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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..."

Super Selectivity for Your Receiver

Super Selectivity for Your Receiver, August 1965 Popular Electronics - RF CafeRestoring and/or upgrading vintage radio receivers is still a very popular pastime for hobbyists, and for that matter for some professional servicemen who preform maintenance on established equipment installations. Three of the most significant changes that can be made to older receivers to improve sensitivity are to clean up the power supply DC output, replace noisy components like vacuum tubes and leaky capacitors, and tune / modify / replace RF and IF filters. This article discusses a method of replacing a stock LC filter with a high selectivity mechanical filter. The nice thing about an analog receiver is that narrowband, steep-skirt filters can be substituted without concern for group delay at the band edges that can (and will) wreak havoc on digital signals...

Room Acoustics for Stereo

Room Acoustics for Stereo, January 1960 Electronics World - RF CafeIn the beginning, man created monophonic (mono) radios and phonographs that had sound with no spatial separation (left and right) in the source(s) and featured a single speaker. As such, except for being sure to not locate your radio or phono behind the sofa, sound perception at any point the room was fairly consistent - except maybe for volume level. Still, there was ample opportunity for the time of arrival due to multipath effects to distort the sound. Up until the 1950s or so, most homes had hardwood floors (with a few rugs) and rock-hard plaster walls to reflect sound waves, and rooms were relatively sparsely populated with furniture and wall hangings (look at photos in vintage magazines for proof), all of which provided means for distorted sound at a distance. And man said, "Let there be stereophonic (stereo) sound," which...

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...

The Crosley SCR-284 Field Radio

The Crosley SCR-284 Field Radio, September 1944 Radio News - RF CafeIf you are looking for information on the Crosley SCR-284 Field Radio, you've come to the right place - at least for learning about how manually intensive the manufacturing process for it was. If you want to know about the history and operation, then you'll want to visit the N6CC (Navy 6 Combat Comms) website. It is a wealth of amazing details, including, "The SCR-284 was used extensively during WWII. The basic component is the BC-654-A receiver transmitter. Designed as a portable field radio, the complete field set could be carried by 3 men (three 55 pound loads) or it could be mounted in vehicles. US Army procurement records indicate that 63,972 sets were procured between 1940 and 1945. Apparently all were built by Crosley Corp." That works out to more than 10,000 units per year, each requiring the kind of assembly and testing shown here. Along with the highly skilled and dedicated labor force required to turn out such quantities (while also producing other equipment) are the design, test, and production engineers needed to dream up, implement, and support such a massive effort...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000+ symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing...

More About Wide-Stage Stereo

More About Wide-Stage Stereo, March 1960 Electronics World - RF CafePerhaps one of the most frustrating situations to find yourself in if you are a hard core audiophile is being an unmarried enlisted man in the military, living in the barracks. Unlike residing in a college dorm where comparatively there is no iron hand of peaceful existence enforcement to quell a desire for music hall sound levels with bass saturation that can rock you off your chair (other than dorm mates threatening to beat you to a pulp), in a military establishment there is an immediate threat of arrest, rank demotion, monetary fines, or a letter of reprimand (aka nonpunitive punishment) for blasting a stereo (and your barrack mates might beat you to a pulp). One guy I shared a USAF barracks room with had a couple thousand dollars worth of stereo equipment in a 19" rack in the room. It had something like...

Bell Telephone Labs Project Echo

Bell Telephone Laboratories Project Echo, November 1960 Electronics World - RF CafeEcho 1 launched in August of 1960, finally allowing America to participate in the Space Race, which until then was roundly being won by the USSR. Electronics magazines of the day were filled with prognostications of the future of space communications. Electronics World dedicated most of their November issue to satellite Earth stations and advancements being made in ultra sensitive receivers and powerful transmitters. Since the earliest satellites were literally metallic balls for reflecting radio signals, it was necessary to optimize both ends of the communications path since there were no circuits onboard the satellite to perform signal processing and re-transmission. Bell Labs, of course, was at the forefront of the technology. In fact a famously serendipitous discovery was made by a couple scientists in 1964 using the very antenna featured in this advertisement...

For the Record: Popular Electronics Announcement

For the Record: Popular Electronics Announcement, August 1954 Radio & Television News - RF CafeRadio Amateur News began life in July 1919, then changed its name a year later in July 1920 to Radio News. In August 1948 the title was again changed to Radio & Television News, then shortened to Radio & TV News in May 1959. Publication continued through April 1959. The next month's issue (May 1959) was entitled Electronics World, with Radio & TV News as a subtitle, and ran through December 1971, when it merged with Popular Electronics. Popular Electronics began publication as a new magazine in October 1954 and printed its final issue in October 1982. The next month it became Computer & Electronics, which continued until April 1985. From May 1985 through January 1989 it was called Hands-on Electronics. Believe it or not, in January 1990...

The Maser & Sugar Scoop Antenna: Receiver for Signals from Space

The Maser & Sugar Scoop Antenna: Receiver for Signals from Space, November 1960 Electronics World - RF CafeWhen really good researchers set out to write books on history, they do not simply cull information from the publications of fellow contemporary authors; instead, they look for sources that were published during or around the time of the subject being covered. Doing so helps minimize the possibility that inaccuracies have crept into the knowledge pool and that information other authors might have either deemed insignificant or have missed can be recovered. With a bit of luck, sources are discovered that have never been used before. That is part of my motivation for going to the trouble of buying these vintage magazines and posting articles like this one which reports on early maser developments. It delves fairly deeply into the solid state physics of rare earth minerals that some of the first masers and lasers relied upon to function, including energy band diagrams and cryogenics. If the "sugar scoop" antenna looks familiar, it might be due to its rising to fame...

JFETS: How They Work, How to Use Them

JFETS: How They Work, How to Use Them, May 1969 Radio-Electronics - RF CafeLast Fall I posted part 2 of this Radio-Electronics article first because I did not yet have the May issue that contained part 1. So, if you read "JFET's - Put Last Month's Theory to Work" and have been waiting with bated breath for part 1, you may breathe easily again; here it is. Author Thomas Haskett enthusiastically introduces readers to the junction field effect transistors (JFET) as a more natural replacement than the bipolar junction transistor BJT) for vacuum tubes because of JFET (and other varieties of the FET) operational parameters being much more those of tubes than a BJT. Regarding his conversion, Haskett refers to himself as a "die-hard 'fire-bottle'" man - a term with which I am not familiar. My assumption is that "fire-bottle" is a slang name for vacuum tubes because of how hot they get, and they glow orange like a fire in a glass bottle...

The New Radio Receivers

The New Radio Receivers, September 1945, Radio-Craft - RF CafeListen to the Podcast! World War II came to an end in Europe in May of 1945, and in the South Pacific in September of the year. By the end of 1944, Americans were becoming confident that their fathers, sons, and husbands would soon finally be home. Manufacturers began advertising the eminent return and availability of consumer products that had gone out of production due to material shortages during the war years. Advertisements ran in trade and hobby magazines as early as 1944 promising lines of goods that in many cases had not even been designed yet or production planned. Some products being promised, however, were merely models that were already in production before the attack on Pearl Harbor. A few publishers refused to accept such advertisements until there was more concrete evidence that victory was assured. In fact, Hugo Gernsback, editor and publisher of Radio-Craft magazine, wrote a scathing piece in early 1945 admonishing manufacturers for their overenthusiastic promise and promotion of consumer electronics prematurely...

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 article delves into what causes inductors to...

Cannon Electric Sub-Miniature Plugs

Cannon Electric Sub-Miniature Plugs, April 1954 Radio & Televsion News - RF CafeAccording to the Wikipedia entry, Cannon Electric Company introduced the now-familiar D-Sub (D-subminiature) connector format in 1952. This advertisement in a 1954 issue of Radio & Television News magazine is the first one I recall seeing. D-Sub connectors were a really big deal back in the 1980s when personal computers (PCs) first appeared. CRT monitors used them, printers used them, scanners used them, network interfaces used them, mice and keyboards used them (those that didn't use PS/2 connectors, which were an invention of IBM for their Personal System 2 computers). Nowadays the USB (Universal Serial Bus) and HDMI (High-Definition Multimedia Interface ) connectors have replaced most D-Subs in the computer cable realm. Of course with everything going wireless, connectors and cables of all sorts are rapidly disappearing except those used for charging...

Engineering Themed Crossword Puzzle for November 1st

Engineering Themed Crossword Puzzle for November 1st, 2020 - RF CafeNovember 1st's custom 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.

Atomic Radiation: Types & Relationships

Atomic Radiation: Types & Relationships, May 1969 Electronics World - RF CafeNuclear energy was a big topic in the 1960s and 1970s as it was believed to be the future of electrical power generation for the world (at least up until the 3 Mile Island and Chernobyl incidents occurred). Ships and submarines were being powered by reactors that allowed them to run for months at a time without refueling, atmospheric emissions were practically zero, and the fuel source was abundant (albeit not simple to obtain). Medical and space applications were increasingly dependent on a greater knowledge of radiation and its effects on humans, plants, animals, and electronics. Many people by that...

Mac's Service Shop: Simple Things First

Mac's Service Shop: Simple Things First, January 1960 Electronics World - RF CafeAfter many years of reading Mac's Service Shop sagas, a persistent theme seems to be Barney's refusing to refer to equipment schematics while troubleshooting, thereby often wasting valuable time. According to business owner and electronics sage Mac McGregor, assuming that what is typical for most sets will apply to all sets can and does create a fertile environment for frustration - and profit loss. Mac's advice to check "simple things first," has always been my troubleshooting philosophy - maybe because identifying the "hard things" has nearly been my undoing many times when the trouble is not simple. One of first things I do is check switches, connectors, and user-accessible potentiometers for proper operation (when potentially responsible for the problem, of course). I've written many times about how often a dirty connector is the culprit...

Exploring the Infinitesimal

Exploring the Infinitesimal, June 1948 Radio News - RF CafeTechnology builds on its own successes in order to evolve. This article from a 1948 issue of Radio News magazine reporting on the relatively newly perfected electron microscope. As electronics moved from the macro scale in the form of vacuum tubes and large, high voltage- and power-handling leaded components (resistors, inductors, capacitors) to semiconductors and smaller, lower voltage and power components, using a standard optical type microscope was not good due to small features on the IC die. As more powerful microscopes were developed, engineers and scientists were able to develop semiconductor circuits with smaller features. That enabled more compact, higher performance electronic microscopes to be built ... and the cycle continued to where we are today. It is sort of another way of looking at Moore's law...

"Frequency" vs. "Amplitude" Modulation

"Frequency" vs. "Amplitude" Modulation, August 1935 Radio-Craft - RF CafeA momentous development that changed the field of radio communications warranted merely a half-page announcement in 1935 when frequency modulation inventor Edwin Armstrong had his article published in Radio-Craft magazine. It indisputably changed the world while causing poor Mr. Armstrong much grief while defending his right to the invention. Spread spectrum modulation / demodulation would be the next big communications advance that began with the frequency hopping (FHSS) scheme dreamed up by Hollywood actress Hedy Lamarr and pianist Antheil George during World War II. Direct sequence spread spectrum (DSSS) followed in the digital age, and since then I do not know of any fundamentally new communications technology in that time...

Home TV Via Satellite

Home TV Via Satellite, May 1966 Electronics World - RF CafeIt would be more than a decade after the publishing of this article before the first direct-to-home satellite television broadcasts would be a reality, so it shows how long plans were being made for such systems. Rural landscapes are still peppered with the large vestigial C-band (~4 GHz) satellite dishes, many with faded eyeballs and other clever (and ugly) artwork on them. Before coaxial cable was strung beyond suburbs, country dwellers who either could not pull in over-the-air broadcasts from downtown locations or just wanted more viewing options paid dearly for satellite service. Equipment and installation costs on early systems could run into the $30k realm. Today's satellite TV systems use much smaller antennas operating in the Ku band (~12 GHz), with equipment and installation being free with a 2-year commitment. C-band DBS (direct broadcast satellite) systems are still available, BTW...

First Over-the-Horizon TV Bridge

First Over-the-Horizon TV Bridge, November 1957 Radio & TV News - RF CafeIn the days before satellite communications (Telstar I, c1962), long-range television broadcasts relied on an extensive (and expensive) series of line-of-sight microwave towers. Each site had land ownership and maintenance expenses, so there was an incentive to streamline operations. Development of an over-the-horizon relay system enabled a reduction in sites and streamlining of operations - at least in theory. History shows that these installations must not have provided the improvement needed to implement them on a larger scale than that reported here. Nowadays, the proliferation of cellphone towers for ubiquitous coverage of wireless telecommunications has proven that huge numbers of individual sites can be profitable given a large enough customer base. You can scarcely go anywhere anymore without being able to spy a cell tower sticking out over the landscape...

Measuring Semiconductor Device Input Parameters with Vector Analysis

Measuring Semiconductor Device Input Parameters with Vector Analysis - RF CafeJoe Cahak, owner of Sunshine Design Engineering Services in Ramona, California, has written a white paper entitled, "Measuring Semiconductor Device Input Parameters with Vector Analysis." This article covers a recent test experience that utilized some thinking about the test fixture, the bias requirements and the device mounting and special calibration offsets needed to de-embed the test fixture response from the device response within the test fixture. The device also had to have bias on several ports simultaneously. We had to establish a "reference plane" within the fixture, from which we can use the Vector Network Analyzer's Port Extension or Phase Offset to dial out the distance from our 1 port calibration reference plane to the point of short reference within the fixture. With this phase offset compensation we can then measure...

Emerson Radio and Television Ad from the November 6, 1948 Saturday Evening Post

Emerson Radio and Television Advertisement from the November 6, 1948, The Saturday evening PostHere is an advertisement by Emerson Radio and Television from the November 6, 1948, edition of the The Saturday Evening Post. By 1948, America and the free world was well into the conversion of wartime production back into commercial and consumer products. After many long years of allocating factory space, personnel, and resources to beating back the forces of Communism, Marxism, Socialism, and other evil forms of 'isms," the good times were returning. FM radio broadcasting stations were increasing rapidly in number, providing static-free listening even in areas of weak reception. Television was still a relatively new phenomenon for most households. The tabletop Model 571 "Image Perfection" television carried a price of $299.50 in 1948, which is the equivalent of a whopping $3,186* in 2018...

Are You a "Television Looker?"

QST Looks at Television - 1944, January 1945 QST - RF CafeDid you know that you are likely a TLV? That's right, a Television Looker. The modern equivalent is CP - Couch Potato. In the early years of television, TLVs were as fascinated with the device itself and the technology as they were with the information being displayed. As this story tells, Hams were involved in TV transmission (ATV) early on. I did not know that amateur television was banned during World War II. During WWII, all amateur radio operations were suspended with the exception of those authorized to continue under the Radio Amateur Civil Emergency Service (RACES)...

Space Electronics

Space Electronics, September 1961 Popular Electronics - RF CafeSuccess won in the realm of space-based communications has been fraught with many failures. As with most endeavors, it is thanks to the relative few who have sacrificed and endured against overwhelming odds to bring significant technological advances in communications to the many. Space presents a particularly difficult venue because of the harsh deployment and operational environment, and inaccessibility after deployment. Personal sacrifice has taken the form of depression, financial ruin, lost opportunity for other endeavors, broken families, sickness, substance abuse, and other maladies brought on by an obsession with success. Such sacrifice has built the modern world...

Plug and Jack Quiz

Plug and Jack Quiz, December 1967 Popular Electronics - RF CafeTGIF once again. I keep looking back through issues of Popular Electronics magazine for Robert Balin quizzes that I might have missed, and fortunately this one was found. Unlike quizzes back in school, nobody but you will ever know how you score on it - that's what makes it fun. Your challenge is to determine the total resistance value between points A and B both before and after inserting the plug into the jack. Mercifully, Mr. Balin specifies that all the resistors are the same value. The Before part is a piece of cake even for someone in a first semester electronics course - just be sure to pay attention to whether or not the contacts short out any of the paths. The phono plug is on the left and the corresponding jack is on the right. Interpret the dual resistors plug circuits in figures 5 through 8 as having one resistor connected...

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