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Today in Science History

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..."

Printed-Circuit Laminates

Printed-Circuit Laminates, October 1969 Electronics World - RF CafeThis is another of a series of articles on printed circuit boards (PCBs) that appeared in the October 1969 issue of Electronics World magazine, reporting on the latest and greatest advances in printed circuit board technology. Already in production were rigid multi-layer laminates, flexible plastic laminates, and special-purpose laminates for hazardous duty applications. Author Norman Skow does not mention how many layers were routinely accomplished at the time. Plated-through holes were a relatively recent thing for high volume manufacturing. Of course population of PCB components was still a completely manual procedure since pick-and-place machines were still a couple decades away...

Beyond the Transistor

Beyond the Transistor, July 1963 Radio-Electronics - RF CafeThis "Beyond the Transistor" article by Hugo Gernsback, which was printed in a 1963 issue of Radio-Electronics magazine, had as its subject not the transistor in general, but specifically its potential use as a low noise, high sensitivity radio frequency signal detector. Mr. Gernsback does a useful historical review of signal detectors, beginning with Heinrich Hertz's radio detector in 1888, then progressing through Edouard Branly's 1892 coherer, Gustave-Auguste Ferrie's and Reginald Fessenden's electrolytic detector of 1903, then Greenleaf Pickard's crystal detector in 1906. Lee de Forest's early work on vacuum tubes was directed toward a signal detector, and ultimately resulted in his Audion amplifier. In 1948, Bell Laboratories' Shockley, Brattain and Bardeen...

Swirling Magnons Set to Revolutionize Computing

Swirling Magnons Set to Revolutionize Computing - RF Cafe"Researchers have developed a groundbreaking method to create more compact and energy-efficient computing devices using magnonic circuits. By utilizing alternating currents to generate and steer spin waves in synthetic ferrimagnetic vortex pairs, this new approach promises significant advancements over traditional CMOS technology, potentially leading to the next generation of computing systems. The central processing units (CPUs) in our laptops, desktops, and phones rely on billions of transistors built with CMOS technology. As the demand to shrink these devices..."

Field-Effect Transistor Circuits

Field-Effect Transistor Circuits, May 1967 Electronics World - RF CafeIf you are just entering the field of electronics, the concepts presented in this half-century-old article for basic field effect transistors are still relevant. Significant improvements have been made since then, but the fundamentals stand. One of the most useful items in this article is Table 1, which compares and contrasts vacuum tubes, bipolar junction transistors, and field effect transistors. Topics covered include general properties of FETs, source followers (a la emitter followers in BJTs), common source amplifiers (a la common emitter amplifiers in BJTs), the Miller oscillator, combinations of FETs and BJTs, and a gated amplitude modulator ...

Heat Without Flame

Heat Without Flame, June 1955 Popular Electronics - RF CafeElectric induction heating has been used in manufacturing processes since shortly after Benjamin Franklin invented electricity. Of course I jest about Franklin; he didn't invent electricity but discovered that lightning was a form of electrical discharge. One of the most energy-consuming forms of induction heating is that used by Alcoa for smelting aluminum. Beyond that are many thousands of processes ranging from forming, tempering, and joining metal parts to cooking food and curing adhesives. Both Tocco and Ajax-Northrup, now Ajax Tocco, brands of equipment are featured in this 1955 article which appeared in Popular Electronics magazine. Some processes work by directly inducing a high current in the primary target object - usually metallic - being treated ...

Vintage Littelfuse Advertisement

Littelfuse, October 1953 Radio-Electronics - RF CafeOptical illusions have always been a big attention-getter. Many companies have employed their intrigue to promote their products and/or services. This optical illusion was used by Littelfuse (not Littlefuse), a company founded in 1927 and still in business today, to draw attention to a full-page advertisement in a 1953 issue of Radio-Electronics magazine. More interesting than the illusions, though is the information presented is about how their proprietary glass-encased fuse design will always burn out in the center of the link, where it is visibly obvious. It might seem trivial, but having tested fuses that appeared to be good but tested bad, that is a great feature. Modern plastic-encased fuses with spade terminals like those found in automobiles have a similar feature that makes visual inspection very easy and unmistakable. In another Littelfuse ad, they educate the reader about how a fuse's amperage rating is not the amperage level at which it will blow...

How Far Can You Go in Electronics Without a Degree?

How Far Can You Go in Electronics Without a Degree?, September 1957 Popular Electronics - RF CafeThis story reads like an infomercial for IBM, which it probably is. Of course infomercials had not been invented by 1957, so IBM was ahead of its time. The answer to the article's title, "How Far Can You Go in Electronics Without a Degree?" was the same 55 years ago as it is today: As far as your intellect and ambition will take you. Back then, as with today, few people could rise to the level of design engineer without a college degree. However, there are many aspects of electronics that requires no formal education at all if you possess the requisite skills. I never have bought into the feel-good lie about anyone being able to be whatever he or she wants to be. Some people simply cannot achieve the mastery necessary to do a particular job...

Operation Telephone 1965

Operation Telephone 1965, September 1961 Popular Electronics - RF CafeCall forwarding, call waiting, call holding, speed dialing, conference calling, all of these features are taken for granted with mobile phone and VOIP phone service and are included in the base service package. It will cost you extra if you subscribe to a local legacy POTS (Plain Old Telephone Service) provider. What is standard now was considered ground-breaking technology in the early1960s when this article appeared in Popular Electronics magazine. When phone calls were processed via human operators manipulating patch cords and then electromechanical relays, it was enough to simply place a successful call and not be interrupted or disconnected. Once transistorized circuits entered the scene, much more was possible, and phone system engineers were quick to exploit the technology. Sophisticated decision making requires both logical circuits and a form of memory. Logic could be provided using hard-wired diode steering...

Do You Know Your Bipolar Transistors? Part 3

Do You Know Your Bipolar Transistors? (Part 3), October 1973 Popular Electronics - RF CafeMr. Lothar Stern, of Motorola Semi, published a 3-part series on transistor theory in Popular Electronics magazine in 1973. This is part 3. Part 1 introduced the basics of the bipolar transistor, and Part 2 addressed transistor circuit configurations - common emitter, common gate, common collector, Darlington, differential - as well as presenting gain equations and delving a bit into the physical construction of the semiconductor elements. Finally, the author talks about the newest processes in use at the time and what was available for low power and high power RF applications. In 1973, high power semiconductors were just pushing past the 100 MHz barrier. GaAs and GaN were still in university and corporate laboratories being prepared for the amazing devices...

The Future of Thin-Film Active Devices

The Future of Thin-Film Active Devices, January 24, 1964 Electronics Magazine - RF CafeWhen Charles Feldman published this article on thin-film transistors (TFTs) in a 1964 issue of Electronics magazine, he had no idea that the devices would eventually play a major role in liquid crystal displays (LCDs) in everything from wristwatches to large screen television and computer displays. Materials and fabrication techniques have evolved considerably since 1964, but the fundamentals remain the same. Other than LCDs and some solid-state sensors, I am not familiar with any other applications that are heavy users of TFT technology. This 2016 paper titled, "Review on thin- film transistor technology, its applications, and possible new applications to biological cells," gives a little historical perspective and a comparison of CMOS versus TFT...

Send Your Meters to War

Send Your Meters to War, November 1942 QST - RF CafeWith today being the 77th anniversary of America's entry into World War II with the Japanese bombing of Pearl Harbor, I thought this advertisement from a 1942 issue of the ARRL's QST magazine would be of interest. Most of us have heard about the neighborhood collections for tires, glass, newspaper, cans, and cloth in order to help support the war effort. Probably not many have also heard about the Signal Corps' call for milliammeters! That's right, the huge, rapid build-up of electrical and electronic equipment for radios, vehicles, and factory equipment. Many meters were needed for monitoring status and making process adjustments. America had an ample supply of meters in the hands of Amateur radio operators; all that was required was to separate the Hams from their meters. Fortunately, an appeal to patriotism was sufficient motivation back then...

Bell Telephone Laboratories: New Twist in Memory Devices

Bell Telephone Laboratories: New Twist in Memory Devices, February 1958 Radio & TV News - RF CafeUpon seeing this advertisement by Bell Laboratories for their "Twistor" form of magnetic memory data storage in a 1958 issue of Radio News magazine, my thought was that it was just another flash in the pan, so to speak, in the history of breakthrough, paradigm-changing inventions. It was a variation of the non-volatile magnetic core memory that used sections of ferromagnetic wire twisted around copper wire in such a way that electrical currents directed to particular intersections in an x-y grid would cause a magnetic orientation to be set (store a bit) and a set or read and sense wires permitted detection of the stored magnetic field to be determined (read a bit). The Twistor was hailed as a much more manufacturable form of the magnetic core memory, which required production workers with small hands and finger to manually thread...

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...

Direct-Impedance Amplification

Direct-Impedance Amplification, April 1936 Radio-Craft - RF CafeI tried to find some information on "direct-impedance amplification," but alas none could be located. At first, I suspected that it being in the April edition of Radio-Craft might have meant it was a ruse on readers, especially since author L. Mitchell Barcus focused on the nearly sub-audible portion of the sound spectrum down to around 16 Hz. Careful reading of the article reveals, however, that his pièce de résistance was designing the circuit with a minimum of biasing resistors, capacitors, and inductors that might otherwise attenuate low frequencies. Success was in the form of direct coupling of stages sans Rs, Ls, and Cs. I'm guessing the...

Westinghouse Directional Equipment

Westinghouse Directional Equipment, June 1945 Radio News - RF CafeWestinghouse is yet another of the original stalwart titans of companies that helped build America to her state of greatness, but is now mostly a footnote in the historical notes of the many companies which over the past few decades have bought out portions of the business. Founded in the late 1800s by George Westinghouse as a locomotive air brake manufacturer, the company added other markets including, notably, electric power generation and distribution. Emerging as the winner in the famous "War of the Currents" fought between Westinghouse and Thomas Edison secured George's place in history. Westinghouse also got into the commercial, military, and domestic electronics and appliance markets. I worked at the Westinghouse Oceanic Division in Annapolis, MD, from 1982 through 1986 and though it was a great company to work for. This advertisement for "Westinghouse Directional Equipment;" i.e., antennas, appeared in a 1945 issue of Radio News magazine.

Solder Gun Thermal Wire Stripper

Solder Gun Thermal Wire Stripper, May 1959 Electronics World - RF CafeHidden away on page 134 of a 1959 issue of Electronics World, at the end of a Mac's Service Shop-like electronics shop docudrama (Another Day in the Shop) is this handy tip on how to fabricate a make-shift thermal wire stripper from a soldering gun or a soldering iron. The beauty of thermal strippers over mechanical strippers is that they do not nick the underlying metal wire. Heated elements melt the insulation and then a blunt edge is used to slide the insulation off the end of the wire. Another advantage is that you can strip a wide range of wire gauges and insulation types without needing to adjust the jaws or change to a different hole location - although a proper temperature setting is required to avoid a gloppy, stringy mess...

Radar Scores SAC Bombing Test

Radar Scores SAC Bombing Test, December 1956 Popular Electronics - RF CafeMost people have heard of the incredibly accurate Norden bombsight that was credited for revolutionizing accuracy of heavy bombers like B-17s, B-25s, and B-29s. It was an electromechanical device that took bombardier inputs of altitude, airspeed, heading, and wind speed and direction, then calculated the impact point of the bomb. An accuracy of 75 feet was claimed under ideal conditions - provided by a mechanical computing device. By 1956 when this article was published, the Norden had been replaced by radar-integrated bombing systems. Additionally, ground-based radar measurement systems were...

Engineering Themed Crossword Puzzle for September 27th

Engineering Themed Crossword Puzzle for September 27th, 2020 - RF CafeSeptember 27th's custom Engineering themed crossword puzzle contains only only words from my custom-created lexicon related to engineering, science, mathematics, chemistry, physics, astronomy, etc. (1,000s of them). You will never find among the words names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You might, however, find someone or something in the otherwise excluded list directly related to this puzzle's technology theme, such as Hedy Lamarr or the Bikini Atoll, respectively. The technically inclined cruciverbalists amongst us will appreciate the effort...

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...

Bell Telephone Laboratories Lens Antenna

Bell Telephone Laboratories Lens Antenna, May 1946, Radio-Craft - RF CafeAt first look this antenna from Bell Telephone Laboratories appears to be a phased array, but in fact it is a "lens" that uses reflecting metal fins to direct incoming and outgoing radio waves into a narrow beam. This is a new approach to the standard method of using a curved (usually parabolic) reflective dish with a feedhorn. No detail is given about how, if at all, the phases of the received signals are phase-adjusted at the point they converge on the back-side waveguide feed. It is sort of akin to the Osgood optical lens used in lighthouses. Shortly after the end of World War II, Bell Telephone Labs began a major effort to interconnect the entire country with microwave relay stations to enhance efficiency and reliability of long distance telephone calls...

Electronics Technician Training Part 1: Resident Schools

Electronics Technician Training Part 1: Resident Schools, September 1965 Popular Electronics - RF CafeThe decade of the 1960's was an exciting and fast-moving time for electronics, being that it was the beginning of a major paradigm change from vacuum tubes to transistors, from discrete circuit components to integrated circuits, and from point-to-point wiring to printed circuit boards. Computers were on the verge of moving out of university labs and corporate research and development centers to small businesses and retail headquarters. Electronic calculators were replacing mechanical calculators. Digital systems were replacing analog systems. Electronics training schools were in their collective heyday. Training prospects lined up in droves and competed to gain acceptance into the institutes. Home-study courses provided theory and hands-on building and troubleshooting...

Why Key Clicks?

Why Key Clicks?, October 1966 QST - RF CafeWaveform shaping is essential in today's crowded communications spectrum. Spectral masks are precisely defined in order to prevent "spreading" beyond the allocated frequency ranges at defined power levels. Whenever anything other than a continuous sinewave is being broadcast, there is spectral content generated in addition to the fundamental frequency. A Fourier transform of the waveform reveals which frequencies at what power levels comprise the waveform. The CW signal used by Morse code operators is a pure sinewave (or nearly so), but there is a spectral problem with it every time the signal turns on or off because of the square-ish edges involved during switching. RC networks are used in the transmitter circuits to tame the edges so that they do not turn on and off so quickly and in doing so reduce the extraneous frequency content. Author George Grammer argues that even though the signal could theoretically be made "clickless" (aka "chirpless"), there is an auditory benefit to the clicks or chirps that aids operators listening to high speed code transmissions...

Cosmic Radio Signals

Cosmic Radio Signals, March 1948 Radio-Craft - RF CafeNational defense needs have pushed back the frontiers of science and technology since time immemorial. Mechanics, chemistry, medicine, mathematics, psychology, astronomy, electricity, and as of the late nineteenth century, electronics. Astronomy was useful as a navigational tool and required a very sophisticated knowledge of geometry and algebra to make it accessible to seafaring men, cartographers, and land surveyors. Since the early 1900s, radio astronomy has played a huge role in the advancement of super-sensitive receiver designs. Most people think of information arriving to them in two or maybe three forms: sound, visible light, and some (but not many) even consider radio waves. As over-the-air AM and FM radio broadcasts die out, even fewer people are aware of radio waves; they certainly don't think of their WiFi or cellphone signals...

Tennode microwave devices - RF Cafe
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