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"These days, scientists & doctors will believe anything they're paid to believe" - Anon

Today in Science History

Electronics & Tech  Headlines

Tech Industry Headlines - RF Cafe - Archive -

• SpaceX Orbits 53 Starlink Satellites

• Ofcom Enforces 3G Switch-off and Online Safety

• Recycling Wide Range of Batteries Simple and Economical

• Aftershocks of EV Transition Could Be Ugly

• USB Power Sensor Market Analysis & 2028 Forecast

• Why Tech Jobs Are Vaporizing

• DOD, NTIA Launch 2023 5G Challenge for O-RAN

• Amplified Search for New Forces

• Lawmakers Try Again to Tax Radio

• Automotive IC Shortage Will Last Throughout 2023

4 New Sources of Power

Four New Sources of Power, May 1960 Radio-Electronics - RF CafeWhen this "Four New Sources of Power" article appeared in Radio−Electronics magazine in 1960, most people had never heard of a fuel cell, the Seebeck effect, thermionic effects, or magnetohydrodynamics. All had been around as features embedded in common products in some manner, like thermionics in vacuum tubes. It is pointed out that Sir Humphrey Davy invented the fuel cell technique in 1802, thermoelectricity by Thomas Seebeck in 1821, thermionic effects by Thomas Edison in 1878, and magnetohydrodynamics by Michael Faraday in 1831. Today, all four types of power sources have been integrated into a host of products. Whereas thermionics was among the most common in 1960, it might be the least common of the four nowadays...

1st American Made Quartz Watch

First American Made Quartz Watch, March 1972 Popular Electronics - RF CafeThis Bulova Accuquartz wristwatch is not the first quartz-controlled wearable timepiece; however, it was the first to be manufactured in the U.S. Interestingly, it is not a fully electronic watch because the quartz crystal stimulates a mechanical tuning fork which ultimately drives the hands. Bulova's first tuning-fork-driven "Accutron" was introduced in 1960. It sported a 360 Hz tuning fork that was stimulated by a pair of electromagnets. The story appeared in a 1972 issue of Popular Electronics magazine. The retail price at the time (pun intended) was $395, which in 2023 money is equivalent to $2,832 (per the BLS Inflation Calculator)! I found a couple nice photos of the Accuquartz...

World's Fastest 5G Phased Array Antenna

BT, Stratospheric Platforms' World's Fastest Phased Array Antenna - RF Cafe"'This partnership will build on SPL's world-first 5G demonstration from the stratosphere in 2022,' said SPL CEO Richard Deakin. Funded by Innovate UK, the trials will be at BT's labs at Adastral Park and 'could offer transformational opportunities for sectors operating in remote areas such as transport, maritime security and search and rescue,' said BT. Stratospheric Platform's (SPL's) antennas are designed to communicate directly with standard 3G, LTE/4G, 5G phones. The eventual aim is to create a 20 kW >3 m diameter version for flight, with 500 individually steerable beams, each intended to be equivalent to a cell created by traditional terrestrial masts - delivering up to 150 Mbit/s, and covering a 140 km diameter, or 15,000 km2 land area. 'Virtually any shape of beam coverage can be painted on the ground,' according to SPL..."

Arvin Models 150TC Schematic & Parts List

Arvin Models 150TC, 151TC 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 Arvin Models 150TC, 151TC combination radio / phonograph - 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. 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 (check the lists first, please) of Radio News, Radio-Craft, etc. known to contain the information you need...

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 Triad RF Systems to Thank Them for Their Support

Triad RF SystemsTriad RF Systems designs and manufactures RF power amplifiers and systems. Triad RF Systems comprises three partners (hence "Triad") with over 40 years of accumulated knowledge of what is required to design, manufacture, market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating amplifiers are available, in formats including tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology partner than a vendor for our line-of-sight communications product line." Please check to see how they can help your project.

Ohm's Law Quiz - How's Your E=IR?

Ohm's Law Quiz - How's Your E=IR?, March 1969 Popular Electronics - RF CafeAll but two of these circuits in this "How's Your E=IR? Quiz" can be analyzed by inspection, without even needing a calculator or writing down equations, because the component, voltage, and current values given are integer ratios that make the math easy. It appeared in a 1969 issue of Popular Electronics magazine. You might end up with an order-of-magnitude error when mentally calculating milli, kilo, etc., but your base number will be correct. Numbers 8 and 10 are a bit trickier. Your approach might be to rearrange the schematic to create more recognizable series and/or parallel component configurations. For number 8, I ended up writing equations for the three circuit loops and solving the simultaneous equations because I did not see the balanced bridge configuration at first. However, my mesh equations yielded I25Ω = 0 mA. Be careful with number 10 to not assume...

Please Thank RF & Connector Technology for Their Support

RF & Connector Technology - RF CafeProviding full solution service is our motto, not just selling goods. RF & Connector Technology has persistently pursued a management policy stressing quality assurance system and technological advancement. From your very first contact, you will be supported by competent RF specialists; all of them have several years of field experience in this industry allowing them to suggest a fundamental solution and troubleshooting approach. Coaxial RF connectors, cable assemblies, antennas, terminations, attenuators, couplers, dividers, and more. Practically, we put priority on process inspection at each step of workflow as well as during final inspection in order to actualize "Zero Defects."

Wireless EV Charging Threat to AM Reception

Wireless EV Charging Threat to AM Reception - RF CafeRegular EV chargers are bad enough with power factor and harmonics issues, but the gross inefficiencies in power transfer with contactless charging will make matters even worse. Imagine a world full of them! "Consumers are eager to cut the cord on their electronics charging devices, a trend that could soon benefit drivers of electric vehicles (EVs). HD Radio developer and licensing company Xperi is seeking to raise awareness about a potential new threat to AM radio broadcast reception: the proposed introduction of wireless power transfer systems for electric vehicle charging, or WPT-EV, that use switching frequencies that generate harmonics in the lower AM band. Xperi recently filed comments about this concern in response to a notice of inquiry at the FCC about radio receiver performance. It hopes to raise awareness and also believes its HD Radio technology can be of help. Interference to AM from unintentional radiators including low-cost switching power supplies in EVs is a concern..."

YL News and Views

YL News and Views, April 1953 QST - RF CafeI wonder why today's editions of the ARRL's QST magazine does not have a column dedicated to the "YL" (Young Lady, or female in general) contingent of the amateur radio realm? Ham radio, as most - if not all - historically male-dominated hobbies has fairly significant outreach efforts to try attracting women into activities. My Model Aviation magazine has a monthly column written by a lady whose enthusiasm for model airplanes equals that of most males - and she's funny to boot! - but it is not dedicated to female modelers. If there is a girl or woman present at a competition, she is almost guaranteed to receive coverage in the form of a photograph and/or mention in an article. Any lack of other-than-male participation these days can only be attributed to a lesser degree of interest by other than males. Could there really be a difference between men and women (in general) after all?

EMI Issues Caused by Structural Resonances

Troubleshooting EMI Issues Caused by Structural Resonances - RF Cafe"Has it happened to you? When troubleshooting an electromagnetic interference (EMI) issue, you've tried various combinations of components and saw the signal of interest reduced. But another frequency signal unexpectedly raised above the limit line. Or, you introduced a chassis plane on your printed circuit board (PCB), only to find the radiated emissions became much worse instead of getting better. These are typical cases of 'tuning the resonances of a circuit.' Most EMI emissions are related to structural resonances. Structural resonances are also one of the main reasons that electromagnetic compatibility (EMC) can be mystifying. Unknowingly, engineers often spend days and months tuning the resonances of a circuit by adding passive elements such as inductors and capacitors. Sometimes, they are lucky enough to finally arrive at a combination that would give them a pass. But most of the time, solutions are hard to find. A tremendous amount of work has been done on the subject of structural resonances. Two practical case studies are presented to demonstrate methods to identify, locate, and fix EMI issues that are associated with structural resonances. EMC engineering often requires problems to be resolved..."

Electronics Themed Comics

Electronics Themed Comics, August 1944 Radio-Craft - RF CafeIt's time for little levity. These electronics-themed comics from a 1944 issue of Radio−Craft magazine have an electronics theme, so you can claim looking at them is work-related since you might use one for your next conference or project status presentation. Some of the concepts are utterly foreign to contemporary readers, like user-serviceable electronics apperati [sic] and radio sets that receive over-the-air signals with analog information modulated on the carrier. Radio was still somewhat of a novelty to much of the public, and "radio can do anything" memes were common in comics. I took the liberty of colorizing them. There is a list of many more similar comics at the bottom of the page in case you haven't seen them yet. Enjoy.

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

Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

Thanks 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.

Spiral Conical Antennas

Spiral Conical Antennas, April 1960 Radio-Electronics - RF CafeUsing modern blazing speed computers and sophisticated programs, designing and analyzing something as complex as a spiral conical antenna is child's play - and many school-age children actually do it. It wouldn't surprise me if there is a phone app capable of performing such tasks. However, back in 1960 when this article appeared in Radio−Electronics magazine, a lot of intuition, guesswork, and trial and error on physical models was necessary to model and parameterize the spiral conical antenna shown on the cover. This particular antenna resonates at 14 MHz with a 1.25:1 VSWR, however across the 7-17 MHz intended bandwidth the VSWR can be as high as 6:1. Surprisingly, an image search for spiral conical antenna radiation patterns did not turn up much. This paper from the International Center for Radio Astronomy Research is about the best I could find...

Thanks Again for Windfreak Technologies' Continued Support!

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

Zenith Models 5R080 & 5R086 Schematic & PL

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...

The Future of Automation at Digi-Key

The Future of Automation at Digi-Key - RF CafeThis story on the Supply Chain Connect website caught my attention because of the photo of the huge new Digi-Key building in Thief River Falls, Minnesota (about as far north you can go in the USA). "Join us as we explore the latest development in supply chain automation when we visit Digi-Key's newly opened, 2.2 million-square-foot, PDCe in Thief River Falls, Minnesota. After the ribbon is cut, we learn how one of the 10 largest warehouses in the country plans to accelerate into the next decade. We sit down with Digi-Key leadership, including Vice President, Order Fulfillment at Digi-Key, Chris Lauer, to talk about new areas of growth and the implementation of technology that pushes the envelope of supply chain automation. We answer questions like: What are the challenges that come with shipping 13.4 million products to more than 857,000 customers each year in 180 countries..."

How's Your Math?

How's Your Math?, December 1942 QST - RF CafeIf you are just starting out in the realm of electronics or maybe just need a little freshening up of your basic math skills, this rather extensive article from a 1942 issue of QST magazine is just what you need. Author Dawkins Espy does a really nice job of laying out the basics of algebraic operations, Ohm's law, trigonometry, and logarithms. Examples are provided for each category. In this day of calculators doing all the hard work of calculating logs, antilogs, and trig functions, it does even seasoned veterans at electronics calculations a bit of good to do a quick read-through to knock off cobwebs in the gray matter. How long has it been since you have seen tables of sine, cosine, and tangent values and/or tables of logarithms? Not long enough, you say?

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

Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

Thanks to 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.

Chinese Spy Balloon Finally Shot Down

Chinese Spy Balloon Shot Down - RF CafeAs of September 16, 2022, if I fly my radio-controlled model airplane, helicopter, or drone even an inch off the ground anywhere in the U.S. without having a specially designed and certified electronics device - at my expense - broadcasting identification and position data ("Remote ID of Unmanned Aircraft"), I can be fined and/or jailed and/or have my equipment confiscated by the U.S. government. The stated justification is concern for safety of property, persons, and national security. However, if a country established as a military and economic threat to the U.S. flies a huge uncontrolled (other than by altitude in air currents) aircraft burdened by maybe 1000 pounds of equipment, including batteries, from coast to coast across populated areas, no action is taken. Here is a video of the Chinese balloon finally being shot down over the ocean after it was allowed to collect and relay data, and even possibly release pathogens over wide areas for days (NOAA HYSPLIT trajectory). Here's Trump impersonator Shawn F. with his take on the Chinese spy balloon debacle. Another victory for China!

Electronics Theme Crossword for February 5

Electronics Theme Crossword Puzzle for February 5, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for February 5th contains words and clues which pertain strictly to the subjects of electronics, mechanics, power distribution, engineering, science, physics, astronomy, chemistry, etc. If you do see names of people or places, they are directly 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...

Carl & Jerry: Going Up, Up, Up

Carl & Jerry: Going Up, Up, Up March 1955 Popular Electronics - RF CafeThanks to Mr. Ferrous Steinka for submitting this commentary on the episode of Carl & Jerry appearing in the March 1955 issue of Popular Electronics. "Radio and television waves are reflected in the same way as light waves. As both light and radio waves are forms of electromagnetic waves, they are both subject to the same basic laws and principles. Visual examples of light reflection are everywhere from specific mirrors to flat reflective surfaces like glass, polished metal and the like. So too, radio waves can experience reflection. Conducting media provide the optimum surfaces for reflecting radio waves. Metal surfaces, and other conducting areas provide the best reflections, so the story below is feasible and within the known technology at the time. The use of a highly directional Yagi antenna would have been very important because without it the reflected waves would have been inverted (out of phase) with the normal signals, thereby reducing the overall received signal..."

Please see the RF Cafe Homepage Archives for previous items of interest...

everythingRF RF & Microwave Parts Database (h1) - RF Cafe
ConductRF Phased Matched RF Cables - RF Cafe
Innovative Power Products Passive RF Products - RF Cafe
RF Electronics Shapes, Stencils for Office, Visio by RF Cafe
Triad RF Systems Amplifiers - RF Cafe

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About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024


    Kirt Blattenberger,


RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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