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Homepage Archive - April 2022 (page 4)

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

Friday the 29th

Packaged Radar

Packaged Radar, October 1952 Radio & Television News Article - RF CafeRyan Aeronautical Company was founded in 1934, and became part of Teledyne in 1969, eventually being owned Northrop Grumman in 1999. Ryan, which produced many airplanes and drones, was perhaps most famous for building the Spirit of St. Louis (Ryan NYP) used by Charles Lindbergh on his historic transatlantic flight. Ryan also dabbled in jet engines and electronics. The "packaged radar" concept described in this 1952 Radio & Television News magazine article was the precursor to modular circuit assembly commonly used in military systems to facilitate rapid field repair...

Axiom Test Equipment Now NH Research Partner

Axiom Test Equipment Is Now an NH Research Official Rental Partner - RF CafeAxiom Test Equipment, and NH Research have reached an agreement for Axiom to become an NHR official rental partner in the U.S. Backed by over 50 years of experience, NH Research is able to offer world class test instruments and systems for a wide range of industries. Axiom Test Equipment, a premier provider of electronic test and measurement equipment rentals, sales and repair services, further expands its rental fleet of high-quality test instruments. As NH Research's rental partner, Axiom is excited to offer NHR's high-quality products as solutions to fill customers short-term project testing needs. This partnership allows Axiom Test Equipment to introduce NHR's grid simulators and battery test systems to users with shorter-term projects and those that want to "try before buying." Users now have a choice to rent or purchase equipment, based on their specific requirements. The list of industries now able to benefit from the partnership include, Aerospace, Automotive, Battery, Military, Industrial Power, and Renewable Energy...

Locating Your New Store

Locating Your New Store, April 1947 Radio News - RF CafeLocation, location, and location. Those are always half-jokingly cited as the three most important factors to consider when deciding where to best set up a retail business. Unfortunately, the days of scouting out a spot to set up an electronics sales and service shop are long gone. Except for a cellphone screen replacement service at a mall kiosk and maybe the Geek Squad desk at the Best Buy store, there are not many places left that do consumer electronics repair - at least as a primary vocation. This story makes a good read for anyone contemplating setting up shop where serving the local population is a prime objective. About two years ago, I visited a couple up-for-sale buildings being looked at by daughter, Sally, for a business location. One building was a former TV and radio repair shop that...

5 Key Workflows that Deliver 3D IC Packaging Success

5 Key Workflows that Deliver 3D IC Packaging Success - RF CafeIf you are into such things, this whitepaper entitled "Five Key Workflows that Deliver 3D IC Packaging Success" from Siemens might be a useful bit of info. Several factors are converging and driving the "chiplet" design revolution. This paper explores these factors and outlines five key workflows that address and manage the associated, new challenges. These five workflows span several interlinked domain areas: Architecture definition, design activities, multi-physics analysis, device-level test, and manufacturing. This paper recommends workflow adoption focus areas that provide immediate heterogeneous integration capability benefits while establishing...

Astrometry.com Plate-Solving Star Identifier

Astrometry.com Plate-Solving Star Identifier - RF CafeThe term "plate solving" (aka "astrometric solving") in astronomy has its roots in the days when dinosaurs roamed the earth and images of the sky were captured on, gasp, glass plates with photosensitive emulsion coatings. Attempting to identify astronomical items on a plate, or paper photograph developed from a plate, was/is similar to finding an unfamiliar star, nebula, or galaxy when viewing the heavens through binoculars or a telescope. You begin with a nearby entity you are familiar with, and then move in the direction of the object being sought. Sometimes a process known as "star hopping" is used to move from point to point in a predictable combination of direction and distance from the current star (or whatever). With the advent of digital photography, software programmers have developed algorithms that assess and map all the points in an image, then compare it to a calibrated set of points from carefully processed images and attempt to identify all the astronomical objects in the investigated image. Only fairly recently has a highly efficient method of computer plate solving been available. Fortunately, the community of professional and amateur astronomers has produced a plethora of software tools...

Diode Modulators

Diode Modulators, April 1953 QST - RF CafeByron Goodman published a very thorough diode modulator article in a 1953 issue of the American Radio Relay League's QST magazine. It was one of the first of such articles that used the very recently available semiconductor diodes rather than the previously used vacuum tubes. Single-balanced bridge and ring modulator circuits are presented, along with the theory behind their operation. It would be a few years more before double balanced mixers with their abilities to reject even intermodulation products, and triple balanced mixers with very high overall spurious product rejection, would become commonplace...

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 Again for Windfreak Technologies' Continued Support!

Windfreak TechnologiesWindfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project.

Thursday the 28th

600,000 U.S. Transmitters

600,000 U. S. Transmitters, March 1954 Radio-Electronics - RF Cafe1954 was in middle of a time of many transitions in the electronics world. Vacuum tubes were being replaced by semiconductors, point-to-point wiring in chassis was giving way to printed circuit boards, FM was overtaking AM as the preferred radio medium, and color TV was (for those who could afford it) shoehorning itself into homes across America and the world. This article in Radio-Electronics magazine has the Federal Communications Commission (FCC) extolling the many virtues of telecommunications. I have not been able to ascertain whether it is a direct reprinting of an FCC publication or an excerpted section. At the time, there were 600,000 licensed transmitters including commercial and amateur radio operations. Interestingly, Industrial, scientific and medical (ISM) equipment is mentioned, although nothing about an unlicensed band have been allocated yet...

Why Aren't We Recycling Lithium Batteries?

Why Aren't We Recycling Lithium Batteries? - RF Cafe"Electric vehicles, power tools, smart watches - Lithium-ion batteries are everywhere now. However, the materials to make them are finite, and sourcing them has environmental, humanitarian, and economic implications. Recycling is key to addressing those, but a recent study shows most Lithium-ion batteries never get recycled. Lithium and several other metals that make up these batteries are incredibly valuable. The cost of raw lithium is roughly seven times what you'd pay for the same weight in lead, but unlike lithium batteries, almost all lead-acid batteries get recycled. So there's something beyond pure economics at play. It turns out that there are good reasons why lithium battery recycling hasn't happened yet. But some companies expect to change that, which is a good thing since recycling lithium batteries will be an essential part of the renewable energy transition. How extreme is the disparity between lithium and lead batteries? In 2021, the average price of one metric ton of battery-grade lithium carbonate was $17,000 compared to $2,425 for lead North American markets, and raw materials now account for over half of battery cost..."

Modern Radio Practice in Using Graphs and Charts

Modern Radio Practice in Using Graphs and Charts - Parallel Resistors, May 1934 Radio News and the Short-Wave - RF CafeThe value of memorizing multiplication tables, the proper spelling of words, the location of countries on a map, et cetera, is being questioned by many people these days based on an easy access to data on the Internet and other media. All such people need to do is get fairly close to spelling topics of interest correctly and other people who do not subscribe to the aforementioned philosophy have seen to it that the laziness and ignorance of those who do subscribe are duly accommodated. I'm referring to basic life skills of course, not nuclear science or phenology. The obvious advantage gained in memorization is developing an intuitive feel for what the entire realm of subject entails. Strong visual clues during the learning process augment retention of data. For instance, electronic calculators in their various forms are great for arriving at precise numerical answers with given input conditions. Enter an exact set of numbers and get an exact result on the display (right or wrong, depending on the input data and the correctness of the algorithm). Whether or not the answer makes sense and should be believed depends on the user's familiarity with expected results...

Rare Planetary Alignment Today

Rare Planetary Alignment TodayAccording to astronomical authorities, a once-in-a-millennium (1,075 years to be more precise) year alignment of the planets is occurring now. "During the last week of April 2022, a rare and unique planet parade will take place when Venus, Mars, Jupiter and Saturn will line up in the eastern sky around one hour before sunrise. This will be a planet parade of the third kind as described above. The last such parade of these planets occurred in 947 AD, around 1,000 years ago," said Indian planetarium Director Subhendu Pattnaik. The sun rises shortly before all are visible, so an unobstructed view of the eastern horizon is needed, which I do not have. The thumbnail above (click it) is a TheSkyX simulation I just did of the sky for this morning and for the year 947 AD. Sure enough, there they are again. History shows the last time this occurred hoards of people bought unfired clay bowls (aka software) from a vendor called Ready-to-Fire Cafeteria (aka RF Cafe). Will there be a repeat this time?

PCBs for the Automotive Industry

San Francisco Circuits: PCBs for the Automotive Industry - RF CafeSan Francisco Circuits (SFC) has launched its latest industry focus page, this time on PCB manufacturing & assembly for the automotive industry. This new industry focus page on PCBs for the Automotive Industry covers common uses for PCBs in automobiles, automotive PCB technologies, production capabilities, & best practices. As the circuit boards in automobiles become increasingly more complex and sophisticated, the need for reliable manufacturing has never been more important because they're most commonly utilized for safety measures. Automobile PCB applications include: airbags, anti-lock brakes, LED lighting, on-board & remote diagnostics, security systems, rear-view cameras, blinkers, & more. Adhering to Standard IPC-6012DA ensures the quality and reliability of PCB design & fabrication...

Mathematics in Radio - Differential Calculus

Mathematics in Radio - Differential Calculus, September 1932 Radio News - RF CafeThis entry level introduction of differential calculus as it applies to electronic circuit analysis appeared way back in a 1932 edition of Radio News magazine. It was written by none other than Sir Isaac Newton himself (just kidding, of course). Author J.E. Smith created an extensive series of lessons that began with simple component and voltage supply descriptions and worked up through algebraic manipulations and on finally to calculus. I remember not being the best math student in high school (OK, one of the worst), but once I got an appreciation for the power of mathematics for analyzing electronics, mechanics, physics, and even economics, my motivation level soared to where I craved more of it and ended up receiving "As" in all my college math courses. That is truly an indication that while not everyone can excel at math, the proper environment can make a world of difference...

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 (of course a gratuity will be graciously accepted). 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors ...

Thanks to Anritsu for Their Support!

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

Wednesday the 27th

Microwave Klystron Oscillators

Microwave Klystron Oscillators, May 1952 Radio & Television News - RF CafeBy now, engineers and scientists have managed to replace most vacuum tubes with solid state devices - at least for consumer products. The one place tubes remain are in microwave oven. Those klystron tubes operate in the 2.4 GHz band and typically output ranging from about 500 W to 2 kW. No doubt materials and methods have changed since the 1950s, but fundamentally klystrons of today are the same as klystrons then. Between this article and Part 1 that appeared in the April 1952 issue of Radio & Television News magazine, authors Joseph Racker and Lawrence Perenic provide a very nice introduction on the topic. 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 ...

IPP-8090 SM Dual Directional Coupler for 500-3000 MHz

Innovative Power Products IPP-8090 Surface Mount Dual Directional Coupler - RF CafeInnovative Power Products (IPP), with more than 30 years of experience designing & manufacturing RF & microwave passive components, is pleased to introduce their new model IPP-8090 dual directional coupler that handles 200 watts CW and comes in a SMD style package which is only 1.000 x 1.000 x 0.148 inches. The IPP-8090 is a unique broadband design which provides separate coupled ports for both forward and reflected signals with internal Terminations. Insertion loss is less than 0.30 dB, main line VSWR is less than 1.30:1, coupled flatness is ±1.0 dB and directivity is greater than 17 dB. Applications include commercial, military, dual use, industrial, medical, test and measurement applications for signal monitoring...

Series Circuit Quiz

Series Circuit Quiz, May 1966 Popular Electronics - RF CafeThe circuit drawings in this Series Circuit Quiz are a little hard to read in a few places because the original page used light red on top of a gray background. The magic of image processing did a pretty good job of cleaning them up to where you shouldn't have any trouble reading them. This quiz from Robert Balin appeared in the April 1966 issue of Popular Electronics magazine. It is one of the easier of his quizzes (although it does have capacitors and transformers in addition to resistors), so don't tell anyone if you score less than 100% ;-)

Wisconsin Couple Electrocuted Doing Fractal Wood Burning

Wisconsin Couple Electrocuted Doing Fractal Wood Burning - RF CafeNominating these unfortunate people for the Darwin Award (slogan "Evolution in Action) would be a bit insensitive, so I won't. I will, however, point out that this is a prime example of why the old saying "ignorance is bliss" is not always true. According to the news report, a man and woman were attempting to create fractal wood burning art (aka Lichtenberg wood burning), in which a lethally high voltage is applied to damp wood, producing fractal-like scorch patterns on the surface. High voltage transformers from microwave oven klystrons and from neon signs are popular power supply sources. Around 2 kV is the minimum for achieving impressive patterns. More than 30 people have died while engaging in the hobby. This fractal wood burning video demonstrates the "right" way to do it. RIP, erstwhile fractal wood burners.

21 Years a Ham

21 Years a Ham, September 1950 Radio & Television News Article - RF CafeThe title says "21 Years a Ham," and that was true in 1950 when this story appeared in Radio & Television News magazine. However, 72 years later author Helen Cloutier can claim "93 Years a Ham," if she has not yet obtained Silent Key (SK) status. As with today, as far back as the middle of the last century organizations and publications went out of their way to celebrate and promote "non-traditional" participants, in this case a woman, engaged in the hobby, sport, or profession. Concurrently, those same groups were accused of discouraging and shunning women and minorities from participation (yes, of course some were guilty of it). Special accommodations - even laws - were made to right the accused wrong. It simply can't be that males (particularly white males) might be more interested in those particular activities than others. For many decades, white males have been placed at a disadvantage regarding access to schools, jobs, political office, and organizations, in favor of everyone else. It is the only acceptable form of discrimination (see the update with her incredible obituary from 2002)...

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...

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."

Tuesday the 26th

Electronics-Themed Comics

Electronics-Themed Comics, May 1956 Radio-Electronics - RF CafeHere are a couple more technology-themed comics that appeared in the May 1956 issue of Radio-Electronics magazine. Both are indicative of the issues commonly encountered in the day. The era was during the transition between vacuum tubes and semiconductors, but inhabitants of either can understand and appreciate the humor. The comic from page 52 does require you to be familiar with the copper oxide or selenium type of rectifier that spanned both eras. Otherwise, you might wonder what the funny-looking hat on the guy's head is (hint - it's not a hat). The 1950s was also a time of transition from electromagnetic speaker magnets to iron magnets, so AC hum in radios could get in not just through the audio circuits but also through the speaker itself. The page 126 comic addresses that issue...

70 Years of Semiconductors

70 Years of Semiconductors - RF Cafe"A brief glimpse at semiconductor history, from SCRs and TRIACs to NVIDIA's 80-billion-transistor Hopper GPU." Says William Wong: "Electronic Design [magazine] has been around a bit longer than I have worked in the industry - but not by much. Having lived through it, you might think I had a good handle on how the technology progressed. However, so much has happened over the years that's been amazing even to me. Silicon and germanium transistors have been around since the 1950s when vacuum tubes were king. There were metal-oxide-semiconductor field-effect transistors (MOSFETs) in 1959, starting with p-type MOS (PMOS) and n-type MOS (NMOS) logic and eventually complementary metal-oxide-semiconductor (CMOS). Silicon has been the mainstay since the early '60s, bumping germanium out of the way over time. There also are some very broad areas, including digital, analog and power, when it comes to semiconductors. Optoelectronics should be in the mix, too, but that's yet another area of discussion..."

Mac's Radio Service Shop: Barney, Beauty, and BCI

Mac's Radio Service Shop: Barney, Beauty, and BCI, October 1948 Radio & Television News - RF CafeBefore most people listened to radio and television programming via cable, satellite, and/or the Internet, broadcasts were received over the air, usually from local stations. A common problem in the days of vacuum tube Ham transmitters back in the day was inadvertently causing broadcast interference (BCI) or specifically in the case of television, TVI, due to insufficient filtering, shielding, or design. Nowadays, we generally refer to all such unintentional and incidental radiation as radio frequency interference (RFI). Lots of articles were written on the subject in the 1940s through about the 1970s. Some RF spectrum is shared by more than one entity per FCC and other countries' band plans, with primary and secondary allocations assigned for some. For example, in the U.S., the 33 cm amateur radio band coexists with the 902-928 MHz unlicensed Part 15 ISM (Industrial, Scientific, and Medical) band. Ditto for some of the other ISM bands. If you're not a Ham, you might be surprised to learn that licensed amateurs have primary rights to the band's use...

PMI April 2022 Product Announcement

Planar Monolithic Industries' (PMI) April 2022 Product Announcement - RF CafePlanar Monolithic Industries (PMI), a leading supplier of custom, high-reliability MIC/MMIC components and subsystems for applications in space, military, communications, commercial and consumer electronics systems for more than three decades, recently introduced five new products in their extensive line of RF and microwave components. Included are an 8-12 GHz digitally tuned phase shifter, a 0.01-20 GHz ultra-low-noise amplifier, a 0.1-18.0 GHz, digital attenuator w/USB interface, a 0.01-18.0 GHz limiter, and a 0.5-18.0 GHz SPST reflective coaxial switch. Contact PMI today for more information.

Listening to the World

Listening to the World, January 1946 Radio News - RF CafeDuring and immediately following World War II, the "Monitoring Service" of the British Broadcasting Corporation (BBC) relentlessly listened to radio broadcasts from all over the world in order to be able to break headline news and, if appropriate, pass strategic military information on to Allied command centers (who were simultaneously doing their own monitoring). This 1946 Radio News magazine article tells of some of the more significant messages intercepted and how the facility was a highly guarded secret in order to prevent sabotage and infiltration. At the height of activity, 32 languages were being transcribed into English daily, consisting of more than 300,000 words. Voice, teletype, and Morse code were processed...

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...

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.

Monday the 25th

Drones - Prelude to "Push-Button" Warfare?

Drones - Prelude to "Push-Button" Warfare?, October 1946 Radio News Article - RF CafeThe term "drone" is relatively new to being common parlance throughout society. Prior to the early 2000s, a drone was thought of as either the mate to a queen bee or a special remotely controlled aircraft used by the military for target practice or for carrying out special missions not deemed safe for human pilots. When this article appeared in a 1952 issue of Radio & Television News magazine, drones were the exclusive purview of the military and research institutions because of high procurement and operational costs. With the advent of inexpensive, highly advanced spread spectrum radio control systems by the hobby community, lightweight and powerful brushless motors and lithium polymer (LiPo) batteries, sophisticated miniature stability and guidance integrated circuits (processors and sensors), and advanced computer simulation, incredibly capable and relatively inexpensive multirotor drones are widely available. From simple toys for erstwhile non-pilots to serious R/C flyers to professional operators, drones are everywhere. A couple days ago I saw a utility company worker using one to inspect power lines along a country road...

Electronic Manufacturing Supply Chain Risk

Electronic Manufacturing Supply Chain Risk - RF CafeWith the well-publicized electronics component supply chain issues disrupting normal manufacturing cycles, you might want to see this whitepaper entitled, "Electronic Manufacturing Supply Chain Risk: Are You Vulnerable?" Many companies turn to contract electronic manufacturers to outsource elements of their products, such as circuit board assemblies, wire harness and cable subassemblies, full-system assemblies, and enclosure fabrication. Products that are complex, highly engineered, and custom configured depend on the integrity of these assemblies. Most mission-critical product manufacturers, such as in the medical, aerospace, and defense industries, understand the importance of protecting their supply chains from costly disruptions. Therefore, taking active steps to reduce your supply chain risks is crucial for ensuring continuity of your manufacturing operations...

Kluge Electronics Advertisement

Kluge Electronics Advertisement, January 1946 Radio News - RF CafeHaving an unusual last name like "Blattenberger" in the U.S. has caused me some abuse over the years as many people have felt the need to either purposely mispronounce it or make make snide comments about its length and number of syllables. Even school teachers joined in the fray, especially on the first day of class when attendance was being taken. My drill sergeant in USAF basic training (circa 1978), TSgt. Ramerez, felt the need to needle me about it. People in America with surnames of German origin were often the victims of physical abuse, alienation, and derision during both World War I and World War II. You hear a lot about the government's internment of Japanese Americans during WWII, but some Germans were also rounded up merely because of their names...

Microwave Pulse Modulation

Microwave Pulse Modulation, April 1946 Radio News - RF CafeTry Googling 'cyclodos' and 'cyclophone' and see what you come up with. I found that Cyclodos is a German company which makes apparel from recycled inner tubes and tents (among other things), and cyclophone is a weird bicycle-mounted contraption for blasting sound while peddling down the street. In 1946 when this article appeared in Radio News magazine,, the terms cyclodos and cyclophone referred to modulator and demodulator tubes, respectively, for pulse-time modulation applications. Fortunately, the science of pulse modulation quickly evolved past such devices. This article goes into quite a lot of detail on the beginnings of pulse modulation techniques developed for radar systems during World War II. It is very informative without going into the gory details of equations that govern the theory...

Promote Your Company on RF Cafe for as Little as $40/Month

Sponsor RF Cafe for as Little as $40 per Month - RF CafeNew Scheme rotates all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000 website visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 12,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be.

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!

Sunday the 24th

Electronics Theme Crossword Puzzle for April 24th

Electronics Theme Crossword Puzzle for April 24th, 2022 - RF CafeHere is your custom made Electronics-themed crossword puzzle for April 24th, 2022. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only 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...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features...

Many Thanks to 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.

Friday the 22nd

B&K Dyna-Quik Tube Tester

B&K Dyna-Quik Tube Tester, November 1957 Radio-Electronics - RF CafeAs mentioned a while back, in the 1980s while working at Westinghouse Oceanic Davison in Annapolis, Maryland, an engineer who worked for knew I had recently obtained a 1941 Crosley Model 03CB console style radio. He generously gave me his B&K Dyna-Quik Model 650 Vacuum Tube Tester which, although formerly a very active Amateur radio operator (since boyhood), he didn't need it anymore. The Model 650 is a very comprehensive portable tester used at one time by many professional radio and television servicemen. My tester also had the Model 510 Accessory Socket Panel that added an ability to test 50% more tube types. An indication that it is one of the later model tube testers is the inclusion of a transistor testing socket. Unlike testing vacuum tubes, all of which plugged into sockets to make them easily replaceable, testing a transistor or solid state diode required unsoldering or clipping the device out of the circuit and then soldering back in either the verified still good device or a replacement. It was one of the reasons electronics servicing people eschewed the adoption of semiconductors. That, and a lot of money was made by the sales of replacement tubes, with a typical profit of a dollar or so per tube. The $169.95 price in 1957 is the equivalent of about $1,720 in 2022...

Semiconductor Patent Portfolio Profitability by Reverse Engineering

Semiconductor Patent Portfolio Profitability Through Reverse Engineering - RF CafeHere is an interesting whitepaper from UnitedLex entitled "Semiconductor Patent Portfolio Profitability Through Reverse Engineering." Having spent a few years doing this type of work, I know it is quite interesting, and you might even find some infringement on your own company's IP in the process. Semiconductor companies hold untapped profitability in their intellectual property (IP) portfolio. Advancements in reverse engineering (RE) have made it possible to scale patent enforcement, enabling companies to create new revenue opportunities, effectively monetizing patented holdings...

Ken-Rad Radio Tube Advertisement

Ken-Rad Radio Tube Advertisement, April 1947 Radio News - RF CafeAchieving what we consider relatively simple results with electronics indicators used to be cutting edge technology. This 6AL7-GT Electron-Ray Indicator Tube by Ken-Rad (a division of General Electric) provided a dual-channel electrofluorescent (i.e., cathode ray) display of relative signal strength or tuning the new-fangled FM radio stations. It was promoted in this 1947 issue of Radio News magazine. The tube could also be used, of course, for many other applications where signal strength from any measured process: fuel level, voltage, temperature, stock price, phase angle, sound volume, speed, etc., needed to be measured. Today, we have electrochemical indicators so cheap that they are built into off-the-shelf batteries at Walmart...

Coilcraft EMI Power Choke Impedance Finder

Coilcraft EMI Power Choke Impedance Finder - RF CafeColicraft has added another online app for selecting their products. The new EMI Power Choke Impedance Finder takes your parameter inputs, then searches its inventory of inductors and presents a list of parts that fit. You specify operational frequency and optionally set a value range for impedance, self-resonance, current handling, package size, DC resistance, core material, etc. After looking through the list of qualifying coils and selecting those of interest, click on the "Analyze and Graph" button to get a screen like the one in this thumbnail image. The components shown here are the same ones Colicraft used in their magazine advertisement...

The Junction Transistor

The Junction Transistor, April 1952 Radio & Television News - RF CafeIn April of 1952 when this article appeared in Radio & Television News magazine, the bipolar junction transistor (BJT) had only made it out of the experimental laboratory of Messrs. Bardeen, Shockley, and Brattain at Bell Labs a mere three years earlier in December of 1948. It did not take long for commercial production to begin. Along with being a great primer for anyone new to transistors, herein is also some background on how the now ubiquitous BJT schematic symbol was created. Interestingly, only Dr. William Shockley is mentioned, making me wonder whether the contributions of Dr. John Bardeen, and Dr. Walter H. Brattain was not widely publicized early on. Not to worry, though, because all three were duly recognized as recipients of the 1956 Nobel Prize in Physics...

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 Aegis Power Systems for Their Continued Support!

Aegis Power Systems - RF CafeAegis Power Systems is a leading supplier of AC-DC and DC-DC power supplies for custom and special applications. Aegis has been designing and building highly reliable custom power supplies since 1995. They offer a complete line of switch mode power supplies and power converters for a variety of markets including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft, EV, telecom, and embedded computing applications. Design and manufacture of custom power supply solutions to meet each customer's exacting specifications. Please visit Aegis Power Systems today.

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