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RF Cascade Workbook 2018 - RF Cafe

Homepage Archive - March 2021 (page 4)

See Page 1 | 2 | 3 | 4 of the March 2021 homepage archives.

Wednesday the 31st

Bliley Crystals

Bliley Crystals, October 1944 Radio News - RF CafeBliley Electric Company is one of the relatively few companies that advertised regularly in electronics magazines during the World War II era that is still in business today - at least under the same name (Bliley Technologies now, but still the same base name). While the company is no longer located in the Union Station Building as indicated by the 1944 Radio News magazine appearance, it does still live in Erie, Pennsylvania, only a few miles from where Melanie and I live just west of the Erie International Airport. They still make crystals today. Here is a 2018 article about Bliley's operations from the Erie Times News newspaper.

Thanks to PCB Directory for Continued Support!

PCB  Directory - RF CafePCB Directory is the largest directory of Printed Circuit Board (PCB) Manufacturers, Assembly houses, and Design Services on the Internet. We have listed the leading printed circuit board manufacturers around the world and made them searchable by their capabilities - Number of laminates used, Board thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing, fabrication, assembly, prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.

Reconfigurable Electronics Based on Multiferroics and Nanomagnetism

Reconfigurable Electronics Based on Multiferroics and Nanomagnetism - RF Cafe"Multifunctional magnetoelectric materials with high exchange represent a missing 'holy grail' of materials physics. To combine polarization and magnetization in the same solid is nothing short of actually controlling the fundamental nature of electromagnetism in matter. Although magneto-electricity (ME) is an intrinsic phenomenon in some natural materials at low temperature, such single-phase materials suffer from an extremely weak ME exchange. In contrast, composites consisting of magnetostrictive and piezoelectric phases can feature dramatically larger ME coefficients. This proposed program focuses on achieving the disruptive potential of emerging multifunctional magnetoelectrics, and in so doing lay the foundations for their use as a materials platform that would benefit future AFOSR..."

Eavesdropping on Satellites

Eavesdropping on Satellites, February 1963 Popular Electronics - RF Cafe1963 was five years since America's first communications satellite, Echo, was placed in orbit. Echo was a passive, spherical reflector that merely provided a good reflective surface for bouncing radio signals off of. By 1963, the space race was well underway and active communications satellites were being launched at a rapid pace. This 1963 issue of Popular Electronics magazine reports on satellite signals being received by other than their intended targets. Spotting and tracking satellites has long been a popular pastime with two types of hobbyists: amateur astronomers using telescopes and binoculars, and amateur radio operators using antennas and receivers. Today's amateurs are picking up signals from spacecraft orbiting Mars (NASA's Mars Reconnaissance Orbiter in 2018, and China's Tianwen-1 probe in 2021) and are finding long-lost and presumed-dead (aka "zombie")...

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.

Tuesday the 30th

Hytron's Master Tube Tester

Hytron's Master Tube Tester, October 1944 Radio News - RF CafeFounded in 1921 in Salem, Massachusetts, Hytron Corporation started out making vacuum tubes, then after being bought by CBS in 1951 they moved into the realm of semiconductor production. This story from a 1944 issue of Radio News magazine extolled the virtues of Hytron's Master Test Station for its ability to quickly and accurately measure a wide variety of tubes. Auto-ranging voltage regulators, parallax-free meters with auto-ranging scales, safety fusing, and easy servicing were among it notable features. To me, a parallax-free meter is one with a mirror behind the needle used to assure the operator is looking straight-on at the scale, but in this case it meant the array of meters was arranged in a semi-circle so that the operator was naturally looking perpendicular to the meter faces from a fixed vantage point. The level of automation no doubt reduced measurement errors...

ConductRF Zero Halogen / Low Smoke Cable Solutions

ConductRF Zero Halogen/Low Smoke Cable Solutions - RF CafeConductRF is pleased to offer Low Smoke / Zero Halogen Jacketed RF Cables for various applications indoor and outdoor for Naval Ship-Board applications. We have two ranges of solutions aimed at differing RF requirements with our SBA series aimed at Higher Frequency 18 GHz needs. These are 100% factory tested to exacting VSWR and Loss standards because, We know, Results Count! ConductRF manufactures a range RF Cables in support of shipboard applications, where low smoke, zero halogen requirements are mandated. These cable have low smoke polyolefin jackets that are suitable for shipboard environments. The cable solutions are commonly available in 3 sizes with cable OD of 0.240", 0.405" and 0.590". Common standard interfaces are available with standard gasket seals...

What Is Your Electronics Business Acumen?

Biz Quiz, April 1947 Radio News - RF CafeWell, at least I know now why my efforts to sell things usually don't work out too well. A salesman I ain't - neither by c1947 standards or by contemporary standards. I have a hard time even giving things away based on the low response rate on notifications for winning free books each month. My score on this "Biz Quiz" in Radio-News magazine was around 50% (south of, actually), but that was probably due to being subconsciously biased to answer what I thought the creator would expect for a good salesman. It would probably be embarrassing to have a professional assessment of my true personality, assuming that professional is not a quack with an agenda...

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. Amplifiers, test equipment, power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers, power supplies, and everything else. Please visit everythingRF today to see how they can help you.

R&S Offering Free Wi-Fi History & Future Poster

Rohde & Schwarz Offering Free Wi-Fi History & Future Poster - RF CafeRohde & Schwarz is now offering for free a newly designed "The History and Future of Wi-Fi" poster. Wi-Fi has been around for more than 3 decades, but still some struggle with the numerous Wi-Fi specifications. Find everything you need on one poster: - Numbering and structuring from the first Wi-Fi 802.11b to the latest 802.11be also known as Wi-Fi 7 - Technology evolution in terms of bandwidth, spectrum, modulation and antenna schemes - Different Wi-Fi variants for automotive applications (11p, 11be), IoT use cases (11ah, 11af) and couch & desktop networks (11ad, 11ay) Download the digital copy of the poster or request the poster to be mailed to you.

Please Thank San Francisco Circuits for Their Support!

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

Monday the 29th

Signals in Britain's Army

Signals in Britain's Army, October 1944 Radio News - RF CafeHere is a good summary of where the Brits were in the way of wired and wireless telegraphy and telephony towards the end of World War II. Captain A. Reid, Signals Directorate, British War Office, provides some photographs and descriptions of the field equipment. Chief among the wired units was the long-revered Fullerphone, brainchild of Capt. A.C. Fuller (who retired as a Major General), who initially developed it during WWI as a solution to long range (up to 3 miles) secure communications. It was considered essential frontline equipment. Of course wireless gear became necessary as fighting units were dispatched farther and farther from established headquarters. Interestingly, Capt. Reid mentions the use of Lamson tubes for dispatching secret messages into and out of secure vaults. They were the forerunners to the vacuum tube system used at bank drive-up stations and within businesses for physically (no copper or ether involved) ferrying items between locations...

Transistor Design Prevents IC Reverse Engineering

Transistor Design Prevents IC Reverse Engineering - RF Cafe"A hacker can reproduce a circuit on a chip by discovering what key transistors are doing in a circuit - but not if the transistor type is undetectable. Engineers have demonstrated a way to disguise which transistor is which by building them out of a sheet-like material called black phosphorus. This built-in security measure would prevent hackers from getting enough information about the circuit to reverse-engineer it. Reverse-engineering chips is a common practice both for hackers and companies investigating intellectual property infringement. Researchers also are developing x-ray imaging techniques that wouldn't require actually touching a chip to reverse-engineer it. The approach would increase security on a more fundamental level..."

CMT VNA 101 Bootcamp Webinar Series

Copper Mountain Technologies 2021 VNA 101 Bootcamp Webinar Series - RF CafeCopper Mountain Technologies has published the 2021 schedule for its VNA 101 Bootcamp Webinar series. Copper Mountain Technologies' VNA 101 Bootcamp Webinar series, hosted by Applications Engineering Lead Subbaiah Pemmaiah, features beginner technical content regarding various aspects of Vector Network Analysis use. This series combines valuable RF theory with relevant measurement demonstrations to provide a complete understanding of the basics of a VNA topics. Viewer submitted questions are answered throughout each webinar. There is no cost for attendance...

A Typical Day of Radio Station Repair for Jim Flinn

[Jim] Flinn Engineering (Radio Station Repairs) - RF CafeWhat's wrong with this picture? Believe it or not, that is how my former USAF buddy, Jim Flinn, of Flinn Engineering, found this connection for an AM broadcast station that he and his team were called in to fix. Per Jim, "Before we started you couldn't hear this 1000 watt AM radio station five miles out of town. After we were done it could be heard 50 miles away." Paying advertisers probably were not happy about the 5 mile range since their audience would have been reduced considerably. It is a wonder that the transmitter even survived what must have been an atrocious mismatch. The photo is not detailed enough to show the intricacies of the center conductor connection, but the ground / return / shield connection is nothing more than a piece of copper wire bolted to the coax feed cable shield. So, in addition to the awful return loss, the potential for PIM (passive intermodulation) generation is enormous. I'm guessing if a spectrum survey of the tower output had been conducted, it would have shown a huge blob of crap all around the carrier that would have warranted a severe violation issuance by the FCC...

New for 2021! RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Stencils are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing. The file format is XML so everything plays nicely with Visio 2013 and later...

Many Thanks for Alliance Test Equipment's Support!

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

Sunday the 28th

RF Engineering Theme Crossword for March 28th

RF Engineering Theme Crossword Puzzle for March 28th, 2021 - RF CafeThis RF Engineering Theme Crossword Puzzle for March 28th has many words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. 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!

Friday the 26th

Advanced Radio Theory for FCC Operator's Exams

Advanced Radio Theory for FCC Operator's Exams, October 1944 Radio News - RF CafeHere is an overview of the sort of topics an applicant for an FCC Commercial Radio Operator License needed to know - back in the 1940s, anyway. Much of it still applies to obtaining the same license today. Per the FCC website: You need a commercial operator license to operate, and/or to repair and maintain, specified ship, and aircraft radio communication stations. The licensing requirements for operating such radio stations and the licensing requirements for repairing and maintaining such radio stations are discussed [herein]." Examples are ships or aircraft traveling to foreign destinations, ships employing radiotelegraphy (some still do for emergency communications; e.g., ••• −−− •••), and vessels carrying more than six passengers. A license is required to repair and align radio, radar, and navigation equipment...

Microsoft-Backed Quantum Computer Research Retracted

Microsoft-Backed Quantum Computer Research Retracted - RF Cafe"Controversial Microsoft-backed research on elusive theoretical particles that could have proved a major advance in quantum computing has now been retracted after other scientists pointed out critical flaws in the work. The original research focused on Majorana fermions, long-theorized particles that are their own antiparticles. First predicted more than 80 years ago by Italian physicist Ettore Majorana, scientists have yet to detect these self-annihilating particles inside particle accelerators. However, in the past decade or so, researchers have detected signs of a kind of Majorana fermion known as a Majorana zero mode. This quasiparticle manifests in the form of groups of electrons and other particles collectively behaving as single particles. In a 2018 study in Nature, Microsoft-backed scientists claimed they found strong evidence of these quasiparticles..."

Advantages of Outdoor Antennas

Advantages of Outdoor Antennas, June July 1940 National Radio News - RF CafeBoth funny and ridiculous I thought as I read this article from a 1940 edition of National Radio News where author Julius Aceves, a consulting radio engineer, makes the case for not buying a newfangled, cheap radio that is supplied with a built-in antenna when using a good old-fashioned outdoor antenna is the better option. It's not that he doesn't have a valid point about the larger, obstruction-free outdoor antenna providing superior signal strength and a greater signal-to-noise ratio; it's that part of his argument is that in doing so you are denying the outdoor radio antenna companies revenue. That mindset is akin to telling people they should not buy notebook computers because in doing so you are denying computer monitor and keyboard manufacturers their rightful sales volumes. He does, to his credit, finally admit that there are "a few well-engineered antenna kits" that are worth consideration if you insist on taking food from the mouths of antenna salesmen's children. As you probably know, it is rare to find a radio today that does not have at least an internal AM antenna...

CMT 2021 Master Class Webinar Schedule

Copper Moountain Technologies 2021 Master Class Webinar Schedule - RF CafeCopper Mountain Technologies has published the 2021 schedule for its Master Class Webinar series. CMT's VNA Master Class Webinar Series, hosted by Design Engineering Manager Brian Walker, features high-level technical content regarding various aspects of VNA use. This series combines valuable RF theory with relevant measurement demonstrations to provide a complete understanding of complex topics. Viewer submitted questions are answered throughout each webinar. There is no cost for attendance. Sessions in the Master Class Series include Important VNA Performance Parameters, Making mmWave Measurements with a VNA, Full 1-Port VNA Calibration Math with Python Code, Time Domain Measurement and Time Domain Gating, Full 2-Port VNA Calibration Math Explained...

New for 2021! RF & Electronics Symbols for Office™ r2

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!

Please Thank RF Superstore for Their Continued Support

RF Superstore coaxial cable, connectors, adapters - RF CafeRF Superstore launched in 2017, marking the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and microwave Industry. Pasternack fundamentally changed the way RF components were sold. Partner Jason Wright manages day-to-day operations, while working closely with Mr. Pasternack to develop RF Superstore into a world class RF and microwave component supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies, surge protectors, attenuators. Items added daily. Free shipping on orders over $25. We're leading the way again!

Thursday the 25th

Sperry Gyroscope Company

Sperry Gyroscope Company, October 1944 Radio News - RF CafeThis 1944 advertisement from Sperry Gyroscope Company claims it owns the copyright for the word "Klystron." According to the Wikipedia entry: "The name klystron comes from the Greek verb κλύζω (klyzo) referring to the action of waves breaking against a shore, and the suffix -τρον ("tron") meaning the place where the action happens. The name "klystron" was suggested by Hermann Fränkel, a professor in the classics department at Stanford University when the klystron was under development." Furthermore, it says American electrical engineering brothers Russell and Sigurd Varian were the inventors of the klystron. The video helps explain how the klystron tube works. I am always amazed at how someone came up with such an idea in the first place. This is the earliest patent, dated 1938...

How Our Commies Defame America Abroad

How Our Commies Defame America Abroad, February 11, 1950, The Saturday Evening Post - RF CafeJoseph McCarthy is a name widely recognized for his efforts in the 1950s to expose Communist sympathizers in the United States, be they common citizens or holders of high office. His exploits were routinely dismissed as folly and he was accused of "finding a Commie behind every rock." The derisive term "McCarthyism" was used to describe anyone exhibiting supposedly paranoid obsession with investigating suspected wrong-doing. After many decades of successful application of the charge to shut people up (like calling someone a racist today), a misfortune befell its libelants. In 1995, the Venona papers (secret messages between Moscow and its U.S. agents decrypted by our government), data from Soviet archives and executive-session transcripts of Senate committees were finally opened after a 50-year ban. The information showed that McCarthy was justified in his suspicions after all...

FCC Umbra Synthetic Aperture Radar Satellite

FCC Umbra Synthetic Aperture Radar (SAR) satellite - RF Cafe"Umbra, a geospatial intelligence data provider, was granted a license from the Federal Communications Commission (FCC) to operate its Synthetic Aperture Radar (SAR) satellite with 1,200 MHz of bandwidth. This bandwidth allocation will allow them to generate images with as low as 15-centimeter (6 inch) ground sampling distance (GSD). At this resolution, Umbra's satellites will be able to detect items as small as a soda can from space. Umbra is the first commercial satellite provider in U.S. history to receive a license enabling this level of capability from Space..."

Webinar: THz Communication - Beyond 5G

Webinar: THz Communication - A Key Enabler for Beyond 5G? - RF CafeRohde & Schwarz is holding a free live webinar entitled, "THz Communication - A Key Enabler for Beyond 5G?," today, Thursday, March 25th, at 1:00 pm EDT. "Sub-terahertz and terahertz (THz) waves, ranging from 0.1 THz to 10 THz, fall in the spectral region between microwave and optical waves. The prospect of enabling transfer rates in the terabit/sec range make them a key research area of 6G mobile communication. Sub-THz technologies require highly integrated frontends, including array antennas, that necessitate advanced over-the-air testing methods with a frequency range up to 300 GHz. To fully exploit the potential of this frequency range for future wireless communications, it is also crucial..."

Yagi vs. Quad

Yagi vs. Quad, October 1966 QST - RF CafeHere is a story of one Ham's experience in determining how the performance of his Yagi antenna compared to his identically configured (number of elements, height off of the ground, etc.) cubical quad antenna. His location was a farm field in Tennessee, back in the mid 1960s, so there was really not much in the way of obstacles to perturb signals arriving at one antenna versus the other, except of course when the direction of operation happened to have the antennas in line with each other. Both antennas were tuned for optimal performance at 14.22 MHz, which is in the high frequency (HF) band. Today's radio operator has software tools at his disposal for predicting the performance of single and multiple antenna setups that can save a lot of time and money. EZNEC* antenna software is a good example where for as little as...

Online Archived Electronics Databooks & Books

"The Eye" Online Archived Electronics Databooks & Books - RF Cafe BitSavers databook magazine article archive - RF CafeEven with the power of the Google search engine, finding seemingly things like old component databooks and magazine articles can sometimes be a chore. Part of the problem is previously available volumes being removed due to copyright violation claims by owner companies - or by anyone claiming ownership, even if invalid. An RF Cafe visitor recently ley me know of a website called "The Eye," which contains a vast collection of databooks, magazine articles, books, whitepapers, etc. They have a service where removed info can be provided to you by request. Bitsavers.org is another great resource to check. They have manuals and articles for software, test equipment, electronics components, and magazine articles.

Please Thank Reactel for Their Long-Time Support!

Reactel Filters - RF Cafe

Reactel has become one of the industry leaders in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity, and waveguide designs, as well as state of the art high performance suspended substrate models. Through a continuous process of research and development, they have established a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact Reactel today to see how they might help your project.

Wednesday the 24th

Mathematical Puzzles from the 1980 OFA

Mathematical Puzzles, 1980 Old Farmer's Almanac - RF CafeEach autumn I used to anxiously await the appearance of the newest edition of The Old Farmer's Almanac on the store shelf. It is not that I was/am an avid farmer, just that I enjoy reading the anecdotes, tales, and interesting historical tidbits included amongst the pages along with tables of high and low tides, moon and sun rising and setting times, astronomical events, and weather patterns expected for the year that lay ahead. Most of all, I liked working the puzzles and riddles. Over the years the difficulty levels gradually got lower and lower (aka dumbed down), to the point where for the last decade or so I have not even bothered buying the OFA. Now it is full of numbnut stuff. Because quite a few of the Mathematical Puzzles from the older editions are worthy of an engineer's cerebration, contemplation, and deliberation, I am posting the ones I own here on RF Cafe. Answers to numbers 1 through 11...

Eravant (SAGE Millimeter) Microwave Products

Eravant (SAGE Millimeter) Microwave Products - RF CafeIn case you haven't heard yet, SAGE Millimeter, which was formerly SAGE Laboratories (if I recall correctly), is as of year 2020 called Eravant. mm-wave waveguide components are always très-cool in appearance, and there are a bunch of them shown on the High Frequency Electronics website. Seeing them arrayed under special lighting in an exhibit at a trade show reminds you of a jewelry store display case. The precision machining and often polished surfaces make them gleam. Here is a great idea (IHMO) for the marketeers at one of these mm-wave companies: Create a children's play set a la LEGOs consisting of plug-together waveguide components molded to look like common parts. Many of them could be full-size if modeled after higher frequency lines. Rigid and flexible, rectangular and round waveguide, antennas, towers, couplers and amplifiers, circulators, rat races, and many other shapes in bright colors would make for some awesome-looking projects and just might produce some of the world's next RF / microwave / millimeterwave engineer. Maybe call them WEGO (WavEGuideO). Or, create a breakfast cereal using those shapes and call them Engineerios (Cheerios). You're welcome.

Concentric Rings Antennas Radically Increase Data Carried by Light Waves

Concentric Ring Antenna - RF Cafe"Researchers at the University of California, Berkeley, have found a new way to harness properties of light waves that can radically increase the amount of data they carry. They demonstrated the emission of discrete twisting laser beams from antennas made up of concentric rings roughly equal to the diameter of a human hair, small enough to be placed on computer chips. The research, reported in a paper in the journal Nature Physics, throws wide open the amount of information that can be multiplexed, or simultaneously transmitted, by a coherent light source. A common example of multiplexing is the transmission of multiple telephone calls over a single wire, but there had been fundamental limits to the number of coherent twisted light waves that could be directly multiplexed..."

$5.00 for Best Short Wave Kink

$5.00 For Best Short Wave Kink, April 1935 Short Wave Craft - RF CafeAre you a project builder? If so, then you probably make a point of reading hints and tips offered by fellow do-it-yourselfers. Even with the ready availability of just about anything you need already pre-manufactured, there are still times that you either just want to figure out a better way of doing something or happen to have a challenge that does not have a solution that can be purchased from a catalog or on eBay. I have posted a few DIYer features from some of the vintage electronics magazines, many of which are still relevant, or might at least give you an idea for how to accomplish your goal...

Pay Attention to Harry Nyquist and Claude Shannon

Pay Attention to Harry Nyquist and Claude Shannon - RF CafeJames Mazzei has a good primer entitled, "A Reminder: Pay Attention to Harry Nyquist and Claude Shannon ," on information theory at the Electronic Design website, where he admonishes that, "Many CIOs, CTOs, and architects tend to forget this telecommunications throughput issue." Further, "It's a very easy and normal thing to focus on the principal characteristics of the principal components of a communications system or link, and regard other items and issues as peripheral and not so important. That it has happened a surprising amount with satellite communications links, especially remote mobile ones, is the reason for this missive. Here's a hypothetical situation. You are a soldier. You're deployed in a mountainous area of the Middle East, carrying an older Intelsat satellite terminal for immediate access back to headquarters, and the headquarters has leased a 72-MHz transponder for your exclusive use..."

Many Thanks to Electro-Photonics for Their Continued Support

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

Tuesday the 23rd

Electronics Themed Comics

Electronics Themed Comics, January 1945, Radio-Craft - RF CafeFrank Beavan must have earned a nice paycheck with this 1945 issue of Radio-Craft. He drew many of the electronics-themed comics for magazines back in the 1940s through the 1960s. While some months had no comics at all or only one or two, the January edition sported no fewer than six. I'm guessing Mr. Beaven worked on a per-comic basis, so the bank account was looking good. One of my favorite features in his comics is the "Technical Terms Illustrated" gig where a reader suggested that he create a comic based on, in this case, "A Crystal Detector" and "Audio Amplifier." You can find others in the rather large list of comics at the bottom of the page. As is often the case, you need to have an appreciation for the radio trends of the era to "get" some of the themes...

Teledyne e2v HiRel Intros High-Power PIN Diode Limiter Modules

Teledyne e2v HiRel Intros Two New High-Power PIN Diode Limiter Modules - RF CafeTeledyne e2v HiRel today announced two new additions to its family of high power limiters, the TDLM052402, a quasi-active, 2 kW, L/S/C-band SMT PIN Diode Limiter and the TDLM961122 High Power Limiter Module a quasi-active, 1 kW, ARNS/IFF-band SMT PIN Diode Limiter. Both devices offer "always on" high power CW and peak protection. The new power limiter modules are packaged in a small 8 mm x 5 mm form factor designed for demanding electronic warfare and radar applications and utilize proven hybrid assembly technology. Parts are screened and qualified for high reliability applications. Each has an operating temperature range of -65 °C to 125 °C. They boast excellent thermal management features, with a proprietary design methodology that minimizes thermal resistance from the PIN Diode junction-to-base plate (RTHJ-A). The limiter design...

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...

Transistor Based on Metal Nanoparticles and Ionic Gradients

Transistor Based on Metal Nanoparticles and Ionic Gradients - RF Cafe"Transistors, devices that can amplify, conduct or switch electronic signals or electric current, are key components of many electronics on the market today. These devices can be fabricated using a variety of inorganic and organic semiconducting materials. Metals are generally considered unsuitable for fabricating transistors, as they screen electric fields and thus make it difficult to realize devices with tunable electrical conductivity.. A possible way to create electronic components based on metals is to use gradients of counterions in films of metal nanoparticles functionalized with charged organic ligands. In the past, engineers have successfully used this strategy to create a variety of devices, ranging from resistors to diodes and sensors. Nonetheless, modulating the electrical conductivity of these devices has often proved to be very challenging..."

Bureau of Standards Role in IGY

Bureau of Standards Role in IGY, December 1957 Radio & TV News - RF CafeThe International Geophysical Year (IGY) ran from July 1957 through December 1958 and was designed to promote cooperation between countries in the earth sciences realm of research. In all, 67 countries participated in various IGY projects. China declined involvement based on objections to Taiwan being involved, arguably perpetuating its people's languishing behind the Iron Curtain of Communism much longer than it otherwise would have. Global studies were carried out for the aurora and airglow, cosmic rays, geomagnetism, gravity, the ionosphere, longitude and latitude determinations, meteorology, oceanography, seismology, and solar activity. It was during this period that the USSR launched Sputnik and the Van Allen radiation belts were discovered. This article reports on the radio-communications-related IGY...

Withwave Intros 2.4 mm to SMPM Adapters (DC - 50 GHz)

Withwave Intros 2.4 mm to SMPM Adapters (DC to 50 GHz) - RF CafeWithwave's precision 2.4 mm to SMPM Adapter Series are designed based on precision microwave interconnection technologies. These adapter series are manufactured to precise microwave specifications and constructed with male and female gender on both side. The precision microwave connector interfaces ensure an excellent microwave performance up to 50 GHz. Stainless steel bodies with gold-plated beryllium contacts. 1.4:1 maximum VSWR...

Please Visit NorthEast RF's Website in Appreciation of Their Support

NorthEast RF - RF CafeNorthEast RF's comprehensive antenna testing services include linear | circular polarized antenna measurements and OTA cellular device pre-compliance. Up to 18" diameter and <10 kg weight. Antennas can be rapidly evaluated and optimized using our fast near field spherical system. Test results supplied in data file with pattern viewer software. A picture of the test configuration is included to help aligned axis. Our selection of human head and hand phantoms are ideal for verification of body worn devices. Turnaround time is usually 3-days.

Monday the 22nd

Introduction to Modern Television

Introduction to Modern Television, February 1939 Radio News - RF Cafe"Modern" used in the title of anything has always bothered me since it is utterly ambiguous unless you know the era of the authorship. There are plenty of books using "Modern Medicine" in the title that describe bloodletting as a treatment for various diseases or swallowing mercury to cure constipation (and just about everything else). Accordingly, apologies to anyone searching for 2021-modern television information who might have wandered in here hoping to find useful information. However, if you are looking for historical data regarding the evolution of broadcast television, then you might be in the right place. As usual when reading this kind of article from a 1939 issue of Radio News magazine, I am amazed to see accounts of the very first thoughts on the path technology takes toward where we find ourselves in 2021. There are basically two types of "visionaries" - those who first come up with a new idea and those who actually implement the vision. Often the same person qualifies for both categories. Being the first person to think up the idea of sending voice signals or images through the air to a remote location...

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.

Indian Army Lays Groundwork for Futuristic Communications

Indian Army Lays Groundwork for Futuristic Communications - RF Cafe"The network would facilitate a state of the art mobile communications and sensor network for tough terrain using handheld communication devices. The Indian army is planning a LTE-based communications grid with Internet of Military Things (IoMT) sensor network for providing failsafe and secure communications to its units along the northern and eastern borders. This will require designing and developing, with industry support, a communication grid with its radio access network, core network and IoMT compatible network along with sensors and interfaces to provide surveillance, situational awareness, sensor network and compatible interfaces for legacy surveillance devices currently in the Indian army's inventory..."

1940 Sears Amateur Radio & Test Equipment Catalog

1940 Amateur Radio & Test Equipment Catalog Sears Catalog Kirt's Cogitations #326 - RF CafeRF Cave visitor and contributor Joseph Birsa (N3TTE), sent me a note about yet another edition of a special purpose catalog published by Sears - the Sears 1940 Amateur Radio, Test Equipment, Sound System Catalog. A little research revealed that it was actually an extended version of the 1940 Sears, Roebuck and Co. Superior Amateur Equipment and Radio Service Supplies - 64 versus 48 pages, respectively. Even the standard edition Sears, Roebuck Fall 1941 Catalog contained a large section dedicated to radios and equipment. The cover on the shorter catalog makes me think of The Radio Boys series of books, where a cadre of four early 20th century teenagers experienced adventures centered around building and operating wireless equipment. Hallicrafters, National Company, Meissner, and Hammarlund receivers and transmitters were offered for sale. Bliley and Silvertone...

"Plug-In" RF Cable Assemblies for D38999 & VITA67

"Plug-in" RF Cable Assemblies for D38999 & VITA67 - RF CafeConductRF knows many times you want to just buy your RF assemblies to plug in to your circular D38999 connector or your VITA67 module. We offer multiple solutions for both styles of multi-port connector all available on short lead times based on our on hand materials stock. D38999 integrates BMA, SMPM & SMPS connectors, also other #8, #12 & #16 coax contact solutions. VITA67.1/2 uses SMPM solutions, but the new VITA67.3 also offers SMPS and NanoRF to support your coax. These are 100% factory tested to exacting VSWR and loss standards because we know, Results Count!

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.

Sunday the 21st

Engineering Theme Crossword for March 21st

Engineering Theme Crossword Puzzle for March 21st, 2021 - RF CafeThis Engineering-Theme Crossword Puzzle for March 21st has many words and clues related to... you guessed it... engineering - including RF, microwave, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

New for 2021! RF & Electronics Symbols for Office™ r2

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!


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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