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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..."

Comics: Ham Radio Ain't What It Used to Be

Comics: Ham Radio Ain't What It Used to Be ... As Seen by Walt Miller, August 1967 Popular Electronics - RF CafeGood luck trying to find a good ham radio related comic in any magazine today. I am convinced that publisher boards either discourage or outright prohibit comics these day for fear of hurting some overly sensitive person's feelings and inviting lawsuits, or worse yet social media flaming frenzies. Fortunately, I am not afraid and am glad to make these vintage comics available. You and I, being reasonable people, cannot possibly find anything insulting or denigrating in any of these five comics, but somebody could. BTW, for the non-ham, a "pink ticket" from the FCC is a notice of violation, which could be anything from neglecting to announce your call sign every ten minutes to having a faulty transmitter that is spewing noise outside your band...

What Do You Know About Resistors?

What Do You Know About Resistors?, April 1974 Popular Electronics - RF CafeOK, I am ashamed to admit that with just a quick guess I thought Rx in question 6 would be 180 Ω rather than the correct value of 20 Ω. I knew the ratio of 150 Ω to 50 Ω (3:1) would be the same as for 60 Ω to Rx, but stupidly went the wrong way. In order for the bridge to be balanced, the voltage division between the left and right arms of the bridge had to result in the voltages on both sides of the meter to be 0 V. I did manage to get the equivalent resistances of Q8 ...

Microtubes - A New Milestone in Electronic Developments

Microtubes, November 1947 Radio-Craft - RF CafeA month before Bell Laboratories' announcement of the transistor invention by Mssrs. Bardeen, Shockley and Brattain, Radio-Craft magazine editor Hugo Gernsback published a piece extolling the virtues of a newly developed microtube, aka a "rice-grain" tube. As connected as Gernsback was in the electronics industry, it is doubtful he knew of the impending game-changing invention. Commercialization of the transistor took a few years to get to the point where the devices could be manufactured cheaply and reliably enough to begin being integrated (pun intended) into products, so vacuum tubes still reigned for another decade or more. While the microtubes were designed into such products as portable radios, hearing aids, and other things in desperate need of size reduction, standard tubes continued to be used in the majority of things...

Anaconda Copper Ad in the April 29, 1950 Saturday Evening Post

Anaconda Copper Advertisement in the April 29, 1950 Saturday Evening Post - RF CafeIt's not often that you will see a full-page ad promoting a particular element in the periodic table, but in 1950 that wasn't the case. This advertisement for Anaconda Copper Mining Company which appeared in a 1950 issue of The Saturday Evening Post magazine extolled the virtues of element number 29 - copper (Cu , from the Latin "cuprum"). Aluminum and iron were other popular topics of advertising. If you do a search on the history of Anaconda, which is today owned by the Atlantic Richfield Company (ARCO), what dominates is the harm done to workers and to the environment. The short video below is one of the less vicious reports on the company's operations in Butte, Montana and in Chile. COPPER... Time's Friendly Enemy Time and copper get along well together - because of one simple reason: Copper chooses to ignore time completely. For nature has given copper the great quality of almost eternal youth - the ability to resist the slow but steady ravages of the elements, for centuries if need be...

SimSmith Smith Chart Software

SimSmith Smith Chart Software - RF Cafe Cool ProductRandy Rogers*, AD7ZU, mentioned in the May 2020 issue of QST magazine the Smith Chart software called "SimSmith," by Ward Harriman, AE6TY. SimSmith first appeared around 2011. Being written in Java, it will run on any operating system that supports Java (Win64, Win32, Apple Mac OS X, Solaris, and Linux). If you are using Win64 as I am, you will want to download the "windows64-with-JRE.exe" file. Windows security will try to block it, but it is safe to run after your antivirus program scans it and gives a green light. AE6TY recommends using the installation files rather than just downloading the "SimSmith.jar" file even if you already have a version of Java installed. When launching the program, the window might not be very large, so grab a corner and stretch it out so the components are easier to see. After playing around with SimSmith for a while, you might want to click on the "SimSmith->preferences" menu selection...

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...

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...

Fair Programmed for Fun - 1964 New York World's Fair

Fair Programmed for Fun (NY World's Fair), April 6, 1964 Electronics Magazine - RF Cafe

Anytime I see a photo or story about the 1964 New York World's Fair, I immediately think of the scene at the end of the first "Men in Black" movie when Agents K and J face off with the alien invader who has come to Earth in search of "The Galaxy." This story from an April 1964 issue of Electronics magazine reports on preparations made for the grand opening on April 22 of that year. Based on the typical three to six month lead time for publishing magazines back in the day, this material would have been gathered long ahead of time. Of course now that half a century has passed we hardly consider any of the whiz-band technology presented there as being anything wonderful, but then half a century from now our grandkids will laugh at what we consider amazing at the present time. Here is an interesting statement from the article that really gives you an idea of generational progress: "The World's Fair alone will contain some 300 television..."

Metal Circuit Systems Corporation

Metal Circuit Systems Corporation, September 1974 Popular Electronics - RF CafeThe claim of a "non-conducting metal sheet" as a substrate for drawing electronic circuit traces seemed suspicious, so I did a search for non-conducting or at least low conductivity metal, and there is no such thing. The advertisement says components can be soldered directly to the board without effecting a connection. Even low conductivity metals to which solder will adhere are good enough electrical conductors to prevent components from being attached on a common surface without significant conduction (i.e., short circuits) between them. A pen with conductive ink is used across the surface to create interconnecting paths. My guess, although I could not locate any information on the company's substrate fabrication, is that the board had an array of isolated copper pads that would be bridged by the conductive pen. Metal Circuit Systems Corporation was ...

Electronics-Themed Comics, April 1970 Radio-Electronics

Electronics-Themed Comics, April 1970 Radio-Electronics - RF CafeWind down the week with these four electronics-themed comics from a 1970 issue of Radio-Electronics magazine. As mentioned before, radio and television technology was a big deal in the era. People hadn't been born into a world of transistorized microcircuit media devices that perform nearly every conceivable function - phone, TV, radio, computer, heart rate monitor, voice recorder, remote control, camera, compass, game, social media, etc., etc., etc. Unlike today's electronics products that typically don't break with normal use and do not require periodic alignment, folks from my demographic were used to turning on a TV or radio and having to readjust it or have it repaired...

Air Corps Radio Phraseology Training

Air Corps Radio Phraseology Training, January 1945 Radio News - RF Cafe"Say again." That phrase is heard often in telephony conversations both wired and wireless. It was coined near the end of World War II by Air Corpsman 2nd Lt. Byron A. Susan, as reported in the January 1945 edition of Radio Craft magazine. Lt. Susan was responsible for setting standards for "radio phraseology" to eliminate ambiguity between aviators and ground forces. "Say again" replaced "Repeat" because the latter is an artillery term used to order another round of assault from a gun salvo. The history of the confirmation "Roger" is murky, but many agree it comes from the older military phonetic pronunciation of the letter "R" being "Roger," and in radio the letter "R" meaning "received." Another common bit of radio phraseology is "Wilco," which is a contraction of the words "will comply."

Electrons and Magnetic Fields

Electrons and Magnetic Fields, November 1968 Radio-Electronics - RF CafeUniversity of Southampton, England, professor James Holbrook suggests in this 1968 Radio-Electronics magazine article an "easy-to-follow substitute for the left- and right-hand rules," but I'm not so sure that the good professor's "Electron Orbit Method" is any better or easier to remember. Admittedly, it is hard to remember whether the use a left-hand rule or a right-hand rule for the various physical laws - motor rotation direction, current induction, torque, vector cross products, etc. Those involving current flow are made even more confounding because you need to know whether the creator of the rule refers to conventional current flow (positive-to-negative) of electron current flow (negative-to-positive). Note in Figure 110 from the Electricity volume of Basic Navy Training Courses how the generator rule is described as a left-hand rule with conventional current flow...

Realistic TRC-409 Portable Citizens Band Radio

Realistic TRC-409 Portable Citizens Band Radio (Radio Shack) - RF CafeIt has been a long time since I've had a citizens band (CB) radio in my car. Back in the 1970s when the CB craze was at its peak, with songs like C.W. McCall's "Convoy"* topping Casey Kasem's American Top 40 (AT40) charts, my high school compadres were all installing 23-channel CBs (standard at the time) in their cars and pickups. I joined in with a Radio Shack unit (don't recall the model number). In those days the FCC required operators to register and mail a check for a few bucks - same with radio control (R/C) systems for model airplanes also operating in the same 26-27 MHz radio band - in return for a "Citizens Radio Station License" document to carry in your wallet. Most CB channels were spaced at 10 kHz, but the R/C frequencies were in-between some CB channels spaced at 20 kHz. For instance, my 3-channel OS Digitron R/C system was at 27.195 MHz, which resided between CB channels 19 (27.185 MHz) and 20 (27.205 MHz). Some electronically savvy CBers would illegally modify their radios to include operation on those in-between frequencies (e.g. Ch 19A at 27.195 MHz), thereby creating a scenario where merely keying up the transmitter could "shoot down" a model airplane if close enough...

Electronics-Themed Comics, December 1949 Radio-Electronics

Electronics-Themed Comics, December 1949 Radio-Electronics - RF CafeHere are a few examples of what was considered cutting-edge technology humor back in 1949. These three tech-themed comics appeared in Radio-Electronics magazine. The first one won't mean much to anyone who has never watched a television with a cathode ray tube (CRT), but only on an LED or LCD screen. The next comic is a bit corny and plays off the confusion some people had with the name assigned (actually the spelling thereof) to the lower audio frequencies. The last is a pun on the extreme measures sometimes needed to pull in a TV broadcast station before the days of cable and satellite service.

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...

Radio Industry Marks 20th Anniversary - Harrisburg Telegraph c1940

Radio Industry Marks 20th Anniversary - Harrisburg Telegraph c1940 (Kirt's Cogitation #309) - RF CafeHello. My name is Kirt, and I'm a vintage magazine and newspaper addict. This affliction has had a hold on me for two decades now. Call it my middle age crisis. At sixty years old, there is no sign of abatement in enthusiasm. Nearly every day I still find myself reading and commenting on articles and advertisements from mid-last-century magazines, newspapers, and catalogs. Maybe I'm hopeless and will never be able to kick the habit. I'm not alone, though, based on some of the feedback received from RF Cafe visitors. For that reason and others, maybe, in truth, I've grown comfortable with my addiction. While perusing a few vintage newspaper editions from the World War II era looking for relevant stories, I ran across this November 1, 1940 (exactly 78 years ago) special section in the Harrisburg Telegraph titled, "Radio Industry Marks 20th Anniversary...

Radio & Radar Crossword Puzzle for November 29th

Radio & Radar Crossword Puzzle for November 29, 2020 - RF CafeFor the sake of avid cruciverbalists amongst us, each week I create a new crossword puzzle that has a theme related to engineering, mathematics, chemistry, physics, and other technical words. This November 29th Radio & Radar Crossword Puzzle, as always, contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Theory and Application of UHF

Theory and Application of UHF, December 1944 Radio News - RF CafeThis is part 8 of a series authored by Milton Kiver entitled, "Theory and Applications of UHF," that appeared in Radio News magazine in the mid 1940s. As you might expect it is a very extensive delve into the relatively new realm of UHF generation, transmission, propagation, and reception. You might not know that up through the 1930s, UHF circuit and practice had been relegated to the amateur radio operators because those frequencies from 300 MHz to 3 GHz were considered too unexploitable for professional use. It was not until Hams did the hard work of figuring out practical methods of building circuits and antennas and characterizing geographical and atmospheric conditions that affected propagation that suddenly industry and government decided UHF might be useful after all...

Tropospheric Scatter: A Bridge to Alaska

Tropospheric Scatter: A Bridge to Alaska, October 1963 Popular Electronics - RF CafeCommunications links are so ubiquitous these days that we pretty much take for granted the ability to connect to the Internet and to other people. How many times have you been in public and heard someone have a fit because she couldn't get a good enough signal to make a call? It requires the person to get up and walk a few feet or maybe turn her chair in another direction to get an extra bar on the iPhone. How inconvenient. Even when placing a call to Hawaii or Alaska the expectation is that things just work. In 1963 when this tropospheric scattering network was installed for linking Alaska to the lower 48 states, satellite communications was still in its infancy and coverage was nowhere close to global. Even radio relay towers were relatively scarce across the landscape...

Negative Feedback Transistor Amplifiers

Negative Feedback Transistor Amplifiers, May 1957 Radio & TV News - RF CafeThe big graphic with Figures 1 through 17 reminds me of the kinds of study sheets I used to make when cramming for exams in my college circuits courses. Did I ever tell you about the wise guy instructor I had for my first Circuits class at the University of Vermont? Anyway, this article provides an introductory level treatment of using negative feedback in amplifier circuits. Lots of illustration and formulas are included. Frequencies are at baseband, so you won't learn any secrets for high frequency amplifier stabilization, but then even RF and microwave circuits eventually need to convert down to baseband at some point for sampling or for use as audio or video...

After Class - Special Information on Radio, TV, Radar and Nucleonics

After Class - Special Information on Radio, TV, Radar and Nucleonics, December 1957 Popular Electronics - RF CafeThis installment of the After Class series in the December 1957 edition of Popular Electronics deals with inductors. It is a beginner-level introduction to how reactive components behave in circuits. For some reason the concept of magnetism's influence on electrical current (present with inductors but not capacitors) seems to be more difficult to comprehend than that of electrons, even though James Clerk Maxwell shows in the mid 1800s that the two phenomena are interrelated. I am tempted to say that back in the 1950s when this article appeared, people were less familiar with the relatively new concept of electronics, but in thinking about it, your typical 2019 reader is probably even less likely to know anything at all about electronics or the way basic components work. I would bet that maybe 1% could even tell you the difference between AC and DC current...

Science in Music

Kirt's Cogitations™ #244 - Science in Music - RF CafeIf you are not in the habit of listening closely to the words of songs, you could easily miss the the fact that many make passing mention of topics on science and mathematics, while others integrate it as the primary theme. There are a lot of songs written and produced by people whose primary vocation is in the sciences; their songs are a secondary "hobby" type of endeavor - often with a touch of humor. Don't miss Tom Lehrer's incredible "Elements Song." Other songs are created by mainstream popular groups and happen to integrate themes of science, mathematics, engineering, etc. One of the earliest examples I can recall noticing was produced by the Moody Blues - "The Word." At the time, I did not fully appreciate the profoundness of the lyrics in terms of how they described the electromagnetic spectrum in its entirety, but an examination of the lyrics (below) reveals the profundity of the words...

How an Electronics Brain Works

How an Electronics Brain Works, June 1951 Radio-electronics - RF CafeIt takes a while - and money - to accumulate issues of the vintage electronics magazines for posting articles here on RF Cafe. Often I can find groups for sale that comprise a full calendar year, but often they are groups of random months and years. That makes getting a complete series of articles like this one on "How an Electronic Brain Works" difficult. A lot of times installments appear every other month, so when a series has more than ten articles, it can run well over a year. For instance Part I of "How an Electronic Brain Works" appeared in the September 1950 issue of Radio-Electronics. The final chapter, Part XIII, appeared in October 1951. Throughout the series, authors Edmund C. Berkeley and Robert A. Jensen describe the workings of "Simon," their compact electronic computer - some even call it the first "desktop computer." Here is an article (with photos) about "Simon" in the November 1950 Scientific American magazine...

Burgess Battery Company

Burgess Battery Company Advertisement, January 1941 QST - RF CafeBefore there were electric generators onboard airplanes to power communications equipment, aviators relied on storage batteries to operate their radios. Before that, there were no radios at all aboard airplanes. Although Wilbur and Orville Wright first piloted their Wright Flyer in 1903, by the end of the decade airplanes were becoming a common sight across the country and across the civilized world. By the middle of the second decade experiments were being done with airborne radio. They were heavy vacuum tube units with heavy lead-acid batteries. Antennas sometimes hundreds of feet long needed to be reeled out and in once at altitude. The earliest transmitter (for 2-way communications) were spark gap types, meaning of course Morse code was the medium. That's right, the pilot - often alone without an assistant - sent messages by tapping out dits and dahs using a straight key strapped to his thigh. Moving into the 1920s, radio telephony had become standard equipment aboard transport and military aircraft. Much of it early-on was battery powered...

NEETS Module 8: Introduction to Amplifiers

NEETS Module 8: Introduction to Amplifiers 1-1 - RF CafeThis chapter is a milestone in your study of electronics. Previous modules have been concerned more with individual components of circuits than with the complete circuits as the subject. This chapter and the other chapters of this module are concerned with the circuitry of amplifiers. While components are discussed, the discussion of the components is not an explanation of the working of the component itself but an explanation of the component as it relates to the circuit. The circuits this chapter is concerned with are Amplifiers. Amplifiers are devices that provide Amplification. That doesn't explain much, but it does describe an amplifier if you know what amplification is and what it is used for. What Is Amplification? Just as an amplifier is a device that provides amplification, amplification is the process of providing an increase in Amplitude...

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