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Today in Science History

The Bridged-T

"The Bridged-T Filter, February 1964 Radio-Electronics - RF CafeThe bridged-T filter is a quick-and-dirty construct used to notch out a specific frequency that is interfering with a desirable frequency or band of frequencies. It is a resonant LC (inductor-capacitor) circuit consisting of a single inductor "bridging" a pair of series capacitors having a resistor to ground between them, or, if preferred, a capacitor bridging one or two inductors. A convenient nomogram (aka nomograph) is provided by the author in this 1964 Radio-Electronics magazine article for quickly selecting values, which was a very popular design aid in the pre-calculator era. A slide rule could be used to calculate a range of values when only a single variable was in play, but juggling more than one variable (component value) was greatly aided by a multivariable nomograph. Truth is nomographs can still...

Carl & Jerry: TV Picture

Carl & Jerry: TV Picture, June 1955 Popular Electronics - RF CafeTelevision, in 1955, was still a relatively new phenomenon to many - maybe even most - people. According to multiple sources, the portion of American households with a TV set went from under 20% in 1950 to nearly 90% ten years later in 1960. That was a meteoric rise, particularly considering the expense of even a minimal TV. The technology was not even available commercially when most people were born, so the rush to join in on the craze was akin to the mass adoption of cellphones in the 1990s. "Carl & Jerry" creator John Frye used his pair of electronics-savvy teenagers to help make the "magic" behind recreating a moving picture on a CRT miles away from where it was created. Water flowing through a garden hose has often been employed as an analogy for current flowing through a wire to explain electricity to laymen and beginning students of the craft. Here, it is not water flowing through the hose but water leaving the hose and flowing through the air that serves to represent an electron stream travelling from the electron gun to the phosphor-coated glass front of a CRT. Frame rates, scan lines, deflection coils, and other relevant terms are i

RF Front-End Tech Drives Automotive Innovation

RF Front-End Tech Drives Automotive Innovation - RF Cafe"The RF front-end (RFFE) industry, valued at $21 billion, is expanding beyond its traditional focus on mobile and infrastructure to drive innovation in the automotive sector. Each segment within the industry presents unique dynamics and growth opportunities. After a difficult 2022, the smartphone market is showing signs of recovery, with expected year-over-year growth of 4%, projected to reach 1.2 billion units by 2024. The mobile RFFE market is predicted to hit US$18 billion by the end of 2024, though it may face stagnation due to market saturation and pricing pressures. This market is expected to expand, with the 2027 launch of RedCap..."

Magnetoresistance: Better Than Hall-Effect Multipliers

Magnetoresistance: Better than Hall-Effect Multipliers, April 6, 1964 Electronics Magazine - RF CafeI'm having a hard time writing this with my eyes rolled back in my head. The last time I experienced this level of overwhelmedness was probably the third or fourth week of my feedback and control class at UVM. Even though electricity and magnetism shares many complimentary and parallel concepts, for some reason thinking in terms of magnetics when describing amplifiers, mixers, modulators, etc., has always caused brain freeze. Maybe it has to do with an ingrained bias due to my earliest dealings with circuits being from a technician background before earning an engineering degree. The equations of electric fields and magnetic fields are very similar so that helps lower...

Thanks to Temwell for Their Support!

Temwell (filters) - RF CafeTemwell is a manufacturer of 5G wireless communications filters for aerospace, satellite communication, AIoT, 5G networking, IoV, drone, mining transmission, IoT, medical, military, laboratory, transportation, energy, broadcasting (CATV), and etc. An RF helical bandpass specialist since 1994, we have posted >5,000 completed spec sheets online for all kinds of RF filters including helical, cavity, LC, and SMD. Standard highpass, lowpass, bandpass, and bandstop, as well as duplexer/diplexer, multiplexer. Also RF combiners, splitters, power dividers, attenuators, circulators, couplers, PA, LNA, and obsolete coil & inductor solutions.

What's Your EQ?

What's Your EQ?, February 1962 Radio-Electronics - RF Cafe Here we are with another set of three "What's Your EQ?" circuit challenges, these from the February 1962 issue of Radio-Electronics magazine. As usual, those challenges provided by Jack Darr are the purview of television servicemen of the era. The photo shown of the problematic CRT display looks like a chest x-ray or maybe hieroglyphics in the dark corner of a cave, but evidently the artifacts are readily identifiable to an initiated few. The Forbidden Current Path circuit answer is not what I thought it would be. I maintain that whether my answer or the designer's answer is correct depends on the physical...

New Wireless Data Rate Record Set

New Wireless Data Rate Record Set - RF Cafe"A new world record in wireless transmission, promising faster and more reliable wireless communications, has been set by researchers from UCL. The team successfully sent data over the air at a speed of 938 Gb/s over a record frequency range of 5–150 GHz. This speed is up to 9,380 times faster than the best average 5G download speed in the UK, which is currently 100 Mb/s or over. The total bandwidth of 145 GHz is more than five times higher than the previous wireless transmission world record. Typically, wireless networks transmit information using radio waves over a narrow range of frequencies..."

Sputnik: A Brief History

Sputnik: A Brief History - RF CafeSputnik refers to the first series of satellites launched by the Soviet Union. The word "Sputnik" means "satellite" in Russian. The launch of Sputnik 1 on October 4, 1957, marked a monumental moment in human history, heralding the dawn of the Space Age and sparking a fierce technological competition known as the Space Race between the United States and the Soviet Union. This satellite, the world's first artificial one, orbited Earth at an altitude of roughly 215 to 939 kilometers and broadcast a radio signal that astonished the world, particularly in the United States, where it spurred rapid advancements in aerospace and scientific research. The successful launch of Sputnik was an achievement that was years in the making, involving a combination of visionary planning, political motives, and intensive engineering by some of the Soviet Union's top scientists.

Blog: Air Quality Measurements with Particle Counters

Axiom Test Equipment Blog: Provide Essential Air Quality Measurements with These Particle Counters - RF CafeTranscat | Axiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post entitled "Provide Essential Air Quality Measurements with These Particle Counters" that covers how particle counters can provide essential measurement capabilities that can help avoid contamination and support high manufacturing yields. These measurement tools can detect and measure microscopic particles suspended in air that can contaminate the most carefully planned manufacturing lines. Air particle counters can be designed for various...

Receiving U.S. Satellite Signals

Receiving U.S. Satellite Signals, March 1958 Radio News - RF CafeIn 1958, most people were not accustomed to seeing the now-familiar maps plotting sinusoidal courses of satellites across the face of the earth. It had only been in October of the previous year that any object other than the moon was in orbit around our home planet - that was U.S.S.R.'s Sputnik. Just as people of all ages and all backgrounds enthusiastically joined in the newfangled phenomenon of aeroplanes after the Wright Brothers flew their fragile craft at Kitty Hawk, electronics communications and scientists worldwide hopped aboard the satellite train. This article from a 1958 issue of Radio & TV News magazine provided insight into the construction and flight characteristics...

Thanks Again to LadyBug Technologies for Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Radio and Television News - Predictions

Radio and Television News, January 1969 Electronics World - RF CafeWhat were some of the top issues of the radio and television industry half a century ago? In a lot of respects, the same things that concern it today. A ready supply of service technicians was a concern that was taken seriously by the Electronics Industry Association (EIA). While there are not many local repair shops for electronics products nowadays, there is still a huge demand to techs who are willing and able to do the hard work of keeping the world's communication infrastructure operational - climbing towers, repairing cell equipment. Now, as then, good pay, job security, benefits, and respect for the job being done were at the top of...

RIGOL Introduces Oscilloscope & Generator Lines

Impressive Performance at an Impressive Price: RIGOL Introduces Oscilloscope & Generator Lines - RF CafeIn a parallel to the traditional test setup of signal generation and signal acquisition, RIGOL Technologies announced today the latest additions to its portfolio of performance measurement equipment with the introduction of the DG5000 Pro Series Generators and DHO/MHO5000 Series Oscilloscopes. The DHO/MHO5000 Series bring next-level performance to RIGOL's respected line of high-resolution oscilloscopes, while the DG5000 Pro generators do the same for the company's capable Pro Series arbitrary waveform generators...

Basic Electronic Counting

Basic Electronic Counting, March 1958 Radio News - RF CafeWhen selecting articles for posting here on RF Cafe, I like to include ones that are directed toward newcomers to the field of electronics as well as for seasoned veterans. This piece from a 1958 issue of Radio & TV News magazine entitled "Basic Electronic Counting," is a prime example in that it introduces the concept of binary numbers. We've all been there at some point in our careers. A big difference between now and when this article appeared is that in 1958, almost nobody was familiar to binary numbers, and fuggetabout [sic] octal and hexadecimal. Only those relatively few people designing and working with multimillion dollar, vacuum tube-based digital computers installed in universities, megacorporations, and government research facilities had ever dealt with digital numbers. The earliest example of powers of two I remember was back in junior high school. It had to do with a

Art of Invention Constantly Reinvented

Art of Invention Constantly Reinvented - RF cafe"Every invention begins with a problem - and the creative act of seeing a problem where others might just see unchangeable reality. For one 5-year-old, the problem was simple: She liked to have her tummy rubbed as she fell asleep. But her mom, exhausted from working two jobs, often fell asleep herself while putting her daughter to bed. 'So [the girl] invented a teddy bear that would rub her belly for her,' explains Stephanie Couch, executive director of the Lemelson MIT Program. Its mission is to nurture the next generation of inventors and entrepreneurs. Anyone can learn to be an inventor, Couch says, given the right resources and encouragement. 'Invention doesn't come from some innate genius, it's not something that only really..."

Mechanical Filters

Mechanical Filters, April 1969 Electronics World - RF CafeMechanical filters of the type described in this 1969 Electronics World magazine article are yet another example of the genius of some people. They are actually a form of electromechanical device in that the applied electrical signals are first converted into mechanical signals, followed by resonant mechanical elements that discriminate according to frequency, and finally a conversion back to an electrical signal is made. It is fundamentally the same principal as a crystal, SAW, or BAW filter, albeit each with distinctly different methods and topologies. Mr. Donovan Southworth, of Collins Radio, presents the basics of mechanical filters in this brief write-up...

Thanks Again to LadyBug Technologies for Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Electronic Test Paper

Electronic Test Paper, July 1963 Radio-Electronics - RF CafeAttempts at making an electronically printed facsimile (fax) of an original document at a location distant from the source have been around for quite a while. As mentioned by Radio-Electronics magazine editor Hugo Gernsback in this article, Samuel Morse had a crude working device for printing messages on paper even before his eponymously named code of dots and dashes became famous in 1837. A couple decades earlier, a fellow named John Redman Coxe, of Philadelphia, Pennsylvania, devised a method of electronically printing images and text on paper using a conductive solution and a direct current pile (aka battery). Dr. Coxe, a physician, is not a well-known figure in the electronics world, but in his day...

"Edge of Chaos" High-Performance Microchips

"Edge of Chaos" High-Performance Microchips - RF Cafe"Researchers have discovered how the 'edge of chaos' can help electronic chips overcome signal losses, making chips simpler and more efficient. By using a metallic wire on a semi-stable material, this method allows for long metal lines to act like superconductors and amplify signals, potentially transforming chip design by eliminating the need for transistor amplifiers and reducing power usage. A stubbed toe immediately sends pain signals to the brain through several meters of axons, which are composed of highly resistive fleshy material. These axons operate using a principle known as the 'edge of chaos,' or semi-stability, enabling the swift and precise transmission of information..."

Japanese Trade-Name Directory

Japanese Trade-Name Directory, August 1969 Electronics World - RF CafeThe January 1969 issue of Electronics World magazine published an extensive list of Japanese company trade names and their addresses. Many of them went out of business or were bought by other corporations long ago, as occurs in all countries. "Aiwa" is listed twice, but that might have been a legitimate duplication due to separate locations (BTW, I owned an Aiwa stereo at one time). My first "real" cassette tape deck was made by TEAC (founded in 1953 as the Tokyo Electro Acoustic Company) and my first "real" stereo receiver was made by Sansui. I remember the line in "Back to the Future 3" where Doc Brown, having time-travelled from 1955, makes a disparaging remark about a circuit in the DeLorean failing because of it being labeled "Made in Japan." Marty counters...

Engineering & Tech Headlines <Archives>

• ARRL Defends 902-928 MHz Amateur Radio Band

• FCC's Auto Safety Spectrum Rules

• $5M in U.S. Chips Act Money to Metrology Projects

• U.S. State Department Approves Surveillance Radar System Sale to Romania

5G Americas ITU IMT-2030 Vision for 6G White Paper

John Redman Coxe: A Short Biography

John Redman Coxe: A Short Biography - RF Cafe - RF CafeJohn Redman Coxe was a prominent American physician, scientist, and innovator born on September 20, 1773, in Philadelphia. Coxe's intellect and curiosity drove him toward an illustrious career in both medicine and early scientific exploration, which included experimentation in electrochemistry. He graduated with a degree in medicine in 1794, setting the course for his lifelong journey into medicine and early scientific innovation. Coxe broadened his approach to medicine and science, inspiring him to explore the convergence of scientific methods and practical applications. John Redman Coxe is most remembered not only for his contributions to medicine but also for his interest in experimental physics, particularly in the field of electrochemistry...

Thanks to TotalTemp Technologies for Continued Support!

TotalTemp Technologies - RF CafeTotalTemp Technologies has more than 40 years of combined experience providing thermal platforms. Thermal Platforms are available to provide temperatures between -100°C and +200°C for cryogenic cooling, recirculating & circulating coolers, temperature chambers and temperature controllers, thermal range safety controllers, space simulation chambers, hybrid benchtop chambers, custom systems and platforms. Manual and automated configurations for laboratory and production environments. Please contact TotalTemp Technologies today to learn how they can help your project.

Vibration and Shock - Nature's Wrecking Crew

Vibration and Shock - Nature's Wrecking Crew, August 1966 Radio-Electronics - RF CafeWhen I saw this 1966 Radio-Electronics magazine article entitled, "Vibration and Shock - Nature's Wrecking Crew," for some reason the first thing I thought of was "The Wrecking Crew," that anonymously played the music for a huge number of popular singers - mostly those without prominent bands of their own during the 1960s and 1970s rock-and-roll era. ...but I digress. My introduction to the potential deleterious effects of vibration on electronics was in the 1970s, with airborne receivers and servos in my radio controlled model airplanes. Even though they were transistorized, vibration from glow fuel engines could wreak havoc with potentiometers in servos and solder joints everywhere, including battery packs. I remember seeing the control surfaces jitter...

Raytheon Needs Tube Design Engineers

Raytheon Manufacturing Company Needs Vacuum Tube Engineers, July 1944 QST - RF CafeYou don't see jobs advertisements like this anymore. Here is an ad that appeared in the the July 1944 edition of QST (the American Radio Relay League's, ARRL's, monthly magazine), placed by Raytheon Manufacturing Company (now just Raytheon Company), looking for vacuum tube design, test, and processing engineers. Licensed amateur radio operators were in high demand during the war years because of their knowledge and enthusiasm for electronics and wireless communications. I hope you didn't come to this page hoping to really find a tube designer job available. Of course, there are still vacuum tubes being designed for TWTs and magnetrons, but those are few and far between...

The Carborundum Signal Detector

The Carborundum Signal Detector - RF CafeThe "carborundum" signal detector, an innovative device developed by engineer General H. H. C. Dunwoody in the early 20th century, represents a significant advancement in radio technology, particularly in the context of crystal detectors used for receiving radio signals. This device utilized the unique properties of silicon carbide, also known as carborundum, which was synthesized in the late 19th century by Edward Goodrich Acheson. The connection between Dunwoody and the material lies in the application of carborundum as a semiconductor in radio signal detection. The operational theory of the carborundum signal detector is rooted in its ability to rectify alternating current (AC) signals. When radio waves, which are essentially electromagnetic waves...

Lossless Electronics with Innovative Quantum Sandwich

Lossless Electronics with Innovative Quantum Sandwich - RF Cafe"Researchers have created a cutting-edge structure by placing a very thin layer of a special insulating material between two magnetic layers. This new combination acts as a quantum anomalous Hall insulator, significantly broadening its potential use in developing ultra-efficient electronics and innovative solar technology. A Monash University-led research team has found that a structure featuring an ultra-thin topological insulator, sandwiched between two 2D ferromagnetic insulators, transforms into a large-bandgap quantum anomalous Hall insulator. This heterostructure opens the door to ultra-low energy electronics and even topological photovoltaics..."

Meet Popular Electronics, October 1954

Meet Popular Electronics, October 1954 Popular Electronics - RF CafeOctober 1954 arrived with the first-ever issue of Popular Electronics. Editor Oliver Read wrote this introductory note describing the magazine's grand plans for providing its audience with a sampling of as many facets of electronics as possible, with projects for the do-it-yourself type (many needed to be at the time), related hobbies like amateur radio and radio controlled airplanes, military and commercial applications, short stories, tutorials, and an endless supply of advertisements offering just about anything your budget could afford. It turned out to be a pretty nice magazine, and many of the well-written articles are still useful in today's world of nano-everything circuits - the fundamentals haven't changed much: voltage still equals resistance times current ...

Switzerland Electronics Market

Switzerland Electronics Market, December 27, 1965 Electronics Magazine - RF CafeThis is the electronics market prediction for Switzerland, 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. This statement was a bit unexpected: "Although the Swiss are renowned for their precision work in watchmaking, machine tools and instruments, their country is regarded as 'a bit backward' in electronics." Not many major national production companies resided in Switzerland; IBM and RCA had a large presence, though. Unless you can find a news story on the state of the industry, detailed reports must be purchased from research companies...

Electronics-Themed Comics

Electronics-Themed Comics, September and November 1949 Radio-Electronics - RF CafeLet us finish off the year 2021 with some humor; goodness knows we need it after yet another 365 days of what has been awfully close to a worldwide COVIDictatorship. "15 Days to Slow the Spread" back in early spring of 2020 mutated like a coronavirus into unlimited variants of government mandates restricting or destroying freedom of movement, freedom of association, freedom of personal health choice, freedom of comfort, and numerous other freedoms. These electronics-related comics appeared in a couple 1949 issues of Radio-Electronics magazine. Enjoy (if you still can). I do wonder why the octopus only does the work of three servicemen...

New 500 kW Super-Power Beam Triode

New 500 kW Super-Power Beam Triode, May 1950 Radio News - RF CafeIf there is or ever has been a solid state device that required as much painstaking, precise, manual assembly required as some of the magnificent vacuum tubes developed over the years, I don't know of it. This 500 kilowatt "super-power beam triode" featured in a 1950 issue of Radio & Television News magazine is a good example. Think of the electrical, mechanical, chemical, and manufacturing engineering that went into designing, building, and testing such devices. Half a megawatt from a single tube is quite an accomplishment. It required a 900 watt control grid signal for modulation. The article refers to an electron-optical system, and I'm not sure what it meant unless it is the array of 48 sharply focused electron beams...

Inertial Guidance Directs Planes and Missiles

Inertial Guidance Directs Planes and Missiles, December 1958 Radio-Electronics - RF CafeWerner von Braun and his team of rocket scientists are credited with developing the first useful inertial stabilization platforms for ballistic missiles. The infamous and formidable V2 rocket wreaked terror upon the heads of Londoners during the latter days of World War II. It served to keep the rocket in a fixed orientation during the boost phase of the flight, but did not serve any active targeting function. Inertial navigation systems, on the other hand, are used to provide both accurate positional and attitude information for the pilot (if the platform has one) and to steer the platform (vehicle) to a predetermined destination. Inertial navigation systems are therefore much more complex. Early inertial navigation systems relied on physical spinning gyroscopes mounted within a series of nearly frictionless gimbals to maintain a fixed reference position in space. Contactless encoders about the rotation axes of the gimbals sent positional information to a computer, which then performed necessary calculations and sent formatted data to visual flight instruments...

RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Adoption of TV Standards Paves Way for Commercial Service

Adoption of Television Standards Paves Way for Commercial Service, August September 1941 National Radio News - RF CafeThis story from a 1941 edition of National Radio News reports on the FCC's having passed regulations to allow the rollout of commercial television service as of July 1, 1941. These standards, observes the Commission, "represent, with but few exceptions, the undivided engineering opinion of the industry." They "satisfy the requirement for advancing television to a high level of efficiency within presently known developments." Furthermore, "Frequency modulation is required for the sound accompanying the pictures. Thus, television is now benefited by the recent developments of frequency modulation." It was an era of wonder and excitement in the world of wireless communications...

Atomichron - World's Most Accurate Clock

Atomichron - World's Most Accurate Clock, January 1957 Radio & Television News - RF CafeThe National Company, of Malden, Massachusetts, which made this cesium-based Atomichron in the mid-to-late 1950s, began life as a toy manufacturer. It had an output frequency at the nominal resonance frequency of cesium - 9192.631830 MHz - and was accurate to better than a second in 600 years. The unit was 7 feet tall and weighed 500 pounds. Modern cesium standards are more stable and are portable. As of January 2013, the NIST-F1 cesium fountain primary frequency standard is accurate to within one second every 100 million years! That's a tad better than the Atomichron, non?

Sawtooth Sticklers Quiz

Sawtooth Sticklers Quiz, November 1960 Radio-Electronics - RF CafeHere is an unusual twist in waveform recognition presented by Radio-Electronics' and Popular Electronics' quizmaster, Robert Balin. If you happen to be a former analog television repairman, then you will probably recognize the answers based on your many years of diagnosing faulty horizontal or vertical sweep circuits. If not, then you might need to strain the "little gray cells" a bit, as Agatha Christie's premier sleuth Hercule Poirot might say. The instructions say to assume that if you choose the horizontal sweep sawtooth to be the errant signal, then assume the vertical sweep sawtooth is correct, and vice versa. Right off the bat, waveform 8 is unique enough to easily identify the sweep that would produce it since only one has two repeating components. Most of the others can be readily deduced, too, by mentally following the x and y points as the "correct" sweep...

Hams in the FBIS

Hams in the FBIS, January 1945 QST - RF CafeWe hear and read a lot in the news about the electronic surveillance carried out by governments - on both foreign entities and civilians. If you think this is a phenomenon that has only existed since the age of cellphones and the Internet, you might be interested in this article that appeared in a 1945 issue of the ARRL's QST magazine. Long before the entire textual content of the Encyclopedia Britannica could be carried on a USB stick in your pocket - and access virtually all the information in the world on your iPhone, engineers were developing recording media to facilitate the capturing and later analysis of over-the-air and wired communications. They wanted both encrypted and unencrypted conversations. The National Archives has a huge store of magnetic tapes, vinyl discs...

Mac's Radio Service Shop: Service Shop Advertising

Mac's Radio Service Shop: Service Shop Advertising, June 1954 Radio & Television News - RF CafeThe opening paragraph of this installment of Mac's Radio Service Shop includes a reference to someone named Dr. Kildare. As the article appeared in a 1954 issue of Radio & Television News magazine, you are excused for likely not being familiar with the good doctor. I remember Dr. Kildare (a fictional character) as a Prime Time TV show that aired in the 1960s, but his legacy goes back to the 1930s in movies and radio. Back to the story line, though. Mac is wearing a newfangled type of headphone that must have looked like a stethoscope, and that triggered Barney's comment. However, as is often the case, the subject quickly changes to advertising techniques where Mac explains his philosophy of honesty being the best policy. Along with such probity must be an effort to convince potential customers that preventative maintenance is a sign of responsible ownership. Just as you would take your car in for a relatively low cost annual checkup to hopefully avoid a major bill later, TVs, radios...

Mac's Radio Service Shop: A Sound Conversion

Mac's Radio Service Shop: A Sound Conversion, November 1951 Radio & Television News - RF CafeListen to the RF Cafe Podcast! A November edition of "Mac's Radio Service Shop" is appropriate given today's date, especially since author John T. Frye nearly always had the story's setting coincide with the month in which it appeared in Radio & Television News magazine; the year was 1951. The unspecified dateline is somewhere in the upper Midwest, most likely Indiana. Mac's mention of converting a black-and-white television set to color by installing a "color wheel" really betrays the era. The NTSC (National Television System Committee) had not yet adopted an industry standard for color TV, and the various manufacturers were selling a mix of mechanical, electro-mechanical and all-electronic sets. In 1953, the NTSC settled on a 525-line interlaced scan (only 468 lines are part of the visible scan). Knowing that a better color system would be available soon due to massive public demand, Mac put his efforts into talking customers out of a color conversion...

Father of Radar Gets His Reward from Patent Office

Father of Radar Gets His Reward from Patent Office, December 1957 Popular Electronics - RF CafeWell, this might get some dander up amongst the believers that Sir Robert Watson-Watt is "the Father of Radar." In the December 1957 edition of Popular Electronics magazine, Colonel William R. Blair was given that honored designation based on his work on a pulse-echo method of direction finding in the 1920s. The Wikipedia entry for Col. Blair refers to him more specifically as the "Father of American Radar." William R. Blair was awarded U.S. patent #2,803,819, titled "Object Locating System," on August 20, 1957 - a full 13 years after the patent application was submitted. Watson-Watt was issued a patent in 1935 on a radio device for detecting and locating an aircraft. His research was born out of an investigation into a "death ray" which had reportedly been invented by the Germans.

Basic Digital Logic Course - Part 3

Basic Digital Logic Course, December 1974 Popular Electronics - RF CafeHere is the final installment in the "Basic Digital Electronic Course" series that ran in three issues of Popular Electronics magazine. The first two parts laid the groundwork with an introduction to binary, octal, and hexadecimal arithmetic, Boolean logic, AND, OR and NOT gates, and some truth tables. Armed with those fundamentals, the authors now dive into flip-flops, encoders and decoders, debouncing circuits for switch inputs, integrated circuit (IC) types, and interconnect methods to design and build a simple digital computer with a 7-segment LED display. Don't expect too much from the computer since it was only three years earlier, in 1971, that Intel introduced the world's first integrated microprocessor - the 4-bit model 4004 central processing unit (CPU) ...

Engineering the Integrated Communications System

Engineering the Integrated Communications System, December 1950 Radio & Television News - RF CafeAs a follow-on to the "Planning Integrated Signal Communications" story, this article is the next step in the U.S. Army Signal Corps' implementation of ubiquitous communications systems. Along with powerful transmitters and super-sensitive receivers at command communications hubs are the many hand-held, back-pack, and vehicular radios needed to complete strategic and tactical operations across the face of the Earth. It wasn't just wireless systems that Signal Corps engineers and technicians were responsible for, but also all the wired equipment and interconnecting cabling. The possibility of software configuration for network switches, radios, modems, telephones, antennas, and ancillary components had never been thought of in 1950 (by very few, anyway). Everything was set up with patch panels...

Electronic Analogy Quiz

Electronic Analogy Quiz, August 1960 Popular Electronics - RF CafeThis electronics analogy quiz is a little easier than many of the others published in Popular Electronics magazine because all of the electrical and mechanical objects depicted here are very familiar. The concepts might seem trivial to those of us who have been immersed in the science for decades, but I for one can remember when first hearing these analogies how helpful they were. Not only that, but I also recall during physics and mechanics courses in college being amazed at the similarity of equations shared by electrical and mechanical processes. Wikipedia has a huge page describing many of the most familiar mechanical-electrical analogies...

Electrochemistry Quiz

Electrochemistry Quiz, March 1966 Popular Electronics - RF CafeA lot of RF Cafe visitors might not be familiar with some of the electronic devices presented in this Electrochemistry Quiz by Popular Electronics' resident quizmaster, Robert Balin (a big list of his other quizzes is at the bottom of the page). I offer my assistance. A is a photocell, B is an early type of rectifier, C is a varistor, D is a cathode ray tube (CRT), E is an electrolytic capacitor, F is a heated cathode in a vacuum tube, G is a flashlight battery, H is an early receiver crystal detector, I is a magnetic audio recording tape, and J is phonograph cartridge. I scored...

Electronics Theme Crossword Puzzle for May 16th

Electronics Theme Crossword Puzzle for May 16th, 2021 - RF CafeThis Electronics Theme Crossword Puzzle for May 16th has many words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. 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., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Electronics-Themed Comics from May 1947 Radio-Craft

Electronics-Themed Comics, May 1947 Radio-Craft - RF CafeMany topics of the electronics-themed comics which appeared in Radio-Craft were suggested by the magazine's readers. Staff artists like Frank Beaven turned those suggestions into cartoons. For a while there was a special feature called "Radio Term Illustrated" where, as the name suggests, terms like "Signal Generator" and "High Potential" are rendered in farcical form. These four comics, two of each type, appeared in a May 1947 issue of Radio-Craft. I have to admit that even with my familiarity with vintage electronics memes I do not get the Television "Organ" comic (yes, I understand the organ grinder, but not how it applies to TV).

A Two-Band Piece of Wire

A Two-Band Piece of Wire, February 1950 Radio & Television News - RF CafeReading this article from a 1950 issue of Radio & Television News magazine reminds me of a basic truth - at least for receiving, it is usually possible to realize obtain useful operation with just about any reasonable length of straight wire for an antenna. Transmitting is a different story since poor VSWR conditions on the antenna connection can damage or cause to shut down the output stage of an RF power amplifier. Still, if your transmitter can survive a high VSWR, then chances are you can send out a useful signal. You won't be breaking any DX records or winning any contests, but you won't be dead in the water. Surely anyone over 40 years old has jury-rigged an FM radio antenna out of a length of straight (or bent) wire and/or fashioned a sheet of aluminum foil around a set-top television antenna to pick up an acceptable signal. In many cases where the 300 Ω twin-lead cable was improperly snaked along an aluminum gutter or aluminum siding on a house on its way to the rooftop antenna or had a long length of excess cable coiled...

Crane Aerospace Electronics Microwave Solutions

withwave microwave devices - RF Cafe

RF Cascade Workbook 2018 by RF Cafe