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Homepage Archive - September 2023 (page 2)

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

Thursday the 14th

How We Fight with Words

How We Fight with Words, May 1952 Popular Science - RF CafePrior to the turn of the century, mobile communications consisted mainly of Citizens Band (CB) radio and Amateur (Ham) radio. Limited range and sometime crowded channels on CB meant contacting fellow "good buddies" was a shot in the dark. Hams signals could go much farther distances, but the number of available contacts was much more limited. People living in Communist countries were often nearly impossible to reach because their oppressive governments prohibited even receiving foreign "propaganda" signals - under threat of imprisonment and/or fines (like where even today the Nazi state of Virginia prohibits the reception of police radar gun transmissions). Accordingly, the U.S. government used extreme measures to broadcast messages of Western world freedom (which we are losing rapidly) to the oppressed masses. This "How We Fight with Words" article from a 1952 issue of Popular Science magazine discusses some of the methods employed, including some darn large antenna arrays...

Microchips Take on Fake Foods and Drugs

Sand-Size Microchips Take on Fake Foods and Drugs - RF Cafe"Labels on your grocery store products might say 'Spanish extra-virgin olive oil' or 'New Zealand grass-fed beef,' but these are just words. How can such broad claims ever be verified? Food fraud - things like additives, dilutions, mislabeling, and substitution - affects over 1% of the global food industry, according to studies cited by the U.S. Food and Drug Administration, and can cost as much as $40 billion a year. To fight counterfeits, some food makers are turning to chips, not of the edible kind. Makers of authentic Parmigiano-Reggiano cheese in Italy are putting silicon chips smaller than a grain of sand and priced at a few cents apiece on their cheese wheels. The microchips made by Chicago-based p-Chip use blockchain technology to trace products all the way from growers to grocery shelves..."

Radio Telemechanics

Radio Telemechanics, September 1934 Radio-Craft - RF CafeOnce again, electronics and overall tech visionary Hugo Gernsback, editor at the time of Radio-Craft magazine, prognosticated in the 1930s what was then a pipe dream but what is today commonplace - remote control of multi-functioned apparati (sic) via secure wireless digital communications. Adolph Hitler had risen to power a year earlier and was a precursor to what would officially become World War II. By 1937, nations were thinking about what kinds of technologies would be necessary should the little mustachioed dictator decide to invade his neighbors' countries in an attempt to rule over the Earth. That this was so is apparent in many magazine articles in the decade of the 1930s: The Saturday Evening Post, Life, Popular Mechanics, and even Good Housekeeping...

Optical SpecAn Sheds Light on Fiber-Optic Cables

Optical Spectrum Analyzers Shed Light on Fiber-Optic Cables - RF CafeAxiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post entitled "Optical Spectrum Analyzers Shed Light on Fiber-Optic Cables" that covers the process of evaluating the performance of fiber-optic cables by picking the proper optical spectrum analyzer for the job. Numerous test equipment provides insights into fiber-optic cable quality, but one of the handiest and most versatile for the task is the optical spectrum analyzer (OSA). For the best results, fiber-optic cables should be measured before installation and tested as part of a regular maintenance schedule. An OSA measures and displays the distribution of light across a single wavelength or wavelength range. It can be used to explore how environmental effects, such as temperature, impact fiber-optic cable performance within its range, and how physical effects, such as bending or looping of cable, can affect performance. Evaluating the performance of fiber-optic cables requires a unit such as an OSA with the wavelength range to cover the bands and wavelengths used within any applications of interest...

Ultrasonic Frequency Spectrum

Ultrasonic Frequency Spectrum - Definitions and Applications - RF CafeThe ultrasonic frequency spectrum refers to a range of sound frequencies that are above the upper limit of human hearing, which is typically considered to be around 20,000 hertz (Hz). Ultrasonic frequencies start above this threshold and extend into the megahertz (MHz) range. Ultrasonic waves are characterized by their high frequency and short wavelength compared to audible sound waves. Ultrasonic frequencies generally start at around 20,000 Hz (20 kHz) and can extend up to several gigahertz (GHz). The specific range considered "ultrasonic" can vary depending on the context and application. Ultrasonic waves have much shorter wavelengths than audible sound waves. This property allows them to be used for precise measurements and imaging, as they can interact with small objects and features. Ultrasonic waves can be transmitted through various media, including air, water, and solids...

Get Your Custom-Designed RF Cafe Gear!

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

Many Thanks to Anatech Electronics for Long-Time Support!

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

Wednesday the 13th

Anaconda Copper

Anaconda Copper, April 29, 1950 The Saturday Evening Post - RF CafeAnaconda Copper was a major mining company that operated in the United States during the late 19th and early 20th centuries. It was known for its extensive mining operations in Montana, particularly in the Butte-Anaconda mining district. Anaconda Copper was founded in 1881 in Anaconda, Montana, by Marcus Daly, a copper magnate (as opposed to a magnet, which copper isn't, unless an electric current is running through it). The company quickly grew to become one of the largest copper producers in the world. The Butte-Anaconda area was rich in copper, silver, and other minerals, and became known as "The Richest Hill on Earth" due to the enormous copper deposits found there. Anaconda Copper faced economic challenges over the years, including fluctuations in copper prices and increased environmental regulations. Anaconda provided defense and civilian companies with the majority of their copper. World War II was long over by 1950 when this advertisement appeared in The Saturday Evening Post magazine, but many raw materials companies continued promoting to the public through such efforts...

PILOTing Through the Magnetosphere

PILOTing Through the Magnetosphere - RF Cafe"Not so long ago (2022), Advanced Space collaborated with a team of science and engineering organizations to help design a science mission to study the effects of the biggest space weather maker in the solar system: the Sun. The mission concept, called Plasma Imaging, LOcal measurement, and Tomographic experiment (PILOT), is designed to measure the flow of cold, dense plasma into and out of Earth's magnetosphere to better understand how the interaction between Sun and Earth's planetary magnetic field defines the evolution of our planetary atmosphere. To measure these flows in real time requires a fleet of 34 satellites revolving around the Earth in two different orbits to capture plasma movement at different spatial and temporal scales. Advanced Space's role was to help design the orbits for the 34 spacecraft as they performed..."

Miniature Lamp Drawings & Specifications

Miniature Lamp Drawings & Specifications - RF CafeTraditional incandescent miniature lamps (bulbs) are described by a letter indicating shape and a number that is an approximation of diameter expressed in eighths of an inch. For example, B-4 is "B" shape, 4 eighths or one half inch in diameter. Profile sketches of the most popular glass domes and metal bases are provided for visual identification, and they are also useful in engineering drawings. These bulb types are found mostly in equipment manufactured prior to the early 2000s, because they have been replaced with more energy efficient and longer lasting white LEDs (which are actually blue LEDs with a phosphor coating to obtain a wide spectral content). Sources such as Digi-Key and Amazon still carry most of these bulbs, both incandescent and LED equivalents...

ConductRF VITA67 & D38999 "Plug-in" RF Cable Assemblies

ConductRF VITA67 & D38999 "Plug-in" RF Cable Assemblies - RF CafeWe know, many times you want to just buy your RF assemblies to plug in to your circular D38999 connector or your VITA67 module. Well now ConductRF offers 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 ConductRF cables are available off-the-shelf from Digi-Key...

Electronics-Themed Comics

Electronics-Themed Comics, April 1970 Radio-Electronics - RF CafeMellow out a tad with these four electronics-themed comics from a 1970 issue of Radio-Electronics magazine. As mentioned before, radio and television technology was a big deal in the era. People hadn't been born into a world of transistorized microcircuit media devices that perform nearly every conceivable function - phone, TV, radio, computer, heart rate monitor, voice recorder, remote control, camera, compass, game, social media, etc., etc., etc. Unlike today's electronics products that typically don't break with normal use and do not require periodic alignment, folks from my demographic were used to turning on a TV or radio and having to readjust it or have it repaired. These comics reflect that time in history. Of course artist Marvin Townsend adds humor to the situation. I got a good laugh at the ones on pages 16 and 22...

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!

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.

Tuesday the 12th

Apollo TV Uses SEC Tube

Apollo TV Uses SEC Tube, August 1969 Radio-Electronics - RF CafeThe recording and transmission of color video today is accomplished entirely with semiconductor sensors and digital circuitry. Yes, light levels are analog by nature (although some would argue they are quantized, hence not truly analog), but the sensor cells are addressed and read digitally. The data is then put into a digital video transmission standard format for distribution either by cable or over the air. In the early days of color television, a handful of system standards competed for universal acceptance (see list of articles at bottom of page). Some were electromechanical and others were totally electronic. One of the electromechanical schemes involved a rotating segmented color wheel (red, green, and blue glass) in front of the vidicon tube and assembling the detected light levels into a serial video train of analog signals (aka composite video). Each segment of the signal has a set duration, so the receiver knows how to decode the composite video timing and route the signals (both audio and video) to the appropriate circuits and mechanisms. This setup allows a black and white (B&W) camera to send color images. Believe it or not, the video cameras deployed with Apollo 10 and Apollo 11 were of the color wheel type...

Rare Earth-less Motors

Rare Earth-less Motors - RF CafeLots of brilliant people out there. "Advanced electric motors can help give tomorrow's electric vehicles more range and performance while reducing or eliminating the need for rare-earth minerals found in the permanent-magnet synchronous motors (PMSMs) that have been widely used until now. Part 1 of this series explored several wound-rotor synchronous motor (WRSM) architectures and how they can be near-drop-in replacements for PMSM units. Part 2 examined the properties and application challenges of switched reluctance motors (SRMs), one of the most common types of so-called induction machines. Part 3 looks at synchronous reluctance motors (SynRMs), another promising sub-species of induction-type machines. As with the other installments, we will introduce their operating principles, advantages, and disadvantages, as well as what it will take to turn them into a practical technology for powering next-generation EVs..."

Kirchhoff's Voltage & Current Laws

Kirchhoff's Voltage & Current Laws - RF CafeThe concepts of Kirchhoff's Current Law and Kirchhoff's Voltage Law follow. Both assume a totally contained system where energy is conserved. Kirchhoff's Current Law (aka Kirchhoff's 1st Law) is one of the fundamental principles in electrical circuit theory. It's named after Gustav Kirchhoff, a German physicist who formulated this law in the mid-19th century. KCL is used to analyze and describe the behavior of electric currents at junction points within electrical circuits. The statement of Kirchhoff's Current Law is as follows: "At any junction (or node) in an electrical circuit, the sum of the currents entering the junction is equal to the sum of the currents leaving the junction." In other words, when you consider a point in a circuit where multiple conductors or wires meet (a node), the algebraic sum of the currents flowing into that node is always equal to the algebraic sum of the currents flowing out of that node. This law is based on the principle of conservation of electric charge, which means that no electric charge is lost or created at a junction; it simply flows in and out. Σ (incoming currents) = Σ (outgoing currents)...

RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

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.

Monday the 11th

Philco Has Opened "U.S. Television Highway 1"

Philco Has Opened "U.S. Television Highway 1", September 10, 1945 Life - RF CafeIn 1945, when this "Philco Has Opened 'U.S. Television Highway 1'" infomercial appeared in Life magazine, the Dwight D. Eisenhower National System of Interstate and Defense Highways had not yet begun to be constructed. Dwight was busy wrapping up his 5-star general duties at the end of World War II. It was not until 1956, during his term as the 34th American president, that work commenced on build the nationwide network of transportation routes that is credited with helping to establish the country as the world's most powerful nation both economically and militarily. Producing copious amounts of goods and services doesn't do much good if they cannot be moved efficiently and effectively to where they are needed. U.S. Highway 1 was notable for providing a multilane, high speed thoroughfare up and down the entire east coast - from Key West, FL, to Fort Kent, ME. I write all that to give perspective to how Philco saw their developing of a microwave relay system as being akin to Highway 1 (aka Route 1) for its technological equivalent for efficiently and effectively transporting electronic information across great distances...

TotalTemp C900 Benchtop Temperature Chamber

TotalTemp Technologies C900 Benchtop Temperature ChamberTotalTemp Technologies, a worldwide leading provider of research laboratory and production temperature chambers and thermal platform equipment, introduces their model C900 Benchtop Temperature Chamber. Also known as an environmental test chamber, the C900 performs thermal tests through the use of forced air convection. Internal capacity is 9 cubic feet (225 cubic liters). Employing a temperature controller sensing the air temperature with a setpoint of the desired temperature, temperature stability at various points can be achieved. Heat is removed by directly injecting cryogenic liquid into the chamber or heat is added by resistance heaters in the airstream. Features include caster stand or benchtop, left or right hinge doors, tandard duty or heavy duty shelf, redundant valve failsafe systems...

Can Dry Cells Be Recharged?

Can Dry Cells Be Recharged?, July 1967 Popular Electronics - RF CafeAs one who has been dealing with using and recharging batteries - both individual cells and wired packs - for about five decades, I have used many varieties of chargers and battery chemistries. As you probably know, there are two basic types of cells: primary and secondary. Based on their construction and chemistry, the former are not designed to be recharged while the latter are. Primary cells include zinc-carbon and standard alkaline. Secondary cells include nickel-cadmium (NiCd), nickel-metal-hydride (NiMH), and lithium polymer (Li-Po). Rechargeable batteries can have their discharge cycle reversed by running an externally supplied current through the cell in the opposite direction. Of course there are optimal conditions by which that current must be fed in order to preserve the cell's properties (peak voltage, charge storing capacity, discharge current, internal resistance, current leakage, etc.) and lifetime. There have been many occasions where I put primary batteries in a charger for a few hours in order to squeeze a little more use out of them. In all the years, I have never had one explode, catch fire, overheat, leak...

Electrical Charge Unit Conversions

Electrical Charge Unit Conversions - RF CafeElectric charge is a fundamental property of matter that describes the intrinsic electrical property of particles such as electrons and protons. It is one of the key concepts in physics and plays a fundamental role in understanding the behavior of matter and the interactions between particles. There are two types of electric charge: positive and negative. Protons are positively charged, while electrons are negatively charged. Positive charges repel each other, and negative charges repel each other, but positive and negative charges attract each other. The principle of conservation of electric charge states that the total electric charge in a closed system remains constant. In other words, electric charge cannot be created or destroyed, only transferred from one object to another. Electric charge is quantized, meaning it comes in discrete, indivisible units. The elementary charge (e) is the charge of a single proton or electron and is approximately equal to 1.602E-19 coulombs...

September 11, 2001 - Never Forget

Islamic terrorist attack on UAL Flight 93, September 11, 2001 - RF CafeIslamic terrorist attack on the Pentagon, September 11, 2001 - RF CafeIslamic terrorist attack on the twin towers, September 11, 2001 - RF CafeIncredibly, 22 years have passed since the extremist Islamic attack on American soil on the morning of September 11, 2001. Nearly 3,000 citizens died that day. World leaders have embarked on a path of colonizing our homelands with groups of people that are known to harbor sympathies for the terrorists. They dwell among us now and mean to do us harm when opportunity presents itself - which it has on numerous occasions in the past many years. Never forget the people who died in the burning towers, the Pentagon, and the airplanes, and those left behind to grieve and get on with life. Never forget the police and military members who fought - and some died - to keep us safe and free. Never forget the rotten politicians who imperil our existence with their selfish agendas.

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 visits each weekdayRF 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...

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.

Sunday the 10th

Electronics Theme Crossword for September 10th

Electronics Theme Crossword Puzzle for September 10th, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for September 10th contains words and clues which pertain exclusively to the subjects of electronics, science, physics, mechanics, engineering, power distribution, astronomy, chemistry, etc. Given that today is the 10th day of the month, many words in this crossword start or end (or contain) the 10th letter, "J." If you do see names of people or places, they are intimately related to the aforementioned areas of study. 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...

Get Your Custom-Designed RF Cafe Gear!

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

Thanks to PCB Directory for Continued Support!

PCB  Directory - RF CafeThe leading website for the PCB industry. PCB 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.

Friday the 8th

Fairchild Semiconductor - Dual Inline Package

Fairchild Semiconductor Ad, Dual Inline Package, December 13, 1965 Electronics Magazine - RF CafeMaybe at one time I knew this, but the claim by Fairchild Semiconductor in this 1965 Electronics magazine advertisement took me by surprise. They claim to have invented the dual-inline-package (DIP) format. According to Wikipedia, a trio of chaps - Don Forbes, Rex Rice and Bryant Rogers - all Fairchild engineers, developed the DIP package in 1964, a year prior to the ad. Previously, a round can designated TO# (Transistor Outline) with # (number) leads around the perimeter was used for integrated circuits, but as the I/O pin count increased, that form factor became unwieldy. An extensive search for a patent on the DIP, assigned to Fairchild and/or the three inventors, did not turn up anything. I did find this one for "Lead frame design," which is for a TO-220 type outline...

Robots to Maintain World's Only Giant Radiotelescope

Robots to Maintain World's Only Giant Radiotelescope - RF Cafe"Robots will soon be deployed to carry out maintenance work at China's giant radio telescope, state media reported, holding out hope for eliminating the potential hazards posed by human repair workers. Five intelligent robots, capable of automatically performing tasks without human instruction, have passed inspection for maintenance work at the Five-hundred-metre Aperture Spherical radio Telescope (FAST), Xinhua reported late last month. Located in China's southern Guizhou province, FAST is the world's largest single-dish radio telescope. It is now also the world's only giant radio telescope, after the collapse of Puerto Rico's Arecibo Observatory telescope in 2020. The Arecibo collapse shocked many worldwide, but for those in charge of maintaining the 305-metre-wide instrument, alarming signs including poor maintenance..."

Thévénin's Theorem

Thévénin's Theorem (ChatGPT-generated content) - RF CafeThévénin's Theorem is a fundamental concept in electrical engineering that simplifies complex linear electrical networks into simpler, equivalent circuits. It's named after the French engineer Léon Charles Thévénin, who formulated the theorem. Thévénin's Theorem is particularly useful for analyzing and solving circuits with multiple components and sources. The theorem states that any linear electrical network with multiple sources and resistive elements can be replaced by a single voltage source (Thévénin voltage) in series with a single resistor (Thévénin resistance). This simplified equivalent circuit is called the Thévénin equivalent circuit. Here are the key components of the Thévénin equivalent circuit: Thévénin Voltage (Vth): The Thévénin voltage (Vth) is the open-circuit voltage measured across the two terminals of interest in the original circuit after all the independent voltage sources have been replaced with short circuits and all the independent current sources have been replaced with open circuits. In other words, Vth is the voltage you would measure between the two terminals when no load is connected. Thévénin Resistance (Rth): The Thévénin resistance (Rth) is the equivalent resistance measured across the same two terminals in the original circuit...

Idiots from My USAF Tech School Days

Idiots from My USAF Tech School Days - RF CafeHere is an old RF Cafe Forums post from November 21, 2005, I ran across today, and thought you might enjoy the flashback of Idiots from My USAF Tech School Days. It begins: "For some reason while retrieving change from a vending machine today, I was reminded of a story from my Air Force tech school days - two of them. Story #1 actually involved a vending machine. The barracks at Keesler AFB, MS, had three floors and, oddly enough, the only floor with vending machines was the one at ground level. The soda machine was notorious for taking your dollar bill or quarters and not giving back any change. Wise airmen quickly learned to use exact change. But, there were always new people coming into the barracks, so the vending machine operator always had a fresh batch of suckers for their machine. At least that's what I though, too, until one day I observed some guy slamming the machine after it ate his change. After he left, I figured I'd try shaking the machine a while to see if I could get his change. No luck. However, I went up to my room and got a clothes hangar and poked an end up into the change slot. I found a wad of napkins crammed up in there. When I dug them out, voila, about $5 in change fell onto the floor. Some scumbag had been collecting his fellow servicemen's money for who knows how long. After I spread the word, he must have figured we were on to him and didn't do it any more. Never did find out who it was..."

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!

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."

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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Innovative Power Products Cool Chip Thermal Dissipation
Anritsu Test Equipment - RF Cafe

everythingRF RF & Microwave Parts Database (h1)

withwave microwave devices - RF Cafe