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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..."

A Survey of Silicon Junction Diodes

A Survey of Silicon Junction Diodes, July 1969 Electronics World - RF CafePrior to the emergence of silicon-based semiconductors, selenium and copper(cuprous)-oxide rectifiers were the alternatives to vacuum tubes. Copper-oxide (Cu2O) was popular as a small signal detector since its forward voltage drop was similar to a Schottky type diode - typically around 0.2 V. Copper-oxide diodes were used in radios and test equipment meters. Selenium (Se) has a forward voltage drop of around 1 V, but its high reverse voltage withstanding of 20 V or more made it popular for voltage rectification, with as many layers as necessary being stacked serially as required. Selenium rectifier stacks...

Geniac Problem Solving Computer

Geniac Problem Solving Computer, June 1955 Popular Electronics - RF CafeI remember seeing advertisements for the "Geniac Electric Brain" in technical magazines like Popular Electronics, Mechanix Illustrated, Popular Science, etc., back in the 1960s and 70s. Even then it seemed like a hokey attempt to pitch a mechanical gizmo as an honest-to-goodness computer. Personal computers were still a decade or more away and only multi-million-dollar mainframe computers were available, so the opportunity for Joe Sixpack to own a "problem solving" computer was a real temptation. No, I never bought one; my first computer was a second-hand Timex Sinclair 1000 with a membrane keyboard and a cassette tape deck as a program storage device. Anyway, when I found this article in a 1966 issue of Popular Electronics, I figured maybe other people of my vintage would enjoy reading about its inner workings ...

Synkote Wire & Cable

Synkote Wire & Cable, November 1953 Radio-Electronics - RF CafeI'm always tempted to wax nostalgic over ads like this one since they remind me of more care-free childhood and early teenage years when our household had the typical single television set with an antenna on the roof and a 300 Ω twin lead cable running haphazardly down the roof surface and over the metal gutter, stretching under the eave to where it was crushed between the window sill and lower window pane, and snaked along the wall and floor to the TV. In the early days, our antenna was fixed (no rotator). Situated in Mayo, Maryland, about midway between Baltimore and Washington, D.C., where our nearest broadcast stations resided, we somehow managed to get acceptable reception on our low-end black & white television. I don't recall in which direction the antenna was pointed (maybe northwestish to cover both directions equally). It wasn't until sometime in the early 1970s that we finally got our first color TV that the system showed its weakness...

Mac's Service Shop: How It Started

Mac's Service Shop: How It Started, February 1960 Electronics World - RF CafeMac's staff service technician, Barney, asked a great question when he mentioned that Pittsburgh radio station KDKA made the country's first commercial broadcast in 1920: "Who was listening?" It is a reasonable question since prior to the beginning on commercial radio broadcasts there would have been no reason for there to have been a lot of people to own a radio for receiving commercial broadcasts. The answer, of course, is that there were plenty of multi-band radios in homes and businesses for listening in on shortwave broadcast from around the world - a very popular pastime in the era. Just as today we are bombarded with admonitions to not stare at computer monitors or cellphone screens for too long lest we suffer near-sightedness or worse, radio listeners of yore who used headsets were told, "Youths of this generation will never have as protruding ears as some of their older brothers." I suppose...

Attack Planes Hug Hostile Terrain with New Radar

Attack Planes Hug Hostile Terrain with New Radar, February 21, 1964 Electronics Magazine - RF CafeAccording to this 1964 article in Electronics magazine, the U.S. Air Force's decision to build radar systems that would enable low altitude, terrain-following flight paths for strategic and tactical aircraft was in response to the shooting down of Gary Powers' U-2 spy craft in 1960. The event made clear that simply flying high over enemy territory and dropping bombs would not be a reliable strategy since surface-to-air missiles could reach and destroy aircraft before they got to their targets. Terrain-following capability on the part of bombers and fighters would add a major element of surprise since approach paths could be masked until it was too late to take offensive action. That approach was not without its risks and faults, as made apparent by the Dr. Strangelove movie satire that poked fun at the very concept...

Spot News - Electronic Industry News

Spot News - Electronic Industry News, April 1960 Electronics World - Television broadcast stations were quickly growing in number in the post-Korean War era and the FCC needed to devise a scheme for accommodating more channels. There were only 13 channels (only 2-13 used) allocated in the VHF spectrum with 6 MHz-wide bands. Even though VHF propagates primarily in a line-of-sight mode, reflections and earth-bounce can extend the range fairly significantly, limiting density in closely spaced cities. The military refused to yield any spectrum so a decision was made to add new channels (14-83, also 6 MHz wide) in the UHF band. UHF presented its own problems with more difficult equipment manufacturing issues and higher atmospheric attenuation. It never really caught on because cable TV was being widely installed in metro areas and even into suburbs by the early 1960s. Over-the-air (OTA) transmission issues were eliminated...

What Does My Overheated Transmission Have to Do with Admiral Grace Hopper?

What Does My Overheated Transmission Have to Do with Admiral Grace Hopper?r, Kirt's Cogitations #330 - RF CafeLast week Melanie and I drove down to Greensboro, North Carolina, to attend our daughter's wedding. The weather was typically hot there, but not out of the norm. All went well at the small ceremony. Both bride and groom showed up, as did the minister and necessary witnesses. After the blessed event was over, we headed back northward to our humble abode in Erie, Pennsylvania. Our route upon exiting NC is I81 for a few miles in Virginia, then north onto I77, up to Rt. 19, then I79 all the way home up and down mountains for a few hundred miles. Our 2011 Jeep Patriot has never had any mechanical issues, but then it only has 81k miles on it and is kept in the garage. That day, though, the transmission overheating idiot light illuminated while on I81 - not a particularly hilly stretch. The outside temperature there was about 80 °F. I had noticed a slightly higher pitch sound from it while going uphill, but didn't think anything of it until the light came on. (On-Trak Automotive Services)...

Electronics Crossword Puzzle, April 1967 QST

Electronics Crossword Puzzle, April 1967 QST - RF CafeQST, the monthly publication of the American Radio Relay League (ARRL), occasionally ran a crossword puzzle with an electronics theme. This one appeared in the April 1967 edition. Unlike the weekly RF Cafe crossword puzzles, this one does have a few words that are not strictly technology and science themed. However, many of the clues and words require some familiarity with Ham radio subjects and lingo ...

Engineering & Science Crossword Puzzle for March 1st

Engineering & Science Crossword Puzzle March 1, 2020 - RF CafeAs with my hundreds of previous science and engineering-themed crossword puzzles, this one for March 1, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you.

Who Killed the Signal?

Who Killed the Signal?, February 1943 QST - RF CafeIf you're a newcomer to the game, it may seem that radio theory already has enough mystery without adding more. True, the technical journals - even QST, sometimes - do make it a mysterious subject with their textbook language and complex notations. Radio isn't really any more mysterious or complex than many a detective story - at least not after you've read the last page and know "who­dunit." The difference lies in the method of presentation. There may be some utility, then, in the idea of presenting radio fundamentals in the manner of detective fiction. That's what this is - a series of radio lessons in the guise of a detective-mystery yarn. Instead of human characters we'll use another kind - but we'll try to make the characterizations true and the background and incident realistic. Our purpose is to divert ...

Electronic Factor Quiz

Electronic Factor Quiz, November 1966 Popular Electronics - RF CafeRobert Balin created this Electronic Factor Quiz for the November 1966 edition of Popular Electronics magazine. Your challenge is to match the drawing of a particular electronics circuit or implement with the corresponding "factor." Examples are "current amplification factor," "damping factor," "modulation factor," "duty factor," "form factor," "quality factor," etc. There are ten in all. Of course on a quiz like this you cannot get just one answer wrong - or any odd number for that matter. I managed to reverse #5 and #10 (I and B, respectively). For some reason I couldn't remember what "form factor" was, but was sure that #10 was a scale factor of sorts... wrong - a clear case of cranial rectumitis...

Engineering & Science Crossword Puzzle January 26th

Engineering & Science Crossword Puzzle January 26, 2020 - RF CafeAs with my hundreds of previous engineering and science-themed crossword puzzles, this one for January 26, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you...

Channel Master Antenna Advertisement

Channel Master Antenna Advertisement, October 1959 Electronics World - RF CafeA few months ago I posted a write-up on the vintage Alliance Model U-100 Tenna-Rotor that I installed in the garage attic with a Channel Master CM5020 VHF / UHF / FM antenna atop it. There are not many television antenna manufacturers around anymore; their numbers have been decreasing continually due first to the advent of cable-delivered TV and now with Internet-delivered TV. The "cord-cutter" movement is helping to give over-the-air television broadcasting a rebirth due to the outrageous cost of subscription programming. Anyone contemplating installing a television antenna today has the same concerns as those back in 1959 when this Channel Master advertisement appeared in Electronics World magazine - gain, directivity, bandwidth, ruggedness...

Vintage International Resistance Co. Ad

International Resistance Co., September 1944 Radio News - RF CafeWhen reading the opening copy from this 1944's era Radio News magazine advertisement from the International Resistance Company, I wonder whether the same can be said of today's population: "Americans are not sissies. When they know the truth, they can take it - especially when it relates to the war. It's only when somebody tries to fool them, that they rear up on their hind legs and yowl." At the time the "war" was WWII, but today the war and the enemies of our existence as a sovereign nation is not as well defined. The latest example is the COVID-19 virus cooked up in a Wuhan research laboratory and released on the world, while politicians, pundits, and media receiving fortunes and favors from China do their best to excuse and cover the deed. In 1944, people of the free world would never have succumbed to the useless mask and business restriction mandates imposed in 2020 and continued through today...

Protect Against Lightning

Protect Against Lightning, July 1955 Radio & Television News - RF CafeLightning has not changed since the days when Benjamin Franklin flew his special kite during storms. Contrary to some peoples' belief, he did not "discover electricity;" rather, the experiment proved his theory that lightning was a form of electrical discharge. Maybe someone has already pointed this out, but in effect Franklin put into service the world's first lightning rod. The conductive (wet with rain) hemp rope between the metal wire spike on the kite and ground (the plate of a Leyden jar) performed the task a lightning rod is meant to do - lower the difference of potential between the charged clouds and ground, thereby reducing the likelihood of an electrical discharge. An induced current traveled along the rope and charged the Leyden jar. If lightning had actually struck the kite as fables suggest, Franklin would probably have been killed even though he was holding on to a silk string attached to the bottom of the hemp string to provide some insulation. Mr. Kirchhoff's current law would have apportioned the lightning strike current at the knot joining the two strings according to the respective...

Phenomena Underlying Radio

Phenomena Underlying Radio (part 8), July 1934 Radio News - RF CafeThis is part of a series published by Radio News and the Short-Wave magazine in the early 1930s. As with most topics pertaining to electronics, the theory is still relevant and applicable to many modern circuits and systems. Piezoelectric principles are introduced for determining the frequency of oscillators. I have to admit to not having heard of the 'pyroelectric' effect. A pyroelectric crystal when heated or cooled develops charges on the extremities of its hemihedral (another new word for me, meaning "exhibiting only half the faces required for complete symmetry") axes. Types other than the familiar quartz include tourmaline, boracite, topaz, Rochelle salts, and even sugar. Read on to learn more ...

Wireless Engineering Theme Crossword Puzzle for July 18th

Wireless Engineering Theme Crossword Puzzle for July 18th, 2021 - RF CafeThis Wireless Engineering Theme Crossword Puzzle for July 18th contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Du Mont Television Advertisement

Du Mont Television Advertisement, January 1948 Radio-Craft - RF CafeThe Allen B. Du Mont Laboratories was one of the earliest manufacturers of television sets for consumer purchase. They were in operation long before committees like the NTSC were formed to standardize television broadcast signal formats. There were various methods competing for reproducing the image at the receiver end - including electromechanical and purely electronic schemes. Regular readers of electronics magazines like this edition of Radio-Craft followed the evolution of TV with great, though somewhat guarded,  enthusiasm. As with many technologies that seemed at the time to have mostly commercial and consumer applications, development during the war years yielded to the needs of victory for the Allied forces. Television prices were relatively high even in the late 1940s, so most households still did not have a TV set; radios still ruled in the domestic entertainment realm...

Denmark Electronics Market

Denmark Electronics Market, December 27, 1965 Electronics Magazine - RF CafeThis is the electronics market prediction for Denmark, circa 1966. It was part of a comprehensive assessment by the editors of Electronics magazine of the state of commercial, military, and consumer electronics at the end of 1965. Unless you can find a news story on the state of the industry, detailed reports must be purchased from research companies. Their websites have a lot of charts on Denmark's current electronics market showing revenue in the consumer electronics segment amounts of US$1,020M in 2018...

Channel Master Corporation

Channel Master Corporation, November 1951 Radio & Television News - RF CafeAs evidenced by this advertisement in a circa 1951 issue of Radio & Television News magazine, Channel Master has been producing commercial broadcast television and radio antennas and antenna accessories for a really long time. They are one of the very few companies still making such items, with RCA being another. A few years ago I bought a high gain Channel Master VHF-UHF-FM antenna for use with my vintage Alliance Model U-100 Tenna-Rotor. Both companies still sell remote control (wired) antenna rotators. Being an ardent over-the-air broadcast adherent, having a good old-fashioned steerable, multielement antenna is quite nice. I can dial in any TV or FM radio station within 50 miles, and some from over 100 miles away. I would like to have a similar setup for AM radio, but the antenna length gets out of hand at 530 to 1,700 MHz (525 to 1,705 MHz including 10 kHz channel spacing)...

Comics with an Electronics Theme

Comics with an Electronics Theme, September 1965 Popular Electronics - RF CafeThese electronics-themed comics from vintage issues of electronics magazines were usually funny even without being privy to the particulars of the topic to which it alludes. A couple guys shipwrecked on a floating hunk of wooden hull is usually the basis for a laughable comic. However, in this case the zip code mention was particularly significant in 1965 since the U.S. Post Office had only recently, in 1963, implemented the nationwide 5-digit zip code system, so it was in the news and in the forefront of people's minds. High fidelity stereo systems were also all the rage in the mid 1960's, as evidenced by all the print space allocated to it in Popular Electronics and other magazines...

Electronics-Themed Comics from a 1958 Radio-Electronics

Electronics-Themed Comics September 1958 Radio-Electronics - RF CafeGood, clean humor has always been a welcome addition to my day whether it comes in the form of a printed comic strip, a TV show, or someone's mouth. My father's side of the family was populated with many jokesters who could be counted on to deliver an ad hoc pun or zinger at the appropriate moment. The environment instilled a great appreciation for such entertainment, so these electronics-themed comics that appeared in editions of Radio-Electronics, Popular Electronics, et al, are a refreshing distraction from the workaday world. An old saying claims "laughter is the best medicine," and while it cannot cure cancer, a good dose of humor often helps ease the pain...

RF Engineering Theme Crossword Puzzle for March 7th

RF Engineering Theme Crossword Puzzle for March 7th, 2021 - RF CafeThis RF Engineering Crossword Puzzle for March 7th has many words and clues related to... you guessed it... RF engineering - and mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed...

Electricity in Motion: Current

Electricity in Motion: Current, Basic Navy Training Courses, NAVPERS 10622, Chapter 3 - RF CafeOne of the Notable Tech Quotes which has appeared on RF Cafe is, "The nice thing about standards is that you have so many to choose from," by computer scientist Andrew Tanenbaum. In the middle of the last century, a change in the fundamental understanding of current flow precipitated what has become a very large opportunity for people to misunderstand descriptions of current direction caused by a difference in voltage potential (voltage) - depending on the era a particular description was written. Beginning with Benjamin Franklin, electron current flow was assumed to be from positive to negative, ostensibly but incorrectly, because a positive thing must contain an excess of something (charge carriers - electrons) and a negative thing must have a deficiency. Hence, current flowed from an excess source to a deficient sink. We now know that negative things contain more electrons (relatively) than a positive...

Innovative Power Products (IPP) RF Combiners / Dividers


Amplifier Solutions Corporation (ASC) - RF Cafe

Rigol DHO1000 Oscilloscope - RF Cafe