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Homepage Archive - December 2022 (page 4)

See Page  1 | 2 | 3 | 4 of the December 2022 homepage archives.

Friday the 30th

Mac's Service Shop: Two Years of CATV

Mac's Service Shop: Two Years of CATV, November 1965 Electronics World - RF CafeI don't know why, but from May 1963 through December 1971, John T. Frye's familiar and much loved "Mac's Service Shop" column in Electronics World magazine abandoned the line drawing header and "Mac's Service Shop" title, and used instead an image of Mr. Frye's bust with no mention of Mac or his shop. The stories used all the same familiar characters - Mac, Barney, Matilda - and scenarios. I took the liberty of adding "Mac's Radio Service Shop" to the header image for this November 1965 issue. ...but I digress. The topic of this episode's discussion is the newfangled cable television. Although a paid subscription service, many people were willing to shell out hard-earned money in order to receive dependable, clear TV programs. It did nothing for the country dweller who was putting 20-element directional antennas atop 50-foot towers in order to get acceptable reception. Not until cable Internet came of age (combined with megafunding by the government) was the building out of rural networks a profitable venture. There are still homes less than 50 miles from some cities...

Anritsu ME7873NR Facilitates 5G mmWave UE Rollout

Anritsu ME7873NR Facilitates 5G mmWave UE Rollout - RF CafeAnritsu Company has developed the new Compact Antenna Test Range (CATR) Anechoic Chamber 2 MA8172B configuration for its New Radio RF Conformance Test System ME7873NR to support 5G millimetre wave (mmWave) 2 Angle of Arrival (2 AoA) Radio Resource Management (RRM) tests. Anritsu’s MA8172B solution is unique in industry as it is based on hybrid of IFF (Indirect Far Field) and DFF (Direct Far Field) test methodologies and this really helps customer save real estate space. A solution based on all DFF or IFF will be bulky and expensive. Anritsu helps in providing value to customer by making this new solution lower cost, smaller footprint, upgradable, and serve multiple test areas. Evaluating UE communications quality and connection stability during handovers between base stations is a difficult technical challenge for mmWave mobile communications. Consequently, Anritsu has developed its MA8172B upgrade model for the Over-the-Air (OTA) CATR...

RF Cafe: Website of the Stars

Website of the Stars Galaxy Font - RF CafeThere is now a computer font available to astronomers: Galaxy. Well, not really, not yet, but at some point there probably will be. The rendition of "Happy New Year 2023 rfcafe.com" was generated automatically by a website called "My Galaxies." Thanks to thousands of volunteers worldwide that have participated in The Galaxy Zoo's project of classifying galaxies, a set of letter-shaped galaxies has been identified that can be used to write words like "rf cafe." It appears that so far God (or the Big Bang - take your pick) did not create a full set of upper case letter-shaped galaxies. Some letters can be considered upper or lower case, like Cc Ii Jj Oo Pp Ss Uu Vv Ww Xx Zz. As you might expect, there are number-shaped galaxies as well. After all, mathematics is the language of the universe. Judging by the shape of the numbers ""1" and "7," and the fact that MyGalaxies.co.uk domain is registered in the UK, I'm guessing the selected galaxy shapes are modeled after the European-style numeral set...

1947 Radio Shack Advertisement

Radio Shack Advertisement, August 1947 QST - RF CafeRadio Shack, like so many of America's original great companies, was born in the early formative year of electronics and lived long and prospered through the rest of the century during its glory days, then eventually waned into insignificance and obsolescence after around Y2K. It is not always simply an unwillingness to adapt to new technologies and methods that doomed Radio Shack and those like them. The forces behind those life cycles are often beyond their control because start-ups vying for market share do not carry the burden of and have to deal with established investments in people, facilities, and infrastructure. This advertisement from a 1947 issue of QST magazine was from the original Radio Shack in Boston, Massachusetts. The company was bought by Tandy Corporation in the 1960s, then sold to hedge fund operator General Wireless in the mid 2000s. Radio Shack filed for bankruptcy in 2015 and the few remaining outlets...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook 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 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.

Thursday the 29th

Ballistic Missile Early Warning System - BMEWS

Ballistic Missile Early Warning System - BMEWS, August 1960 Electronics World - RF CafeThe Cold War is generally agreed to have begun between the U.S. and the U.S.S.R. on March 12, 1947, less than two years after the end of World War II, precipitated by the Truman Doctrine on March 12th, thereby enraging Stalin. It was thus considered "cold" because while no armed conflict ("hot" action) occurred directly between the two countries, third party countries fought with each other at the behest of USSR and the U.S. using weapons and finances provided by the aforementioned countries. The Cold War officially ended on December 26, 1991, following the dissolution of the Soviet Union. In the interim, threats of nuclear war haunted the Earth's inhabitants. Once missiles were developed capable of delivering nuclear warheads between Russia and America - in both directions - it became necessary to build a network of over-the-horizon radars that could detect the flights of such projectiles and provide advanced notice of incoming atomic disaster. Fortunately (or unfortunately), a philosophy of Mutually Assured Destruction (MAD) ultimately prevented such an unfathomable scenario from ever taking place. The Ballistic Missile Early Warning System, reported here in a 1960 issue of Electronics World magazine...

Electrons on the Run: Chirality, Tunneling, Light Fields

Electrons on the Run: Chirality, Tunneling, Light Fields - RF Cafe"Will an electron escaping a molecule through a quantum tunnel behave differently depending on the left- or right-handedness of the molecule? Chemists have borrowed the phrases "left-handed" and "right-handed" from anatomy to describe molecules that are characterized by a particular type of asymmetry. To explore the concept of chirality, look at your hands, palms up. Clearly, the two are mirror images of one another. But try as we might to superimpose them, they will not overlap completely. Such objects, termed "chiral," can be found at all scales in nature, from galaxies down to molecules. Each day, we experience chirality not only when we grab an object or put on our shoes but also when we eat or breathe: our taste and smell can distinguish two mirror images of a chiral molecule..."

Sparton Model 7-46 Schematic & Parts List

Sparton Models 7-46, 7-46PA, 8-46, 8-46PA Schematic & Parts List, February 1947 Radio News - RF CafeRF Cafe visitor Jim F. writes occasionally to fill me in on some details of his experiences with some of the vintage radios that I post schematics and parts list for. In this case it is the Sparton Model 7−46, on which he fondly remembers as a boy listening to the Cassius Marcellus Clay, Jr. (aka Mohammad Ali) fight during the 1960 Summer Olympics in Rome, Italy. "The party line telephone sat on top of it," recalls Jim. He sent a photo of a 7−46 cabinet and a radio Star Roamer multi-band receiver which was a Knight-Kit. This schematic and parts list set from the February 1947 issue of Radio News magazine includes not just the Sparton 7−46, but also the 7−46PA, 8−46, and 8−46PA radios. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information...

The Vacuum Tube Voltmeter

Test Instruments Part 4: The Vacuum Tube Voltmeter - D.C. Ranges, April 1959 Popular Electronics - RF CafeWhile we're on the topic of VTVMs, Popular Electronics magazine ran a 5-part series on test equipment usage. This installment (part 4) is on the use of a vacuum tube voltmeter (VTVM) for making DC measurements. Don't pass over the article just because it refers to a vacuum tube tester since there are lessons that apply to even the most modern transistorized, computerized meter. Author Larry Klein discusses mainly the DC functions, providing both functional descriptions of the circuits and how to use them for making accurate measurements. FET-input digital multimeters (DMMs) have largely replaced VTVMs, but they can still be found in some older electronics development labs and hobby benches...

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 (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Please Thank IPP for Their Long-Time Support!

Innovative Power ProductsInnovative Power Products has been designing and manufacturing RF and Microwave passive components since 2005. We use the latest design tools available to build our baluns, 90-degree couplers, directional couplers, combiners/dividers, single-ended transformers, resistors, terminations, and custom products. Applications in military, medical, industrial, and commercial markets are serviced around the world. Products listed on the website link to detailed mechanical drawings, electrical specifications, and performance data. If you cannot find a product that meets your requirements on our website, contact us to speak with one of our experienced design engineers about your project.

Wednesday the 28th

Recent Developments in Electronics

Recent Developments in Electronics, August 1960 Electronics World - RF CafeFor many years, Electronics World magazine ran a "Recent Developments in Electronics" feature that highlighted guess what? Yep, recent development in electronics. This July 1965 issue reported on, amongst other things, the largest (at the time - 60 feet) three-axis radio frequency antenna, manufactured by Philco, for use in satellite tracking. Not even a full two years had passed since the launch of America's first transponder-equipped satellite, SCORE. Also shown was a "Frigistor" for electronic cooling, exploiting the thermoelectric effect. The only patent I could find is registered in Great Britain (GB1033018A). The trademark (expired) says, "Thermoelectric Cooling Assemblies Consisting of One or More Couples of P and N Type." Another key item was a huge (for the time - a whopping 60 feet) RF anechoic chamber...

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! 

Electronics-Themed Comics 1952/53

Electronics-Themed Comics February 1952 & January 1953 Radio & TV News - RF CafeThese three electronics-themed comics appeared in circa 1952 and 1953 Radio & Television News magazine. For some reason the early 50s were a little comic challenged, that is to say only one or two usually appeared in each edition. I really like the one with the guy hanging from the antenna! He needs the rotator to turn him back over the roof. You probably have to have lived in the vacuum tube TV era to appreciate the humor in the comic with the homeowners rolling out the red carpet for the repairman. It's hard to make out the artists' names, but they have appeared on other comics of the era. If you enjoy comics like this, there is a growing list of other comics at the bottom of the page you can check out...

Fine Structure Constant Directly for 1st Time

Fine Structure Constant Directly for 1st Time - RF Cafe"The value of the fine structure constant - perhaps the most important constant in nature as it dictates the strength of electromagnetism - has been measured directly by researchers in Austria and the U.S. The technique they used involves measuring how much the polarization of light rotates as it passes through a magnetic topological insulator, and while it is not as accurate as other methods, the researchers believe its directness could lead to cleaner tests of whether this supposed constant varies over time. The fine structure constant, denoted α, is a dimensionless number with a physical interpretation that has evolved alongside physicists' understanding of electromagnetism. When Arnold Sommerfeld introduced it in 1916, it was the velocity of an electron in the first circular orbit of the Bohr model of the atom, divided by the speed of light in vacuum. In quantum electrodynamics, it is the coupling constant that determines the strength of interactions between electrons and photons. Its value is around 1/137, and if it were even slightly different – perhaps just 1/138..."

Sylvania Electric Advertisement

Sylvania Electric Advertisement, January 1950 Radio & Television News - RF CafeAs evidenced in these mid-last-century magazine advertisements, Sylvania Electric marketing moguls learned early what sells products by exploiting the nature of their audience. The cartoon-style ads shown here appeared in social publications like Look, Life, and Collier's, where both men and women - many of them numbnuts - were the expected audience. Compare these with the type of cartoon ads run by Sylvania in "serious" magazines like Radio-Craft. Of course when you consider some of the other comics printed in the same "serious" magazines, you could excuse Sylvania if they ran those social magazine ads here...

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...

Many Thanks to Berkeley Nucleonics for Continued Support!

Berkeley Nucleonics Corp - RF CafeBerkeley Nucleonics Corporation (BNC) is a leading manufacturer of precision electronic instrumentation for test, measurement, and nuclear research. Founded in 1963, BNC initially developed custom pulse generators. We became known for meeting the most stringent requirements for high precision and stability, and for producing instruments of unsurpassed reliability and performance. We continue to maintain a leadership position as a developer of custom pulse, signal, light, and function generators. Our designs incorporate the latest innovations in software and hardware engineering, surface mount production, and automated testing procedures.

Tuesday the 27th

Nomograph Construction - Part II

Nomograph Construction Part II, July 1946 Radio-Craft - RF CafeFred Shunaman, author of the two-part "Nomograph Construction" article in Radio-Craft magazine (c1946), notes that the nomogram is "equal to an infinite number of charts." Part I covered the basics of nomograph construction with voltage, current, and resistance. Part II discusses strategies for best placement and scale types to use for optimizing the accuracy and usefulness of a nomograph. An inset key is added to guide the used on how to interpret the results. Figures 1 through 4 and Nomographs A and B are in Part I...

Milestones in U.S. Patenting

USPTO Timeline: Milestones in Patents - RF CafeThe USPTO, issued its first patent on July 31, 1790, assigned to Mr. Samuel Hopkins for a process of making potash. That was three years after creation of the office in 1787. President George Washington signed that one. You might think the country's first issued patent is numbered one (later designated X000001), but that's not the case. Enumeration did not begin until July 13, 1836 when U.S. patent "No 1" was issued to Mr. John Ruggles for a traction wheel for steam locomotives. The U.S. government had issued 9,957 patents before starting a numbering system so for any patent number, add 9,957 for its actual place in line. The one millionth patent was assigned in 1811. #2,000,000 happened in 1935. The ten millionth patent was issued in 2018 for coherent ladar using quadrature detection. #11,000,000 was awarded just three years later. By process of elimination, I found that as of this very moment (10:30 am EST, December 27, 2022), the highest patent number assigned per the USPTO's website is #11,540,433...

Geometric Tensor in Superconducting Quantum Circuit

Geometric Tensor in Superconducting Quantum Circuit - RF CafeI just couldn't pass up this headline and graphic. Those spinning electrons look like something the The Jetsons. "Researchers at Nanjing University in China have used a superconducting quantum chip to simulate a system of particles that are neither fermions nor bosons. As part of this simulation, they measured a parameter known as the quantum geometric tensor that provides local information about the system's topological properties. The work marks the first time this quantity has been measured in a so-called non-Abelian system - a result that will be useful for studying the physics of complex systems such as topological materials. According to quantum mechanics and quantum field theory, all elementary particles fall into one of two groups: fermions or bosons. Fermions such as electrons obey the Pauli exclusion principle, meaning that no two fermions can ever occupy the same quantum state. This propensity..."

The Vacuum-Tube Voltmeter

Test Instruments Part 5: The Vacuum-Tube Voltmeter - A.C. and Ohmmeter Ranges, May 1959 Popular Electronics - RF CafeIn 1959, Popular Electronics magazine ran a 5-part series on test equipment usage. This final article is on the use of a vacuum tube voltmeter (VTVM) for making accurate AC and resistance measurements. Also in this edition is a construction article for RCA's VoltOhmyst VTVM kit, so the two compliment each other. Author Larry Klein discusses mainly the AC and ohmmeter functions, providing both functional descriptions of the circuits and how to use them for making accurate measurements. A very high input impedance is important to minimize the loading effect of the instrument by keeping it from becoming a part of the circuit under test. FET-input digital multimeters (DMMs) have nearly totally replaced VTVMs, but they can still be found in some older electronics development labs and hobby benches...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook 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 Amplifier Solutions Corporation (ASC) for Continuing Support!

Amplifier Solutions Corporation (ASC) - RF CafeAmplifier Solutions Corporation (ASC) is a manufacturer of amplifiers for commercial & military markets. ASC designs and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers for low, medium and high power applications using Gallium Nitride (GaN), Gallium Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility in the town of Telford, PA. We offer excellent customer support and take pride in the ability to quickly react to evolving system design requirements.

Monday the 26th

Carl & Jerry: A Light Subject

Carl & Jerry: A Light Subject, November 1954 Popular Electronics - RF CafeMany thanks to website visitor Mr. Ferrous S. for providing an OCR version of this Carl & Jerry story, and for writing the following: "The earliest optoelectronic devices are photodetectors, and the basis of photodetectors is the discovery and research of photoelectric effects. In 1873, Willoughby Smith discovered the photoconductivity of selenium. In 1888, German Heinrich Hertz observed that when ultraviolet light irradiated the metal, it could make the metal emit charged particles. In 1890, Philipp Lenard determined the charge−mass ratio of charged particles and proved them to be electrons, thus clarifying the essence of photoelectric effect. In 1900, German physicist Planck introduced energy quantum into the study of blackbody radiation, and proposed the famous Max Planck formula to describe the phenomenon of blackbody radiation, which laid the foundation for quantum theory. In 1929, Kohler made a silver-oxygen-cesium photocathode and a photocell resulted. In 1939, Vladimir Zvorakin of the Soviet Union made a practical photomultiplier tube...

Heinrich Hertz Proves Existence of Radio Waves

Heinrich Hertz Proves Existence of Radio Waves! 50 Years Ago, December 1937 Radio-Craft - RF CafeWell... anyway it was 50 years ago referenced to the year this story was published in the 1937 issue of Radio-Craft magazine. That makes it 85 years ago referenced to 2022. The story's point is that half a century had passed already since the confirmation of existence of electromagnetic (EM) waves as proposed by James Clerk Maxwell. Heinrich Hertz's "Funken-Induktor" (spark inductor) and his "Knochenhauershen Scheiben" (Karl-Wilhelm Knochenhauer's disk-type capacitors) were key to Hertz's ability to generate, transmit, and receive EM energy. The work originated from attempts to prove that light was a form of electromagnetic waves...

Space-Based SDR: NASA's ScaN Testbed

Space-Based SDR: NASA's ScaN Testbed - RF Cafe"Data obtained from SCaN Testbed experiments is paving the way for the future of space radio, with cognitive communication systems combining software-defined radios with AI/ML to improve performance and resilience of RF units. Developing electronics for space applications is certainly an exciting task, but it can become a real problem if the designer fails to address the critical robustness requirements of the application. It’s crucial to consider not only the harsh environment of space, but also the fact that physical maintenance is very scarce and expensive. Therefore, it’s not a surprise that RF devices for space communication are evolving from fixed and single-purpose hardware-based systems to flexible, robust, and reprogrammable software-defined radios (SDRs). To ensure proper operation in space, SDRs must be prepared to endure harsh conditions. Thus, they must employ radiation-hardened electronics..."

Relating Some High Points in Photocell Progress

Relating Some High Points in Photocell Progress, October 1932 Radio News - RF CafeEdward Weston was a pioneer in the photoelectric cell field. His "photronic" cell was one of the first successful devices for commercial use. Just like with early battery cells, photoelectric cells of the era required a liquid medium to facilitate electron transfer and thereby generate electric current. The lead nitrate compound used by Weston is now considered a possible human carcinogen. Mr. Brooke Clark has a web page with extensive data on the history of Weston's photoelectric sensors, meters, test data, patents, and history of his company - which now has the name Huygen Corporation. Photoelectric science has advanced significantly in the 80 years since this article was published. A good website to visit regularly if you like following progress on photocell technology is Semiconductor Today...

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

Many Thanks to Bittele Electronics for Continued Support!

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.

Sunday the 25th

Radio Theme Christmas Crossword for December 25th

Radio Theme Christmas Crossword Puzzle for December 25th, 2022 - RF CafeThis Radio Theme Christmas Crossword Puzzle for December 25th has many words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects, along with a holiday message. There is also a holiday greeting contained within. 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., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Please Visit Triad RF Systems to Thank Them for Their Support

Triad RF SystemsTriad RF Systems designs and manufactures RF power amplifiers and systems. Triad RF Systems comprises three partners (hence "Triad") with over 40 years of accumulated knowledge of what is required to design, manufacture, market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating amplifiers are available, in formats including tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology partner than a vendor for our line-of-sight communications product line." Please check to see how they can help your project.

Polymer Shapes - Supplies & Fabrication

Polymer Shapes company - RF CafeBy request, the Polymer Shapes company of Santa Fe Springs, CA, has been added to the Plastics Manufacturers & Services vendor pages. For more than 70 years, Polymer Shapes has supplied plastic sheets, rods, tubes, film, and similar products from material such as ABS, acetyl, acrylic, expanded foam, PVC, nylon, PAI, phenolic, PET, PETG, polyurethane. A wide range of services are available from their knowledgeable and highly skilled staff includes thermoforming, fabrication, CNC machining, laser cutting, and CAD design and programming.

Friday the 23rd

NORAD Santa Tracker

NORAD Santa Tracker - RF CafeEver vigilant for ICBM's rocketing across the North Pole from Russia, NORAD maintains a constant watch on the area, and needs to be careful not to get a false alarm when Santa Claus takes off The Night Before Christmas (aka Christmas Eve) with his sleigh full of toys for good boys and girls. Assuming his sled has not been upgraded to some non-metallic material, and that the bells on on Dasher, on Dancer, on Prancer, on Vixen, on Comet, on Cupid, on Donner and on Blitzen (and Rudolph, of course) are still made of brass, the radar cross section (RCS) is pretty significant and could easily be mistaken for a missile in flight. After all, that sleigh must be moving at supersonic speeds to cover the entire Earth in one day. Some people argue against a Santa Clause by citing he could not possibly deliver presents to everyone in just a few hours, but by trekking westward at an average of about 1,000 mph (relative to the equator) he can exploit the surface rotation and remain in a given time zone. From everyone at RF Cafe (that's Melanie and me), we say, "Happy Christmas to all, and to all a good night!"

Vertical GaN Junction Barrier Schottky Diodes

Vertical GaN Junction Barrier Schottky Diodes - RF Cafe "Nagoya University and Toyota Central R&D Labs in Japan claim a record low on-resistance (RON) for vertical gallium nitride (GaN) Schottky barrier diodes (SBDs) of between 0.57mΩ-cm2 and 0.67mΩ-cm2. The breakdown voltages (BVs) of between 660V and 675V, dependent on dimensions, were 84.4% of the value expected for ideal parallel plane structures. One target for such devices is low-loss power switching applications. Although vertical GaN pn diodes have similar performance in terms of RON and BV, the higher turn-on voltage (VON~3V for pn, compared with 0.74 for Nagoya/Toyota's SBDs) results in wasted power. The team comments: 'Compared to silicon carbide (SiC) JBS rectifiers, the GaN JBS diodes represent an early stage of development. Thus, the ability to realize high-performance vertical GaN JBS diodes can bring GaN power electronics to the next level.' The researchers used a junction barrier Schottky (JBS) diode structure (Figure 1). The 10μm drift layer of silicon (Si)-doped n-GaN was grown on freestanding..."

QST Spotlight: Dr. Joseph Hooton Taylor, Jr., K1JT

QST Member Spotlight 2023: Dr. Joseph Hooton Taylor, Jr., K1JT - RF CafeThe January 2023 issue of QST magazine highlights Dr. Joseph Hooton Taylor, Jr., K1JT. An accomplished radio astronomer, Dr. Taylor's feature is the first of what will be a year-long theme to "highlight amateurs who have achieved recognition in areas outside of, or related to, amateur radio." I think that is a great idea and look forward to seeing who they come up with. Too bad that the ARRL doesn't post stories like this so that non-members can have access to them; they would serve as a great motivation to people considering earning a new license or upgrading to a higher class. "JT. Since 2001, those two letters have signaled digital transformation in ham radio. They are the initials of the pioneering scientist and amateur radio innovator, Joe Taylor, whose software suite, WSJT - updated to WSJT−X - revolutionized ham radio. Today, the warble of JT8 dominates, but the tones of FT4, JT9, SWPR, and Q65 all emerge from the static to connect hams the world over with signal-to-noise ratios as low as −44 dB..."

Quantic PMI December Product Announcement

Quantic PMI December 2022 Product Announcement - RF CafeQuantic PMI, a leading supplier of custom, high-reliability MIC/MMIC components and subsystems for applications in space, military, communications, commercial and consumer electronics systems for more than three decades, introduced six new products this month of December in their extensive line of RF and microwave components. Included amongst them are an ultra-high speed, high sensitivity threshold detector for 4-4.5 GHz, a broadband variable attenuator / modulator for 0.5-18 GHz, and a directional coupler for 33-36 GHz. Contact Quantic PMI today for more information...

Foil Those Tube Forgers

Foil Those Tube Forgers, January 1957 Popular Electronics - RF CafeGray market electronic components are not just a recent problem. Long before IC foundries were set up in China, Indonesia, Vietnam, etc., to produce counterfeit semiconductor components, there were unscrupulous manufacturers turning out bogus components of all sorts. Marking unauthorized microprocessor and amplifier packages with an industry-leading brand name and part number is a real problem, but such practices extend back to the vacuum tube era. This story from a 1957 edition of Popular Electronics magazine tells the story of how companies like General Electric and Sylvania dealt with the situation...

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...

Thanks Again for Windfreak Technologies' Continued Support!

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.

Thursday the 22nd

Transformer Turns Ratio Nomogram 

Transformer Turns Ratio Nomogram, November 1965 Electronics World - RF CafeNomograms (aka nomographs) have always been a great method of providing a quick visual means of relating various quantities to each other. Careful adjustment of the numerical scales allows a straight line to be drawn between any two values to determine the value of the third (or more). An extreme example is the Link Coupling Nomogram which uses two straight line scales and a curve graph. As can be seen in this Transformer Turns Ratio nomogram from a 1965 issue of Electronics World magazine, a square root function (TR=√Z1/Z2) can be easily accommodated with a straight line from the input impedance scale to the output impedance scale, and extending it to the third turns ratio (TR) scale. A similar nomogram can be constructed for turns ratio needed for specific input and output voltage, current, or power. A list of many other nomographs/nomograms is given at the bottom of the page...

X-ray Step Towards Superfast Nanoelectronics

X-ray Step Sowards Superfast Nanoelectronics - RF Cafe"When a material with magnetic properties, constructed from appropriately selected layers, is illuminated by a pulse from an X-ray laser, it instantly demagnetizes. This phenomenon, so far poorly understood, could in the future be used in nanoelectronics, to build, for example, ultrafast magnetic switches. An important step toward this goal is a new simulation tool developed by a Polish-German-Italian team of scientists as part of a joint research project between the European XFEL and IFJ PAN. No information-processing device can operate at a speed faster than that at which the physical phenomena underlying its operation occur. That is why physicists continue to seek phenomena that run on increasingly shorter spatial and temporal scales, yet can be controlled relatively easily. One promising research direction seems to be the demagnetization process of ferromagnetic multilayer materials..."

Hallicrafters' Christmas Message for 1940

Hallicrafters: Message for Christmas, January 1941 QST - RF CafeHalli(gan) and (hand)crafters, a portmanteau of those two indicated words, was founded in Chicago in 1932 by William J. Halligan. The company designed and manufactured radio equipment for hobby, commercial, and military applications and quickly became very popular amongst their users. As was customary for U.S. businesses, Hallicrafters ran a Christmas advertisement in the January issue of magazines where they appeared, as with this 1941 issue of QST. The January edition, as is common even now, is typically mailed in early December, getting it in the hands of readers in time for Christmas... 

Anatech Electronics December Newsletter

Anatech Electronics December 2022 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his December 2022 newsletter that features his short op−ed entitled "The Resurgence of Microwave Directed Energy Weapons." The premise of directed energy (DE) weapons is to blast RF/microwave energy at a specific frequency or band of frequencies at a high enough power to confuse or totally disable drones and/or missiles while in flight, before reaching their intended targets. Sam argues reasonably that the relatively low power and aiming requirements of a microwave directed energy system can be much more effective than a high power laser beam that must be aimed and track the target precisely enough to make surface contact. An RF system can make multiple "shots" in the same time required for a laser power supply to recharge between shots. A great example of how DE works can be seen in this decade-old video of an Active Denial System use to disperse unruly crowds. The targets are humans, but the reactions are analogous to how radio receivers are affected...

The Christmas Equation

The Christmas Equation - RF CafeAn RF Cafe visitor sent this equation to me a few years ago. It can be found all over the Internet (including here), but I cannot determine a definite origin. Mathematicians claim that math can explain everything in the universe, which is not quite true. It can't for example, explain why my next-door neighbor is a junk hoarder. This Christmas equation does not appear to begin with a particular application; it looks like something from a set of textbook end-of-chapter problems. Even if you don't celebrate Christmas, it provides a secondary benefit by demonstrating rules for the manipulation of logarithms and exponents along with basic algebraic rearrangements of terms.

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeNew Scheme rotates all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000 website visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 12,000 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 Anritsu for Their Support!

Anritsu (electronics test equipment) - RF CafeAnritsu has been a global provider of innovative communications test and measurement solutions for more than 120 years. Anritsu manufactures a full line of innovative components and accessories for RF and Microwave Test and Measurement Equipment including attenuators & terminations; coaxial cables, connectors & adapters; o-scopes; power meters & sensors; signal generators; antenna, signal, spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth & WLAN testers; PIM testers; amplifiers; power dividers; antennas. "We've Got You Covered."


These archive pages are provided in order to make it easier for you to find items that you remember seeing on the RF Cafe homepage. Of course probably the easiest way to find anything on the website is to use the "Search RF Cafe" box at the top of every page. About RF Cafe.

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About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024


    Kirt Blattenberger,


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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