Homepage Archive - April 2020 (page 2)

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Friday 17

Bell Telephone Laboratories 10th Anniversary Transistor

Bell Telephone Laboratories 10th Anniversary Transistor, June 1958 Radio & Television News - RF CafeThis Bell Telephone Laboratories (aka Bell Labs) advertisement appearing on the inside back cover of the 1958 issue of Radio & TV News magazine celebrated the 10th anniversary of their announcement of the world's first point contact transfer resistance (transresistance) semiconductor device  - aka the transistor. John Bardeen, William Shockley and Walter Brattain recorded the monumental event in a lab notebook on December 23, 1947 - a nice Christmas present for the world! The trio's invention was not like the robust bipolar transistors used today, or even ten years later in 1958. Rather than employing point-contact "cat's whisker" metallic probes for making the emitter and collector contacts with the germanium PN base substrate, commercially viable bipolar transistors use a doping element diffused into the purified crystal substrate to effect the emitter, base, and collector regions on a single crystal (with gold contact pads for attaching external leads)...

NASA Nanosat Swarm to Probe Solar Eruption Source

NASA Nanosat Swarm to Probe Solar Eruption Source - RF Cafe"NASA has selected a mission to dispatch six CubeSats, each the size of a toaster oven, to an orbit more than 20,000 miles from Earth to study massive particle ejections from the sun. The Sun Radio Interferometer Space Experiment, or SunRISE, mission will launch no later than July 1, 2023, after its selection by NASA as a mission of opportunity under the agency's Explorers program. SunRISE will consist of six CubeSats flying as close as 6 miles (10 kilometers) from each other. The nanosatellites will together act as a giant radio telescope, detecting low-frequency emissions from solar activity and downlinking the measurements through NASA's Deep Space Network. Data gathered by the SunRISE CubeSats will tell scientists about the source of coronal mass ejections, which launch huge bubbles of gas and magnetic fields from the sun. Employing a constellation of small satellites will allow researchers..."

Entertaining Uncle Oscar

Entertaining Uncle Oscar, August 1939 QST - RFCafePopular comic strips (aka 'funnies') in the 1930s and 1940s featured numbskulls, ne'er-do-wells, and simpletons. There was usually one character in the strip's cast that was smart - at least in a relative way if not absolute. Being familiar with some of the old comics like Blondie, Barney Google, Krazy Kat, Beetle Bailey, Gasoline Alley, etc., I can see a definite relationship between the story line of "Entertaining Uncle Oscar" and the comics of the era in this short story that appeared in a 1939 edition of the ARRL's QST magazine. As you might guess, the feller named 'Ham' is the smart one. Q: Is it irony, coincidence, or premonition on the author's part that the uncle's name is the same as the ARRL's OSCAR series of Orbiting Satellite Carrying Amateur Radio(s)?

Empower RF Systems Intros Compact SS GaN-on-SiC Pulse Amplifier

Empower RF Systems Intros Compact SS GaN-on-SiC Pulse Amplifier - RF Cafe

Empower RF Systems Model 2213 is a compact solid state GaN-on-SiC amplifier delivering 10 kW of peak pulsed power. This air cooled 10 kW, 6% duty cycle pulse amplifier system brings sophisticated monitoring, protection, and control functions to mission critical applications. It's an intelligent amplifier system with a flexible software and embedded firmware design that can be customized to add mission support capabilities specific to the users integrated system. Remote control and monitoring is included. The 2213 is based on Empower's established and field proven Next Generation architecture that is tactically deployed and operating on multiple levels in support of a variety of critical DOD missions...

Post Your Engineer & Technician Job Openings on RF Cafe for Free

Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge (of course a gratuity will be graciously accepted). 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

Please Thank RF Superstore for Their Continued Support

RF Superstore coaxial cable, connectors, adapters - RF CafeRF Superstore launched in 2017, marking the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and microwave Industry. Pasternack fundamentally changed the way RF components were sold. Partner Jason Wright manages day-to-day operations, while working closely with Mr. Pasternack to develop RF Superstore into a world class RF and microwave component supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies, surge protectors, attenuators. Items added daily. Free shipping on orders over $99. We're leading the way again!

Thursday 16

Mac's Radio Service Shop: Cabinet Crisis

Mac's Radio Service Shop: Cabinet Crisis, March 1955 Radio & Televsion News - RF CafePlastic is one of those materials that seems like it has been around since the dawn of time - like metal. There was an Iron Age in the 1,000 BC timeframe (depends on location), but the Plastic Age - not that there officially was one - did not begin in the commercial world until World War II. If you note in older photos and films, there was not much, if any, in the way of objects made of plastic before the 1940s. In fact, the formulation and production of some types of plastic like Plexiglas and polycarbonates was considered a matter of national security for a while both for Allied and Axis powers. Bomber and fighter aircraft windshields were made of the material. After the war, use of plastics for industrial and consumer products exploded due to the much easier manufacturing of product enclosures, knobs, and parts with complex shapes. Lighter weight, lower cost, easy application of color, and in some cases greater robustness made plastic very popular with consumers. Plastic does have its drawbacks compared to the wood, metal, and phenolic materials previously used for radios, TVs, and phonographs, and Barney experienced one of them...

Mitigate Clock Intermodulation Effects in Characterization Setups

Mitigate Clock Intermodulation Effects in Characterization Setups - RF CafeMessrs. Krunal Maniar and Ryan Andrews have published an article on the EDN website entitled, "Mitigate Clock Intermodulation Effects in Characterization Setups." Intermods have been an issue since the beginning of electronic - even before digital circuits. It begins: "Mixed-signal PCBs present unique challenges in high-performance applications, such as vibration analysis and other multi-channel data acquisition systems. Nonlinear signal-chain elements introduce unwanted harmonic distortion, increasing the magnitude of the input signal's harmonic content. Meanwhile, multiple switching elements produce intermodulation artifacts that present themselves as frequency spurs asynchronous to the signals of interest. The noise and distortion degradation introduced by these nonidealities can significantly limit the overall performance of applications aiming for high resolution at high bandwidth. In this article, we'll explain how clocks and other switching elements produce intermodulation artifacts..."

The Maser & Sugar Scoop Antenna: Receiver for Signals from Space

The Maser & Sugar Scoop Antenna: Receiver for Signals from Space, November 1960 Electronics World - RF CafeWhen really good researchers set out to write books on history, they do not simply cull information from the publications of fellow contemporary authors; instead, they look for sources that were published during or around the time of the subject being covered. Doing so helps minimize the possibility that inaccuracies have crept into the knowledge pool and that information other authors might have either deemed insignificant or have missed can be recovered. With a bit of luck, sources are discovered that have never been used before. That is part of my motivation for going to the trouble of buying these vintage magazines and posting articles like this one which reports on early maser developments. It delves fairly deeply into the solid state physics of rare earth minerals that some of the first masers and lasers relied upon to function, including energy band diagrams and cryogenics. If the "sugar scoop" antenna looks familiar, it might be due to its rising to fame...

Apple, Google Partner on Wuhan Flu Contact Tracing Bluetooth Tech

Apple, Google Partner on Wuhan Flu Contact Tracing Bluetooth Technology - RF Cafe"The tech giants Apple and Google are throwing their joint might behind the use of Bluetooth technology to help governments and health agencies reduce the spread of Covid-19. And the focus is on contact tracing. The image above envisages scenarios around privacy-safe contact tracing using Bluetooth Low Energy. In countries where the impact of Covid-19 has been minimized - for example Taiwan and South Korea - contract tracing has been a major element of a national strategy. A number of leading public health authorities, universities, and NGOs around the world have been doing important work to develop opt-in contact tracing technology..." Of course you just knew the example would have the guy responsible for passing the contagion on to the gal, never the other way around.

Skyworks 5 GHz FEM Supports Simultaneous Wi−Fi Connectivity and LAA

Skyworks 5 GHz Front-End Module Supports Simultaneous Wi-Fi Connectivity and LAA - RF CafeSkyworks Solutions is pleased to introduce the SKY5®-5501-11, a 5 GHz front-end module (FEM) designed for Wi-Fi enabled devices including handsets and tablets. This advanced FEM supports simultaneous Wi-Fi and licensed assisted access (LAA) protocols for high speed data throughput in the 5 GHz WLAN and LAA spectrum. The SKY55501-11 is highly integrated and includes a low-noise amplifier, low-loss bypass path, power splitter, and single-pole, double-throw transmit and receive switch. The SKY55501-11 builds on Skyworks' portfolio of revolutionary products for 5G applications. The SKY55501-11 is a highly integrated, 5 GHz front-end module (FEM) that supports simultaneous 5G WLAN and licensed assisted access (LAA) systems. The SKY55501-11 incorporates a 5 GHz low-noise amplifier (LNA) with bypass supporting 5G WLAN and LAA...

Bittele Electronics: PCB Fabrication & Assembly

Bittele Electronics PCB Fabrication - RF CafeSince 2003, Bittele Electronics has consistently provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly services. It specializes in board level turnkey PCB assembly for design engineers needing low volume or prototype multi-layer printed circuit boards. Free Passive Components: Bittele Electronics is taking one further step in its commitment of offering the best service to clients of its PCB assembly business. Bittele is now offering common passive components to its clients FREE of Charge.

Wednesday 15

Littelfuse Advertisement

Littelfuse Ad, April 1954 Radio & Televsion News - RF CafeQuestion: If a fuse is rated at 3 amps, at what value of current should it "blow?" Answer: Not at 3 amps. As this Littelfuse company advertisement from a 1954 issue of Radio & Television News magazine informs us, fuse ratings do not indicate the current value at which a fuse opens to protect a circuits, but rather the maximum current level at which it will NOT blow (open circuit). The same goes for circuit breakers. Various types of fuses are available to handle certain types of applications. For instance, a highly capacitive load will according to the well-known equation iC(t) = C * dv/dt could draw a very large amount of initial (inrush) current if there is not enough series resistance to limit it to prevent a standard fuse from blowing. The same goes for a heavy physical inertial load at startup (e.g., an air compressor motor). Highly inductive loads can cause extreme counter-emf currents to be impressed at shutdown. Both of those circuits...

SimSmith Smith Chart Software

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

Range-Doubling GPS-Guided Army Artillery Hits Targets 40 Miles Away

Range-Doubling GPS-Guided Army Artillery Hits Targets 40 Miles Away - RF Cafe"Testing last month at the Army's Yuma Proving Ground in the Arizona desert showed a precision-guided artillery shell that destroyed an enemy target from nearly 40 miles away during a recent live-fire exercise. The demonstration of the emerging Long Range Precision Fires program had an Army 155-mm howitzer that blasted a Raytheon Excalibur GPS-guided artillery round out to ranges twice that of what existing artillery weapons. The new smart munitions weapon in development, called Extended Range Cannon Artillery, not only preserves the GPS-guided precision attack options of the Excalibur ammunition, but also extends attack ranges from roughly 19 miles to almost 44 miles..."

Blonde QRM

Blonde QRM, March 1940 QST - RF CafeHere's a little dose of Ham comedy to help take the edge off a busy day - straight from the ARRL's QST magazine in a piece entitled, "Blonde QRM." It's a little bit kooky by today's standards, but in 1940 the style of humor it fits right in. This could easily have been the plot in an old TV show like The Honeymooners, or one of the radio sitcom programs like The Life of Riley. It reminds me of how in the "Nancy Drew Detective," movie from the 1930s, Ted is a Ham radio operator, and he tells his fellow Ham that he has experienced "local QRM" when Nancy Drew suddenly enters his shack (Nancy is a blonde). QRM, by the way, is Ham lingo for man-made signal interference, as opposed to QRN, which is atmospheric or "natural" signal interference...

ConductRF High Flex VNA Test Cables for 40, 50 & 70 GHz

ConductRF High Flex VNA Test Cables for 40, 50 & 70 GHz - RF CafeConductRF offers RF Engineers a large selection of Hi Flex cable for vector network analyzers (VNAs). We have standards for applications at 18-40 GHz, 50 GHz & 70 GHz. Our torque resistant connector heads and phase stable constructions ensure great performance for many tests to come. Other key features include: 2.92 mm, 2.4 mm & 1.85 mm connector options, low VSWR & insertion loss, low phase change with flexing, options available swept right angle connectors. ConductRF VNA series provides customers with reliable ruggedized solutions for Lab and Production Vector Network Analyzer testing. With options for 18 GHz, 26.5 GHz, 40 GHz, 50 GHz, & 70 GHz, these cables offer cost leading alternatives to original OEM VNA cable solutions...

Windfreak Technologies: USB-Powered RF Synthesizers, Mixers

Windfreak TechnologiesWindfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project.

Tuesday 14

How Radio-Control Systems Work

How Radio-Control Systems Work, May 1974 Popular Electronics - RF CafeRadio control (R/C) systems operating in the 2.4 GHz ISM band, using one of or a combination of frequency hopping and direct sequence spread spectrum scheme, have been in widespread use since the early 2000s. As with any new technology, there was a lot of reluctance to adoption of the systems based on a few reports (valid or not) of performance issues - primarily lack of control range where communications between the transmitter (Tx) and receiver (Rx) with a pilot and aircraft was lost and a crash ensued. Tx power was already at the FCC-mandated maximum, so manufacturers quickly improved receivers by adding diversity with a second Rx antenna. The receiver microprocessor continuously monitors signal integrity from both antennas and uses the best one. It is the same scheme that was already being used by WiFi routers also operating at 2.4 GHz...

Bump up Semiconductor Efficiency with GaN

Bump up Semiconductor Efficiency with GaN - RF CafeIt might seem like GaN (gallium nitride) as an RF semiconductor has been around forever, but it has only been available in affordable commercial production quantities for a little over a decade. When I worked at RFMD (through 2007, now Qorvo), their labs were still working on growing a boule greater than 2" in diameter, and military / space applications we the primary customers. 3" seemed to be the industry goal for moving into the commercial realm for both RF and power supply products. Dave Browne has a good article on his Microwaves & RF website entitled, "Bump up Semiconductor Efficiency with GaN," that delves into the technology. "GaN is a semiconductor material that's well-suited for the fabrication of high-power, high-frequency, as well as ultraviolet LED devices..."

COVID-19's Impact on the Semiconductor Market

COVID-19's Impact on the Semiconductor Market - RF Cafe"The U.S. semiconductor market is still trying to understand and adjust to the global coronavirus pandemic. In mid-March, the U.S. stock market was still trying to understand what was happening with the global coronavirus pandemic, having lost nearly 20% of its value in one week. Cooling-off periods (also called 'Circuit Breakers') automatically stopped overheated trading at different intervals. Market indexes fell sharply, as shown in a chart from Google Finance, which shows the relative performance over the first part of the year for both the Dow Jones Industrials and NASDAQ. It's been a roller-coaster ride since that date, with the market rising sharply last week and once again tumbling to start off this week..."

Laser Modulators

Laser Modulators, April 1967 Electronics World - RF CafeAs reported in this 1967 Electronics World magazine piece, lasers were still the things of science fiction to most people. Real-world applications seemed to be far off in the future, but in fact, work was underway setting the stage for today's blazingly fast communications systems. The author here references attaining 5 THz optical transmission speeds through fiber and through the air. At the time, a laboratory filled with bulky prototypes chassis and optical tables were required to get those results. I can remember reading articles in the 1970s when laser power output was measured in "Gillette power," referring to the beam's ability to burn through a number of razor blades (a big deal at the time). In 2020, devices that greatly surpass 5 THz are available in consumer quality IC packages...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 Is Available Now! - RF CafeRF Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this. It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features...

San Francisco Circuits: PCB Fabrications & Assembly Service

San Francisco CircuitsSF Circuits' specialty is in the complex, advanced technology of PCB fabrication and assembly, producing high quality multi-layered PCBs from elaborate layouts. With them, you receive unparalleled technical expertise at competitive prices as well as the most progressive solutions available. Their customers request PCB production that is outside the capabilities of normal circuit board providers. Please take a moment to visit San Francisco Circuits today. "Printed Circuit Fabrication & Assembly with No Limit on Technology or Quantity."

Monday 13

Radio-Electronics Monthly Review

Radio-Electronics Monthly Review, May 1947 Radio-Craft - RF CafeA column entitled "Radio-Electronics Monthly Review" appeared in each issue of Radio-Craft magazine. As now, things were moving quickly at the time. With WWWII recently ended, a lot of the new technology developed to help beat back Nazism and Communism was being transferred to peacetime uses. The May 1947 issue contained, amongst other items, info regarding how radio servicemen were organizing efforts to get its ranks educated on FM sets as AM was being replaced and/or supplemented with the new miracle noise-free broadcast systems. It also reported that the IRS decided not to go forward with earlier plans to tax television shows being displayed in public places. Attempts to tax the air that you breathe are to this day still being worked on, though. The U.S. Bureau of Standards (now NIST) announced adoption of international standards of measure for certain electrical units...

Harley-Davidson All-Electric LiveWire Motorcycle

Harley-Davidson All-Electric LiveWire Motorcycle - RF CafeSome hard core bikers consider an electric-powered Harley to be sacrilegious. Can a Harley-Davidson that doesn't make the classic "poTAYto - poTAYto - poTAYto" be considered a Harley? This article on the Electronic Design website does a great job of summarizing all the technical features of H-D's 2020 LiveWire all-electric motorcycle (first released in 2019). The number of sensors and active feedback stabilization and control features is amazing. Its anti-lock braking system features a Rear-Wheel Lift Mitigation system that "borrows the C-ABS sensors and six-axis inertial measurement unit to manage rear-wheel lift during heavy braking, while balancing deceleration and rider control." Hopefully, the 553-pound (~same as ICE version), $30k bike doesn't rely too heavily on all the computer control to the point that its ultimate stability is as dependent on microprocessor control that it has become like the Boeing 737 MAX's MCIS...

Thanks Once Again to everythingRF for Long-Time Support!

everything RF Searchable Database - RF CafePlease take a few moments to visit the everythingRF website to see how they can assist you with your project. everythingRF is a product discovery platform for RF and microwave products and services. They currently have 265,628 products from more than 1380 companies across 313 categories in their database and enable engineers to search for them using their customized parametric search tool. Amplifiers, test equipment, power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers, power supplies, and everything else. Please visit everythingRF today to see how they can help you.

Yet More Tech-Centric Jokes

Yet More Tech-Centric Jokes - RF CafeTake a break from the drudgery with some of these tech-centric jokes, song parodies, anecdotes and assorted humor that has been collected from friends & from websites across the Internet. This humor is light-hearted and sometimes slightly offensive to the easily-offended, so you are forewarned. I have taken care to censor out "humor" with reproductive function innuendo and hateful tirades, so it is all workplace-safe. I have also tried to warn of any links that will result in audio clips so you can take appropriate precautions. As usual, there is no easy way to determine the true origin of any of these jokes. Unless otherwise noted, that prolific author "Anon" is the progenitor...

World War I, British Biplanes Had Wireless Phones

World War I British Biplanes Had Wireless Phones - RF Cafe"Pilots on reconnaissance missions could immediately call in their findings. As soon as the first humans went up in hot air balloons in the late 1700s, military strategists saw the tantalizing possibilities of aerial reconnaissance. Imagine being able to spot enemy movements and artillery from on high - even better if you could instantly communicate those findings to colleagues on the ground. But the technology of the day didn't offer an elegant way to do that. By the early 20th century, all of the necessary elements were in place to finally make aerial reconnaissance a reality: the telegraph, the telephone, and the airplane. The challenge was bringing them together. Wireless enthusiasts faced reluctant government bureaucrats..."

Alliance Test Equipment: Used & Refurbished, Purchase & Rental

Allied Test Equipment Products - RF CafeAlliance Test Equipment sells used / refurbished test equipment and offers short- and long-term rentals. They also offer repair, maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP, Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization with ability to source hard to find equipment through our network of suppliers. Alliance Test will purchase your excess test equipment in large or small lots. Please visit Allied Test Equipment today to see how they can help your project.

Sunday 12

Engineering & Science Crossword Puzzle for April 12

Engineering & Science Crossword Puzzle April 12, 2020 - RF CafeWorking crossword puzzles can be contagious. This April 12, 2020, tech-themed crossword puzzle may even go viral - the second in a series. It contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have personally built over nearly two decades. That includes the cause for our planet's current dilemma. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia...

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