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Homepage Archive - April 2023 (page 2)

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

Friday the 14th

Limits Raised for Superconductivity

New & Timely: Limits Raised for Superconductivity, March 1969 Radio-Electronics - RF CafeIn 1969 when this news item appeared in Radio-Electronics magazine, any temperature of superconductivity above absolute zero (0 K) was considered a major accomplishment. Dreamers dreamed of room temperature (RT) superconductivity from the time it was first predicted theoretically in 1911, but not even the people telling us we would be driving anti-gravity cars by the turn of the century thought we'd get there anytime soon - and we didn't. High temperature superconductivity is defined today as occurring at 77 K or above. Some exotic compounds have exhibited superconductivity under extreme pressures at temperatures as high as about 250 K (-23 °C, 10 °F). Unfortunately, we are still nowhere near the point that practical industrial or commercial applications are possible...

Transistor Development History Videos

Transistor Development History - RF Cafe Video for EngineersA few days ago Bob Davis sent me a link to a YouTube video documentary, "Transistorized," of the development of the transistor. It was originally produced in 1989. Narrator Mr. Ira Flatow begins by saying that the story behind the transistor, arguably one of the most important inventions of the 20th century, was one of "clashing egos and top secret research." Anyone familiar with the collaborative effort of Drs. John Bardeen, William Shockley and Walter Brattain, at Bell Telephone Laboratories (aka Bell Labs) knows of the strain between them at times. I will not attempt to embellish the huge amount of information presented; you will get all you want to know from the film. As you might expect, in addition to the "Transistorized" video there are other videos telling the story of the transistor's history. A couple really good ones are also embedded below. One covers Japan's successful climb to the top of the electronics product food chain based on their early adoptation of transistor...

British Radars for Pleasure Boats

British Radars for Pleasure Boats, July 1972 Popular Electronics - RF CafeYou probably know that it was Scottish engineer Robert Watson-Watt who pioneered the first successful radar systems. During World War II, America benefitted from improved magnetron designs from Great Britain to help build both ground-based air defense radars and, later in the war, airborne radars. This article from a 1972 issue of Popular Electronics magazine reports on state-of-the-art (at the time) marine radars from England for pleasure boats. In 1972, a radar with a 16-mile range was priced at around $2,000, which is equivalent to a little more than $14,000 in 2023 dollars. By comparison, you can now buy a compact microprocessor-controlled color marine radar (Si-Tex) with a 27-mile range for a mere $1,900 from Amazon...

Guidelines for Mixed-Signal PCB Layout Design

Guidelines for Mixed-Signal PCB Layout Design - RF cafe"A mixed-signal printed-circuit-board (PCB) design requires basic understanding of analog and digital circuitry to minimize, if not prevent, signal interference. Modern systems consist of components that are operational with both digital and analog domains, and they must be carefully designed to ensure signal integrity all throughout the system. PCB layout - an important part of the mixed-signal development process - can be intimidating and component placement is just the beginning. Other factors must be considered, too, including board layers and how to properly manage them to minimize interference caused by parasitic capacitors that can be unintentionally created between the PCB's interplane layers. Grounding also is an integral process in the PCB layout design of a mixed-signal system. While grounding is a frequently debated topic..."

Stromberg-Carlson No. 29 Superhet Receiver

Stromberg-Carlson No. 29, 9-Tube Superheterodyne Receiver Radio Service Data Sheet, May 1932 Radio-Craft - RF CafeHere is another addition to the growing collection of radio service data sheets for vintage radio sets. Most people will have no need for them, but for the few who have one of these old sets and want to restore or service it, this information can mean the difference between owning a non-working conversation piece or a functional piece of America's history. This Radio Service Data Sheet for for the Stromberg-Carlson No. 29, 9-tube superheterodyne receiver appeared in a 1932 issue of Hugo Gernsback's Radio-Craft magazine. Note that its name derives from "number of its design feature." All 29 are delineated, including Optosynchronic (Visual) Tuning, and a Mono-vision Dial and Tuning Meter. The photo thumbnails are just two of many for a very fine example of a Stromberg-Carlson No. 29a claiming to be in its original finish, with no rework having been performed on the cabinet or electronics. A full list of all radio service data sheets is at the bottom of the page...

Please Support RF Cafe

Amazon Prime - RF CafeThe RFCafe.com website exists partly on the support of its visitors by way of a small percentage earned with your Amazon.com purchases, which typically works out to less than $20 per month. That does not even cover the domain registration and secure server fees for RFCafe.com. If you plan to buy items via Amazon.com, please click on this link to begin your shopping session from here so that I get credit for it. Doing so does not cost you anything extra. Thank you for your support.

Many Thanks to LadyBug Technologies for Their Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Thursday the 13th

Electronics-Themed Comics

Electronics-Themed Comics, August 1960 Radio-Electronics - RF CafeIn the joke-telling realm, probably the most oft-adopted axiom is to "know your audience." Another is that if you need to explain a joke, you have failed in your attempt at humor. In this case, a little insight into the mindset of the era (from a 1960 Radio-Electronics magazine) might help you appreciate the electronics-related comics messages since we don't typically think in the same terms today. The page 42 comic leverages the huge obsession many technophiles had with stereo equipment. Believe it or not, really powerful public address (PA) systems were a big deal, too, as the page 95 comic intimates. Given that almost no consumer products use voltage supplies of high enough voltage and/or frequency to impart an RF burn to a serviceman, the page 122 comic probably also portrays a foreign concept. Now that you are privy to the motives behind the comics, feel free to laugh accordingly...

Phase-Noise Modeling & Propagation in PLLs

Phase-Noise Modeling, Simulation, and Propagation in Phase-Locked Loops - RF CafeThis is part 2 of "Phase-Noise Modeling, Simulation, and Propagation in Phase-Locked Loops," appearing in Microwaves & RF magazine. "As noted in Part 1, phase-locked loops (PLLs) are ubiquitous in today's high-tech world. Almost all commercial and military products employ them in their operation and phase (or PM) noise is a major concern. Frequency (or FM) noise is closely related (instantaneous frequency is the time derivative of phase) and is generally considered under the umbrella of phase noise (perhaps both might be considered 'angle noise'). Amplitude (or AM) noise is another consideration. Part 1 discussed brief theory and typical measurements of phase noise along with the analysis (modeling, simulation, and propagation) thereof, and showed the method used by most computer-aided-design (CAD) applications. Part 2 digs into the design of a hypothetical PLL frequency synthesizer to be used for analysis. To demonstrate the concepts and methods reviewed in Part 1, we design a hypothetical single loop 8- to 12-GHz/50-MHz step (channel spacing) integer synthesizer with a 25-MHz reference (50 MHz being the smallest achievable step..."

Ring Oscillators for UHF Transmission

Ring Oscillators for U.H.F. Transmission, January 1947 Radio News - RF CafeAchieving clean oscillations above about 300 MHz (1 meter wavelength) from standard glass and metal vacuum tubes is difficult due to interelectrode capacitances and self-inductance of internal wires and grid plates. Generating high power for applications like radar and long distance communications was made possible with the invention of klystron, magnetron, and ring oscillator tubes during World War II years. The UHF radio band spans from 300 MHz to 3 GHz, and it is the upper end of the band where the wavelength is short enough (3.93 inches | 10.0 cm for 3 GHz) to provide adequate spatial resolution for radar. The ring oscillator, unlike a magnetron with a solid chunk of metal with machined cavities and coupling windows, uses separate high power tubes with tuned coaxial lines between sections to isolate mutual inductance and capacitance loading effects that would otherwise limit the upper frequency of operation...

Anritsu Extends Range of Field Master™ MS2080A to 6 GHz

Anritsu Extends Frequency Range of Field Master™ MS2080A to 6 GHz to Support 5G FR1 - RF CafeAnritsu Company expands its Field Master™ MS2080A, a multi-functional spectrum analyzer that combines nine instruments into a single solution, to operate up to 6 GHz. With extended frequency coverage, the MS2080A addresses growing congestion in the 6 GHz spectrum caused by rapid growth in satellite services; cellular, commercial and LMR networks; radio location services; and industrial scientific and medical networks. The compact and portable spectrum analyzer provides insights into interference and intermodulation that degrade network performance through its best-in-class performance and features, bringing distinct benefits to base station installation and maintenance (I&M) applications. At 6 GHz, the MS2080A features fast sweep speed of 45 GHz/s for greater insight over wider spans. It also has advanced user features, such as AM/FM audio demodulation, and best-in-class RF performance, including ±1 dB amplitude accuracy. Additionally, it supports a cable and antenna analyzer...

Hoffman A500 Radio / Phonograph Schematic

Hoffman Model A500 Radio / Phonograph Schematic & Parts List, December 1947 Radio News - RF CafeThere are still many old-timers and beginning nostalgic collectors out there who nurse heirloom and otherwise procured vacuum tube radios - like this Hoffman Model A500  Radio / Phonograph console - back to health (operating condition) and/or keep them in good health. While it is possible to purchase schematics, parts lists, and service instructions from many different models, there are still some that have escaped the scanners of those publishers. I could not find any photos of a Hoffman A500, I did find this page from Sams Photofacts. For those kindred spirits in search of such reference materials, I happily scan, clean up as necessary, and post this collection (see complete list at bottom of page). I have dozens more that will eventually be added over time, so check back later or send me an e-mail if I have an issue of Radio News, Radio-Craft, etc. known to contain the information you need...

RF & Electronics Symbols for Visio

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

Thanks 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.

Wednesday the 12th

The Resonant Sky - Arthur C. Clarke

The Resonant Sky, August 1963 Radio-Electronics - RF CafeWhen Arthur C. Clarke talks, people listen (to paraphrase the old E.F. Hutton commercial).  Mr. Clarke wrote many books and papers about space technology and was a popular commentator on space-related issues. He also made several predictions about the future of technology that proved to be remarkably accurate, such as the use of geostationary satellites for telecommunications. Clarke famously published his "Extra-Terrestrial Relays: Can Rocket Stations Give World-Wide Radio Coverage?" in a 1945 issue of Wireless World magazine. Nearly a decade later he penned this "The Resonant Sky" article for the August 1963 edition of Radio-Electronics magazine. The former essay predated the 1957-1958 International Geophysical Year (IGY) atmospheric studies which laid the groundwork for space exploitation, while the latter followed on the successful orbiting of a few satellites. Basically, everything Clarke presents here has come to fruition, albeit a bit later than he thought it might take...

Rohde & Schwarz Oscilloscope Days

Rohde & Schwarz Oscilloscope Days 2023 - RF Cafe"Delivering expertise - application oriented presentations - based on day to day testing challenges It is common for electronics engineers to face challenges when trying to achieve their testing goals. During this two-day "Oscilloscope Days" event, experts from Rohde & Schwarz and our partners will deliver the latest updates of fundamentals and test features of the neXt-generation Oscilloscope, with online theoretical and practical sessions on the following topics: Oscilloscopes and Probing Fundamentals Power Electronics Power and Signal Integrity EMC This FREE virtual event will be streamed in English, French, German, Spanish and Brazilian Portuguese..."

Radio-Craft's List of Trade Names and Model Numbers

Radio-Craft's List of Trade Names and Model Numbers, January 1933 Radio-Craft - RF CafeMany people have provided resources on the Internet that made my life easier, and I have been amazed at being able to find photos and descriptions of very esoteric subjects for which I figured there was no chance of finding anything. In appreciation, there are times I post stuff that probably almost nobody will ever need, but maybe there is one guy (or gal) out there who will breathe a sigh of relief when finally finding the needed data. This list of radio trade names and model numbers appeared in a 1933 edition of Radio-Craft magazine. Page scans are provided at the top, and since search engines do not yet OCR images to be able to index their textual content, I have also included my OCR results at the bottom. Because the list is so extensive, no attempt has been made to clean it up...

U.S. Big Tech Hired 34k H-1B Workers, Laid off 85k in Last Year

Big Tech Hired 34k H-1B Workers, Laid off 85k in Last YearTech and outsourcing companies continue to exploit the H-1B visa program at a time of mass layoffs. The top 30 H-1B employers hired 34,000 new H-1B workers in 2022 and laid off at least 85,000 workers in 2022 and early 2023. The H-1B program is the largest U.S. temporary work visa program, with a total of approximately 600,000 workers employed by 50,000 employers. The program's intent is to allow employers to fill labor shortages for jobs that require a college degree, by providing work authorization for migrant workers in fields like accounting, journalism, health and medical, and teaching. Most H-1B workers, however, are employed in occupations like computer systems analysis and software development. Visas for new workers are capped at 85,000 per year, but many employers are exempt from that annual cap, including universities and their affiliated nonprofit entities, nonprofit research organizations, and government research organizations. Approximately 130,000 temporary migrant workers will receive new H-1B visas...

Hitler Takes up Television

Hitler Takes up Television, January 1935 Radio-Craft - RF CafeI am constantly amazed when reading stories about how easily Adolph Hitler rose to power in Germany by encouraging and exploiting resentment of his countrymen over being forced, among other concessions outlined in the Treaty of Versailles, to disarm militarily and make reparations for atrocities committed in World War I. Part of the Nazi (National Socialist) party success was extensive use of propaganda via print, radio, and the relatively new technology of television. Government exercised complete control over the mainstream media (i.e., not "underground") by dictating content that promoted the proclaimed virtues of Nazism and the Aryan race and the vices of just about every other form of government and race (particularly Jewish). At the height of Hitler's reign of terror during the Third Reich era, radio and television sets were only permitted to use crystals tuned to state-sponsored channels; to be caught possessing crystals for other frequencies meant certain death - often at the hands of the infamously cruel Gestapo. A large portion of the German population had no idea what the true status of the war was...

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 Wireless Telecom Group for Their Support!

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

Tuesday the 11th

Digital-to-Analog Fundamentals

Digital-to-Analog Fundamentals, February 1967 Radio-Electronics - RF CafeIrwin Math - what a great last name. My preferred last name list also includes Piper, Cessna, Rockett, Wright, Goddard, Einstein, Marconi, Hertz, Coulomb, Ampere, Edison, de Forest. That is not to disparage other worthy names like Bell, Moore, and Franklin, it's just that the latter are common enough that they would not likely illicit an association with an accomplished scientist. If I can't have fame in common with a great person, at least the name would be somewhat of a consolation. ...but I digress. This "Digital-to-Analog Fundamentals" article authored by Mr. Math appeared in a 1967 issue of Radio-Electronics magazine. With the advent of transistors and a growing selection of integrated circuits, digital signaling and processing was getting a lot of attention. Univac-size vacuum tube computers were being compacted into a small fraction of the volume, consuming a small fraction of the power, and requiring a small fraction of the maintenance. History shows that rapid progress ensued in both digital circuitry and the application thereof...

Zenith Model 5R080  Radio/Phono

Zenith Models 5R080 & 5R086 Schematic & Parts List, August 1947 Radio News - RF CafeHere are the schematic and parts list for Zenith model 5R080 and 5R086 radio/phonograph combos, from a 1947 issue of Radio News magazine. It must have been a fairly popular set because many have been sold on eBay; in fact, that's where I got the photos shown here. The schematic page from the Sam's Photofact also came from an eBay listing. Note where it says that unless otherwise noted, all resistors values are ±20%. I suppose when your phonograph turntable uses a metal chain drive mechanism, precision isn't a huge concern. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information; that's why I keep a running list of all the data sheets I find to facilitate searches...

EMI Affects on Various Electronic Systems

How Does EMI Affect Various Electronic Systems? - RF Cafe"The phenomenon known as electromagnetic interference (EMI) occurs when any device with electronic circuitry becomes exposed to an electromagnetic (EM) field. The broad electronic spectrum is being used by an ever-growing number of these devices, many of which will have EMI issues affecting their performance. EMI will lead to poor operation, malfunctioning, and can even ultimately stop circuitry from working at all. Needless to say, system circuit designers need to design their architectures to prevent EMI disturbances that can negatively impact their electronics. Man-made or even natural EMI sources can be minimized or even blocked with electrical shields. The choice of using higher-quality electronic components can help as well. Error-correction methods may reduce EMI effects, too..."

Radio Frequencies and Their Allocation

Radio Frequencies and Their Allocation, June July 1940 National Radio News - RF CafeNational Radio News magazine was published bi-monthly by the folks at the National Radio Institute (NRI). NRI used to be a major training center for electronics technicians beginning in the early part of the 20th century. This article was provided for them by the Federal Communications Commission (FCC) as a synopsis of radio frequency spectrum allocations at the time. Compare a 1940 spectrum allocation chart (just a simple description here) to one for 2016 and you will see a remarkable difference in not just the number of bands, but in the extension of the frequency range. This link produces the FCC Online Table of Frequency Allocations (July 1, 2022) document, and this one is a more user-friendly equivalent graphical U.S. Frequency Allocations chart published by the U.S. Department of Commerce's National Telecommunications and Information Administration (NTIA) Office of Spectrum Management, using 2016 data, which appears to be the most recent...

Promote Your Company on RF Cafe

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 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. New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the place to be.

Many Thanks to Amplifier Solutions Corporation (ASC) for Continuing Support!

Amplifier Solutions Corporation (ASC) - RF CafeAmplifier Solutions Corporation (ASC) is a manufacturer of amplifiers for commercial & military markets. ASC designs and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers for low, medium and high power applications using Gallium Nitride (GaN), Gallium Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility in the town of Telford, PA. We offer excellent customer support and take pride in the ability to quickly react to evolving system design requirements.

Monday the 10th

Psychology of Pay TV

Psychology of Pay TV, February 1967 Radio-Electronics - RF CafeThe more things change, the more things stay the same. That old saying will live on forever. Radio-Electronics editor Forest Belt discusses in a 1967 issue of the magazine the debate between those companies and customers who are Pay-TV proponents and those who are Pay-TV opponents. Although you can read the entire article to draw your own conclusions, basically it boils down to whether being required to pay hard-earned money for commercial-free programs and movies will improve the quality. You can probably make a similar argument being made at every stage of broadcast entertainment on cable, Internet, and smartphones. Personally, I gave up on 99.9% of all programming newer than around 1985, so I have no dog in the hunt, so to speak. Mr. Belt presciently states regarding current-day airings, "Viewers therefore disparage the quality of programs they now get on TV (while watching them insatiably), call the commercials lousy, and grumble that TV is the country's great time-waster..."

Precision Steering at 18,000 mph

Precision Steering at 18,000 M.P.H., September 1957 Radio & TV News - RF CafeThese days, I'm always a bit hesitant to publish or do Internet research on items mentioning chemical compounds any more toxic than rubbing alcohol, lest some digitally eavesdropping government agency send storm troopers with fully automatic weapons to my house at 5:00 am to drag my family and me out onto the lawn while in our pajamas. This article reports on early plans of the Vanguard satellite launch platform for America's first orbiting satellites. Although the main focus is on the electronic steering and stabilization systems, it mentions the fuel composition of nitric acid and unsymmetrical dimethylhydrazine (that sentence alone is probably enough to at least put me on some sort of surveillance list). Less exotic fuel constituents like LOX (not to be confused with the fish used on bagels), kerosene, and liquid hydrogen, which powered most of the man-carrying booster stages, might similarly likely raise a flag even when taken in context with the article's thesis...

Many Thanks to LadyBug Technologies for Their Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Vintage Audio Electronics by Riddim Restoration

Vintage Audio Electronics by Riddim Restoration - RF Cafe Cool ProductWebsite visitor R. Carson Vizina, owner and chief miracle worker of Riddim Restoration, recently wrote to inquire whether I had a resource for repairing or replacing a damaged glass radio dial bezel for a Packard Bell AM/FM radio he is working on. Unfortunately, I do not know of anyone who can make a new dial plate, 'thou surely there is someone out there who does custom silkscreen printing, but the cost would probably be prohibitive. I suggested that he might try an automotive window repair kit. I have used the Rain-X method on two windshields and it does an amazing job of "disappearing" the crack. Use a hair dryer after injecting it onto the surface facilitates it flowing into the narrowest parts of the crack. Please contact Carson if you have a suggestion. Zenith Chair Side Record Player Vacuum Tube Stereo Ventura 65amps Magnavox Portable Record Player After perusing his RiddimRestoration.Rocks website and seeing the amazing audio components he has restored, I offered to post a description of it on RF Cafe. As the old saying goes, a picture is worth a thousand words, so rather than me attempt to do Carson's handiwork justice with a written description, feast your eyes on about 7k worth of words to the right. When asked to provide a short blurb on Riddim Restoration, he responded thusly...

Winning the National Radio Control Meet

Winning the National Radio Control Meet, March 1940 QST - RF CafeYou might wonder why an article entitled "Winning the National Radio Control Meet" for model airplanes would appear in the ARRL's QST magazine. The answer is that back in 1940 when it was published, a Ham license was required to operate a radio control (R/C) transmitter. There were no license-free bands for hobbyists as there are now. In fact, it wasn't until 1976 that the FCC suspended their requirement for registration as an operator, which has returned in the form of an FAA "drone" (aka USAS) pilot directive. The author, William E. Good, was the twin brother of Walter A. Good, both of whom held doctoral degrees in and physics and Ham licenses, and were referred to as "the fathers of radio control." The photo of Bill shows his station identification (W8IFD) displayed on the transmitter enclosure, as required by the FCC. They were born in 1916 and won the R/C championship in 1949, at the age of 33. In the early days, R/C operators built (and often designed) their systems, including the electronics and mechanics. They were the pioneers that took the figurative arrows while forging the frontiers of this hobby. A couple notable items mentioned in the article are the needing a QSA "5" level signal (the highest quality of reception) in order to assure reliable control of the aircraft, and of how Hams helped advance the design of small internal combustion engines. Also, Fig. 4 shows the rudder escapement located in the vertical fin, with the wound rubber there as well...

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 KR Electronics for Long-Time Support!

KR ElectronicsKR Electronics has been designing and manufacturing custom filters for military and commercial radio, radar, medical, and communications since 1973. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop, equalizer, duplexer, diplexer, and individually synthesized filters for special applications - both commercial and military. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Please visit their website today to see how they might be of assistance. Products are designed and manufactured in the USA.

Sunday the 9th

Electronics Theme Crossword for Easter Sunday

Electronics Theme Crossword Puzzle for Easter Sunday, April 9, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for April 9th, Easter Sunday, contains words and clues which pertain exclusively to the subjects of electronics, science, physics, mechanics, engineering, power distribution, astronomy, chemistry, etc. It'll keep you busy while the kids hunt for Easter eggs. 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...

Many Thanks to ISOTEC for Continued Support!

ISOTEC Corporation - RF CafeSince 1996, ISOTEC has designed, developed and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components and filters for wireless service providers including non-magnetic connectors for quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM RF connectors components such as power dividers and directional couplers. Off-the-shelf and customized products up to 40 GHz and our low-PIM products can meet -160 dBc with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and high-performance. Designs that are cost effective practical and repeatable.

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