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Homepage Archive - February 2020 (page 4)

See Page 1 | 2 | 3 | 4 | of the February 2020 homepage archives.

Friday 28

New Germanium Source, March 1953 Radio-Electronics

New Germanium Source, March 1953 Radio-Electronics - RF Cafe For a few years, each month's edition of Radio-Electronics magazine included a column entitled "The Radio Month," which was a collection of a dozen or so relevant news items. The March 1953 issue reported on transistorized hearing aids (those old vacuum tube types didn't fit in your ear very well), how the number of TV sets in the U.S. had out-paced the number of telephones thanks to new UHF channels, the continued rapid expansion of television in Europe, and the upcoming 1953 I.R.E. Show (Institute of Radio Engineers) in New York City. Of particular note was the new germanium ore source discovered in Kentucky - not the first place I think of with a semiconductor mother lode. At the time, germanium (Ge) was still the primary element used in transistors and diodes, although silicon was making rapid inroads. The story was germanium sold for $350 per pound in pure metallic form...

The Atmosphere as Global Sensor

The Atmosphere as Global Sensor - RF Cafe"Fundamental science effort to explore if disturbances on earth can be sensed throughout the atmosphere. Sensors are usually thought of in terms of physical devices that receive and respond to electromagnetic signals - from everyday sensors in our smartphones and connected home appliances to more advanced sensors in buildings, cars, airplanes and spacecraft. No physical sensor or aggregation of electronic sensors, however, can continuously and globally detect disturbances that take place on or above the earth's surface. But the physical atmosphere itself may offer such a sensing capability, if it can be understood and tapped into. To that end, DARPA recently announced its Atmosphere as a Sensor (AtmoSense) program, whose goal is to understand the fundamentals of energy propagation from the ground..."

7031 kHz, September 1972 QST

7031 kHz, September 1972 QST - RF Cafe RF Cafe visitor Kevin A., of Roanoke, VA, sent me this article from the September 1972 edition of the American Radio Relay League's QST magazine. He was motivated to send it after reading some of the articles I posted from WWII era QSTs. We can all probably relate a story similar to the one told here. How many "Old Al" types - the antithesis of an "Elmer" - are out there who knowingly or unknowingly frustrate others from participating in an otherwise fun activity because he insists on beating up on a trivial topic ad nauseam? You can feel the angst in the author's voice while reading. Ray, are you out there? Is this story real or fictitious? It could easily be either...

New RF Fundamentals Website by Copper Mountain Technologies

RF Fundamentals Website by Copper Mountain Technologies - RF CafeCopper Mountain Technologies (CMT) created an RF Fundamentals resource website with content for beginner engineers or people without an RF Engineering background. CMT has generated a large number of videos and application notes and consolidated them on a dedicated website. The Vector Network Analyzer (VNA) Basics area includes topics like "What is a Smith Chart?," "Getting Started with a VNA: Top 10 Tips and Tricks," and "What are S-Parameters?" App Notes features titles like "Why USB Vector Network Analyzers?," "What Makes a Good VNA?," and "Calibration Types and Considerations for VNAs." Making Measurements offers "Time Domain Analysis with a VNA," "Fixture Removal from VNA Measurements," and more. The new RF Fundaments website will grow over time...

Promote Your Company on RF Cafe for as Little as $45/mo.

Sponsor RF Cafe for as Little as $45 per Month - RF CafeRF Cafe typically receives 8,000-15,000 website visits each weekday and about half that on weekends. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 8,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. 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. I also re-broadcast homepage items on LinkedIn, Facebook, and Twitter. If you need your company news to be seen, RF Cafe is the place to be. Advertising begins at $45/month.

Forced Air Cooling vs. Wind Chill

Forced Air Cooling vs. Wind Chill - RF CafeThere has always been something nifty keen about colorized gradient maps be they thermal, electric or magnetic field, mechanical stress, etc. Bill Schweber has a good article on the EDN website entitled, "Forced Air Cooling vs. Wind Chill: Same Principle, Different Reality." He begins, "Forced-air convection cooling via fans is a widely used approach for keeping the temperature of electronics below some threshold value. It's more aggressive than 'natural' convection cooling and ensures that air flows across the electronics and heat is removed (ensuring that the heat has a place called 'away' to go to [excellent line! -KRB], that's another story and challenge). While engineers might prefer natural, unforced convection cooling to avoid the perceived negatives of fans (cost, noise, reliability, space, to cite a few), the reality is that the available airflow mass and rate in many unforced cases is either inadequate or unreliable, so fans must be used. The obvious question is, 'How much airflow do I need?,' followed quickly..."

Electro-Photonics Offering RF & Microwave Products

Electro-PhotonicsElectro-Photonics is a global supplier of RF & Microwave components. Their products include SMT hybrid and directional couplers, wire bondable passive components, mounting tabs, filters, transmission lines, and very useful test boards for evaluating components (spiral inductors, single-layer capacitors). The Electro-Photonics team can support your small R&D design requirements with RF & Microwave test fixtures and save you valuable design and characterization time. Please take a moment to visit Electro-Photonics' website and see how your project might benefit.

Thursday 27

Mac's Service Shop: Always Something New

Mac's Service Shop: Always Something New, February 1958 Radio & TV News - RF CafeAfter discussing the virtue of not letting someone else's opinion on the likely cause of a problem direct your own actions when troubleshooting, service shop proprietor Mac McGregor asks Barney about issues he has run into related to the area's having recently had television channel 13 broadcasting added to the area. When he mentions the trouble cause by homeowners leaving excess lengths of twin-lead 300 Ω lead−in wire coiled up behind the TV set, it brought to mind my own mentioning a couple days ago that very scenario in comments made on the "A Two-Band Piece of Wire" article. You and I would be tempted to criticize people for making such an "obvious" mistake, but most people then - and now - have no knowledge of the particulars of routing such cable. A switchover to coaxial cable with the advent of cable TV removed most of the need for being concerned over installation, other than assuring tight connects, proper terminations, and keeping cable length as short as possible to minimize signal loss. Other than that, properly shielded...

Fairview's Class AB High Power Amplifiers w/Optional Heatsinks

Fairview Microwave Unveils New Class AB High Power Amplifiers with Optional Heatsinks - RF CafeFairview Microwave, an Infinite Electronics brand and a leading provider of on-demand RF, microwave and millimeter wave components, has released a new series of Class AB broadband high power amplifier modules that incorporate GaN, LDMOS or VDMOS semiconductor technology. Fairview's comprehensive new line of class AB broadband high power amplifiers consists of 18 new models spanning frequency bands from 20 MHz to 18 GHz. These designs are unconditionally stable and operate in a 50 ohm environment. They offer power gain up to 53 dB and saturated output power levels from 10 watts to 200 watts. This line includes 2 new heatsink modules with DC controlled cooling fans specifically designed for the 18 new models to ensure optimum baseplate temperature for highly reliable performance..."

Anaconda Copper Ad in the April 29, 1950 Saturday Evening Post

Anaconda Copper Advertisement in the April 29, 1950 Saturday Evening Post - RF CafeIt's not often that you will see a full-page ad promoting a particular element in the periodic table, but in 1950 that wasn't the case. This advertisement for Anaconda Copper Mining Company which appeared in a 1950 issue of The Saturday Evening Post magazine extolled the virtues of element number 29 - copper (Cu , from the Latin "cuprum"). Aluminum and iron were other popular topics of advertising. If you do a search on the history of Anaconda, which is today owned by the Atlantic Richfield Company (ARCO), what dominates is the harm done to workers and to the environment. The short video below is one of the less vicious reports on the company's operations in Butte, Montana and in Chile. COPPER... Time's Friendly Enemy Time and copper get along well together - because of one simple reason: Copper chooses to ignore time completely. For nature has given copper the great quality of almost eternal youth - the ability to resist the slow but steady ravages of the elements, for centuries if need be...

Tiny Satellites Are the Future of Space Exploration

Tiny Satellites Are the Future of Space Exploration - RF Cafe"The future of space exploration might be through tiny satellites that can fit in the palm of your hand. Space exploration has infatuated generations for decades now. What started as a race to master human achievement between superpowers has evolved into a human endeavor concerned with the future of humanity. For what is essentially the entire history of human space exploration, the process has necessitated one thing: money. The economics of space When the shuttle program was in full force between running launches between 1981 and 2011, the average cost of sending one pound of material into space ran about $10,000 by conservative estimates, according to Business Insider. Ever since, the space race has largely turned private, and with this shift, competition is driving that cost per pound down..."

Skyworks High-Power Front-End Modules for Wi-Fi 6 Apps

Skyworks High-Power Front-End Modules for Wi-Fi 6 Applications - RF CafeSkyworks is pleased to introduce SKY85333−11 (2.4 GHz) and SKY85747−11 (5 GHz) – two new front-end modules (FEMs) in our portfolio of solutions designed for high-power Wi-Fi 6 (802.11ax) applications and systems. These highly integrated FEMs incorporate switching, low-noise amplifier (LNA) with bypass and power amplifier (PA) for devices such as networking and WLAN-enabled wireless video streaming systems. Both devices feature very low EVM floor with 1024 QAM signal which improves throughput and meets requirements for MU-MIMO operation. The modules offer extremely high linear output power – up to regulation limits for improving coverage range. The SKY85333−11 and SKY85747−11 are available now in a compact LGA (24-pin, 3 x 5 mm) package and support leading reference designs...

Demystifying Electronic Calibration

Demystifying Electronic Calibration - RF CafeMr. Bob Zollo, Solution Architect at Keysight Technologies, posted an article on the Electronic Design website entitled "Demystifying Electronic Calibration," which, among other things, reminds readers that modern high power voltage and current sources are capable of being re-calibrated in-situ without the need to remove test equipment from the setup in order to access potentiometer. It's all done electronically nowadays. Calibration tables are generated and stored internally in nonvolatile RAM. Ambient temperature variations and response to various level of load can be compensated in many cases...

MPDevice: RF & Microwave Circulators & Isolators

MPDevice - RF CafeMPDevice (MPD) has become a trustworthy and reliable company in the global RF market as a manufacturer of passive RF Devices. Included are attenuators and terminations, coaxial connectors, adapters, and cable assemblies, DC blocks, surge arrestors, power combiner / dividers, and directional couplers. The Korean Telecommunication market is now entering into the era of hyperconnected society. With continuous enhancement in R&D capabilities and quality control, MPD will continue in an effort to become the No. 1 technologically innovative company with a focus on the emerging 5G marketplace.

Wednesday 26

Lee de Forest and the Navy

Lee de Forest and the Navy, January 1947 Radio-Craft - RF Cafe This is another of the articles written about Lee de Forest that appeared in the January 1947 issue of Radio-Craft magazine, in celebration of the 40-year anniversary since the industry-changing Audio vacuum tube was invented. Author George H. Clark, a member of the first "radio-man" to be graduated from the Massachusetts of Technology (MIT), was, in addition to working for Marconi Wireless Telegraph Company, RCA, and the Telegraph and Telephone Company, the U.S. Navy's "Sub-inspector of Wireless Telegraph Stations." He dealt extensively with de Forest regarding installation and operation of radio systems both on ships and on shore. Interestingly, he mentions that the first Audions were used as detectors more so than as signal amplifiers, which in fact was de Forest's original goal (a more sensitive detector) in his experimentation...

ThinkRF Integrates Its RF Spectrum Analyzers with CelPlan Software

ThinkRF Integrates Its RF Spectrum Analyzers with CelPlan Software - RF Cafe ThinkRF Corporation, the leader in software-defined spectrum analysis, today announced a fully integrated wireless network testing system with CelPlan Technologies, Inc. The solution allows RF engineers to conduct drive tests and evaluate network performance, map coverage, or identify issues with Citizens Broadband Radio Service (CBRS), a new network standard which leverages the previously underutilized 3.5 GHz spectrum range for shared public use in commercial wireless services. With the high-performance ThinkRF Spectrum Analyzer as the scanning receiver and leading drive test software from CelPlan, the solution offers the highest frequency range in the smallest form factor, with 100 MHz real-time bandwidth...

Best Tube Amps for Electric Guitar

Best Tube Amps for Electric Guitar - RF CafeA dispute about the relative quality of vacuum tube versus solid state electric guitar amplifiers has been ongoing since the dawn of transistors. Tube amp loyalists claim that a vibrato-like quality is imparted to audio by the microscopic mechanical vibrations in the metal components that make up the cathode, screen grid, and plate elements. An RF Cafe visitor sent me a hyperlink to a piece entitled "Best Tube Amps for Electric Guitar," on the Beginner Guitar HQ website with a rather extensive treatise on the subject. It of course favors the vacuum tube amplifier for the reason stated. Here is a report on blind and double-blind tests that have been conducted in an attempt to scientifically determine a result. The jury is still out on this one...

Minimizing Power-Supply Voltage Drop on PCBs

Minimizing Power-Supply Voltage Drop on PCBs - RF CafeHere is an interesting article on the EDN website by Bill Schweber entitled, "Minimizing Power-Supply Voltage Drop on PCBs." He discusses the importance of managing PCB trace resistance to facilitate the high-current, low-voltage typical of today's layouts. "Despite the widespread availability and use of low-power components, today's printed circuit boards (PCBs) can require a significant amount of current, with boards drawing 50, 100, and even 200 A in common use. Whenever current is delivered to a load, there will be IR-based voltage drop, and designers must take this loss into account when laying out the board and placing the supply, dc supply rails, and loads..."

Exodus Advanced Communications: RF & Microwave Power Amplifiers

Exodus Advanced Communications - RF CafeExodus Advanced Communications is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. Power amplifiers ranging from 10 kHz to 51 GHz with various output power levels and noise figure ranges, we fully support custom designs and manufacturing requirements for both small and large volume levels. decades of combined experience in the RF field for numerous applications including military jamming, communications, radar, EMI/EMC and various commercial projects with all designing and manufacturing of our HPA, MPA, and LNA products in-house.

Tuesday 25

$5.00 for Best Short Wave Kink

$5.00 for Best Short Wave Kink, November 1935 Short Wave Craft - RF CafeHere is a handy-dandy baker's dozen of 'kinks,' otherwise known as tricks of the trade, shortcuts, or clever ideas, that could prove useful while working in the lab at work or in your shop at home. One suggestion is to place a sheet of tracing paper over your schematic while wiring a circuit and draw each connection as it is completed, rather than mark up the original drawing. That was definitely good for a time when making a spare copy of a magazine page or assembly instruction from a kit was not as simple a matter as it is today. Whether it be a schematic or a set of plans for a model airplane, I always make a copy to work and draw notes on rather than defacing the original...

World's Smallest All-Digital PLL

World's Smallest All-Digital PLL - RF Cafe"Scientists at the Tokyo Institute of Technology and Socionext have designed the world's smallest all-digital phase-locked loop (PLL). PLLs are critical clocking circuits in virtually all digital applications, and reducing their size and improving their performance is a necessary step to enabling the development of next-generation technologies. New or improved technologies, such as artificial intelligence, 5G cellular communications, and the Internet-of-Things, are expected to bring revolutionary changes in society. But for that to happen, high-performance system-on-a-chip (SoC) devices are indispensable. A core building block of SoC devices is the phase-locked loop (PLL), a circuit that synchronizes with the frequency of a reference oscillation and outputs a signal with the same or higher frequency..."


The ARRL RFI Book - RF CafeThe ARRL RFI Book 3rd Edition, written by Mike Gruber (W1RM), will help you to find and resolve interference. This book covers the causes and cures of many interference problems that you may experience. Everything from automotive to television, from computers to DVD players, and audio equipment to telephones can create a problem. The ARRL RFI Book offers a convenient, step-by-step process to eliminate problematic radio frequency interference. As technology increases, the likelihood of interference increases, too. Be ready to battle the noise with The RFI Book 3rd Edition from The American Radio Relay League.

Archie's Ham Radio Adventure

Archie's Ham Radio Adventure - RF CafeStan Goldberg is a familiar name to comic book aficionados for his artistry in Spider Man, the Incredible Hulk, and the Archie series. QST magazine had him listed in the "Silent Keys" column in the November 2014 issue because he passed away in August. A Silent Key, in Hamdom, is usually a title reserved for a deceased licensed operator (the 'key' reference being a Morse code key), but a search of the Internet and the FCC license database web page did not turn up a call sign for him. Unless his record has been dropped from the database, Mr. Goldberg might never have actually been a Ham, but earned the Silent Key acknowledgement because of his involvement in a 1986 special edition comic book titled "Archie's Ham Radio Adventure." It was quite an extensive story that involved all the familiar Archie characters, and even had a section addressed to parents encouraging them to promote both their kids' and their own interest in amateur radio as an educational and character building tool...

RF & Microwave 2020

RF & Microwave 2020 - RF CafeThe RF & Microwave 2020 event will be held on March 18th & 19th at Porte de Versailles, Paris. According to the brochure, 7 good reasons to participate include: "RF & Microwave est le seul rendez-vous en France pour les domaines des radiofréquences, des hyperfréquences, du wireless, de la CEM; Vous rencontrez et échangez avec des visiteurs qualifiés; Vous bénéficiez de l'importante communication du salon: newsletters, catalogue, site internet, et gagnez en vivibilité; Ce rendez-vous vous permet de gagner un temps précieux..."

Withwave: RF & Microwave Components

Withwave RF & Microwave Components - RF CafeWithwave manufactures an extensive line of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch, board edge, panel mount), calibration kits (SOLT), a fully automated 4-port vector network analyzer (VNA) calibrator, between- and in-series connector adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes & probe positioner. Special test fixtures for calibration and multicoax cable assemblies. Frequency ranges from DC through 110 GHz. Please contact Withwave today to see how they can help your project succeed.

Monday 24

A Two-Band Piece of Wire

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

Satellite 2020

Satellite 2020 - RF CafeIf you are an Elon Musk acolyte, which to a degree, I am, then you might want to plan on attending Satellite 2020 in Washington, D.C., from March 9-12. Mr. Musk, whose enterprises include SpaceX and Tesla, will be the keynote speaker. The cost of admittance to just the exhibit hall is $99, and prices go up from there (a la IMS2020). Sometimes you can find an exhibitor to sponsor your attendance since they are usually provided with a number of free tickets. Check the exhibitor list and try contacting someone from a company whose products you use. "SATELLITE's purpose involves cultivating an environment where the individual AND the collective can thrive. We're very proud of our international DNA, it's reflective of our belief that we can achieve so much more when we work together. It may sound cheesy, but breaking the traditional barriers between people, companies, countries and industries can lead to outcomes that we never imagined possible when we stay in our silos..."

Highway Patrol TV Show: "Radioactive"

Highway Patrol TV Show: "Radioactive" - RF Cafe Video for EngineersQST reader Dave Berman, WA2PAY, wrote in the March 2020 issue's "Letters from Our Members" column about an episode of the old "Highway Patrol" television show entitled, "Radioactive," wherein the ARRL (American Radio Relay League" is mentioned and Ham radio operator Pat Conway plays a lead role in the show. Broderick Crawford stars as head highway patrolman Dan Mathews. I did some screen shots of Mel's shack showing the massive transmitter cabinet and the receiving station desk. On a table across the room is a Precision Apparatus Co. E-200-C Signal Generator. Do you recognize any of the other equipment? Note on the chalkboard that the nuclear scientist has beryllium misspelled as "berilium," unless he happens to be an Indonesian, in which case it's OK...

Anatech Electronics February 2020 Newsletter

Anatech Electronics February 2020 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his February newsletter that features his short op−ed entitled "Dynamic Spectrum Sharing Coming Next Year," which discusses the quandary the wireless industry finds itself in with very limited spectrum available in the millimeter-wave bands that can accommodate high data rates necessary for 5G schemes. I like a statement made from another source about 5G being the first wireless protocol to perform like wired connections, but without the wires. Until more spectrum is freed up, some form of spectrum sharing plan is needed, and service providers are working on what had been dubbed "dynamic spectrum sharing" (an innovation claimed Ericsson), which allows available segments of spectrum to be accessed...

DARPA to Develop Integrated Mixed-Mode CMOS RF Electronics

DARPA to Develop Integrated Mixed-Mode CMOS RF Electronics - RF Cafe"DARPA has selected nine research teams to develop advanced RF mixed-mode electronics critical to emerging defense applications in communications, radar, and electronic warfare under the Technologies for Mixed-mode Ultra Scaled Integrated Circuits (T-MUSIC) program. T-MUSIC was first announced in January 2019 as a part of the second phase of DARPA's Electronics Resurgence Initiative (ERI). These RF mixed-mode interfaces will target the current limitation of in-efficiency of CMOS platforms, where they are unable to support operations at higher frequencies with larger signal bandwidths. Today's defense electronics systems rely on radio frequency (RF) mixed-mode electronics..."

NEW - RF & Electronics Symbols for Visio

RF Electronics Wireless Analog Block Diagrams Symbols Shapes for Visio - RF CafeWith more than 1000 custom-built symbols, this has got to be the most comprehensive set of Visio Symbols for RF, analog, and digital system and schematic drawings! Every object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Symbols are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing. The file format is XML so everything plays nicely with Visio 2013 and later...

TotalTemp Technologies: Thermal Platforms for −100°C to +200°C

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.

Sunday 23

Engineering & Science Crossword Puzzle for February 23

Engineering & Science Crossword Puzzle February 23, 2020 - RF CafeAs with my hundreds of previous science and engineering-themed crossword puzzles, this one for February 23, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you.


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RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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