from a list of descriptions. You'll probably do better than I did on this quiz that appeared in the October 1963 issue of Electronics World magazine.

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...

Standing Waves on Transmission Lines

Standing Waves on Transmission Lines, December 1942 QST - RF CafeIn this article from a 1942 issue of QST magazine, author T.A. Gadwa employs a standing wave mechanism analogy that I don't recall having read before - that of a dam on a river. The river is the transmission line with a lake as the source (presumably) and then he imagines a dam load. The dam standing waves, per his description, have phase and amplitude characteristics that depend on how tall the dam wall is relative to the surface height of the dammed river. An extensive array of graphs is provided showing how the current of the dam standing waves react to the dam transmission line termination impedance. I always wonder when seeing electrical-mechanical parity examples whether, as with this case, there are any dam magazine articles out there that use an electrical transmission line to help fellow civil engineers...

Power from the Sun with Silicon

Power from the Sun with Silicon, February 1973 Popular Electronics - RF CafeAround the time this article was written, the first wave of the solar and wind (which essentially is also solar) power generation craze was settling in. A few small windmill generators popped up around where I lived in the Annapolis, Maryland area, but they were mostly owned by hippie Earth worshipers who eschewed modern conveniences and didn't need hot water for bathing anyway. Most of that generation (pun intended) of windmills put out direct current (DC - typically 12 or 24 volts) rather than tying in with the AC line power, and required separate electric wiring in the house. People used appliances and light fixtures designed for recreational vehicles. We knew a very nice older man and his wife who lived "off the grid" and grew most of their produce and even kept a goat for milk (they were clean people). They had some photovoltaic (PV) solar cells to supplement the windmill...

YL News and Views

YL News and Views, October 1966 QST - RF Cafe"YL" is the shorthand used by amateur radio operators when referring to female operators - Young Lady. Although still chosen as a hobby in larger number by men, ladies have long been avid participants in the art/science of Ham radio. The American Amateur Radio League's QST magazine devoted this "YL News and Views" column to their contributions many years ago - trendsetting in its day. This particular issue introduces Louise Ramsey Moreau as its new editor. Her interest in Ham radio was piqued when she realized "all the women heard on their receivers were not 'just wives,' but licensed operators." The rest, as said, is history...

A.C. Calculations for Parallel and Series-Parallel Circuits

A.C. Calculations for Parallel and Series-Parallel Circuits, June 1944 QST - RF CafeWhen you read a lot of tutorials about introductory electronics on the Internet, most are the same format where stoic, scholarly presentations of the facts are given. Those of you who don't have enough fingers and toes to count all of the college textbooks like that which you have read know of what I speak. When hobby articles are written in a similar fashion, it can quickly discourage the neophyte tinkerer or maybe even a future Bob Pease. QST has printed a plethora of articles over the years that are more of a story than just a presentation of the facts. My guess is the reason is because often the authors are not university professors who have forgotten how to speak to beginners. This article on basic calculations for AC series and parallel circuits is a prime example...

Engineering and Technology History Wiki (ETHW) - Dr. Dave Leeson

Engineering and Technology History Wiki (ETHW), Dr. Dave Leeson - RF Cafe SmorgasbordIf you have not yet discovered the Engineering and Technology History Wiki (ETHW) website, now would be a good time to surf on over and take a look at the vast resources there - particularly the "Oral-History" series of in-person interviews of our field's top scientists and engineers. Among them are Dr. Harold Beverage, Dr. Ulrich L. Rohde (N1UL), Harold S. Black, Harold A. Wheeler, Dr. Irwin Jacobs and Dr. Andrew Viterbi, and of particular significance to me, Dr. David B. Leeson (W6NL), founder of California Microwave and Ham radio contesting champion. Many of the oral interviews were conducted in the pre-Internet era and some of the people are no longer with us. A few days ago, I had the honor of being contacted Dr. Leeson as part of his search for information he wants for some work he is doing. His name is familiar to amateur radio contesters who participate in DX (long distance) events. Most Hams do their part from home-based "shacks" while others join in during Hamfest gatherings. Some adventuresome and hardy souls set up temporary (and sometimes fixed) stations in remote locations around the world in order to provide rare and exotic contact opportunities, where coveted QSL cards can be collected...

The Rest of the Story, by Paul Harvey

The Rest of the Story... (a la Paul Harvey) - RF CafeAs a long-time Paul Harvey fan, I used to listen to his radio news broadcasts and especially looked forward to his "The Rest of the Story" pieces. It was a challenge to listen and try to figure out who or what the alluded-to person, place, or thing at the end of the the story would be. In honor of Mr. Harvey, who left this Earth in 2009, the following Smorgasbord about featured celebrity "Sam" is fashioned after his trademarked style. As is often the case with people of accomplishment, this subject's talents extended beyond the skill for which he is most known. An article in the September 2011 Smithsonian magazine inspired the research ...

Choosing the Right Antenna

Choosing the Right Antenna, September 1958 Radio & TV News - RF CafeWhereas this "Choosing the Right Antenna" from a 1958 issue of Radio & TV News magazine article concerns television antennas, the information applies generally for any application. Folded dipoles, conicals, Yagis, log periodic, and other types were used by homeowners sometimes desperate to receive a good signal from a far away broadcast station or from a location buried in obstacles (terrain, buildings, water bodies, automobiles, towers, etc.) blocking and reflecting otherwise strong signals, thus causing fading and multipath degradation. You might think the advent of cable and satellite TV, along with Internet access, might have removed the need for rooftop type over-the-air antennas, but it is not so. There are still plenty of people located in rural areas that struggle to get a good signal, as evidenced by RF Cafe visitor Dave Jones, (N1UAV) stacked 9- & 17-element yagi TV antenna project...

Antenna Loading Problems and Solutions

Antenna Loading Problems and Solutions, August 1947 Radio News - RF CafeMost of us here in America recognize the Packard Bell name from the line of personal computers they sold in the 1980s and 1990s. I owned three of them, beginning with an Intel 80286 model, then an 80486, and finally a Pentium model. They were in the "pizza box" format that sat on the desk with the CRT monitor on top; I always preferred that configuration over the tower type. Before Packard Bell made personal computers, they made personal radios for the desktop beginning back in the 1930s. That explains why Mr. J.T. Goode, an engineer with Packard Bell, would write an article in 1947 regarding a method to tune antennas using light bulbs...

After Class: Resistor and Capacitor Combinations 

After Class: Resistor and Capacitor Combinations, June 1955 Popular Electronics - RF CafeHere is a short tutorial on resistor-capacitor (R-C) combinations and the time constants created by their combinations. It's pretty basic stuff, but there are new people coming into the field of electronics all the time so it is worth posting. Discussed are coupling circuits, filter networks, differentiators, and time-delay circuits. The "After Class" feature is a series run by Popular Electronics magazine in the 1950s and 1960s. As with this installment, "After Class" presented topics on electricity and magnetism that served not just as new material for beginners, but was a good review even for seasoned practitioners of the craft ...

Servicing Test Instruments: Peter and the Pilot Light

Servicing Test Instruments: Peter and the Pilot Light, October 1952 Radio-Electronics - RF CafeIncandescent pilot lights are definitely a thing of the past; LEDs are the ubiquitous choice these days for obvious reasons (low cost, low current, long life). Nonetheless, there are still lots of equipment still in service that do use them. In 1952 when this article appeared in Radio-Electronics magazine, incandescent (and neon) lamps were standard in test gear, radios, televisions, tape recorders, record players, kitchen appliances, cars, industrial machinery, and many other everyday things. Electronics repairmen needed to deal with them on a regular basis. Although not technically sophisticated, knowing a little something extra about the little bulbs could be quite handy. One tidbit if useful info in this article is how the color of the little glass bead that mounted the filament to the base was often a clue to the current draw of the lamp at nominal operating voltage...

Fix Those Printed-Board Defects

Fix Those Printed-Board Defects, December 1959 Electronics World - RF CafeMy long-established collection of soldering aid and tuning wand tools still gets a fairly regular workout - but not necessarily for soldering tasks. Because of their purpose-designed ends, they come in handy for all sorts of model building activities. Most are non-metallic, meant for bending and poking, and are very strong and heat resistant. The metal types are still required for direct contact with molten solder. One of the best tips offered in this Electronics World article is for when replacing a leaded component on a printed circuit board (PCB). If possible, rather than heating the landing pad and plated through-via to remove the leads, just clip the leads far enough from the PCB surface to create a post or loop to solder the new component to...

Science & Engineering Themed Crossword Puzzle for October 18th

Science & Engineering Themed Crossword Puzzle for October 18th, 2020 - RF CafeOctober 18th's custom Science and Engineering Technology 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). 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.

FM Beep Signals

FM Beep Signals, June 1951 Radio-Electronics - RF CafeThis news bit from a 1951 issue of Radio-Electronics magazine reports on the FCC's declaration of illegality the practice by some FM broadcasting stations of providing a means for blanking out commercials and station identification to entities willing to pay for the special receivers and pay for a subscription. Nobody I have ever known looks forward to enduring commercials on television or radio (or Internet these days). The only way most of us could listen to music without interruption was to by a record, tape, or CD. VHS tapes and DVDs provide some relief from commercials, although even though you pay for them there are typically promotions for other movies at the beginning. Commercials on radio and television (and now the Internet) have consumed a larger part of each hour of programming with each passing year. The DVD collections we have of 1960s and 1970s Prime Time TV shows average run times of about 54-55 minutes...

15 Things We Do Know About Phono Cartridges

15 Things We Do Know About Phono Cartridges, June 1971 Popular Electronics - RF CafeAs the planet's population grows older and people have an increasing amount of disposable income and spare time, the opportunity to engage in nostalgic endeavors has gone up. That includes collecting, restoring, and operating equipment and peripherals that were the mainstay of their lives during their halcyon days of youth. In recognition of the new marketing opportunities, industries are popping up to feed the frenzy. Look no farther than eBay and the amount of vintage items available for purchase - at ever increasing prices. Having myself been an eBay buyer of memorabilia from my early model airplane, model rockets, and electronics hobbies, I have watched prices soar in many cases. Turntables (aka phonographs, or for the lowbrow types, record players) are being manufactured again ...

Meteor Detection by Amateur Radio

Meteor Detection by Amateur Radio, July 1947 QST - RF CafeThe 1940s and 1950s was an era of much advancement in our knowledge of Earth's upper atmosphere and its affects on radio communications - both good and bad as reported by this 1947 issue of QST magazine. Industry, government, academic, and amateur groups all played major roles in conducting experiments and publishing findings for the interested community to share and build upon. Still today a huge amount of research is being carried out to better understand how the various layers of the atmosphere - from ground level to space - are affected by extraterrestrial influences. A year ago I posted an article, along with a bit of editorializing, from the July 1958 edition of Radio-Electronics entitled..."

Engineering & Science Crossword for June 9

Engineering & Science Crossword Puzzle June 9, 2019 - RF CafeSince 2000, I have been creating custom engineering- and science-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. A database of thousands of words has been built up over the years and contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village ...

The Enormous Electron

The Enormous Electron, April 1944 Radio-Craft - RF CafeAnyone who pays attention in a present-day high school physics class would read this article from 1944 and immediately appreciate the advances that have been made in atomic theory during the ensuing 75 years. With modern knowledge, it is hard to believe that even in 1944 someone would seriously suggest that theorized sub-electronic particles (building blocks of electrons) might be responsible for supporting the propagation of electromagnetic energy. We still consider the electron to be an elementary particle (although now not so the proton and neutron), but at this point we are aware of many elementary particles other than the electron (some of which make up protons and neutrons). There are six types of quarks, the gluon, the photon, three types of bosons, and five other types of leptons other than the electron - for a total of 17. The author's characterizing of the electron as having a "flitting and jerking" "enormous" positional presence...

Interference Analysis

Interference Analysis, November December 1941 Radio-Craft - RF CafeImages, harmonics of the intermediate frequency (IF), harmonics of the local oscillator (LO), multiple station IF mixing, inductive and capacitive coupling, other types of noise can find a way into circuits if sufficient shielding and judicious component placement is not implemented. It is as true today as it was in 1941 when this article appeared in Radio-Craft magazine. An interesting interference generator discussed is that of heterodyned signals generated external to the receiver by means of random nonlinear junctions reacting to multiple high power broadcasting stations in a local area, as was fairly common when AM stations were the norm. Rusty bolted joints in buildings, towers, even automobiles can be the source of such phenomena. Even today it is not uncommon for bolted and riveted junctions on antennas and RF connectors to generate what are now termed passive intermodulation (PIM) spectral products...

Air Traffic Control by Electronics

Air Traffic Control by Electronics, January 1960 Electronics World - RF CafeAir Route Traffic Control Centers, now using the acronym ARTCC rather than ARTC as used in this 1960 article, were and still are the human and computer command and control facilities responsible for safe and orderly flow of air traffic in the U.S., and a worldwide network of Area Control Center (ACC) handles everything else in a massive coordinated effort. The advent of radar during World War II and the ensuing evolution of it and electronic computers in the following years struggled to keep pace with the equally rapidly evolving aircraft design and capability. A simple control tower with air traffic controllers using binoculars and a radio mike could not handle the volume of airplanes and helicopters traversing the skies and patronizing busy terminals. Many forms of electronic navigation aids were developed including very high frequency omnidirectional range (VOR), direction finders (DF) using antenna nulling for finding radials to/from FM radio transmitter, long range navigation (LORAN)...

Will You Pay for TV?

Will You Pay for TV?, October 1957 Popular Electronics - RF CafeThe 1950s was a time of transition in the television watching business. Broadcasters were experimenting with pay-TV systems to replace or supplement over-the-air service. Much as people today think that everything on the Internet should be free, the same mindset prevailed then regarding television programming. Early coding and decoding schemes seem really hokey by today's standards, using computer-type punch cards. I remember the area around Annapolis, Maryland, where I grew up, had both over-the-air and cable-based subscription services in conjunction with the open broadcasts. I spent at least a little time playing with the horizontal and vertical picture sync settings on the back of the TV set that, if lucky...

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