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Today in Science History

Stretching the Junk Box

Stretching the Junk Box, April 1952 QST - RF CafeWe live in days of plenty of everything. People throw away and stash away items that our parents - and particularly grandparents - could only dream of having available. Even households that have never seen a penny of earned income in decades are overflowing with stuff. Shopping carts in Walmart, K-Mart, and Target are filled to overflowing when I am there with toys, shoes and clothes, electronic gadgets, sporting goods, automotive accessories, pet food (Target has reefers with fresh meat for dogs) and accessories, lawn and garden implements, hand tools, DVDs and Blu-rays, televisions, disposable diapers (lots of disposable diapers), snack cakes and crackers, soda, bottles of - get this - water (that costs as much as soda), ice cream, frozen pizzas and microwaveable dinners, energy bars and bags of candy. You get the picture. People have so much stuff that one of the largest areas of the store is the plastic storage bin section - reserve one for each giant...

Howard W. Sams & Co. Photofact

Howard W. Sams & Co. Photofact, April 1962 Radio-Electronics - RF CafeThis Sams Photofact ad from a 1962 issue of Radio-Electronics magazine is a good example of why the company's electronics product service packets were so highly regarded. A couple other competitors came and went in the decades of the twentieth century, but Sams kept on because of their reputation. In fact, Sams Technical Publishing is still in business today! By 1962, the electronics industry was in the beginning stages of transitioning from vacuum tube amplifiers and rectifiers to solid state equivalents, and from point-to-point wiring to printed circuits. The illustrations created by Sams artists for point-to-point component hookups were very high quality, and as can be seen here, those for printed circuits were equally good. One and two sided PCBs were the rule in the day, and sweeping curvy trace lines with big round soldering pads were used - partly because they were easy to create, and because the absence of sharp points eliminated peeling points...

Hybrid Bonding Plays Starring Role in 3D Chips

Hybrid Bonding Plays Starring Role in 3D Chips - RF Cafe"Researchers at the IEEE Electronic Components and Technology Conference (ECTC) last week pushed the state of the art in a technology that is becoming critical to cutting-edge processors and memory. Called hybrid bonding, the technology stacks two or more chips atop each other in the same package, allowing chipmakers to increase the number of transistors in their processors and memories despite a general slowdown in the pace of the traditional transistor shrinking that once defined Moore's Law. Research groups from major chipmakers and universities demonstrated a variety of hard-fought improvements, with a few showing results that could lead to a record density of connections between 3D stacked chips of around 7 million links in a square millimeter of silicon. All those connections are needed because of the new nature of progress in semiconductors, Intel's Yi Shi told engineers at ECTC..."

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 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...

Dilbert on Trade Shows - IMS 2024

Dilbert on Trade Shows - RF CafeBeing that the world's largest RF and microwave trade show, IMS2024 (International Microwave Symposium - see Exhibit Floor map highlighting RF Cafe sponsors) is happening beginning June 16th in Washington, D.C., I thought this Dilbert™ comic strip from May 6, 2012, would be a fitting subject for posting on RF Cafe. Having been to a couple of the IMS shows and talking to exhibitors, many seem to actually relate to Dilbert's experience. RF Cafe advertiser booth locations on IMS 2024 exhibit hall floor map. - RF CafeThe main value of having a presence there is often simply being seen in the realm of major players, which confers a certain level of industry gravitas. So, even if spending a week at the show does not directly result in new customers, at least some companies believe the cumulative effect of a persistent presence will pay off in the long run. At least one major RF/microwave manufacturer has concluded otherwise...

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+ 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...

Anatech Electronics June 2024 Newsletter

Anatech Electronics June 2024 Newsletter - RF CafeSam Benzacar, of Anatech Electronics, an RF and microwave filter company, has published his June 2024 newsletter that, along with timely news items, features his short op-ed entitled "The Vital Role of Microwave Technology in Quantum Systems." In it, he discusses the use of microwave components in quantum computers. I have noticed in the photos of the quantum computers, suspended by fine cables giving them a golden chandelier look, that there seems to be lots of small diameter coaxial cable and connectors plugging into what appears to be standard microwave-like packages. Turns out, according to Sam, that those are coaxial cables and components like mixers, amplifiers, directional couplers, circulators and isolators, and of prime interest to him, filters. It all still seems like black magic, as does aka quantum teleportation and entanglement (or "spooky action at a distance" as Albert Einstein referred to it)...

Lord Kelvin and His Analog Computer

Lord Kelvin and His Analog Computer - RF CafeThis tide-predicting machine was one of many advances he made to maritime tech. "In 1870, William Thomson, mourning the death of his wife and flush with cash from various patents related to the laying of the first transatlantic telegraph cable, decided to buy a yacht. His schooner, the Lalla Rookh, became Thomson's summer home and his base for hosting scientific parties. It also gave him firsthand experience with the challenge of accurately predicting tides. Mariners have always been mindful of the tides lest they find themselves beached on low-lying shoals. Naval admirals guarded tide charts as top-secret information. Civilizations recognized a relationship between the tides and the moon early on, but it wasn't until 1687 that Isaac Newton explained how the gravitational forces of the sun and the moon caused them. Nine decades later, the French astronomer and mathematician Pierre-Simon Laplace..."

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, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Electronics-Themed Comics

Electronics-Themed Comics, May 1962 Radio-Electronics - RF CafeHaving been born sometime before around 1970 will make it much more likely that you will be familiar with the scenarios depicted in these three electronics-themed comics. They appeared in a 1962 issue of Radio-Electronics magazine (I colorized them). The comic from page 72 can be applied to to modern day situations where an owner calls in a repairman after he tinkers around trying to save some money on a service call, and makes things worse than they were to begin with, then trying to BS the serviceman into believing he hasn't monkeyed with it. The page 96 comic is a guy thing - which used to be allowed before tender feeling were offended by such things. The last one brings back memories of being in the local convenience store with my father as he is checking the vacuum tubes...

FM Carrier Stabilization: the Phasitron

FM Carrier Stabilization, May 1946, Radio-Craft - RF CafeHere is another instance of an article which, if it had been in an April magazine issue, you might be justified in thinking it might be a gag. "FM Carrier Stabilization," a 1946 Radio-Craft feature, centers around the use of a General Electric (GE) GL-2H21 "Phasitron" vacuum tube. Be assured that it is a real component, developed to address the difficulties in achieving frequency modulation (FM) requirements set forth by the Federal Communications Commission (FCC) at what was really the dawn of the FM commercial broadcast radio era. Only a little over a decade had passed since Major Armstrong announced his broadband FM invention, and radio stations were planning to adopt the superior (to AM) form of broadcasting at a rapid rate, following the end of World War II. The Phasitron was GE's solution to the problem of maintaining the average carrier frequency stability requirement...

Analog Computers Solve Complex Problems

Analog Computers Solve Complex Problems, November 1951 Radio & Television News - RF CafeCharles Babbage's 19th century Difference Engine might be considered the beginning of complex mechanical calculators' use in science and engineering. It really was not all that long ago. Massive single-purpose analog computers were designed and constructed in the middle of the last century for calculating, among other things, projectile trajectories, multi-body orbits, electrical circuit functions, nuclear detonations, calculation of mathematical function tables, and navigation. Eventually electrical computers joined the arsenal of tools available to significantly reduce the amount of time required to carry out complex calculations requiring multiple iterations using a range of input variables. Programmable vacuum tube and then transistorized digital computers expanded the range of applications, but recall that even by the early 1960s, during the early manned space flight projects...

Editorial: Radiobotage

Editorial: Radiobotage, May 1941 Radio-Craft - RF CafeAn incredibly glaring example of the famous admonishment* that those who ignore history are condemned to repeat it, Radio-Craft magazine editor Hugo Gernsback wrote in May of 1941, a full half year before the United States of America officially entered World War II, about how current conditions regarding domestic commercial radio broadcast stations were likely being used by German agents to send coded messages to offshore vessels (ships, submarines, and aircraft). In example, he cited, amazingly, an article he himself published in 1915 in The Electrical Experimenter magazine accusing Dr. K. G. Frank, of the German Telefunken company, of conducting spy operations from the Sayville, NY, station on Long Island. A copy of the letters that were exchanged between Mr. Gernsback and Dr. Frank were reprinted in this edition (see "Sayville Once More"). Spoiler alert in case you don't read the other article: Dr. Frank was eventually arrested for his espionage activities and interred for the duration of WWI...

"Grounds" for Confusion

"Grounds" for Confusion, January 1960 Electronics World - RF CafeRobert Gary waxes philosophical on the subject of ground in his Electronics World magazine article, "'Grounds' for Confusion." He is justified from the viewpoint of someone attempting to make sense of how something as seemingly fundamental as Earth ground is not a constant. The layman probably doesn't care. Practitioners in the electrical and electronics realms who deal only with low frequencies and short distances might occasionally be affected by differences in ground potentials, although they might not realize it is the cause of their problems. Those with more than a casual involvement (designers, installers, and maintainers as opposed to only users) in high frequencies and/or long distance signal interconnections are likely to be intimately familiar with the effects of ground potential differences...

News Briefs

News Briefs, April 1962 Radio-Electronics - RF CafeWhen this News Briefs column appeared in a 1962 issue of Radio-Electronics magazine, solid state infrared (IR) detectors were still a relatively new technology, and integrated circuits had not entered the commercial marketplace. Developing an IR orientation sensor compact enough to fit a pair of them (azimuth and altitude sensing) into an orbiting surveillance platform was quite a feat. A phased array could not be made small enough, so a rotating angled mirror was used for steering - reminiscent of the early electromechanical television scanning systems. Also reported, among other things, were a new ruby laser, fraudulent color TV tube claims, and more women entering the engineering and science fields...

Axiom Blog: Calibration Baths Fine Tune Temperature

Axiom Test Equipment Blog: Calibration Baths Fine Tune Temperature - RF CafeAxiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post that covers how temperature calibration baths provide a dependable means of calibrating temperature sensors of different shapes and sizes, with capabilities of many at one time. Often simply called calibration baths, temperature calibration baths are not just tanks for temperature-controlled fluids. They are integrated systems consisting of a stainless-steel tank, a condensing coil and cooling plate, a heater, propeller, and stirring motor. These components combine to maintain selected fluids within the tank at tightly controlled temperatures across a wide temperature range. When evaluating temperature calibration baths, parameters for comparison include the volume, size, and weight of the bath, its total temperature range, power consumption, heating and cooling times...

Many Thanks to San Francisco Circuits for Continued 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."

Electronics-Themed Comics

Electronics-Themed Comics, January 1969 Electronics World - RF CafeHere are a couple tech-themed comics that appeared in the October 1969 issue of Electronics World magazine. I like the one with the two guys applying for a patent best. Note the size difference. Of course the mother-in-law comics are always funny. There is a huge list at the bottom of the page of links to other comics I have posted over the years. BTW, people have asked why I separate the text from the image. The answer is simple: If someone finds the image using an image search, he/she has to actually visit the webpage to get the punch line. Does that make me a bad person?

Intermodulation Distortion

Intermodulation Distortion, February 1960 Electronics World - RF CafeAudio distortion is most often expressed as total harmonic distortion (THD) as opposed to intermodulation distortion (IMD). As the name suggests, THD is a measure of harmonic power content relative to the fundamental frequency (a single tone) from which harmonics are created. IMD on the other hand, is generated from the nonlinear mixing of two or more tones, with the products being non-harmonically related to the original tones. The author's discussion of audio frequency IMD applies equally to radio frequency IMD. Intentionally generated harmonic components can enhance sound quality due to being consonant, whereas IM products create dissonant tones not directly related to the originals. Audio amplifier frequency vs. power specifications typically include the sum of total harmonic distortion and noise (THD+N), signal-to-noise ratio (SNR)...

Fine Points of Filter Theory

Fine Points of Filter Theory, April 1962 Radio-Electronics - RF CafeSometimes one of the most interesting parts of a magazine is the Letters to the Editor. Most of the time it is composed of notes of appreciation for publishing a certain article, or appreciation for the works overall. Occasionally, a reader will sound off with a criticism of and article - some more polite than others. The magazine editor will usually give the author a chance to respond immediately after the challenge to content veracity. Such was the case in the March 1967 issue of Radio-Electronics magazine when a Zenith company engineer wrote to correct a previous article's claim regarding linear phase filter design in FM radio systems. Author Crowhusrt happened to mention in an AM-to-FM converter circuit that a Zenith scheme might not be the best approach for the application (versus a General Electric scheme). Zenith's Huenemann meant to set the record straight, but Mr. Crowhust did an admirable job defending his writing. Nerd wars...

Exodus AMP2145D-LC, 18-40 GHz, 80-W SSPA

Exodus AMP2145D-LC, 18-40 GHz, 80-W SSPA - Another Industry First! - RF CafeExodus Advanced Communications, is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. We are pleased to announce the Exodus Model AMP2145D-LC, a 18.0-40.0 GHz, 80 W Solid State Amplifier is another industry first from Exodus. Designed for Broadband EMC & Lab Testing, Mil-Std 461 (RS103) standards as well as other High-Power Applications. Exodus Model AMP2145D-LC is a compact 6U design providing outstanding power/gain flatness, Forward/Reflected power monitoring in both dBm & watts, VSWR, voltage/current and temperature sensing for superb reliability and ruggedness. Unprecedented reliability compared to TWT's, with 49 dB gain including gain control, and -20 dBc harmonics...

Glass Packaging for Small Footprint HF Modules

Glass Packaging for Smaller Footprint for High-Frequency Modules - RF Cafe"ED2 Corporation, a company that designs a range of products in electronics and wireless communications, has developed Advanced Glass Packaging Technology (AGPT™) that will enable heterogeneous integration of electronic components and modules. The AGPT technology is based on using Synthetic Quartz (Fused Silica) as the substrate material that exhibits excellent thermal, electrical, and optical properties. It enables ultra-small feature sizes, excellent high frequency response, allowing for tight integration and supporting fabrication as a wafer-level process, for scale and cost. The heterogeneous integration of components is facilitated..."

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, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers" Smith chart design. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. My graphic has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. I only make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way to help support RF Cafe. Thanks...

How Do We Hear?

How Do We Hear? Part II, June 1936 Radio-Craft - RF CafeA story in an electronics magazine on the physics and biology of the human ear is as relevant today as it was in 1936 when this appeared in Radio-Craft magazine. Back then, creating sound in an efficient and effective manner for consumer, commercial, and military purposes was a relatively new science. Thomas Edison introduced his phonograph in 1877. While it did not feature an electrically driven speaker, research determined the shape, size, and material composition of the mechanism that converted minute grooves etched into the surface of a cylinder into sound pressure great enough for perception. Alexander Graham Bell's telephone of the same era (1876), used an electromagnetic coil to power a speaker membrane. 40 years later, radios were appearing everywhere and the race was on to provide high fidelity sound as a means to differentiate quality models from lesser models. Much research - the first of its kind - was performed on the workings of the human in an attempt to quantify its functional parameters...

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 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 Banner Ads are displayed on average 280,000 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...

9 of the Latest New Developments from G-E Research

Nine of the Latest New Developments from G-E Research, March 6, 1964 Electronics Magazine - RF CafeHalf a decade after Texas Instruments (Jack Kilby, 1958) and Fairchild Semiconductor (Robert Noyce, 1960) produced the first semiconductor integrated circuits, General Electric must not have been too confident that the newfangled technology was going to take hold. This 2-page spread from a 1964 issue of Electronics magazine, promotes their "Compactron" integrated circuit vacuum tubes. The Compactron is a building block concept where standardized stages of diodes, triodes, pentodes, etc., are encapsulated in a single vacuum tube package with necessary input and output pins for connecting external components. The incentive was smaller volume, lower parts count, lower power supply current, simpler chassis wiring or circuit board layout, and greater ruggedness. One source I found showed the availability in 1962 of 24 distinct Compactron models...

Thin Air My Foot!

Thin Air My Foot!, July 1956 Popular Electronics - RF CafeWhilst reading this Carl Kohler technodrama™ entitled "Thin Air My Foot!," I happened upon this word new to me: 'din,' as in "It was dinned into me." OK, maybe you already knew that, but surely I should have been aware of its alternate meaning other than being a loud noise ("the agitated cat made quite a din"). Fortunately, I am not subject to a household of people who refuse to put things back in their respective places when through with them, but this tale of woe tells what might be a familiar scenario to you. To be honest, this could have been written about me as a boy - before the U.S. Air Force taught me a thing or two about organization and neatness - since I continually frustrated my father by leaving his tools (and hardware and lumber and paint) scattered...

News Briefs

News Briefs, January 1961 Radio-Electronics - RF CafeTo show how far in advance of publication date magazines used to need to have their content submitted, this January 1961 issue of Radio-Electronics noted the fortieth anniversary of the country's first commercial radio broadcast by KDKA on November 2, 1920 (two months). KDKA's first daily broadcast began on September 20, 2021. Also reported was a record 100 mile underground communication record. Using a buried antenna, it used a new transmission mode that exploits the interface region between the ground surface and the atmosphere. A new international standard meter was changed to the length of 1,650,763.73 wavelengths of the orange-red line of light given out by krypton 86. Since 2019, the meter is defined as the distance light travels in a vacuum in length of the path travelled by light in vacuum in 1/299792458th of a second, based on a cesium time standard. A color TV standard...

Engineering & Tech Headlines <Archives>

ARRL Youth Rally Success at Dayton Hamvention

UK Semiconductor Institute Creation

More Spectrum to Add $27B to India's GDP

• U.S. Tariffs Prompt Supply Chain Shift

• IARC Again Asked to Review RF Cancer Risk

Electronic Crosswords

Electronic Crosswords, April 1960 Electronics World - RF CafeJohn Gill published many electronics-themed crossword puzzles in Electronics World magazine in the 1950s and 1960s. Unlike the weekly RF Cafe engineering crossword puzzles, some of the words used herein are not directly related to science, engineering, mathematics, etc. Some of the words are more particular to the era, but that shouldn't present too much difficulty. You will find the level of difficulty much less than that of a Sunday edition New York Times crossword, but there are some challenging clues, particularly given the era that it was created. Bon chance...

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! 

Zener Diodes Simplified

Zener Diodes Simplified, January 1961 Radio-Electronics - RF CafeZener diodes, named after their inventor, Clarence Zener, were a paradigm-changing introduction to the electronics industry. At a very low price and parts count, precise and stable voltage sources can be built for just about any voltage reference level. Zeners are designed to operate in the breakdown region of the pn junction which is normally avoided with standard rectifier diodes. That voltage level is predictable and consistent. A standard range of voltages (2.7 V, 3.0 V, 3.3 V, 3.6 V, 3.9 V...) are manufactured to satisfy most needs. Notice a familiar pattern there? Yep, they follow the standard 5% tolerance resistor value series. I don't know why that was done - there is no semiconductor physics reason for it. Just as having a standard 5x10n Ω value for resistance would be extremely handy, so it would be for a voltage reference, given the prevalence of 50 Ω for impedances and 5.0 V for digital circuits...

Vintage College Engineering Labs

Vintage College Engineering Labs - RF CafeWhen I think back at the engineering labs from my days in school, I wonder how much things have really changed from then until now. It is hard to believe that freshman and sophomore labs are not still consumed with radial lead resistors, inductors, and capacitors, solderless breadboards, and a variety of light bulbs, motors, transformers, relays, and rheostats. By the time you move into the junior year, labs have gotten a bit more intense with microprocessor controls (mine used an 8088 CPU with machine language programming for the serial port), some high voltage apparati[sic], digital logic circuits (74-series leaded ICs), and a chance to lay out/fabricate/populate a PCB. On-hand test equipment consists of 2nd or 3rd generation oscilloscopes, signal generators, and power supplies...

Radar-Tracking Accuracy Increased

Radar-Tracking Accuracy Increased, May 4, 1964 Electronics Magazine - RF CafeThe many idiosyncrasies of atmospheric phenomena that affect long distance communications are certainly more well known and understood today than they were in the early days of radio. Ionization, temperature and pressure gradients, suspended particulate contamination, and other factors have been extensively studied, measured, and modeled. Daily and seasonal patterns are somewhat predictable and exploitable for purposes of general use, but short term variability that affects long distance radar measures of distance, altitude, and speed requires near instantaneous, pulse by pulse analysis of atmospheric conditions. Research and development of methods for accommodating short term variations that skew measurements are an ongoing science. An extreme example of atmospheric variation compensation is the method used by ground-based telescopes that shine lasers into the ionosphere to create "artificial stars" whose scintillation properties can be used in both software and adaptive optics to cancel out apparent changes in position and intensity...

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.

Temwell's 30% Off Sale for June!

Temwell's 30% Off Sale for June!- RF CafeTemwell is running a 30% Off sale on it's in-stock line of filters --- for the entire month of June. Temwell is a manufacturer of 5G wireless communications filters for aerospace, satellite communication, AIoT, 5G networking, IoV, drone, mining transmission, IoT, medical, military, laboratory, transportation, energy, broadcasting (CATV), and etc. An RF helical bandpass specialist since 1994, we have posted >5,000 completed spec sheets online for all kinds of RF filters including helical, cavity, LC, and SMD. Standard highpass, lowpass, bandpass, and bandstop, as well as duplexer/diplexer, multiplexer. Also RF combiners, splitters, power dividers, attenuators, circulators, couplers, PA, LNA, and obsolete coil & inductor solutions...

Empower RF High-Power S-Band Pulsed Transmitter

Empower RF Systems High-Power S-Band Pulsed Transmitter - RF CafeEmpower RF Systems, the technology leading provider of high-performance RF amplifiers, is proud to announce the launch of the Model 2254 S-Band Pulsed Transmitter. This air-cooled, high-power transmitter operates from 2900 to 3500MHz and is designed to meet the demanding requirements of radar and electronic warfare applications. The Model 2254 boasts an impressive peak power output of 15kW peak power, making it one of the most powerful S-band transmitters in its class. With a duty cycles up to 20% and pulse widths up to 500 micro seconds, this transmitter is capable of delivering sustained high-power pulses for extended periods, ensuring reliable performance in mission-critical scenarios. This transmitter combines cutting-edge technology with robust design, delivering unparalleled performance and reliability for our customers' most challenging applications in radar, electronic warfare and directed energy research.

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 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...

Air Corps Radio Phraseology Training

Air Corps Radio Phraseology Training, January 1945 Radio News - RF Cafe"Say again." That phrase is heard often in telephony conversations both wired and wireless. It was coined near the end of World War II by Air Corpsman 2nd Lt. Byron A. Susan, as reported in the January 1945 edition of Radio Craft magazine. Lt. Susan was responsible for setting standards for "radio phraseology" to eliminate ambiguity between aviators and ground forces. "Say again" replaced "Repeat" because the latter is an artillery term used to order another round of assault from a gun salvo. The history of the confirmation "Roger" is murky, but many agree it comes from the older military phonetic pronunciation of the letter "R" being "Roger," and in radio the letter "R" meaning "received." Another common bit of radio phraseology is "Wilco," which is a contraction of the words "will comply..."

Forgotten History Chinese Keyboards

Forgotten History Chinese Keyboards - RF CafeToday, typing in Chinese works by converting QWERTY keystrokes into Chinese characters via a software interface, known as an input method editor. But this was not always the case. Thomas S. Mullaney's new book, The Chinese Computer: A Global History of the Information Age, published by the MIT Press, unearths the forgotten history of Chinese input in the 20th century. In this article, which was adapted from an excerpt of the book, he details the varied Chinese input systems of the 1960s and '70s that renounced QWERTY altogether. 'THIS WILL DESTROY CHINA forever,' a young Taiwanese cadet thought as he sat in rapt attention. The renowned historian Arnold J. Toynbee was on stage, delivering a lecture at Washington and Lee University..."

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 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 Banner Ads are displayed on average 280,000 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...

Down-to-Earth Discussion - Resistance of a Ground

Down-to-Earth Discussion - Resistance of a Ground, October 1963 Electronics World - RF CafeFor some reason the subject of grounding has been very prominent in my reading in the last few days. The chapter I just finished reading in one of David Herres' books on the National Electric Code (NEC) covering grounding of commercial and residential services, an article by H. Ward Silver in QST titled, "Grounding and Bonding Systems," and now this article by John T. Frye (of Carl and Jerry fame) on grounding, makes for a wealth of knowledge. Mr. Frye takes a unique approach at teaching by exploiting his gift for story-telling. In this article, electronics repair shop owner Mac McGregor gives technician Barney a nice bit of tutelage on what constitutes a good Earth ground and what does not. In some environments, treating the soil with an electrically conductive substance...

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, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Solve Your Problems with Kirchhoff's Laws

Solve Your Problems with Kirchhoff's Laws, April 1962 Radio-Electronics - RF CafeNot to disrespect Gustav Kirchhoff's accomplishments, but his two eponymous laws seem so obvious that you might wonder why they even need to be stated, much less be named after someone. The equivalent for the oft-used water in a hose analogy would be as follows: (#1) The volume of water entering the common port of a manifold is equal to the sum of the water exiting all the other ports. (#2) In a closed system, the sum of the the pressure drops (e.g., constricted pipe) and pressure rises (e.g., water pump) is zero. In fairness, when Mr. Kirchhoff formulated his laws in the middle 19th century not many people were familiar with electric circuits, and instruments for making certified measurements with enough precision to validate the claims were not readily available. This 1962 Radio-Electronics magazine article introduces Kirchhoff's current law and voltage law. Remembering and applying them does make writing equations for multi-loop circuits much simpler...

Engineering & Tech Headlines <Archives>

• U.S. Revokes Huawei Chip Export Licenses

• FCC Investigates Unauthorized Undersea Cables

463,000 Kia e-SUV Should Park Outside Pending Recall

Ofcom Plan for Hybrid Sharing of Upper 6 GHz Band

Quantum Computing Market on 17% CAGR to $1.8B in 2029 

How to Target RFCafe.com for Your Google Ads

Google AdSense - it makes good sense - RF CafeOne aspect of advertising on the RF Cafe website I have not covered is using Google AdSense. The reason is that I never took the time to explore how - or even whether it is possible - to target a specific website for displaying your banner ads. A couple display opportunities have always been provided for Google Ads to display, but the vast majority of advertising on RF Cafe is done via private advertisers. That is, companies deal with me directly and I handle inserting their banner ads into the html page code that randomly selects and displays them. My advertising scheme is what the industry refers to as a "Tenancy Campaign," whereby a flat price per month is paid regardless of number of impressions or clicks. It is the simplest format and has seemed to work well for many companies. With nearly 4 million pageviews per year for RFCafe.com, the average impression rate per banner ad is about 280k per year (in eight locations on each page, with >17k pages)...

D-Day Radio

RF Cafe website visitor Joseph B. sent me this note in regard to this 80th anniversary of the D-Day invasion:

"Below are a few links regarding D-Day (which is today). The first [Radio Comms] is a link to how radio comms were setup during the invasion, the second [Broadcasts Link] is a collection of news broadcasts on the day of the event, and the third is an article about local radio technician and baseball hero, Jim Pinder, who stormed Normandy beach carrying 52 lbs of radio equipment. Lastly, a very heartfelt "Thank you!" to all who served and to those who gave their lives.

Hughes Research and Development Laboratories

Hughes Research and Development Laboratories, October 1955 Radio & Television News - RF CafeWhen I saw this Hughes Research and Development Laboratories employment ad in a 1955 issue of Radio & Television News magazine, I wasn't sure how to take it. The text of the ad makes no reference to the bar graph and the weird drawing. Note the "bottle" is actually a slide rule. The graph can be interpreted to indicate that the more education a person has, the less likely he is to have children. If the typical age of the respondent is in the twenties, then that might reflect how people still in school to earn a higher degree would not be having children. It might also show that people with higher degrees focus more on their careers than on having a family. If you extrapolate the graph backward, does it imply people with an Associate's degree might average 1.5 children, those with just a high school diploma have about 1.7 children, and high school dropouts average maybe 2.0 kids...

WWII Era Electronics Advertisements in QST

Cool Pic - WWII Era Electronics Advertisements in QST Magazine - RF CafeToday is the 80th anniversary of D-Day. Maybe it comes from having crossed the half-century Rubicon, but with increasing frequency I find myself seeking out vintage magazines to learn how the world used to be. I am a realist who has no misconceptions about how things used to be idyllic and that today is utter debauchery, but it is apparent from a lot of the publications that we surely have changed significantly in the last 50+ years - better in some ways, worse in others. Technologically we are much better off; societally, not so much. For many years I have been purchasing of WWII era QST and other electronics magazine titles listed on eBay. I do the same thing for vintage model magazines on my Airplanes and Rockets website. Selected articles and advertisements are scanned...

Temwell Filters

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RF Electronics Shapes, Stencils for Office, Visio by RF Cafe