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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..."

Summer Radio

Summer Radio, July 1934 Radio News and The Short-Wave - RF CafeReceiving information wirelessly or even over a wire is taken for granted today, but 80 years ago it was considered a "miracle of God" - that's what Alexander Graham Bell called it. Some regarded radio as being of the devil. The same is true of today's omnipresent communications - some consider it a blessing while others call it a curse. I'm somewhere in the middle. In 1934 when this Radio News & Shortwave magazine was published, the telecommunications world was in its heyday of growth with a reported 17 million listeners of AM radio (no FM yet). Radio dealers and servicemen were gearing up for customers with unbridled enthusiasm for the fledgling commercial broadcast industry's offerings. Even in the midst of the Great Depression, people were joining in on the wireless craze in large numbers, and amateur radio operators were almost feared for their awesome ability...

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...

Radar Signature Analysis

Radar Signature Analysis, February 1967 Electronics World - RF CafeOperators didn't know how good they had it in 1967. The story talks about the nuisance of having to sift through "hundreds" of satellites, old rockets, and assorted space junk" in order to search for and track potentially threatening objects in orbit around the Earth. We're into the millions of objects in 2019, and the potential threats are infinitely larger. The article mentions the use of an AN/FPS-16 radar operating in C-band to detect and measure the returns and then the results were analyzed in an attempt to determine the character of the object. Open air test sites and anechoic chambers were used to measure the radar cross section and characteristic signature of many shapes to populate a database of recognizable returns that would help to determine whether the space object was friend or foe...

Comics with an Electronics Theme, March 1967 Popular Electronics

Comics with an Electronics Theme, March 1967 Popular Electronics - RF CafeHere are a couple more electronics-themed comics from the March 1967 issue of Popular Electronics magazine for your TGIF enjoyment. The comic on page 100 especially appeals to me since I am finishing the installation of a Channel Master CM-5020 antenna. It has been a long time since I installed a traditional style TV antenna - about 40 years ago when I put a Radio Shack antenna on the roof of my mother's house. The entire 109" long by 100" wide antenna, including mounting hardware, weighs only 11.5 pounds and presents a wind resistance of 30 pounds. This is Channel Master's best antenna...

The Saga of the Vacuum Tube - Part 14

The Saga of the Vacuum Tube, November 1944 Radio News - RF CafeHere is Part 14 of a series entitled "The Saga of the Vacuum Tube," by Gerlad Tyne, that appeared in Radio News magazine in 1944. Part 1 was printed in March 1943, and Part 22, the final chapter, was published in April 1946. It could have been a stand-alone book. If I manage to be able to buy issues with some of the other parts, those will be posted as well. You might be aware of the origins of the amplifying vacuum tubes, beginning with the accomplishments of Dr. de Forest and his Audion. As with most new technologies, progress moved very rapidly once other researchers glommed on to the concept. Here, Mr. Tyne discusses the development of the "Kenotron," "Pliotron," "Dynatron," and "Magnetron," by Drs. Langmuir, Dushman and Hull of the General Electric Laboratories, during the years 1913 to 1921.

What Is Your Electronics Business Acumen?

Biz Quiz, April 1947 Radio News - RF CafeWell, at least I know now why my efforts to sell things usually don't work out too well. A salesman I ain't - neither by c1947 standards or by contemporary standards. I have a hard time even giving things away based on the low response rate on notifications for winning free books each month. My score on this "Biz Quiz" in Radio-News magazine was around 50% (south of, actually), but that was probably due to being subconsciously biased to answer what I thought the creator would expect for a good salesman. It would probably be embarrassing to have a professional assessment of my true personality, assuming that professional is not a quack with an agenda...

Espresso Engineering Workbook™ for Excel

RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeThe newest release of RF Cafe's spreadsheet (Excel) based engineering and science calculator is now available - Espresso Engineering Workbook™. Among other additions, it now has a Butterworth Bandpass Calculator, and a Highpass Filter Calculator that does not just gain, but also phase and group delay! Since 2002, the original Calculator Workbook has been available as a free download. Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is also provided at no cost, compliments of my generous sponsors. The original calculators are included, but with a vastly expanded and improved user interface. Error-trapped user input cells help prevent entry of invalid values. An extensive use of Visual Basic for Applications (VBA) functions now do most of the heavy lifting with calculations, and facilitates a wide user-selectable choice of units for voltage, frequency, speed, temperature, power, wavelength, weight, etc. In fact, a full page of units conversion calculators is included. A particularly handy feature is the ability to specify the the number of significant digits to display. Drop-down menus are provided for convenience...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated in all locations on the page! RF Cafe typically receives 8,000-15,000 visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 17,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. Your Banner Ads are displayed on average 225,000 times per year! New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the place to be...

Diode Function Quiz

Diode Function Quiz, August 1965 Popular Electronics - RF CafeIt's Friday and therefore time for a pop quiz (does that line give you a fearsome flashback to your school days?). Whenever I have one available, I like to post quizzes from vintage electronics magazines, like this one on diode circuit functions. Many of them have vacuum tubes, but this one has the solid state symbols so the under-40 folks won't be uncomfortable. Your job is to look at the diode circuits and match them with the names of the functions. A couple of them will probably cause some head scratching, but you should do well. Don't jump to a quick conclusion with circuit "E" without noticing the two signal generators attached to it...

Hams on the Alaska Highway

Hams on the Alaska Highway, April 1945 QST - RF CafeEven though my fingers stop working when exposed to temperatures below freezing, I love the northern climate - four full seasons, snow, iced-over lakes, migrating birds, fiery autumns, cool summers, the whole experience. Having the option of not participating in the cold outdoor environs is what makes it good. However, the U.S. Army Signal Corps guys pulling duty in Alaska during World War II did not have that luxury. As told by radio engineer Major Colvin in this story from a 1945 edition of ARRL's QST magazine, winter life in Alaska at -40° was a real challenge. It was a world where Prestone antifreeze froze, the sun shone only a few hours a day, vehicles had to be left running 24/7 or risk not being able to be re-started, and mile-long treks between buildings was common. There were no snowmobiles. The success of the communications station...

Understanding Transistor Circuits

Understanding Transistor Circuits, August 1959 Popular Electronics - RF CafeIt had been only a little over a decade since the transistor was invented when this article appeared in the August 1959 edition of Popular Electronics. Transistors were still a mystery to most people, including engineers, technicians, and hobbyists. Author James Butterfield takes a unique approach in presenting the material by writing it as a dialog between an instructor and a student. If you are also new to transistors, this will be worth your while to read. The basics will never change. As an aside (and mentioned in the article), while still a technician I had a manager one time who actually told an engineer working for him that a transistor could be made by soldering two diodes together and using the center node as the base connection...

Mac's Service Shop: Biological Effects of Electrical Shock

Mac's Service Shop: Biological Effects of Electrical Shock, May 1973 Popular Electronics - RF CafeHere is a timeless subject for anyone routinely subject to exposed high voltages. Most RF Cafe visitors already know that technically, it is the amount of electric current through the body that determines severity of electric shock, not the voltage. However, we also know that voltage does play a role because a certain voltage, per Ohm's law, is needed to induce a commensurate current. The body's resistance is determined primarily by perspiration (salt and water) and the path between contact points (e.g., across adjacent skin areas or hand-to-hand via the heart). MIL-STD-883 and JEDEC* have decided that the proper Human Body Model (HBM) for testing semiconductor...

Why Tubes Fail Prematurely

Why Tubes Fail Prematurely, September 1958 Radio & TV News - RF CafeAfter reading so many articles about vintage vacuum tube radios and TVs in the older electronics magazines, it makes me appreciate the relatively trouble-free products we enjoy today thanks to semiconductor technology. Monthly columns were filled with troubleshooting advice and tips for making modifications to factory designs that will enhance performance and/or reduce the likelihood of premature failure. Although many tubes did outlast the lifetime of the chassis in which they were installed, it was pretty much a given expectation that sooner or later some tubes would need to be replaced - that is why they were the only components that came installed in sockets for easy removal and installation. Fortunately, because of the huge volumes produced, prices were relatively low, and many stores - not just electronics shops - had self-serve...

Modern Radio Practice in Using Graphs and Charts

Modern Radio Practice in Using Graphs and Charts - Parallel Resistors, April 1932 Radio News - RF CafeUsing charts and nomographs to solve calculations is not as common in today's world of portable high-powered computers as it was when computers used vacuum tubes or even mechanical gears. One exception might be the Smith chart, especially in the lab or field. You can plug numbers into a programmable calculator or tablet app, but having the solution presented in the form of a number gives you only that - a number. That's usually good enough, but if you are doing troubleshooting or tweaking a design, being able to see how the value got to be what it is by seeing what's around it can be very helpful. The Smith chart is a particularly good example when watching the complex impedance point move around...

Japanese Technology - Bidding for World Leadership in Solid State Microwave Gear

Japanese Technology - Bidding for World Leadership in Solid State Microwave Gear, December 13, 1965 Electronics Magazine - RF CafeThe December 13, 1965 issue of Electronics magazine was largely dedicated to assessing Japan's status in the electronics industry. Japan, with the help of the United States, made a remarkable recovery from defeat during World War II to have become an emerging power in electronics. "Made in Japan" labels on products had transformed from being the butt of jokes because of pre-war low quality products to representing assurance of low cost, high functionality and high value products. It still does to this day. The Japanese people have worked hard to acquire the world's respect as smart innovators and hard workers, and have been sure to maintain manufacturing bases within their borders. When you read this article, be prepared for a few dated terms like a "Kita" diode ...

It's a Man's Job Behind That Microphone

It's a Man's Job Behind That Microphone, April 1932 Radio News - RF CafeThe old-time radio broadcasts available on the Internet are obviously recorded version of shows made long ago. However, back in the day those shows were originally performed live in front of microphones and recorded in a broadcast studio. With a cast of two or three or even more, the actors would voice their lines with as much talent and effort as those performing for movies. The crew usually included a group of people responsible for creating background sound effects like horses running, car horns tooting, airplanes buzzing by, and dogs barking. All was done real-time with split-second timing required to pull it off and sound convincing. Radio audiences were unaware of all the work required as they sat intently listening to the Adventures of the Lone Ranger and The Shadow. Behind the scenes were dozens of engineers and technicians tending local radio broadcasting equipment and all-important telephone landlines used for synchronizing stations across the country...

Electronic Abbreviations Crossword - 1958 Popular Electronics

Electronic Abbreviations Crossword Puzzle, November 1958 Popular Electronics - RF CafeThis crossword puzzle from a 1958 issue of Popular Electronics magazine is a little trickier than some because it uses abbreviations rather than full words. Not everyone uses the same abbreviation, so some answers are a bit more subjective. For instance, many people abbreviate the word 'transformer' as 'xfmr,' while others use 'trans' or 'trr' (I use xfmr). Where you really have to be careful, though, is with evolutional changes in terminology as is the case for frequency units, where 'cps' was most often used in 1958 rather than today's 'Hz." Enjoy.

How the Cathode-Ray Tube Works

How the Cathode-Ray Tube Works, February 1955 Popular Electronics - RF CafeEven with the domination of LED, plasma, and LCD displays, there are still a whole lot of cathode ray tubes (CRTs) on the job. Hobbyists workbenches are filled with them for sure, but design and manufacturing facilities still have huge inventories of test equipment with CRTs, and a lot of computer equipment on the production line with CRTs sitting in racks. LED, LCD, and plasma displays all have their own claims to genius on the part of their designers, but cathode ray tube designers - and the designers of the driver circuits - deserve special recognition. Consider the physics and materials involved: glass, phosphor, magnetics, thermonics, electrostatics and electrodynamics, relativity (electrons traveling at relativistic speeds gain mass, requiring stronger deflection fields)...

The Amazing Collection in Thomas Edison's Garage

The Amazing Collection in Thomas Edison's Garage - RF CafeIf you think electric cars are a new idea, read on. I saw this article, "The Amazing Collection in Thomas Edison's Garage," on another website (the equivalent of Jay Leno's Garage from a century ago) and thought it was a special report, but then I noticed it was actually a paid promotion. So, I contacted the company, B.R. Howard & Associates, Inc., asking for permission to re-post it in its entirety on RF Cafe. They kindly agreed to it. Per their mission statement: "Our company focuses on the conservation of historic artifacts in accordance with the principles defined in the American Institute for Conservation of Historic and Artistic Works Code of Ethics and Guidelines for Practice." Their portfolio of projects include transportation, industrial, scientific, military, and archeological artifacts. An opportunity to help support the preservation effort is provided...

Electronics-Themed Comic, February 1972 Popular Electronics

Electronics-Themed Comic, February 1972 Popular Electronics - RF CafeThis is a great electronics-themed comic from a February 1972 issue of Popular Electronics. It encompasses the essence of the stereotypical salesman ruse, especially in that era when people were sure that electronics repair services were out to rip them off by selling unneeded services and replacement parts. Aspiring TV technicians who couldn't grasp the technology moved on to working as mechanics in a garage, poking tiny holes in brake lines to scare owners into paying for complete braking system rebuilds. I usually like to post multiple comics on each page, but at the moment only this one is available...

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