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Homepage Archive - June 2023 (page 4)

See Page 1 | 2 | 3 | 4 | of the June 2023 homepage archives.

Friday the 30th

News Briefs - Erwin Schrödinger's Passing

News Briefs, March 1961 Radio-Electronics - RF CafeThought experiment: Just because the March 1969 issue of Radio−Electronics magazine announced in the "News Briefs" column the passing of Professor Erwin Schrödinger, does that mean he's really dead? Was his world−famous cat with him at the time? I'm asking for a friend. In other news, an account of what seems to be a grossly inhumane medical experiment of the type Josef Mengele might have performed during World War II is reported whereby a 700 Hz (yes, 700 cycles per second) signal of undisclosed power level was imposed on a patient's brain in lieu of traditional anesthesia gas during a stomach operation. No word of the long-term effects are included. It obviously did not catch on as an alternative method. Many other breaking news items are included as well...

Withwave Reflective MEMS Switch Modules for DC-20 GHz

Withwave Intros Reflective MEMS RF Switch Modules for DC to 20 GHz - RF CafeWithwave is a leading designer and developer of a broad range of RF, microwave, and millimeter−wave test solutions and subsystems with a focus on electromagnetic field analysis and signal processing. Withwave's new MEMS Switch Modules are the reflective type RF switches such as SP4T, SP10T, 4−port matrix switch according to switching applications and frequency range. They deliver 25 W power handling, low insertion loss and high linearity, making this devices ideal for RF signal routing in wireless infrastructure and applications from DC to 20 GHz. External Connectors included 2.92 mm vertical launch connectors for all RF port. They are powered and controlled through USB type−C connector...

Electronics IQ Quiz

Electronics IQ Quiz, May 1967 Popular Electronics - RF CafeUnlike those IQ (intelligence quotient) tests conceived of and administered by Ph.D. college professors with pulsating veins in their foreheads, this "Electronics IQ Quiz," created by Popular Electronics magazine quizmaster Robert Balin, is a true measure of your real-world acumen. Here are a couple hints to assist quiz takers not familiar with last century electronics. You need to have knowledge of the NTSC-mandated broadcast television channel bandwidth for figure A, but you might be able to guess it by process of elimination. For figure E, consider the bandwidth limits in terms of dB, not MHz. Kinks in the characteristic curves of the tube alluded to in figure D betray its number (extra hint: it's not a diode or a triode). Good luck!

An Entire Article in the Title

Asymmetric Surface Plasmon Polariton Defected Ground Structure with Triple-Band Rejection and its Application in a Gysel Power Divider with Harmonic Suppression - RF Cafe"Asymmetric Surface Plasmon Polariton Defected Ground Structure with Triple-Band Rejection and its Application in a Gysel Power Divider with Harmonic Suppression" With a title like that, I feel like I already know everything there is to know. If it had been in the April issue of Microwave Journal magazine rather than in the June issue, I'd suspect it was a Fool's errand. It could have been written by a relative of Mohammed Ulysses Fips, who penned many articles like "Radium−Radio Receiver "for Radio−Craft magazine. Seriously, though, kudos for authors Jun-Bao Du, Lin Li and Xian-Chuang Su, of Zhejiang Sci-Tech University, Hangzhou, China, for coming up with that.

Reduction of Distortion and Noise with Inverse Feedback

Note on Reduction of Distortion and Noise with Inverse Feedback, July 1937 QST - RF CafeFeedback circuits seem simple enough intuitively, at least for simple systems. It is easy, though, for someone not comfortable with algebraic manipulations to arrive at the wrong conclusion for how a given feedback constant figures into the calculation. Such was the case with an article published in the July 1937 issue of ARRL's QST magazine, when many readers wrote to the author accusing him of making an erroneous claim in an earlier article (April) regarding using feedback to cancel out an unwanted harmonic in an amplifier. The criticism turned out being justified. Here is a statement of the error and an explanation of the proper approach which was printed a couple months later...

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

/jobs.htm">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 /jobs.htm">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 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. We have >500,000 RF and Microwave passive components we can ship you today! We offer Quality Precision Parts, Competitive Pricing, Easy Shopping, Fast Delivery. We're happy to provide custom parts, such as custom cables and adapters, to fit your needs. Centric RF is currently seeking distributors, so please contact us if interested. Visit Centric RF today.

Thursday the 29th

Electronics-Themed Comics

Electronics-Themed Comics, August 1963 Radio-Electronics - RF CafeThese three electronics-themed comics appeared in the August 1963 issue of Radio−Electronics magazine. The subjects are things at the forefront of most peoples' minds in the day, but are either completely unknown to the current generation and long-forgotten by nearly everyone else. It's only people like me (and maybe you) who like to wax nostalgic about life during what we perceive as a simpler existence with less social craziness and greater personal freedoms. The comic on page 46 is pretty clever, but it could just be that the artist was inspired by the concept of a horizontally polarized magnetic loop - or a simple wire loop - antenna. Electronic kit building (p96) was a big thing with hobbyists both because of the satisfaction that results when your efforts are rewarded with a functioning radio or TV or multimeter or other such device, and because at the time it was often less expensive than purchasing a factory-built model. Kits often contained higher quality components than what came in ready-to-use equivalents, so they lasted longer, and if they did fail, your familiarity with the construction and operation made them easier to align and/or repair. To understand the page 99 comic, you'd have to have battled with trying to stabilize the picture...

Software-Defined Front End for Next-Gen Wireless

Software-Defined Front End for Next-Gen Wireless - RF Cafe"As wireless solutions become ubiquitous, the need for advanced RF infrastructures and systems becomes more pressing. The growth of advanced portable devices to address the needs of business, industry, and society in data-intensive applications is pushing demand for wider bandwidths and more rapid processing and analysis of data in wireless systems, especially at the network edge. Designers today need to accelerate design cycles and bring products to market faster and more cost-effectively, while future-proofing their product designs. To address this demand, Analog Devices launched the Apollo MxFE, an advanced software-defined, direct RF-sampling, wideband mixed-signal front-end platform. The solution enables higher-speed data conversion and processing capabilities, while reducing electronic testing complexity. Apollo MxFE helps empower next-generation applications like phased-array radar..."

QST: Electronics Crossword Puzzle

QST: Electronics Crossword Puzzle, April 1967 QST - RF CafeQST, the monthly publication of the American Radio Relay League (ARRL), occasionally ran a crossword puzzle with an electronics theme. This one by by S.M. Dunnam, Jr. (K5KEI) appeared in the April 1967 edition. Unlike the weekly RF Cafe crossword puzzles, this one does have a few words that are not strictly technology and science themed. However, many of the clues and words require some familiarity with Ham radio subjects and lingo. Enjoy!

Werbel 2-8 GHz Directional Coupler

Werbel Microwave Intros 2 to 8 GHz Directional Coupler - RF CafeWerbel Microwave presents an impressive array of features in our latest offering. With a wide frequency range spanning from 2 to 8 GHz, the C-0208-10 directional coupler ensures versatility across various applications. Enjoy exceptional coupling flatness, with a typical ±0.2 dB flatness that guarantees precise performance. Experience remarkable directivity, reaching 27 dB up to 8 GHz, providing enhanced signal isolation. Benefit from excellent return loss, reaching 28 dB up to 8 GHz, ensuring optimal signal reflection. Additionally, our product allows for DC current to pass through from input to output, adding to its versatility. From mobile to fixed satellite applications, as well as lab use, WiFi, and radar, our solution meets the demands of diverse industries...

Rationalizing the Autodyne Receiver

Rationalizing the Autodyne Receiver, January 1933, QST - RFCafeAlthough written in 1933 (era of the Great Depression), this QST magazine article on the autodyne receiver has a good discussion of noise sources and how to trade off amplification for signal intelligibility. It originally used the De Forest Audion vacuum tube amplifier. Noise figure and noise temperature were not commonly used at the time, but the concept is encompassed in the treatment. So, what is an autodyne? It is a form of regenerative circuit that, rather than being tuned right at the signal of interest, is tuned slightly off center. It functions as a sort of combined local oscillator and amplifier for demodulating CW (Morse code) signals. Technical writing styles have not changed much over the decades, even as the terminology has...

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 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). 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...

Thanks Again 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! 

Wednesday the 28t

What's a MOS FET?

What's a MOS FET?, October 1967 Radio-Electronics - RF CafeUsually when posting one of the Popular Electronics magazine quizzes that includes vacuum tubes, I suggest the reader mentally replace them with an enhancement mode FET. That is because like the tube, all configurations of FETs have a very high input impedance, which is why vacuum tube voltmeters (VTVMs) were used when it was important to not let the meter load down the circuit under test. Bipolar junction transistors (BJTs), by comparison, have relatively low input impedance, but are still useful as input buffers to mechanical meter movements. In 1967 when this article appeared in Radio-Electronics magazine, the MOSFET - or MOS FET as written at the time - was relatively new to the marketplace. A single 2N3608, made by the Microelectronics Division of Philco-Ford, cost $8.05 in 1967, which is equivalent to $72.65 as of this writing (per the BLS Inflation Calculator). Vacuum tubes were $1 to $2 apiece...

Modelithics COMPLETE Library v23.2 for Sonnet Suites

Modelithics Releases COMPLETE Library v23.2 for Sonnet Suites - RF CafeModelithics is pleased to announce the release of version 23.2 of the Modelithics COMPLETE Library™ for Sonnet Suites. This new release adds 45 new models and is compatible with the latest version of Sonnet (v18.56). With this release, the Modelithics COMPLETE Library for Sonnet Suites now represents highly-accurate models for over 26,000 components. The addition of Modelithics COMPLETE Library models to Sonnet allows designers to combine the accuracy of full-wave analysis of arbitrary interconnect structures with accurate equivalent circuit models for active devices and lumped element components that scale variously with substrate, temperature and bias conditions. With the release of version 23.2, the Modelithics COMPLETE Library for Sonnet Suites now includes Modelithics extensive collection of Microwave Global Models™ for capacitor, inductor, and resistor part series. The library also includes models for other components like attenuators, splitters, and couplers. Version 23.2 adds to the library new models for components from vendors such as AMOTECH, Coilcraft, Kemet, Kyocera-AVX, Smiths Interconnect, Vishay, and others. Among the new additions...

Radio Fights Forest Fire

Radio Fights Forest Fire, September 1932 Radio News - RF CafeBeing that we are entering the forest fire season with the onset of summer, this story from a 1932 edition of Radio News magazine is an appropriate recognition of the sacrifice offered by firefighters who battle the destructive conflagrations. Firefighters of all specialties have relied on radio communications nearly since its inception, and particularly once battery-powered versions became available for portability. It is hard to imagine a time when such a convenience - even a necessity - was not part of the standard firefighting outfit. Nowadays the radios are compact and clip onto a shoulder lapel, but in 1932 the vacuum tubes, large transformers and batteries meant even a primitive radio was in the form of a harness-mounted manpack radio (a word not yet coined at the time). The portable half-wave dipole antenna in the picture looks almost exactly like ones I have seen advertised in contemporary issues of QST magazine...

DigiKey Backs Get MADE Crowdfunding

DigiKey Backs Get MADE Crowdfunding - RF Cafe"DigiKey, a leading global commerce distributor offering the largest selection of technical components and automation products in stock for immediate shipment, has partnered with GroupGets to launch the 'Get MADE' crowdfunding initiative, a collaboration that promotes and funds hardware creators. This program will allow startups to get hardware funded, produced and sold on DigiKey's website. Image of DigiKey Partners with GroupGets to Enable Hardware Startups to Bring Products to Market DigiKey and GroupGets will launch a crowdfunding program to promote and fund hardware creators. GroupGets is a crowd purchasing platform for group buying technology products that helps businesses and individuals launch their products by promoting, funding and distributing electronic devices across the world. Through the 'Get Made' program, GroupGets and DigiKey will cross promote qualifying devices through content, design, distribution and partial funding through DigiKey. Upon successful funding, GroupGets will work with the creators to manufacture the platforms and then DigiKey will list the platforms for sale on its website..."

The Rice-Variarm

The Rice-Variarm, February 1941 QST - RF CafeElectron-coupled oscillators (ECOs) were a real breakthrough in achieving frequency stability in harsh environments that included mechanical vibration, temperature excursions, power supply variations, and load changes. Use of vacuum tubes made the task even more challenging. Such oscillators were necessarily very expensive compared to less sophisticated designs. Henry E. Rice Jr., W9YZH, introduced his "Rice Variarm" model (aka the Millen Model 90700) at a breakthrough price of just $29.50, which in 2023 money equates to $635 per the U.S. BLS Inflation Calculator. That is a lot of moola for amateur radio operators even today. The arm sticking out of the case is for adjusting the frequency - hence, the Variarm...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000 or so symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing. Check them out!

Thanks to Copper Mountain Technologies for Continued Support

Copper Mountain TechnologiesCopper Mountain Technologies develops innovative and robust RF test and measurement solutions for engineers all over the world. Copper Mountain's extensive line of unique form factor Vector Network Analyzers include an RF measurement module and a software application which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware via USB interface. The result is a lower cost, faster, more effective test process that fits into the modern workspace in lab, production, field and secure testing environments. 50 Ω and 75 Ω models are available, along with a full line of precision calibration and connector adaptors.

Tuesday the 27th

BBB Raps Set Manufacturers

BBB Raps Set Manufacturers, March 1961 Radio-Electronics - RF Cafe

The Better Business Bureau (BBB) was founded in 1912 as the National Vigilance Committee for the Promotion of Ethical Business Practices in Advertising. It was later renamed the Better Business Bureau in 1921. The organization was established in response to concerns about fraudulent and deceptive advertising practices, with the goal of improving consumer trust in the marketplace. In the early years, the BBB primarily focused on combating misleading advertising. It worked to establish standards for truthful advertising and to expose businesses that engaged in deceptive practices. One of the key features of the BBB is its accreditation program. The BBB also assigns ratings to businesses based on various factors, including complaint history, transparency, and customer reviews. Less than an A+ rating was to be avoided, especially by larger companies, so having a major publication like Radio−Electronics magazine shine light on the situation no doubt motivated them into corrective action mode...

Many 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 - and don't miss the blog articles!

Say You Saw It in QST

Say You Saw It in QST, December 1933 QST - RF CafeIn the early 1930s, QST magazine (ARRL's monthly publication) usually ran a line at the bottom of every page in the back half of each issue that said, "Say You Saw It in QST - It Identifies You and Helps QST." They even got the capitalization correct (all lower case short prepositions and conjunctions, but I digress). The December 1933 edition was a bit different, however, in that all the left-hand pages had the message translated into one of fourteen different languages while the right-hand pages used English. I deemed that discovery cool enough to scan and post here. Since the only languages I speak with any fluency are English and Pig Latin, I took the trouble of entering the English sentences into the Google Translator engine for each language and posting what it says is the correct translation, at least by 2023 standards. If any of the languages are your native tongue and you would be kind enough to provide me with the "real" translation, I would be mighty grateful and would add that (along with credit to you) to the page...

Satellite Swarms for Science at NASA Ames

Satellite Swarms for Science at NASA Ames - RF cafe"Teamwork makes the dream work, and at NASA that doesn't apply only to humans. Researchers at NASA's Ames Research Center in California's Silicon Valley are developing satellite swarms, which are groups of spacecraft working together as a unit, without being managed individually by mission controllers. A swarm's ability to perform autonomously will make new types of science and exploration possible, particularly as they venture farther into deep space. Ames' work on swarm technologies has been underway for decades. This summer, swarm science will reach a major milestone as NASA launches the Starling mission into space. It will test technologies that let four spacecraft operate in a coordinated manner without resources from the ground. And the results of Starling's experiments will be of great interest to researchers at Ames who..."

Super Selectivity with Crystals

Super Selectivity with Crystals, July 1957 Radio & TV News - RF CafeThis Radio & TV News magazine article on crystal filters will probably be more useful to people responsible for maintenance on old RF systems than for new designs. The technology has come a long way since 1957 when it was published. Crystal filters were heralded as godsends as airwaves became more crowded and simple LC filters could not provide the required Q to prevent cross-channel interference. Of course the problem is many times worse today, but components are better now than then with low-cost integrated circuit front ends that handle a lot of the selectivity issues and SAW filters with better performance than many crystals...

A Bit of Surprising Statistics

Politicians Families Slaveholders - RF CafeWe live in an era where the actions of people and civilizations of distant history are held accountable to contemporary standards. The term is "presentism." If the original perpetrator of the judged sin cannot be punished, then impose a penalty on the descendants, be they people or governments. At the forefront of presentism is slavery. No moral person condones slavery. No living person owns or has owned slaves (well, maybe in Somalia and a few other places we must never mention). Oh, and then there's the current human trafficking organizations around the world, and near-slave workers mining raw materials for and building our tech devices, but I'm not addressing them, either. Reuters just published a piece entitled, "America's Family Secret," that reveals more than 100 U.S. leaders - lawmakers, presidents, governors and justices - who are direct descendants of slaveholders. All appear to be White men and women, except for one Black man. Notably absent are any Orange men.

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...

Please Thank RF & Connector Technology for Their Support

RF & Connector Technology - RF CafeProviding full solution service is our motto, not just selling goods. RF & Connector Technology has persistently pursued a management policy stressing quality assurance system and technological advancement. From your very first contact, you will be supported by competent RF specialists; all of them have several years of field experience in this industry allowing them to suggest a fundamental solution and troubleshooting approach. Coaxial RF connectors, cable assemblies, antennas, terminations, attenuators, couplers, dividers, and more. Practically, we put priority on process inspection at each step of workflow as well as during final inspection in order to actualize "Zero Defects."

Monday the 26th

Anti-Plane-Collision Radar

Anti-Plane-Collision Radar, March 1961 Radio-Electronics - RF CafeWhat a difference a punctuation mark can make, in this case a hyphen. If this 1961 Radio-Electronics magazine article had been titled "Anti-Plane Collision Radar" rather than "Anti-Plane-Collision Radar," the theme might seem to address a radar system biased against airplanes and desiring to promote collisions amongst them, rather than wanting a radar system designed to prevent collisions. In making his point, editor Hugo Gernsback uses as an example a recent (at the time) 1960 mid-air collision between a Douglas DC−8 (4-engine jet) and a Lockheed Super Constellation (4-engine propeller) which occurred over New York City. Another cited was a 1956 mid-air over the Grand Canyon, which also involved a Super Constellation and this time a Douglas DC-7 (4-engine propeller). Airborne collision avoidance systems (ACAS) have been incorporated into airborne radars for many decades, which act independently of ground-based collision avoidance systems. Mr. Gernsback's call...

New Type Switch for Superconductivity

New Type Switch for Superconductivity - RF Cafe"Under certain conditions—usually exceedingly cold ones—some materials shift their structure to unlock new, superconducting behavior. This structural shift is known as a 'nematic transition,' and physicists suspect that it offers a new way to drive materials into a superconducting state where electrons can flow entirely friction-free. But what exactly drives this transition in the first place? The answer could help scientists improve existing superconductors and discover new ones. Now, MIT physicists have identified the key to how one class of superconductors undergoes a nematic transition, and it's in surprising contrast to what many scientists had assumed. The physicists made their discovery studying iron selenide (FeSe), a two-dimensional material that is the highest-temperature iron-based superconductor. The material is known to switch to a superconducting state at temperatures as high as 70 kelvins..."

Radio Signals From Jupiter Studied by N.B.S.

Radio Signals From Jupiter Studied by N.B.S., August 1957 Radio & TV News - RF CafeIn the days before space-based radio astronomy, observations on many frequencies required waiting until nightfall because the Earth's ionospheric activity interfered with signals in many bands of interest. Two such bands are 18 MHz and 20 MHz (16 and 15 meters, respectively), on which information on lightning-type discharges from Jupiter are received. Near-real-time maps of ionospheric absorption in the D layer (caused by solar x-ray activity) are available on the Solar Terrestrial Dispatch website for 5 through 30 MHz, which is where long-range high frequency (HF) communications occur. The F2 layer is where signals are usually reflected, but absorption in the lower D layer can be severe enough to limit reception. This "Radio Signals from Jupiter Studied by N.B.S." story from the August 1957 issue of Radio & TV News magazine presents the state of the science at the time...

Television in Great Britain

Television in Great Britain, January 1945 Radio News - RF CafeTelevision development was a distant memory for most people during the dark days of World War II. Germany's forces launched its second siege of the 20th century against Europe in Fall of 1939. By January of 1945, even the Brits were beginning to feel confident that the seemingly endless days of World War II were about to come to an end. Hitler's forces had been beaten back from its massive sprawl across Europe and into northern Africa. Eisenhower's D-Day campaign six months earlier had broken the back - and much of the will - of German forces. The Battle of Leyte Gulf shortly thereafter severely damaged Japanese naval forces. Slowly but surely improvements were made in TV camera, broadcast, and local viewing technology in spite of the severe restrictions placed on component and manpower availability, both in the UK and in the U.S. John Logie Baird was England's most famous television pioneer...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated 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 17,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. Your 728x90-px and 160x600-px Banner Ads are displayed on average 225,000 times per year! 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. If you need your company news to be seen, RF Cafe is the place to be...

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! 

Sunday the 25th

The Tytler Cycle

Tytler Cycle - RF Cafe"A democracy cannot exist as a permanent form of government. It can only exist until the voters discover that they can vote themselves largesse from the public treasury [we're past this point]. From that moment on, the majority always votes for the candidates promising the most benefits from the public treasury with the result that a democracy always collapses over loose fiscal policy, always followed by a dictatorship. The average age of the world's greatest civilizations has been 200 years. These nations have progressed through this sequence: From bondage to spiritual faith; From spiritual faith to great courage; From courage to liberty; From liberty to abundance; From abundance to selfishness; From selfishness to apathy; From apathy to dependence; From dependence back into bondage."”-- Alexander Fraser Tytler

Electronics Theme Crossword for June 25th

Electronics Theme Crossword Puzzle for June 25th, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for June 25th contains words and clues which pertain exclusively to the subjects of electronics, science, physics, mechanics, engineering, power distribution, astronomy, chemistry, etc. If you do see names of people or places, they are intimately related to the aforementioned areas of study. Being that "B" is the 2nd letter (25 mod 23) of the alphabet, it is used as the first and/or last letter (or even in-between) of many words in today's crossword puzzle. Those clues are marked with an asterisk (*). As always, you will find no references to numbnut movie stars or fashion designers. Need more crossword RF Cafe puzzles? A list at the bottom of the page links to hundreds of them dating back to the year 2000. Enjoy.

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

/jobs.htm">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 /jobs.htm">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 Once Again to everythingRF for Long-Time Support!

everything RF Searchable Database - RF CafePlease take a few moments to visit the everythingRF website to see how they can assist you with your project. everythingRF is a product discovery platform for RF and microwave products and services. They currently have 267,269 products from more than 1397 companies across 314 categories in their database and enable engineers to search for them using their customized parametric search tool.

Friday the 23rd

What's Your EQ?

What's Your EQ?, August 1963 Radio-Electronics - RF CafeFor a couple years in the 1963 era, Radio−Electronics magazine ran a monthly feature called "What's Your EQ?," where EQ stood for Electronics Quotient. It was a play on IQ - Intelligence Quotient. Some the problems posed are real posers, but most are within the capability of RF Cafe visitors - even the ones showing vacuum tubes since you can usually mentally replace them with transistors and solid state diodes. "L-Pad Puzzler" is a fairly simple circuit analysis equation. Be sure to approach it from terminals 3 and 4. The solution given for "Fussy Fuses" is questionable the way I look at it. It seems to me if the five branches have no resistance (or even exactly the same resistance), the current would split equally amongst them, so as current is increased the 1A would blow, then the 2A, up through the 5A, then that would be it. R−E concluded differently. "Voltage Divider" is a little more of a challenge...

Extremely Large Objects in Atacama Desert

Chile's Atacama Desert is getting a lot of news play these days due to some "extremely large" manmade features being created there. Some are good things, and some not so much. Examples of good things are the Very Large Telescope and the Extremely Large Telescope (ELT), the latter being constructed by the European Southern Observatory, is the world's largest and most advanced Earth-based telescope. Its location atop Chile's Cerro Armazones mountain is at an altitude of 9,993 ft (3,046m) in the central part of Chile's Atacama Desert. At 39 m in diameter, it will collect 15x more light than the next largest. It will record many petabytes of data each year while performing entire sky surveys in multiple wavelengths. AI is being developed to assimilate it all because there aren't enough humans available. Another extremely large object being built in the Atacama Desert is a giant pile of brand new, discorded clothing (Google image), about 300 miles north of the ELT. Unsold clothes containing huge amounts of petroleum product components (nylon, polyester, acrylic) will take centuries to decompose. Petroleum-burning cargo ships sail the seven seas to deliver them, thence diesel trucks and excavation equipment dispose of them. Many people will whine about spending money on space science while turning a blind eye to incredible waste and pollution. Hypocrites.

Art Combines with Precision Engineering

Art Combines with Precision Engineering: Scott Transformer Company, March 1930 Radio News - RF Cafe"Art Combines with Precision Engineering," proclaims the Scott Transformer Company advertisement that appeared in a 1930 edition of Radio News magazine. I'm not sure how many radios Scott sold, but a fairly extensive Google and eBay searches turned up only one restored model of the fancy "artistic" cabinet type. Based on the prices in the ad, most people probably could not afford to buy them. According to the BLS* Inflation Calculator, the $703 "Cortez" radio would cost $12,555 in 2023 money. Even the $334 "Cavalier" at an equivalent of $5965 would cost more than many houses in 1930! Black Tuesday had precipitated just a few months prior to this March edition, so all the design and manufacturing accommodations had already been put in place. Plus, publishing lead times were many months in advance so this promotion likely was arranged and paid for before the Stock Market crash in October of 1929. "No station tunes at more than one point on the dial and local stations do not interfere, even to the slightest degree, with distant reception. Four Screen Grid tubes are used in this new Scott Model. Think of it! Four Screen Grid tubes!" Evidently affordable, crappy reception was good enough for the times...

Anatech Electronics June 2023 Newsletter

Anatech Electronics June 2023 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his May 2023 newsletter that features his short op−ed entitled "Filters Save the Day." In it, Sam discusses how two of the biggest issues of the day concerning RF interference - the coexistence of C-band cellphone service and radar altimeters, and AM radio in electric vehicles - are relatively easily solved with filters. I have posted links to many news stories covering both challenges in the last few years. Sam makes a good point about the AM radio in EV's, that being whereas car manufacturers say the noise generated by the propulsion systems (brushless motors which run on high frequency pulses) will wreak havoc with AM radio, there will certainly be other susceptibilities needing to be dealt with by onboard systems. I will add that dense urban environments filled with EMI-spewing EV's might also cause serious problems for external systems as the ambient noise floor rises ever higher...

TrueTone Models D1747, D1748 Schematic & PL

TrueTone Models D1747, D1748 Schematic & Parts List, August 1947 Radio News - RF CafeTrueTone was the brand name for electronic equipment sold through Western Auto (Supply Company). Western Auto started business in 1909 and died, sadly, in 2003. Other well-known companies had branded electronics as well; e.g., Sears had Silverline and Montgomery Ward had Airline. TrueTone models D1747 and D1748 were cabinet-style combination radio receiver and phonograph. This schematic and parts list set from a 1947 issue of Radio News magazine did not include any service data, as was provided for most radios published. 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. A running list of all data sheets is shown at the bottom of the page to facilitate a search...

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 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). 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...

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.

Thursday the 22nd

Electronics Industry News Briefs

News Briefs, August 1963 Radio-Electronics - RF Cafe"News Briefs" in the March 1960 issue of Radio-Electronics magazine contained many very interesting developments related to research and development in communications. Headlines included among other things Tropospheric Telephone Spans Atlantic, TV, Radio Astronomy Struggle for Channel 37, Needle Belt Orbits, Laser Transmits 118 Miles, Diplomat's Dog Is Howling Counterspy, and, Short-Wave Listeners Hear Ham Gossip, Space News. A decade has passed since the International Geophysical Year (IGY) results had come in and much work in tropospheric and ionospheric signal scatter, absorption, and reflection was in process. An intense battle between the Communist world and the free world for technology dominance was a major factor in the process. The Space Race was in full gear, with Apollo 11 scheduled to land the first men on the moon within a few months. Reliable communications between Earth...

ESD Test Requirements Are Designer's Headache

ESD Test Requirements Are Designer's Headache - RF Cafe"The trend toward society's 'smart-electrification' is driving the need for ESD immunity at the system-level. IEC 61000‑4‑2 [1] defines how to perform the electrostatic discharge immunity test at the system level. Until about 15 years ago, protecting against such events involved implementing ad-hoc ESD protections (TVS) at board/system-level in proximity to the connectors interfacing with the 'external world.' However, a new trend of implementing system-level robustness at the component level (i.e., on-chip) is quickly becoming standard practice, mainly stemming from the desire to reduce system/board design costs. While this may sound like a logical step on paper, it poses enormous challenges to the component ESD designer in that: IEC 61000-4-2 is not applicable at the component level, so every company is struggling to understand / design proprietary characterization methods at the component level to extrapolate performance at system-level..."

Television Industry Prepares for Postwar

Television Industry Prepares for Postwar, January 1945 Radio News - RF CafePhilco began selling radios in 1928 after originally being a storage battery manufacturer. Their first television, the Predicta, was introduced in 1957. That was more than a decade after Philco Corporation's James Carmine wrote this article discussing how the American buying public might embrace the concept of TVs in their homes. Many people at the time had no interest in television both due to the expected cost and the relatively poor performance of existing examples. If you have ever seen pictures of early TVs, they typically had very small displays and poor picture quality (obvious scan lines, low contrast, picture distortion, etc.). As with almost all forms of consumer electronics, production and sales of new television sets was put off during World War II so that precious components and materials would be available for the war effort. Once the war ended in 1945, all industries were unleashed and a flood of surplus items, from electronics to mechanics to clothing, hit the distribution markets providing virtually limitless access to designers and resale distributors at prices far below retail...

Remember These Beasts?

Mosquito DDT Spray Truck - RF CafeAre you old enough to remember the mosquito spray trucks running through your neighborhood during the summer? Whilst a child living in Mayo, Maryland, in the 1960s, I vividly remember trucks similar to this one going by our house with a big fan on the back blowing what was almost certainly DDT with such force that it shook the trees. We would hurry to shut all the windows if lucky enough to hear the truck coming. That stuff stunk. Mayo is a peninsula off the Chesapeake Bay, and it was a breeding ground for skeeters. If you went outside in the evening after a rain on a hot, humid day, you would get eaten alive - so to speak. A can of "Off Insect Repellant" sat on our back door stoop all summer long. Remember the "Off" commercial? Mosquitoes don't bite; they don't even light." Boy, am I getting old! According to the hype, all of my friends and I should be dead by now.

Thanks Again for RIGOL Technologies' Continued Support!

RIGOL Technologies (electronics test equipment)RIGOL Technologies is transforming the Test and Measurement Industry. Our premium line of products includes digital and mixed signal oscilloscopes, spectrum analyzers, function / arbitrary waveform generators, programmable power supplies and loads, digital multimeters, data acquisition systems, and application software. Our test solutions combine uncompromised product performance, quality, and advanced product features; all delivered at extremely attractive price points. This combination provides our customers with unprecedented value for their investment, reduces their overall cost of test, and helps speed time to completion of their designs or projects.

Remedies for Poor Notes and Key Clicks

Remedies for Poor Notes and Key Clicks, May 1934 Radio News and the Short-Wave  - RF CafeAlthough the application is a bit outdated, the lesson presented in this 1934 Radio News and Short−Wave magazine article about taming the chirps and thumps of keying Morse code via pulse shaping techniques is still useful today. While fully tamed (aka compensated / damped) commercial keys and keying circuits are available that require no technical knowledge of how they work or how to fine tune their operation, there are still many more older units operating that might need some tweaking. This is part 3 of a multi-issue article, so the few references to nonexistent illustrations are not typos. Figure 1 is reproduced from Part 1 of the article, and then the series picks up with Figure 7. Unfortunately, I have not yet acquired those previous two issues...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000 or so symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing. Check them out!

Thanks to Wireless Telecom Group for Their Support!

Wireless Telecom Group (RF power and noise measurement) - RF CafeThe Wireless Telecom Group, comprised of Boonton, Holzworth, and Noisecom, is a global designer and manufacturer of advanced RF and microwave components, modules, systems, and instruments. Serving the wireless, telecommunication, satellite, military, aerospace, semiconductor and medical industries, Wireless Telecom Group products enable innovation across a wide range of traditional and emerging wireless technologies. A unique set of high-performance products including peak power meters, signal generators, phase noise analyzers, signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable noise generators.

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TotalTemp Technologies (Thermal Platforms) - RF Cafe
Exodus Advanced Communications Best in Class RF Amplifier SSPAs

Rigol DHO1000 Oscilloscope - RF Cafe

Innovative Power Products Passive RF Products - RF Cafe