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Homepage Archive - March 2023 (page 4)

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

Friday the 31st

OTA Superception

Superception, April 1960 Radio-Electronics, Hugo Gernsback - RF Cafe

It is no secret that I consider Hugo Gernsback to have been one of the last century's premier technology innovators, futurists, and publishers. Many of his proposals, prognostications, predictions, forecasts, and maybe even prophecies came to fruition in his lifetime - often due to his own efforts. In the case of the burgeoning wireless entertainment industry (radio and television), Gernsback commented on the contention between household members over which program should be tuned in. To wit from a 1960 issue of Radio-Electronics magazine: "Yes, a family may conceivably have two separate radios and three TV sets, each in a different room - everyone has seen such split households - but we must all agree that this is an asinine and not very progressive solution to the problem, even if sufficient rooms are available. It won't prevail in the future." This didn't really happen until the availability of smartphones and wideband streaming video, so sometime around 2008 - about six decades later...

IC Helps Mobile Devices Block Interference

Chip to Help Mobile Devices Block Unwanted Signals and Interference - RF Cafe"Researchers at MIT, Massachusetts have developed a circuit architecture that targets and blocks unwanted signals at a receiver's input without hurting its performance. They borrowed a technique from digital signal processing and used a few tricks that enable it to work effectively in a radio frequency system across a wide frequency range. This innovation is especially relevant for crowded settings. Imagine sitting in a packed stadium for a pivotal football game - tens of thousands of people are using mobile phones at the same time, perhaps video chatting with friends or posting photos on social media. The radio frequency signals being sent and received by all these devices could cause interference, which slows device performance and drains batteries. MIT's receiver blocked even high-power unwanted signals without introducing more noise, or inaccuracies, into the signal processing operations. The chip, which performed about 40 times better than other wideband receivers at blocking a special type of interference, does not require any additional hardware or circuitry..."

The Transistom

The Transistom, April 1958 Radio-Electronics - RF CafeThe story from a 1958 issue of Radio-Electronics magazine documents development of the "transistom" device back in the 1958 timeframe. Keep in mind that it was just a decade earlier that Mssrs. Bardeen, Brattain, and Shockley introduced the transistor amplifier to the world. The transistom was basically a 3-terminal transistor with two additional leads for a revolutionary power source built from radioisotopes of magnesium and manganese. In the day, school kids, including me, were handed blobs of liquid mercury to inspect and pass around in class, demonstrating how relatively ignorant we were about things we now consider to be extreme health hazards. Accordingly, encapsulating radioactive material in consumer devices was not a concern. The complete absence of transistoms in the marketplace today speaks volumes about its success. Then again, the month of publication of this article, and its author, might have something to do with it...

Black Hole Mass Ejection Approaching Earth Orbit

Black Hole Mass Ejection (Relativistic Jet) Approaching Earth Orbit - RF CafeNews Flash: v - RF CafeAt 04:23 UTC, a consortium of astronomers using the Even Horizon Telescope (EHT) reported confirmation of the presence of a massive cluster of highly energetic deep space particles heading toward Earth orbit. It is believed based on a time sequence of measurements over the past 12 hours that the mass originated in the area of a supermassive black hole in the M87 galaxy (Messier object), approximately 54 light years distant. Currently crossing inside the extreme outer boundary of the Kuiper Belt region, measurements have determined there is a very strong concentration of energy in the 1.225 GHz (1225 MHz) and 2.428 GHz (2428 MHz) electromagnetic spectrum. While the nature of such particle clusters generally consists of a wideband dispersion of frequencies, these two wavelengths are of great concern because 1.225 GHz is very close to the 1.2276 GHz (1227.6 MHz) "L2" signal which is a critical component of the Global Positioning System (GPS) navigation signal, and 2.428 GHz falls within the 2.4 through 2.5 GHz Industrial, Scientific, and Medical (ISM) band used worldwide for unlicensed wireless communications. Highly accurate measurements have not been made yet of the exact trajectory or energy levels worst case scenario since the antenna array's pointing capability has been exceeded as the result of the Earth turning away from the source. Approximately eight more hours will be needed to re-acquire the signal...

Contra-Polar Energy

Contra-Polar Energy, April 1955 Popular Electronics - RF CafeContra-polar (negative) energy is a concept that has been investigated by many researchers beginning in the mid 19th century, when the nature of energy was beginning to be understood from a truly scientific perspective. Entire theories of universe and matter-antimatter creation have been published, reviewed and refined. This article from the April 1955 edition of Popular Electronics magazine reports on then-current applications of contra-polar energy. At the time, most such work was performed in secret government laboratories and at test ranges that were closed to the public and results banned from publication, but since that time freedom-of-information-act requests have opened much contra-energy research information for public access...

Post Your Engineer & Technician Job Openings on RF Cafe for Free

/jobs.htm">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 /jobs.htm">job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

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.

Thursday the 30th

New Radiation Standards Set

New Radiation Standards Set, February 1969 Radio-Electronics - RF CafeGovernments are historically fond of creating laws, standards, regulations, codes, ordinances, directives, notices, prohibitions, restrictions, bylaws, ordinances, and all other manner of ways to control our lives - all for our own good, don't you know. Sometimes those impositions are useful, and other times - maybe most times - they are just forms of control to keep the figurative boot on the equally figurative throats of the proletariat. According to this 1969 issue of Radio-Electronics magazine, the U.S. Department of Health, Education, and Welfare has recently been ordered to create standards for maximum radio frequency radiation exposure levels for various commercial electronic products. The move was largely driven by concerns over radiation from color televisions x-ray emission from super high voltage cathode ray tube (CRT) biases, and from microwave ovens, both of which were relatively new household appliances...

Time Reflection Measured in Microwaves

Time Reflection Measured in Microwaves - RF Cafe"Physicists in the U.S. have observed an effect known as time reflection in an electromagnetic wave for the first time. They detected the phenomenon - the temporal counterpart of familiar spatial reflection - by rapidly switching a series of capacitors in a novel type of metamaterial. They say the result could improve wireless communication and ultimately help bring about long-sought-after optical computing. Everyday reflection involves the transformation of a wave packet when it meets an interface in a distinct region of space. The process preserves temporal ordering, so that the leading part of the incident wave remains ahead after reflection. This means that objects further from a mirror look more distant in the reflection, while sounds in an echo arrive back in the same order they were emitted. Time reflection instead involves a wave packet being transformed as a result of an abrupt change in time that applies equally throughout the medium it is traversing. In other words, the material in question experiences a sudden shift in its properties..."

Mac's Radio Service Shop: Advertising for Dessert

Mac's Radio Service Shop: Advertising for Dessert, July 1949 Radio & Television News - RF CafeReturn on investment for advertising is always a prime consideration for companies, regardless of how wide the perspective audience or the size of the competition. Luck plays some part in whether a certain advertising campaign is successful, but as Mac points out in the July 1949 edition of Radio & Television News magazine, there is great advantage to measuring the effectiveness of each advertising strategy. Advertising has never been cheap, especially in venues with a large contingent of followers. In the Internet age, one of the more popular schemes is 3rd-party pay-per-click ads that are served by a central distributor (like Google and Bing) based on intelligent algorithms designed by teams of business and marketing experts. Based on my conversations with some RF Cafe advertisers who have tried Google's AdWords program, most are not happy with the results because they experience a low ratio of clicks-to-sales. Those who report success are people who have expended a lot of effort learning how the system works and how to exploit it - often after learning the hard way what the wrong way is. Unlike his fellow radio service and sales shops operators in the story, it is doubtful many businesses would be willing to share their hard-earned secrets with competitors...

You Don't See This Every Day!

Whilst on the way to a doctor appointment this morning (3/30/2023), we saw this guy driving his car with the hood smashed into the windshield. It appears the wind stream must have blown it back while driving down the road since the windshield was smashed as well. We followed him for about 5 miles on West Wendover Road, in Greensboro, NC, before he turned off onto a side road. How he managed to see well enough to guide the car is a mystery. There must have been a slim line of sight between the dashboard and under the edge of the hood based on how he was leaning over in the seat. Other drivers kept well away from him, but I had to take a risk and get up next to him to get this video. It was extremely dangerous of him to do so, but awfully funny as well.

Teledyne Relays 50+ GHz Mini Matrix Boxes

Teledyne Relays Announces the Launch of New 50+ GHz Mini Matrix Boxes - RF CafeTeledyne Relays, a leading provider of high-performance coaxial switches, is pleased to announce the addition of 50+ GHz coaxial switches to its Mini Matrix Box product line. The new switches are available in SPDT, Transfer, and Multi-throw configurations each with their own GUI. They can be ordered with or without terminations, offering flexibility for various applications in RF and automated test equipment. Teledyne Relays Mini Matrix Boxes are a compact, plug-and-play solution, offering USB or Ethernet control for efficient and reliable switching in laboratory and production environments. With the addition of the 50+ GHz switches, Teledyne Relays can meet the growing demand for testing higher frequency applications in the industry. "The introduction of the 50+ GHz coaxial switches is an exciting milestone for Teledyne Relays. We are committed to delivering high-quality, reliable, and innovative solutions that help our customers stay ahead of the curve," said Michael Palakian, Teledyne Relays Vice President of Global Sales & Marketing...

Color Television?

Color Television?, December 1949 Radio & Television News - RF CafeThe 1954 Tournament of Roses (aka Rose Bowl Parade) was famously the world's first national commercial color television broadcast, provided by the National Broadcasting Company (NBC). Prior to the NTSC (National Television Systems Committee) finally settling on an all-electronic scheme for TV sets, many electro-mechanical and electro-optical types were developed. The integrated RGB (red, green, blue) color gun within a cathode ray tube (CRT) was a relatively new concept in 1949. This Radio & Television News magazine article presents some of the propositions by the two major research and development players at the time: RCA and CBS. They might seem ridiculous in the light of knowledge available now, but a round wheel wasn't immediately obvious to Oog sitting in his cave, trying to figure out an easier way to transport that mastodon carcass...

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 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. Manufactured in the USA.

Wednesday the 29th

News Briefs: e-Vehicles & More

News Briefs, January 1967 Radio-Electronics - RF CafeHugo Gernsback was the Ulrich L. Rhode of the early 20th century; he was very accomplished in many areas of electronics, was a prolific publisher of technical content, knew everyone of any import in the technology realm, had successful business ventures, and seemed to always be getting presented with awards from one group or another. With guys like Gernsback and Rhode, organizations considered themselves honored to have their offers accepted in order to be worthy of the recipient's attention. This collection of industry New Briefs in the January 1967 issue of Radio-Electronics magazine included the Antique Wireless Association (still in existence) giving an award to Gernsback. It also reported on General Motors using silver-zinc battery packs, SCR's and specially designed ac motors in its experimental Electrovair II - a conversion of its gas-powered Corvair. The government-controlled BBC's domination over "free" radio broadcasting was getting a challenge from the Popular Music Authority (PMA), which was also a government-controlled broadcaster (nothing Soviet about that arrangement, eh?). Increasing sun spot activity opened up the 11-meter shortwave band...

Microsatellites Reduce Space Junk

Microsatellites Reduce Space Junk - RF Cafe"Satellite powered by 48 AA batteries and a $20 microprocessor shows a low-cost way to reduce space junk. Common sense suggests that space missions can only happen with multimillion-dollar budgets, materials built to withstand the unforgiving conditions beyond Earth's atmosphere, and as a result of work done by highly trained specialists. But a team of engineering students from Brown University has turned that assumption on its head. They built a satellite on a shoestring budget and using off-the-shelf supplies available at most hardware stores. They even sent the satellite - which is powered by 48 Energizer AA batteries and a $20 microprocessor popular with robot hobbyists - into space about 10 months ago, hitching a ride on Elon Musk's SpaceX rocket..."

Bell Telephone Labs Coaxial Cable

Bell Telephone Laboratories Advertisement, December 1949 Radio & Television News - RF CafeWhen you read today where someone writes about, "back in the eighties...," you naturally think of 1980-something. This 1949 Radio & Television News magazine advertisement from by Bell Telephone Laboratories mention of "back in the eighties" was referencing the 1880s, not the 1980s. What was six decades ago at the time is now thirteen decades ago - yikes! The picture juxtaposes a telephone pole massively populated with horizontal cross timbers, insulators, and wires, with an engineer holding up a section of coaxial cable that was in the process of replacing the poles and wires. Thanks to Bell Labs' relentless R&D efforts, those early single-channel, short distance twisted pairs were obsoleted by 1,800-channel coax. Fiber optic cables today typically support more than 30,000 voice channels...

Measuring with Humor

Measuring with Humor (Fluke Calibration) - RF CafeA relatively new feature has been appearing on the Microwaves & RF website entitled "Measuring with Humor," compliments of Fluke Calibration. I just saw it and don't know how long it has been running, but there are four of them thus far. The comic depicts situations commonly experienced by people in the test equipment realm. Fluke, of course, is one of America's most well-known and oldest test equipment manufacturers. I have used Fluke (founded in 1948) gear since first entering the electronic and electrical field in the 1970s. It always seemed strange to me that a high end electronic test equipment company would assume the name "Fluke," even though it is the name of company founder John Fluke. Even though a fluke can be defined as an unexpected stroke of good luck, it often has a negative connotation describing an outlier event not typical of the norm. The Fluke company's good reputation is due to smart employees who design and manufacture good products - definitely not a fluke.

Understanding the JFET

Understanding the Junction Field Effect Transistor, April 1973 Popular Electronics - RF CafeAdolph Mangieri, who authored articles in other electronic magazines in the 1970s and 1980s, provides a good introduction to junction field effect transistors (JFETs) in this 1973 piece in Popular Electronics magazine. As mentioned, JFETs were a relative newcomer at the time to the commercial electronics world because of high fabrication costs. Obtaining consistent pinch-off voltages and gains was largely responsible for the relatively high production costs due to substrate purity and doping issues. Semiconductor processing and some circuit application examples are included. One of the first big commercial applications of the JFET was probably transistorized multimeters, which enabled a very high input impedance. Doing so helped minimize the loading effect on the meter on the circuit under test...

Post Your Engineer & Technician Job Openings on RF Cafe for Free

/jobs.htm">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 /jobs.htm">job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

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! 

Tuesday the 28th

Electronics-Themed Comics

Electronics-Themed Comics (p20), April 1963 Radio-Electronics - RF CafeIt's Monday again. Here is another batch of electronics-themed comics to help cheer you up. They appeared in the April 1963 issue of Radio-Electronics magazine. Usually the meaning of the comics is immediately apparent, or maybe after a little critical investigation, but I'm going to need some help with the page 20 comic. I must be missing something obvious. There is nothing else on the page it came from that it is supposed to go with. Maybe it is simply implying the lonely life of a TV repairman on a service call. The page 49 comic plays on the era's popular notion of a husband-wife battle involving his quest for bigger and better (and more expensive) electronics gear. If you don't "get" the humor, note the stacking of the equipment - which is stereo. Page 88's topic is as apt today as it was 60 years ago. Page 105 is yet another instance of man's obsession with stereos back in the day...

IDTechEx Report on 6G Market 2023-2043

IDTechEx Report on 6G Market 2023-2043 - RF Cafe"IDTechEx, an independent market research and business intelligence provider claims that 6G will arrive in 2028 at the earliest in its recently published market research report, "6G Market 2023-2043: Technology, Trends, Forecasts, Players". 6G, compared to its predecessor, is expected to offer significantly better communication capabilities, such as Tbps-level peak data rates, microsecond-level latency, and 99.99999% network dependability. Although 6G promises a lot, it is unlikely that 6G will be in daily life soon, despite the fact that several important companies and nations have already begun 6G research, as shown in the figure below, the telecom industry needs to address several issues before seeing the success of 6G. The difficulties are not only in THz technology but also in identifying applications that will fuel 6G adoption. IDTechEx has been researching 5G and 6G for years. This article will discuss some of the hardware-related hurdles to 6G connectivity..."

Barry Goldwater, K7UGA, Ham Radio Operator

Barry Goldwater, K7UGA, Ham Radio Operator May 1967 QST - RF CafeA lot of famous people have been or are currently amateur radio operators, including many present-day astronauts who broadcast from the International Space Station (ISS). Some media people, like Tim Allen, star of the Home Improvement and Last Man Standing fame, became a Ham after playing a character who is one on his show. A 1958 edition of Popular Electronics magazine published a story titled "VIP's Are Hams Too!," which included Arthur Godfrey (9K4LIB), Herbert Hoover, Jr. (W6ZH), and Arthur Collins (W0CXX). I wrote an article on radio host Jean Shepherd (K2ORS), of "A Christmas Story" fame. Senator Barry Goldwater (K7UGA), of Arizona, was also an active Ham, as evidenced here in this May 1967 edition of the ARRL's QST magazine. Senator Goldwater also appeared in the June 1967 issue of QST...

EMI in Connected Vehicles

EMI in Connected Vehicles - RF Cafe"Automakers need to rein in electromagnetic interference before it pumps the brakes on in-vehicle connectivity innovations. In early 1979, Ralph Liuzzi installed a mobile transmitter in his customer's Cadillac Seville. However, Mr. Liuzzi found that whenever he attempted to transmit, the car's engine would stall, resulting in a serious safety hazard for both driver and pedestrians. At the time, the National Highway Traffic Safety Administration (NHTSA) cited a 'lack of documentation on the effects of Electromagnetic Interference (EMI) on automobile electronic engine control systems,' but reviewed the case and eventually found that indeed EMI played a key role in the system malfunction. 'The problem of EMI is a relatively new one in automotive technology since electronics have only recently been introduced into usage in automobiles,' the NHTSA said in its report. Now, more than 40 years later, the problem of EMI has only grown..."

Hetro Air-Ace Series M, 4-Band Superhet

Hetro Air-Ace Series M, 9-Tube 4-Band Superhet, May 1936 Radio-Craft - RF CafeThis is another Radio Service Data Sheet which appeared in the May 1936 edition of Radio-Craft magazine. I post this schematic and functional description of the Hetro Air-Ace Series M, 9-Tube 4-Band Superhet manufacturers' publications for the benefit of hobbyists and archivists who might be searching for such information either in a effort to restore a radio to working condition, or to collect archival information. A thorough search on the Internet turned up no examples of a surviving instance of the Hetro Air-Ace Series M radio. BTW, the "Air Ace" part of the name refers to the radio air, as in "on the air" or "over the air," not a fighter pilot ace with a certain number of kills painted on the side of his airplane...

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 Berkeley Nucleonics for Continued Support!

Berkeley Nucleonics Corp - RF CafeBerkeley Nucleonics Corporation (BNC) is a leading manufacturer of precision electronic instrumentation for test, measurement, and nuclear research. Founded in 1963, BNC initially developed custom pulse generators. We became known for meeting the most stringent requirements for high precision and stability, and for producing instruments of unsurpassed reliability and performance. We continue to maintain a leadership position as a developer of custom pulse, signal, light, and function generators. Our designs incorporate the latest innovations in software and hardware engineering, surface mount production, and automated testing procedures.

Monday the 27th

Electronics Mathematics Quiz

Electronics Mathematics Quiz, June 1969 Popular Electronics - RF CafeDon't let the title scare you away from this "Electronic Mathematic Quiz." It appeared in the June 1969 issue of Popular Electronics magazine, and was created by quizmaster Robert Balin. There are no scary equations to complete and no mental calculations to bend your brain. Instead, the "mathematics" required is to recognize physical and electrical signal shapes which are described by common mathematics terms. For instance, a cardioid approximates the electromagnetic radiation pattern of many directional antennas, which may include a parabolic dish. Differentiator and integrator circuits generate distinct waveforms. Phase angles and critical angles are familiar to circuit designers and radio operators. Shape letter "E" will likely be familiar according to its name, although you might not know what it is in the world of electronics...

Ultrathin Metasurface Display Rivals LCD

Ultrathin Metasurface Display Rivals LCD - RF Cafe"Currently, LCD screens are the most dominant and popular display technology for televisions and monitors, but they are unlikely to get significantly better in the future. Now a new study finds the kind of physics that make microscopic 'invisibility cloaks' possible may lead to next-generation 'metasurface' displays roughly 1/100 the thickness of the average human hair that could offer 10 times the resolution and consume half as much energy as LCD screens. LCD technology depends on liquid crystal cells that are constantly lit by a backlight. Polarizers in front and behind the pixels filter light waves based on their polarity, or the direction in which they vibrate, and the liquid crystal cells can rotate the way these filters are oriented to switch light transmissions on and off. LCD screens do continue to see advances by improving the liquid crystals, the display technology or the backlight. 'However, improvement on LCD technologies are now mostly just..."

Howard Explorer Model W All-Wave Superhet

Howard Explorer Model W Deluxe 19 Tube All-Wave Superhet Radio Service Data Sheet, September 1934 Radio-Craft - RF CafeHere are the schematics, chassis layout, and service info for the Howard Explorer Model W Deluxe 19 Tube All-Wave Superheterodyne console style (sits on the floor) radio. The wooden cabinet format is somewhat unusual in that the top is a flat surface rather than the having more typical curvaceous lines that radios of the era sported. It looks a lot like the models with built-in phonographs, where the top would tilt upward. The Radio Service Data Sheets that were published in Radio-Craft usually seem to have more information included than those published in other magazines, at least in the same era (1940-ish). It might have to do with how much material is provided by the manufacturer rather than a decision by the magazine editors. This one appeared in the September 1934 issue. Believe it or not, there are still people searching for such data. I could not find an example of a real surviving Howard Explorer Model W radio...

Morse Code Rhythm Patterns from A to Z

Morse Code Rhythm Patterns from A to Z (QST April 2023) - RF CafeGiven that this "Morse Code Rhythm Patterns from A to Z" article (p58) appeared in the April issue of QST magazine, I was careful to ascertain that it was not written for fools. It seems authentic, but for the life of me I don't know how many people would find the proposed Morse Code learning system to be a natural method. Author Bill Cody (K3CDY) is a musician who is accustomed to reading music, so for him and other talented musical types, maybe such a system facilitates the learning of code. To people like me, it's like suggesting a method for more easily learning how to apply a bandage by adapting brain surgery principles. Unfortunately, you'll need to be an ARRL member for access to the online article, or maybe you can borrow a copy of the magazine from a friend (but you'll still need to sign in for the music/code sheets). I'm still trying to figure out which article is the April Fools bait. BTW, I remember using one of those Isolate Pad Circuit-Board Construction tools when making proto boards (p91).

Micro-Waves Span the English Channel

Micro-Waves Span the English Channel, September 1935 Short Wave Craft - RF CafeWe "Baby Boomers" remember a time when cell towers did not present a ubiquitous (and, frankly, ugly) presence across the landscape. Microwave relay towers for television and telephone links could be spotted sitting atop hilltops and mountain ridges in some areas, and giant television and radio station towers sat behind broadcast stations, and multi-element antennas dotted house rooftops everywhere. Our grandparents (Millennials' great grandparents) remember when even microwave relay towers were missing. This 1936 article reports on the first microwave links spanning the English Channel to replace expensive and trouble-prone submerged cable. Part of the impetus, not mentioned within, was the building inevitability of war with Germany and the vulnerability of those communications links to being compromised by Nazi submarines and divers...

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 Exodus Advanced Communications for Their Support

Exodus Advanced Communications - RF CafeExodus Advanced Communications is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. Power amplifiers ranging from 10 kHz to 51 GHz with various output power levels and noise figure ranges, we fully support custom designs and manufacturing requirements for both small and large volume levels. decades of combined experience in the RF field for numerous applications including military jamming, communications, radar, EMI/EMC and various commercial projects with all designing and manufacturing of our HPA, MPA, and LNA products in-house.

Sunday the 26th

Electronics Theme Crossword for March 26th

Electronics Theme Crossword Puzzle for March 26, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for March 26th contains words and clues which pertain exclusively to the subjects of electronics, science, physics, mechanics, engineering, power distribution, astronomy, chemistry, etc. 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.

Many Thanks to Withwave for Long-Time Support!

Withwave RF & Microwave Components - RF CafeWithwave manufactures an extensive line of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch, board edge, panel mount), calibration kits (SOLT), a fully automated 4-port vector network analyzer (VNA) calibrator, between- and in-series connector adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes & probe positioner. Special test fixtures for calibration and multicoax cable assemblies. Frequency ranges from DC through 110 GHz. Please contact Withwave today to see how they can help your project succeed.

Friday the 24th

Electronic Video Recording | Color TV

Electronic Video Recording | Color TV, February 1969 Radio-Electronics - RF CafeIn the pre-VHS era, companies were vying to create and set standards for the home-based video recording and playback industry. The same sort of scenario played out over color television standards a decade earlier, and over B&W television a couple decades before that. Such battles for dominance in emerging technologies were not new, and continue into the current time. Various schemes for Electronic Video Recording systems were being used by commercial media, but creating devices affordable to Harry and Harriet Homeowner was a challenge. Betamax, produced by Sony, hit the store shelves in 1975, then VHS a year later. A sort of 8-track vs. compact cassette battle ensued, but VHS clearly emerged as the winner - followed by DVD and Blu-ray. Also reported was the world's most expensive - and feature-filled - color TV, built by Philips, that was "more computer than television," being able to operate on eleven different modulation standards...

Carbon Nanotube Wiring on Plastic Films

Carbon Nanotube Wiring on Plastic Films - RF Cafe"Researchers at Tokyo University of Science have proposed a novel method to fabricate multi-walled carbon nanotube (MWNT) wiring on a plastic film under ambient conditions using a low-cost laser. The properties of Carbon nanotubes (CNTs) include high strength, low weight, and excellent thermal and electrical conductivities. This makes them suitable materials for applications including reinforcement materials, energy storage and conversion devices, and electronics. Despite their potential, it has proven challenging to incorporate them onto plastic substrates for fabricating flexible CNT-based devices. The breakthrough from Japan involves coating a polypropylene (PP) film with an MWNT film about 10μm thick and then exposing it to a mW UV laser. The result is a conductive wiring made of a combination of MWNT and PP. The research is detailed in Scientific Reports. This process enables the easy 'drawing' of wiring and flexible devices for wearable sensors without the need for complex processes..."

Belmont Model 5D128 Tabletop Radio

Belmont Model 5D128 Tabletop Radio, November 1946 Radio News - RF CafeThe Belmont model 5D128 was a compact, inexpensive tabletop AM radio set. A schematic and parts list for it appeared in the November 1946 issue of Radio News magazine. 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, so I scan and post them whenever they appear in magazines which I own. While researching the Belmont 5D128 tabletop radio, I ran across an excellent video created by Mr. Paul Carson, as part of his Mr. Carlson's Lab series (note how the setting looks like he's in the ISS). Here is a great video of Mr. Carlson troubleshooting an intermittent noise problem in a receiver. That "Carlson RF SuperProbe" he is using looks like a must-have piece of test equipment The Belmont 5D128 was rebranded by other companies such as Airline, Coronado, Lafayette...

IPP-5014, 30-1000 MHz Transformer

Innovative Power Products IPP-5014, 30-1000 MHz Transformer - RF CafeInnovative Power Products (IPP), with more than 30 years of experience designing & manufacturing RF & microwave passive components, Innovative Power Products introduces our model IPP-5014, a 100 watt surface mount single-ended transformer that operates from 30 to 1000 MHz. The IPP-5014 is a single-ended impedance transformer that operates from 30 to 1000 MHz with a 4:1 transformation ratio and 100 watt average power rating. The IPP-5014 transforms impedance from 50 ohms at J1 to 12.5 ohms at J2. The insertion loss is less than 0.75 dB from 30-50 MHz and less than 0.60 dB from 50-1000 MHz. The VSWR is less than 1.43:1. Single-Ended Transformers are used to match devices of differing impedances. Innovative Power Products can also customize our single-ended transformers to fit your project...

National Company: TMS Condensers

National Company Ad: TMS Condensers, March 1939 QST - RF CafeNational Company, an early manufacturer of electronics components for radio products, ran a series of unique advertisements in the ARRL's QST magazine. Rather than using precious cash for directly promoting specific products or product lines, company president John Millen occupied full pages with text explaining why it makes the things it does and how they can be used to solve problems or enhance performance. This article/ad on TMS condensers (aka variable capacitors) was number 61 in the series, which means if they printed one every preceding month, the first would have appeared in the March 1934 issue of QST...

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...

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.

Thursday the 23rd

Electronics News Briefs

News Briefs, April 1960 Radio-Electronics - RF CafeLots of interesting topics were reported in News Briefs from the April 1960 issue of Radio-Electronics magazine. One that is relevant even today is the assigning of new numeric prefixes tera for a trillion; giga for a billion; nano for a billionth, and pica for a trillionth. If you have read vintage science and engineering publications, you know that, for instance, what is now called pica (a la pF, 10-12) used to be written as micromicro (a la μμF, 10-6x10-6 = 10-12). Here is an example of μμF being used. Less commonly seen was something like millimicroamperes, which is 10-3x10-6 = 10-9, now known as a nanoamperes, nA. A new television picture tube which used a solid state electron emitter in place of a heated cathode was announced for portable TVs, potentially doubling battery life. Did you know that in 1960, the South African government felt that TV would be detrimental to children and "the less developed races," thereby justifying its anti-TV policies? Following on the results of the International Geophysical Year (IGY) discoveries, atmospheric ducts for radio signal transmission propagation were being found worldwide...

Accurate Multi-Channel Radar Signal Generation

Phase and Timing-Accurate Multi-Channel Radar Signal Generation - RF CafeEngineers at Berkeley Nucleonics Corporation (BNC) and AnaPico teamed up to write a paper entitled "Phase and Timing-Accurate Multi-Channel Radar Signal Generation." It begins: "Engineers testing radar require the ability to generate multi-pulse streams with each pulse supporting dozens of parameters such as frequency, amplitude, phase, pulse width, time position and intrapulse modulation or chirping. Table 1 summarizes the typical parameter set describing a single radar pulse, known as a pulse descriptor word (PDW). A list of PDWs will fully describe a radar pulse stream. Multi-patch radar antenna arrays require additional parameters for full characterization. For these arrays, inter-channel phase coherence, which addresses relative phase stability becomes important. Phase-coherent switching, where the relative phase between channels is stored in memory and inter-channel timing accuracy are also critical parameters..." A version of this article also appears on the MWJ website.

General Electric Germanium Transistors

General Electric Germanium Transistor Advertisement, November 1953 QST - RF Cafe"If you're not using transistors already, chances are you'll consider them for amplifiers and oscillators in future circuits." So says the line in an advertisement for General Electric vacuum-sealed transistors in a 1953 edition of QST magazine. To say the claim was prescient is an understatement. A lot of people resisted the switch to transistors for many years - especially hobbyists who had grown accustomed to working with vacuum tubes. Maybe GE figured pitching the newfangled devices as being "vacuum-sealed" would help the hardliners soften their opposition to them. Not mentioned in the ad is that these three transistors - the 2N43, 2N44, and 2N45 - are all germanium-based. It wasn't until May of 1954 that Texas Instruments (TI) announced the commercial availability of grown-junction silicon transistors...

Pulse Fidelity for High-Power GaN Radar and EW Tx's

Pulse Fidelity for High-Power GaN Radar and EW Tx's - RF CafeMicrowave Journal magazine has a useful article posted entitled, "Innovations in Pulse Fidelity for High-Power GaN Radar and EW Transmitters." Darren Miles and George Bollendorf, of Empower RF Systems and Bob Buxton, of Boonton Electronics team up to present a method for accurately measuring and compensating distortions in pulses driving the output stage. It begins: "Radar and electronic warfare (EW) have been the primary applications for extremely high-power transmitters, driving the demand for specialized high-power traveling wave tubes (TWTs) and magnetrons. Diminishing sources of TWT supplies, coupled with their poor reliability, inefficiency, large size and high total lifetime cost of ownership are causing a migration away from tubes. While improved pulse fidelity accompanies the shift to solid-state transmitters, next-generation radar depends on further improvements in waveform fidelity and flexibility. Next-generation radar systems utilize long pulse widths, which present specific challenges. In response, Empower RF Systems has developed technology to reduce pulse distortion as a development step towards pulse shape matching, allowing the reproduction of the input pulse without distortion. The pulse correction is performed within the amplifier in real-time. This is important because long pulse width radar is especially vulnerable to over/undershoot and droop...

When Your Phone Is Spying on You

When Your Phone Is Spying on You - RF Cafe"Smartphone spyware apps that allow people to spy on each other are not only hard to notice and detect, they also will easily leak the sensitive personal information they collect, says a team of computer scientists from New York and San Diego. While publicly marketed as tools to monitor underage children and employees using their employer's equipment, spyware apps are also frequently used by abusers to covertly spy on a spouse or a partner. These apps require little to no technical expertise from the abusers; offer detailed installation instructions; and only need temporary access to a victim's device. After installation, they covertly record the victim's device activities - including any text messages, emails, photos, or voice calls - and allow abusers to remotely review..."

Galvin Motorola Model 61 Automotive Receiver

Galvin Motorola Model 61 Automotive Receiver, October 1932 Radio-Craft - RF CafeWhat the heck is an Elkonode? That was my response to its mention in this Radio Service Data Sheet for the Galvin Motorola Model 61 Automotive Receiver. The Mallory-Elkon Elkonode was an electromechanical vibrator device for DC-DC conversion. An oscillating circuit opened and closed a set of contacts being fed with the automobile's DC supply, thereby creating a chopped waveform which was applied to a step-up transformer, then rectified and filtered to provide the high plate voltage for the radio's vacuum tubes. A Google search turned up a datasheet on the Mallory Elkonode. Per the info, "The series 60, 70, and 80 Mallory Elkonodes are described as single-reed, full-wave inverters, with self-contained synchronous rectifiers. These units within themselves supply direct current, high voltage for radio receiver plate supply. No tube rectifiers are required with these types." This 1932 Radio-Craft magazine article recommends against attempting self-repair of Elkonodes (aka interrupters), so restoration buffs will appreciate the instructions offered in the datasheet...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000 or so symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing. Check them out!

Thanks to PCB Directory for Continued Support!

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

Wednesday the 22nd

What Happened at Oslo? Color TV

What Happened at Oslo?, January 1967 Radio-Electronics - RF CafeIt is kind of hard to believe that even by 1966, when the International Telecommunications Union (ITU) met in Oslo, Norway, that the world had not yet agreed in a common transmission standard for color television. In January of 1967, Radio-Electronics magazine editor Thomas Hasket interviewed two major players in the industry, George Brown of Radio Corporation of America (RCA), and Frederick M. Remley, Jr. of Society of Motion Picture and Television Engineers (SMPTE), regarding the stalemate that was unarguably hampering the ramping up of color television set production. Consumers were pining for them, but companies hesitated to invest engineering and manufacturing resources when they couldn't be sure it would not be thwarted by a change in the modulation scheme. A battle was being waged between the U.S. NTSC standard and the European PAL system (and SÉCAM to a lesser sense). Both had strengths and weaknesses, but history has shown, NTSC ultimately won. Possibly due to the impasse, color TV sales in America did not surpass B&W sales until the early 1970s...

Anatech Electronics March 2023 Newsletter

Anatech Electronics March 2023 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his March 2023 newsletter that features his short op-ed entitled "Healthcare Industry IoT Security Under Threat," which discusses some of the issues compromising not just healthcare privacy, but the whole Internet of Things (IoT) effort. The fact is your healthcare records have been anything but secure and private for a long time. The Health Insurance Portability and Accountability Act of 1996 (HIPAA), which is responsible for the glass or Plexiglas barriers with the small transaction opening installed at the reception desks at doctor and dentist offices, was supposed to make people feel that their medical history was being protected against prying eyes, physically and digitally. That has been as effective as requiring everyone to wear a cloth facemask to protect them against a virus. My guess is that nearly every form of personal information is available on the black market from databases breached by not just outside black-hat operators, but by government and private corporate employees seeking financial payouts. Information fences are fairly easily contacted if you seek such information. Consider how prolifically your e-mail and other non-medical information is made available to concerns with enough money to buy it...

Electronics Themed Comics

Electronics Themed Comics, March 1948 Radio-Craft - RF CafeHere are a four more technology-related comics from magazines of the days of yore, this time from a 1948 edition of Radio-Craft magazine. Readers would submit ideas for funnies and then artist Frank Beaven would draw the comics. The page 37 comic is an example. Evidently E.R. Donohue, of Walla Walla, Washington, had issues with his phonograph featuring a record changer mechanism. My interest in rockets makes me really appreciate the page 82 comic with the missile's flight being affected by the musical "interference." In the early days of remote control, audio tones modulated onto a carrier commanded tuning-fork-like (tuned) "reeds," which acted as channel filters for separating and directing signals, in the airborne receiver section to control surface actuators (see video). It is rare to find a comic in a technical or hobby magazine these days. I don't know why that is...

Making Money in Radio - Still Possible?

Making Money in Radio (Bob Davis) - RF CafeMike Simpson homebrew replacement electrolytic capacitor - RF CafeLong-time RF Cafe contributor Bob Davis sent me a link to this very interesting and entertaining story of one man's journey (Mr. Mike Simpson) in his effort to determine whether "Making Money in Radio" is still as guaranteed as the vintage electronics magazine advertisements enthusiastically asserted. To find out, he, researched and purchased a couple vacuum tube radios, then restored them to fine quality, and then put them up for sale on eBay. In some cases minor component replacement or repair was required. Calculations were then made of an estimated effective hourly wage for the effort. The result may (or may not) surprise you. As you will see on his "Analog Dial" website, Mike has collected and restored many old radios, both production models, kits from the era, and homebrew radios. BTW, notice in the photos that he's a model rocketeer as well. A bit of good humor is mixed in with the stories and descriptions. Enjoy!

Battery Types and Their Characteristics

Battery Types and Their Characteristics, April 1973 Popular Electronics - RF CafeAccording to Samuel Milbourne's "Battery Types and Their Characteristics" article in Popular Electronics magazine, in 1973 there were about 400 different battery types to choose from when deciding what to buy for your automobile, electronic device, uninterruptible power supply, flashlight, etc. I don't know what the number of types is today, but it must be in the thousands. Nominal voltage, case size and shape, energy capacity (amp-hour rating), current delivery capacity ("C" rating), environmental accommodation, connection type (contact, solder, screw-on, or push-on terminals), chemistry, number of recharge cycles (for secondary batteries), and a host of other choices are available nowadays. Every time I need to order a new Li-Po battery pack for a model airplane or helicopter, I spend quite a bit of time searching through mAh versus weight and physical size specifications to identify the best - and most affordable - option. There will never be a one-size-fits-all battery. If you are interested in vintage batteries...

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...

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

Empower RF Systems - RF CafeEmpower RF Systems is the technological leader in RF & microwave power amplifier solutions for EW, Radar, Satcom, Threat Simulation, Communications, and Product Testing. Our air and liquid cooled amplifiers incorporate the latest semiconductor and power combining technologies and with a patented architecture we build the most sophisticated and flexible COTS system amplifiers in the world. Solutions range from tens of watts to hundreds of kilowatts and includes basic PA modules to scalable rack systems.

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