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Homepage Archive - February 2023 (page 2)

See Page 1 | 2 | 3 | 4 | of the February 2023 homepage archives.
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Friday the 10th

Thursday the 9th

Wednesday the 8th

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.

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Chinese Flying Wing Drone Raises Bar for Radar Evading

Chinese Flying Wing Drone Raises Bar for Radar Evading - RF CafeWhy go to the trouble and expense when you can get away with floating a cheap balloon over all North America? "In the sky over southwest China, a team of researchers has been testing a new wing design that they said could help unmanned aircraft better evade radar. The drone, which has no tail, appears to be a scaled-down version of the United States Air Force's B2 Spirit bomber, and can fly without the use of elevators, ailerons or flaps - the hinged moving parts known as elevons that help control flight direction - according to the researchers. 'Our work is a first,' the team from the China Aerodynamics Research and Development Centre in Sichuan province said in a paper published on January 19 in the peer-reviewed journal Acta Aeronautica et Astronautica Sinica..."

Minimizing Signal Chain with Direct RF Sampling

Minimizing the Signal Chain with Direct RF Sampling - RF CafeDirect signal sampling at the antenna has been the goal of receiver designers since the early days of digital radio. Doing so eliminates the noise added by the transmission line, and simplifies circuitry by eliminating mixers, filters, amplifiers, etc. Steady progress has been made toward the goal, and direct sampling receivers have been around for many years - limited by the operational frequency of the integrated circuit semiconductor technology. Here is a good synopsis of the state of the art, on the Microwaves & RF website (9-minute video). "Mercury Systems' Ken Hermanny and Rodger Hosking discuss the company's deployment of Direct RF technology in its signal-processing products for defense and aerospace applications. While it's not a brand-spanking-new technology, Direct RF receiver architectures are now coming to the fore in numerous aerospace and defense applications, such as radar and electronic warfare. Direct RF architectures bring a host of advantages. For one, they eliminate the need for a mixer or local oscillator for frequency downconversion...."

Offline Turbines at Wind Farms Kept Warm by Diesel Generators

Offline Turbines at Wind Farms Kept Warm by Diesel Generators - RF CafeThis sort of thing happens all over the place, and the public is rarely made aware of it. I'm a big supporter of alternative energy sources, electric cars, etc., but I resent the gas-lighting and outright lies put out by government, academia, and industry regarding the "greenness" of it all. "Dozens of giant turbines on Scotland's windfarms have been powered by diesel generators, the Sunday Mail can reveal. Scottish Power admitted 71 of its windmills were hooked up to the fossil fuel supply after a fault developed on the grid. The firm said it was forced to act in order to keep the turbines warm during very cold weather in December. But a whistleblower has told the Sunday Mail the incident is among a number of environmental and health and safety failings.'" Amongst other problems reported is "over 4000 litres of [hydraulic] oil leaked from hydraulic units on turbines and sprayed over the countryside." Also does 95% availability seem good to you? That's 57.6 minutes out of every 24 hours...

Microwaves for the Beginner

November 1969 P-E, p40

AMRAD Model 81 Radio

AMRAD Model 81 Radio

 

June 1969 P-E, Kohler p40, Math Quiz p46, I/O Impedances p69

July 1969 P-E, B-Quiz p64

August 1969, Hobnobbing Harbaugh p68

September 1969, Bridge Quiz p68

October 1969, Op Amp Quiz p58

 

Bendix 636A Schematic & Parts List

Bendix Models 636A, C, D Schematic & Parts List, February 1947 Radio News - RF CafeHere is Bendix Models 636A, C, D schematic and parts list as featured in a 1947 edition of Radio News magazine. No operational or alignment information was provided. The 636A is a tabletop radio using five vacuum tubes in the detector and amplifier stages, and a single vacuum tube rectifier in the power supply. Its shiny Bakelite cabinet sported an Art Deco style, which was popular back in the day. The images to the left are from a recent eBay listing, for $60, where the seller says it is in working condition. As mentioned many times in the past, I post these online for the benefit of hobbyists looking for information to assist in repairing or restoring vintage communication equipment...

 

 

 

 

 

 

 

 

Supernova bombarding cell frequencies, akin WEF EMP event

 

Mathematics of equity versus equality

 

https://chargedevs.com/features/a-closer-look-at-power-factor-correction/

 

https://phys.org/news/2022-12-panama-huge-copper-dispute.html

Engineering Job Opening

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 16,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be.

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...

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...

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!

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...

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...

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...

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10x Enhancement Photoluminescent Nanoantenna

10x Enhancement Photoluminescent Nanoantenna - RF cafe"White LEDs' reign as the top light source may soon come to an end with the advent of a new alternative that offers superior directionality. A photonic crystal or nanoantenna, a 2D structure with periodic arrangement of nano-sized particles, is being developed as a cutting-edge optical control technology. Upon exposure to light, combining a nanoantenna with a phosphor plate produces a harmonious mix of blue and yellow light. White LEDs have already been improved upon in the form of white laser diodes, or LDs, which consist of yellow phosphors and blue LDs. While the blue LDs are highly directional, the yellow phosphors radiate in all directions, resulting in an undesired mixing of colors. To address this issue, researchers have developed phosphor plates combined with nanoantennas using metallic aluminum, enabling increased photoluminescence..."

Matrix Multiplications at Speed of Light

Matrix Multiplications at Speed of Light - RF Cafe"'All things are numbers,' avowed Pythagoras. Today, 25 centuries later, algebra and mathematics are everywhere in our lives, whether we see them or not. The Cambrian-like explosion of artificial intelligence (AI) brought numbers even closer to us all, since technological evolution allows for parallel processing of a vast amounts of operations. Progressively, operations between scalars (numbers) were parallelized into operations between vectors and, subsequently, matrices. Multiplication between matrices now trends as the most time- and energy- demanding operation of contemporary AI computational systems. A technique called "tiled matrix multiplication" (TMM) helps to speed computation by decomposing matrix operations into smaller tiles to be computed by the same system in consecutive time slots. But modern electronic AI engines, employing transistors, are approaching their intrinsic limits and can hardly compute at clock frequencies higher than ~2 GHz..."

China's Hypersonic Generator for Power-Hungry Weapons

China's Hypersonic Generator for Power-Hungry Weapons - RF Cafe"Scientists in Beijing say they have developed a generator that can turn hot gas moving at hypersonic speeds into an intense electric current capable of powering futuristic weapons. The electricity produced could be used to charge military lasers, microwave weapons, rail guns and other pulsed energy weapons, according to the team led by assistant researcher Zhang Xiaoyuan with the Institute of Mechanics under the Chinese Academy of Sciences. According to the researchers, the technology could also be used for civilian purposes, such as devices for producing nuclear fusion energy or to send a burst of strong SOS signals in an emergency. The reusable air defence system that could protect China from hypersonic weapons. The device produced more than 10 times the power..."

 

 

 

 

 

 

These archive pages are provided in order to make it easier for you to find items that you remember seeing on the RF Cafe homepage. Of course probably the easiest way to find anything on the website is to use the "Search RF Cafe" box at the top of every page. About RF Cafe.

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About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024

Webmaster:

    Kirt Blattenberger,

    BSEE - KB3UON

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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