Homepage Archive - July 2021 (page 3)

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Wednesday the 21st

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.

Top 5 Secrets of High-Speed PCBs

Top 5 Secrets of High-Speed PCBs - RF Cafe"From assembly development to mitigating crosstalk to signal integrity, these tips can help streamline the high-speed PCB design process. Vigorous competition in the electronics market means developers must keep modification in mind when designing systems. High-speed PCBs are increasingly important to high-performance solutions, but high-speed PCB assembly is costly. That's why you can't experiment with these boards or generate a lot of prototypes. This article offers five tips to help streamline and improve those high-speed PCB designs while keeping costs at bay. High-speed assembly needs some additional components compared to any other type of PCB assembly, such as conventional or rigid-flex assembly. These components change according to every application's need, but all must be given extra care during the manufacturing phase. The main factors that professionals..."

RF Transistors of High-Purity Carbon Nanotube Arrays

RF Transistors of High-Purity Carbon Nanotube Arrays - RF Cafe"Most next generation wireless communication technologies require integrated radiofrequency devices that can operate at frequencies greater than 90 GHz. Two of the semiconductors most widely used to fabricate radiofrequency devices are silicon complementary metal-oxide-semiconductor (CMOS) field-effect transistors (FETs) and transistors based on III-V compound semiconductors, particularly GaAs. Both these semiconductor RF technologies, however, are unable to simultaneously achieve high operating frequencies and be easy to integrate within wireless communication technologies. A promising candidate for the development of high-speed FETs (up to terahertz frequencies) are semiconducting single-wall carbon nanotubes (CNTs), due to their favorable electronic and physical properties. Remarkably, the material requirements of CNTs for the fabrication of RF analog and digital devices are almost the same..."

Basic Navy Training Courses - Static Electricity

Electricity - Basic Navy Training Courses, NAVPERS 10622, Chapter 2 - Static Electricity - RF CafeChapter 2 of the U.S. Navy's Basic Navy Training Courses covers Static Electricity. Chapter 1 is entitled "Matter - Electricity Does It!," and contains Figures 1 through 4, which explains why Figure 5 is the first one here (in case you were wondering). The first few chapters cover the fundamentals of electricity and electronics, and the material is as relevant and true today as it was in the 1940s. Many chapters were originally posted more than a decade ago and many people have written to comment on the quality of the Navy's courses. Employers have long preferred former Navy-trained electronics personnel for technician jobs because of their reputation. Navy hands-on experience combined with an Associate's degree in electronics technology was (and may still be) an almost guaranteed ticket to a great civilian career. If you are young and considering a career in electronics, you might consider enlisting in the military (any branch, really) for training...

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. 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 Visit Empower RF's Website in Appreciation of Their Support

Empower RF Systems - RF CafeEmpower RF Systems is a global leader in power amplifier solutions. Empower RF Systems is an established and technologically superior supplier of high power solid state RF & microwave amplifiers. Our offerings include modules, intelligent rack-mount amplifiers, and multi-function RF Power Amplifier solutions to 6 GHz in broadband and band specific designs. Output power combinations range from tens of watts to multi-kilowatts. Unprecedented size, weight and power reduction of our amplifiers is superior to anything in the market at similar frequencies and power levels.

Tuesday the 20th

Mike Wallace on "60 Minutes" re the 1976 Swine Flu Pandemic

"60 Minutes" re the 1976 Swine Flu Pandemic - RF CafeThis you might find hard to believe. After reading about my sister's severe reaction to the Wuhan Flu vaccination, someone sent me a link to this "60 Minutes" television show video from 1979. Intrepid newsman Mike Wallace reports on the debacle that was the government's effort to hurriedly get everyone vaccinated against the Swine Flu "pandemic" -  which turned out to not be a pandemic at all. It was a knee-jerk reaction that caused more harm than good through misinformation, mismanagement, and, honestly, misanthropy on the part of government and industry "professionals" following the science. Sound familiar? The difference is that now we don't have total lap-dog media abetting the aforementioned string-pullers...

Mac's Radio Service Shop: Mac's "System"

Mac's Radio Service Shop: Mac's "System", May 1950 Radio & Television News - RF CafeReading an episode of "Mac's Radio Service Shop" always has me wishing I had been born a couple decades earlier and had taken the path of running an electronics repair shop. For sure it was no picnic either from the standpoint of needing to keep abreast of constantly changing product designs and finicky customers, but the thrill of the hunt (for the cause of "trouble") and the satisfaction in knocking them out (the "shooting") is something people like us (you, too, I assume, since you're reading this) understand. Back in my USAF days as an air traffic control radar repairman, day-to-day routine system alignments and preventative maintenance could be pretty dull, and most problems were fairly easily resolved in an hour or two. However, every once in a while a real doozy of a case would crop up that would have a full shift or two of fellow technicians agonizing over it until the cause was finally discovered. Often, as with some of the scenarios Mac describes, an intermittent component or connection ended up as the culprit. One time I remember having a particularly bad time with the signal path from the transmitter to the rotating antenna on the roof of the equipment trailer (AN/MPN−14 mobile ASR/PAR radar). We had deployed the system...

Heathkit SA-5010 μMatic Memory Keyer Kit

Vintage Heathkit SA-5010 μMatic Memory Keyer Kit - RF Cafe Cool ProductThis vintage Heathkit SA−5010 μMatic Memory Keyer kit is one the latest unbuilt Heathkit kits which appeared on eBay. I have been saving the images in order to preserve the history. The constantly growing list is at the lower right. The first instance I could find for SA−5010 being offered for sale was in the Christmas 1982 Heathkit catalog, at a cost of $99.95 ($250.40 in 2021 money per the BLS). It went to model number SA−5010A sometime around 1985. Zenith bought Heathkit in 1979 (and kept the Heathkit name), so that explains whey their name appears on the errata sheet in the photo. Heathkit SA−5010 μMatic Memory Keyers can still be found on eBay fairly often, both in unassembled kit form and completed units...

Many Thanks to ConductRF for Continued Support!

ConductRF coaxial cables & connectors - RF CafeConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 

Anatech Electronics July 2021 Newsletter

Anatech Electronics July 2021 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his July 2021 newsletter that features his short op−ed entitled "Wi-SUN: The Most Pervasive Wireless Technology You May Not Heard Of," where he notes "Like ZigBee, WirelessHART, ISA100, SNAP, and 6LoWPAN, Wi-SUN (doesn't even have a Wikipedia entry yet) is based on the IEEE 802.15.4 standard and employs a mesh-type rather than star topology, making it inherently self-healing. There is no need for base stations because each node talks to the others, eliminating a single point of failure." Not only haven't I heard of Wi-SN, but I haven't heard of WirelessHART (HART = Highway Addressable Remote Transducer) or ISA100. Sam also presents some relevant industry news items as well...

Radar Systems for Autonomous Driving

Radar Systems for Autonomous Driving - RF Cafe"The hot next trend in automated driving is L2+, with semi-autonomy guided by both camera and HD radar sensing. What demands does radar add, and how can they be addressed? It's a technology that feels like it's been nearly there for years, but we're still waiting for full autonomy in cars, and it's much further out than we originally thought. Industry body SAE defines six levels of driving automation, from no automation up to full self-driving at level 5. As vehicles become more automated and reach higher levels, they're more tightly regulated and require more sophisticated systems to provide a safe, reliable solution. The automotive industry has been looking to a move to level 3 (L3), but right now this seems unrealistic. Instead, there's a very active push from SAE level 2, conventional advanced driver-assistance systems (ADAS), to something now being called L2+. This is a chance for OEMs and Tier 1s to monetize their investments in full autonomy systems..."

An Inexpensive Impedance Bridge

An Inexpensive Impedance Bridge, July 1944 QST - RF CafeHere is an amazingly detailed article on how to construct and operate a near-lab-quality impedance bridge out of relatively inexpensive components. It appeared in a 1944 issue of QST magazine. A bridge is used to determine the precise value of a resistor, capacitor, or inductor. Prior to modern, easily affordable digital impedance meters, both amateurs and professionals relied on such devices for lab and field work. Why might you need to measure the value of a component when most are marked with a value? One common application is when a variable version of a component (or components) is soldered into the circuit while tweaking for optimal performance, and then the variable is replaced either with a single fixed component or a fixed component with a smaller-range variable component. It is not uncommon when doing the initial tuning on a complete home-built transceiver to have many variable components in place initially, and then solder in fixed versions later...

New for 2021! 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 object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Stencils 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...

Many Thanks to Anatech Electronics for Long-Time Support!

Anatech Electronics logo - RF CafeAnatech Electronics (AEI) manufactures and supplies RF and microwave filters for military and commercial communication systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter and cable assembly products are published in our website database for ease of procurement. Custom RF filters designs are used when a standard cannot be found, or the requirements dictate a custom approach for your military and commercial communications needs. Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please visit Anatech today to see how they can help your project succeed. 

Monday the 19th

Standard Frequency Broadcast Service of NBS

Standard Frequency Broadcast Service of National Bureau of Standards, June 1945 Radio News - RF CafeAccording to the National Bureau of Standards' (now National Institute of Standards, NIST) website, In October 1949, Congress authorized $4.5 million for "the construction and equipment of a radio laboratory building for the National Bureau of Standards," for the planned new location of WWV in Ft. Collins, Colorado. WWV was initially established in 1919 in Washington, D.C., later moved to Beltsville, Maryland, then finally relocated to Ft. Collins, Colorado, in 1955. Construction began on the facility in 1951 and was dedicated in September 1954 by President Dwight D. Eisenhower. This item from the June 1945 issue of Radio News magazine reports on the Colorado location, with WWV's addition of a 15 MHz time standard broadcast...

Source for Rare Subatomic Particles

Source for Rare Subatomic Particles - RF Cafe"A paper based on joint research by Prof. Yuan Changzheng from Institute of High Energy Physics of the Chinese Academy of Sciences, and Prof. Marek Karliner from Tel Aviv University of Israel, was published in Physical Review Letters. It points out a new abundant source of antineutrons and hyperons. These rare subatomic particles are essential for studying forces governing the behavior of matter at the smallest distances, from atomic nuclei to neutron stars. Physicists investigate the subatomic world by bombarding their subjects with a hail of tiny subatomic 'bullets.' Based on how these 'bullets' bounce off their target, one can infer a wealth of detailed information about the target's structure. This method was pioneered by Ernest Rutherford..."

Electronics-Themed Comics

Electronics-Themed Comics 1958 Radio-Electronics - RF CafeBeing a great appreciator of good humor, and especially technology-related humor, I made sure to scan these electronics-related comics from the pages of vintage Radio-Electronics magazines. You might have to have lived through the era of televisions with cathode ray tubes (CRTs) to fully appreciate the frustration of trying to acceptably grab, align, define, sharpen, tone, and lock an over-the-air broadcast signal on track. Stories of people putting feet or baseball bats through the sets were a big source of situational humor.

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 (click here for screen capture). 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...

Thanks to Axiom Test Equipment for Continued Support!

Axiom Test Equipment - RF CafeAxiom Test Equipment allows you to rent or buy test equipment, repair test equipment, or sell or trade test equipment. They are committed to providing superior customer service and high quality electronic test equipment. Axiom offers customers several practical, efficient, and cost effective solutions for their projects' TE needs and is committed to providing superior customer service and high quality electronic test equipment. For anyone seeking a way to offload surplus or obsolete equipment, they offer a trade-in program or they will buy the equipment from you. Some vintage items are available fully calibrated. Please check out Axiom Test Equipment today!

Sunday the 18th

Wireless Engineering Theme Crossword Puzzle for July 18th

Wireless Engineering Theme Crossword Puzzle for July 18th, 2021 - RF CafeThis Wireless Engineering Theme Crossword Puzzle for July 18th contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Many Thanks to Centric RF for Their Continued Support!

Centric RF microwave components - RF CafeCentric RF is a company offering from stock various RF and Microwave coaxial components, including attenuators, adapters, cable assemblies, terminations, power dividers, and more. We believe in offering high performance parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power levels from 0.5-500 watts are available off the shelf. Order today, ship today! Centric RF is currently looking for vendors to partner with them. Please visit Centric RF today.

Friday the 16th

Practical Radar

Practical Radar, June 1945 Radio News - RF CafeIt took me way too long, but I finally got the June 1945 issue of Radio News magazine with Part 1 of the "Practical Radar" series of articles by Jordan McQuay. The opening sentence said a lot to the readers of the day: "The veil of secrecy has been lifted." Radar technology was a highly guarded science during World War II, and, along with its related technology, sonar, is widely credited with providing Allied forces the tools needed to eventually emerge victorious against Axis forces on land and sea. Yes, Germany and Japan (and Italy, but they didn't produce any systems) also had radar and sonar, but American and British engineers managed to keep a step ahead, providing a major advantage. The same goes for countermeasure techniques. This very extensive introduction to radar was followed by four more equally lengthy articles. By the time this edition of Radio News was published, the war in Europe and Africa was over, and would soon be ended in Japan, so divulging "secrets" approved by the Department of War was not a big deal. There were, however, many readers of this and other publications that were upset...

New Laser for More Efficient Communications

New Laser for More Efficient Communications - RF Cafe"A defect-resistant topological laser emits pure telecommunication-wavelength light at room temperatures. Novel devices known as topological lasers can prove more efficient at shining light than conventional lasers. Now scientists have created the first electrically driven topological laser that works at room temperature, which could find use in telecommunications. Topology is the branch of mathematics that investigates what aspects of shapes can survive deformation. For example, an object shaped like a ring may deform into the shape of a mug, with the ring’s hole forming the hole in the cup's handle. However, this object could not deform into a shape without a hole without changing into a fundamentally different shape..."

NISTS's Ammonia and Cesium Atomic Clocks

Cesium Atomic Clocks (NIST) - RF CafeThose of us born in the 1950s and later have for our lifetimes been familiar with atomic clocks and the incredible accuracy they provide for science experiments and physical standards. A 1957 issue of Scientific American magazine published an article on the newfangled devices, and discussed the ammonia-based and cesium-based types. The National Bureau of Standards' (now NIST) first atomic clock used an ammonia molecule (NH3) with the nitrogen atom back and forth within a triangular hydrogen base at a frequency of 23,870 MHz (23.870 GHz). The current NIST time service can be accessed at www.time.com. One of the displays reports the time error of you computer, cellphone, watch, or however you log on. Their latest publication is entitled, "A New Era for Atomic Clocks," which reports on the newest timekeeper - the NIST−F2, a cesium clock. "NIST-F2 would neither gain nor lose one second..."

Carl & Jerry: "BBI"

Carl & Jerry: "BBI", May 1959 Popular Electronics - RF CafeWe are solidly in the middle of baseball season in America, so this "Carl & Jerry" story from a 1950 edition of Popular Electronics comes at a good time. As is the case with many "Carl & Jerry" episodes, this one involves the use of an amateur radio rig. Find out how and why Jerry willingly commits "Baseball Interference" (BBI) to beat the opposing team at their own game. I feel obligated to point out that although it was for a good cause, Jerry actually violated the FCC regulation for Amateur radio operators stating that no broadcaster may intentionally interfere with another person's transmission. Title 47 CFR 97.101(d) General Standards - "No amateur operator shall willfully or maliciously interfere with or cause interference to any radio communication or signal." BTW, up until a few years ago, we didn't have MLB with a bunch of virtual-signaling players and club owners who regularly insult half (or more) of their supporters...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 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 15,000 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. If you need your company news to be seen, RF Cafe is the place to be.

Thanks to NextPCB for Continued Support!

NextPCB - RF CafeNextPCB is one of the most experienced PCB manufacturers in China, has specialized in the PCB and assembly industry for over 15 years. NextPCB provides the most innovative printed circuit boards and assembly technologies in the highest quality standards, turnaround time as fast as 24 hours, the lowest manufacturer direct prices, and the most dedicated customer service in the industry. Turnkey service without a broker including components sourcing, PCB prototyping, manufacturing, assembly, quality testing, and final shipment. Certified by IATF16949, ISO9001, ISO14001, UL, CQC, RoHS and REACH.

Thursday the 15th

Theory and Application of U.H.F.

Theory and Application of U.H.F., June 1945 Radio News - RF CafeThis is the final installment of an 11-part series in Radio News magazine entitled "Theory and Application of U.H.F.," written by Milton Kiver. It spanned from December 1943 to June 1945. Topics included basic electrical, magnetic, and electromagnetic theory, cavity resonators as tuning units of klystron and magnetron oscillators, waveguide, free space propagation, high frequency amplifiers, transmission lines, and coupling energy to/from cavity resonators. As the list suggests, there was a great concentration on field theory. Being that the Radio News readership covered a broad range of experience and education, Mr. Kiver went light on use of equations and heavy on use of diagrams, charts, and textual descriptions. Everything described throughout the series is as valid and applicable today as it was 75 years...

Computing the Harmonic Content of Any Given Periodic Complex Waveform

Computing the Harmonic Content of Any Given Periodic Complex Waveform, Kirt's Cogitations #331 - RF CafeI found a copy of the 1941 Radio Engineering Handbook, by McGraw-Hill Book Company at a Goodwill store. The cover was beat-up, but the inside pages are all good. The "Mathematical and Electrical Tables" section has an interesting method for calculating up to the sixth harmonic of any periodic waveform by dividing the period into twelve equal parts (in time) and noting the amplitudes at each point - aka "The Twelve Ordinate Scheme." Those values are plugged into a host of equations that yield essentially the Fourier coefficients for a 12-element polynomial describing the curve. The text also provides equations for calculating harmonic content. Calculating the polynomial coefficients is a simple process of doing iterations of sums and differences of amplitudes, a la the Fourier analysis. Care must be taken to get the numbers right or the resulting equation will not reproduce the original waveform. In 1941, the user needed to look up in a table or find on a slide rule the sines and cosines of nωt angles associated with each term, then multiply that by the calculated coefficient. Finally, after all twelve points were figured...

RF Cafe Forum Archives

RF Cafe Forum Archives - RF CafeRF Cafe Forums closed its virtual doors in 2012 mainly due to other social media platforms dominating public commenting venues. RF Cafe Forums began sometime around August of 2003 and was quite well-attended for many years. By 2010, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. If the folks at phpBB would release a version with integrated sign-in from the major social media platforms, I would resurrect the RF Cafe Forums, but until then it is probably not worth the effort. Regardless, there are still lots of great posts in the archive that ware worth looking at.

Station Design for DX

Station Design for DX, October 1966 QST - RF CafePart I of this article appeared in last month's (September 1966) edition of QST, which explains why Fig. 3 is the first one in this article. It introduced concepts in antenna types and siting. This second part talks about cost tradeoffs for various aspects of a DX setup. Author Paul Rockwell does a nice job of providing graphs of cost versus performance increases for transmitter power, antenna gain, tower height and constructions, etc. He uses prices typical of the mid 1960s, but even without knowing the equivalent modern day equipment prices, the shapes of the curves are good indicators of where the point of diminishing returns exists. Paul Rockwell wrote a 4-part series on station design for long distance (DX) communications that covered antenna selection and siting (Part I), economics and construction (Part II), station configuration and receiver...

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 (click here for screen capture). 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...

Many Thanks to ConductRF for Continued Support!

ConductRF coaxial cables & connectors - RF CafeConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 

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