Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Forums Magazine Sponsor RF Cafe RF Electronics Symbols for Visio RF Electronics Symbols for Office Word RF Electronics Stencils for Visio Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Anritsu Alliance Test Equipment Amplifier Solutions Anatech Electronics Axiom Test Equipment Berkeley Nucleonics Bittele Centric RF Conduct RF Copper Mountain Technologies Empower RF everything RF Exodus Advanced Communications Innovative Power Products ISOTEC KR Filters Lotus Systems PCB Directory Rigol RF Superstore San Francisco Circuits Reactel RFCT TotalTemp Technologies Triad RF Systems Windfreak Technologies Withwave LadyBug Technologies Wireless Telecom Group Sponsorship Rates RF Cafe Software Resources Vintage Magazines Thank you for visiting RF Cafe!

- Welcome to the RF Cafe Website -
"Can AAA deliver enough electrons to get your stalled EV to the nearest charging station?" - Kirt Blattenberger

spacer
Today in Science History

Electronics & Tech  Headlines

Tech Industry Headlines - RF Cafe - Archive -

• RF GaAs Device Revenue Declining in 2022

• European Microwave Week 2022 Wrapup

• ITU Gets Its 1st Female Leader

• U.S. Space Force Surveillance Telescope Operational in Australia

• Fibre Frustration in Germany

• Ionics Replace Electronics in Analog 16x16 Multiplier

• Report: RF Front-End Module Architectures in iPhones 2017-2021

• FCC Adds China Unicom, PacNet to National Security Threat List

• Semicon Taiwan 2022 Wrapup

Clandestine Broadcasters

Clandestine Broadcasters, November 1967 Popular Electronics - RF CafeWhen this "Clandestine Broadcasters" article appeared in a 1967 issue of Popular Electronics magazine, we were at the height of the Cold War era with Communist forces spreading all over the globe and inching closer to the U.S. mainland with moves in the West, north of the Equator. The Cuban Missile Crisis occurred just five years earlier, and the spy game kept all sides busy trying to hide their own secrets and discover the secrets of others. Mysterious radio broadcasts were routinely picked up and reported by Amateur Radio operators and Short Wave Listeners. Their elusive broadcast content and station location enhanced the intrigue for people. Of those, it was the "numbers stations" that garnered the most attention because they issued a string of numbers, then ceased transmission. It was believed to be a means of sending encoded messages to spies. The practice continues to a lesser extent to this day...

Ubiquitous Connectivity to Land, Sea and Sky

Ubiquitous Connectivity to Land, Sea and Sky - RF Cafe"Keeping IoT applications across the world connected is a challenge, yet imperative. The term 'ubiquitous coverage' is often thrown around in the supply chain and logistics industry - and for a good reason. Breaks in the chain of visibility leave logistics vulnerable, especially as businesses scramble to keep up with the introduction of new technologies and services. This is why the challenge lies in finding a universal solution that connects IoT applications all over the world, providing a continuous view no matter where assets are. The first step to improving the deployment of IoT applications is to understand the common obstacles within the industry, like internal operations. Supply chain and logistics have long struggled to streamline internal processes to monitor the flow of goods and services from supplier to customer. And supply chain demands have only exacerbated this challenge..."

Crosley Roamio Automotive Radio

Crosley Roamio Automotive T.R.F. Receiver Models 90, 91 and 92 Radio Service Data Sheet, April 1933 Radio-Craft - RF CafeAs in the past, I am posting these Radio Service Data Sheets as a service to someone who might be doing research on vintage radios and/or restoring one. Roamio is not producing automobile radios anymore, but they did until recently make TiVo recorders and streaming media players. The Crosley Roamio Automotive T.R.F. Receiver Models 90, 91 and 92 was made in the early 1930's at a time when cars and trucks were just starting to experience such luxury. Crosley did not begin manufacturing its own line of cars until 1939, so none of these radios made it into Crosley autos...

Optimal EMC from Shielded Cables

Optimal EMC from Shielded Cables - RF CafeHere is Part 2 of the InCompliance article "Getting the Best EMC from Shielded Cables up to 2.8 GHz." Every day the electromagnetic noise in our environment intensifies as the world goes more and more wireless. Just as PCB layout needed to adopt distributed element methods for successful operation at higher speeds (digital and analog), interconnect cabling has been forced to accommodate frequencies with wavelengths near to or less than the cable length. At high frequencies, cables and shields begin to act like antennas for both emission and absorption. This installment reviews empirical testing done on cable configurations previously discussed. Note: Use this Part 1 link because the one on the page is bad...

RCA "Ultrafax" System

RCA "Ultrafax" System, January 1949 Radio & Television News - RF CafeDon't let the title fool you. This "Ultrafax" system developed by RCA in the late 1940s was essentially the first attempt at video on demand, or streaming video. Rather than piping the signal over cable or local broadcast frequency towers, a microwave link was used. While initial system equipment space and financial requirements meant only corporations, universities, and governments could procure an Ultrafax, engineers who developed the system envisioned an eventual culmination of equivalent systems in every home. Even at the end of the last century it was still not possible for program providers to personalize broadcasts to individuals. It wasn't until broadband Internet came on the scene in the 2000s that such services were possible. Now, a decade later, people watch any video they want on cellphones while riding in a car. We've come a long way, baby...

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 12,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be.

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

Empower RF Systems - RF CafeEmpower RF Systems is a global leader in power amplifier solutions. Empower RF Systems is an established and technologically superior supplier of high power solid state RF & microwave amplifiers. Our offerings include modules, intelligent rack-mount amplifiers, and multi-function RF Power Amplifier solutions to 6 GHz in broadband and band specific designs. Output power combinations range from tens of watts to multi-kilowatts. Unprecedented size, weight and power reduction of our amplifiers is superior to anything in the market at similar frequencies and power levels.

Color Code Quiz

Color Code Quiz, November 1967 Popular Electronics - RF CafeEven those of us old enough to remember the days when nearly all electronic components had identification markers on them find it challenging to correctly interpret color codes on resistors, capacitors, and inductors. The numbers are easy enough to remember, but getting tolerances and temperature coefficients correct is not guaranteed. Usually the color bands on a component are biased toward one end so there is no ambiguity as to where to begin decoding, but I have seen plenty where getting the right interpretation is a crap shoot unless the last band happens to be gold or silver. Gold and silver have no numbers associated with them, but brown and red are also used for tolerance (brown:±1%, red:±1%, respectively). Reading capacitor dots can also be a little tricky, but after you've read a few, it's a piece of cake...

Folded and Loaded Antennas

Folded and Loaded Antennas, April 1953 QST - RF CafeHere is a fairly major treatise on folded and loaded antennas that appeared in a 1953 issue of QST magazine, with "Suggestions for Mobile and Restricted-Space Radiators." It is not for the faint of heart or anyone with math phobia or math anxiety. Integral calculus is part of the presentation, although an understanding of calculus is not required to get the gist of the article. Equations for calculating the antenna configuration radiation resistances are given for the 3λ/4-wave folded dipole, the λ/8-wave folded monopole, the bottom-, center- and top-loaded λ/8-wave monopole, the bottom-loaded λ/16-wave monopole, and the λ/4-wave monopole folded twice, to name a few...

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.

FOD Discovered on Mars!

NASA Ingenuity 'Copter Picks up FOD on Mars - RF CafeThis is kind of weird. It's either a phenomenal discovery or bad news for the Ingenuity coaxial helicopter making airborne rounds on Mars. The video clip shows the 'copter descending without anything hanging from its landing gear leg, and then there is a wispy object dangling from it after taking off again. It looks like a weak water flow from an aerated faucet - which obviously it cannot be - or maybe a piece of Saran Wrap - which it also cannot be (... or could it be litter from a Martian's sandwich?). NASA has designated it as Foreign Object Debris (FOD). It'll be interesting to learn of NASA's conclusion.

Synzen Low-Profile 5G and 4G LTE Antennas

Synzen Low-Profile, Compact 5G and 4G LTE Antennas - RF CafeSynzen Precision Technology has unveiled ALCOR and ATRIA - two new low-profile antennas which are perfect for the wearable market or any IoT devices which require an ultra-slim design. Both designs deliver excellent performance at a limbo-defying height of only 1.6 mm. ALCOR is a 5G low-profile surface mount antenna that has been developed to be compact but still cover bands from 617-6000 MHz. It has a small footprint of 40 x 10 x 1.6 (mm) and a fallback to 4G/3G/2G. ATRIA is even more compact but still covers bands from 698-2690 MHz (also falls back to 3G/2G). It measures only 30.0 x 7.0 x 1.6 (mm) and requires a small clearance area (don't be fooled by claims of small antennas which often need a much bigger clearance area)...

Arvin Models 444 Tabletop Radio

Arvin Models 444, 444A Tabletop Radio, November 1946 Radio News - RF CafeThis schematic and parts lists for the Arvin model 444 and 444A tabletop radio were scanned and OCR'ed from the November 1946 issue of Radio News magazine. It was a compact, stylish, and affordable radio for the early post-World War II era. From what I can find, it was built in the 1945-1946 timeframe, so it was one of the first having been newly made radios after the three to four year suspension of domestic electronics production while the War Powers Act allowed the government to mandate companies dedicate capacity to wartime products. 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. This is an abbreviated version of the very informational Radio Service Data Sheets usually printed...

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...

Many Thanks to Anatech Electronics for Long-Time Support!

Anatech Electronics logo - RF CafeAnatech Electronics (AEI) manufactures and supplies RF and microwave filters for military and commercial communication systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter and cable assembly products are published in our website database for ease of procurement. Custom RF filters designs are used when a standard cannot be found, or the requirements dictate a custom approach for your military and commercial communications needs. Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please visit Anatech today to see how they can help your project succeed. 

RF Themed Crossword Puzzle for October 2nd

RF Themed Crossword Puzzle for October 2nd, 2022 - RF CafeHere is your custom made RF-themed crossword puzzle for October 2nd, 2022. There are at least 16 instances of this puzzle's theme included. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

Many Thanks to 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! 

Introduction to Radar - Air University

Introduction to Radar, USAF Air University - RF CafeThis "Introduction to Radar" material is from the U.S. Air Force's "Air University" collection of tutorials. I found it in a bin at Goodwill, bound along with a few other sections by the Extension Course Institute including Electronics Fundamentals and Television Principles. This treatise on radar is the first of those sections which will be posted here on RF Cafe. No date is included in the document, but my guess based on the content and drawings is sometime in the late 1950's. No mention is made of Doppler (a 1940's development), although it was used to some degree toward the end of World War II. The existence of over-the-horizon radar (a 1960's development) is alluded to, but not expounded upon. The "A" in the "A-scan" radar display stands for "amplitude;" it is an oscilloscope time-based sweep. An "A-scan" display is what the mountaintop UHF radar operators in Hawaii were monitoring when Japanese aircraft attacked Pearl Harbor on December 7, 1941...

DARPA SBI Sources for Classified Efforts

DARPA Small Business Innovation Sources for Classified Efforts - RF Cafe"The Department of Defense (DOD) seeks innovative and creative solutions to complex, classified challenges, but the DOD is currently only able to access a limited pool of companies cleared to work on them. Companies must have a facility clearance and their employees must hold security clearances to do classified work. But for a company to have a facility clearance, it must have a contract requiring classified work to justify the clearance. This current model results in a cyclical pattern that precludes the injection of new companies and ideas into the classified DOD research and development ecosystem. DARPA announced the Bringing Classified Innovation to Defense and Government Systems (BRIDGES) program, which aims to tap into innovation from companies that traditionally do not work with the DOD on classified research and development efforts. BRIDGES will connect innovators directly to the challenging problems that exist in the classified realm so they can help develop solutions. 'There's a large U.S. innovation talent base at small companies across our country that we currently aren't able to tap into for solutions to classified technology challenges..."

Stereo-itis: Stereo As It Affects Cullen

Stereo-itis: Stereo As It Affects Cullen, November 1961 Popular Electronics - RF CafeHere's a little more electronics humor from the November 1961 issue of Popular Electronics magazine. This time the topic is stereo equipment, which was a big deal in the era. Most equipment was still of the vacuum tube variety, and the country was still enjoying the post-Korean war and low inflation economy, so there was disposable income to be spent on creature comforts. Hobby and home improvement magazines od the day were filled with reviews and recommendations on receivers, speakers, phonographs, tape players, tone arms, stylus types, cables, antennas, and all the support equipment. Articles on room design for optimized acoustic properties included sound absorbing ceilings, walls, and floors, speaker placement, furniture location for the best stereo (and quadrophonic) experience, etc...

Signal Hound SM435C 43.5 GHz 10 GbE SpecAn

Signal Hound Intros SM435C 43.5 GHz 10 GbE Spectrum Analyzer - RF CafeSignal Hound's SM435C 43.5 GHz, high-performance spectrum analyzer and monitoring receiver is now available to order. The SM435C includes a 10 Gigabit Ethernet SFP+ port, enabling the SM435C to communicate with a PC over long distances using a fiber optic cable. Designed for remotely-located accurate RF data analysis at the lowest cost possible, the SM435C also includes a signed calibration certificate and a printed packet of calibration data. The Option-80 variant of the device provides downconverter functionality, allowing engineers working with 5G to utilize 800 MHz of continuous real-time data for in-depth analysis. The SM435C Option-80 is also a perfect fit for applications requiring extremely clean phase noise. The affordability of the SM435C opens the door to industry professionals who were previously unable to attain this power in a compact and economic package. It is available now, with a U.S. retail price of $25,380...

United Electronics Company Advertisement

United Electronics Company Advertisement, April 1945 Radio News - RF Cafe"QRT" is the Q-code used in amateur radio to tell someone to stop transmitting. Hams very much anticipated the day when Germany and Japan would be defeated, the war would end, and they could go home to resume their beloved radio hobby. You might know - or not - that during World War II ham radio transmissions were prohibited in the U.S. for a mix of reasons. Foremost was to inhibit the broadcasting of information, intentionally or unintentionally, that might give away strategic military strategy. Innocent chatter about whose son left for boot camp, where he was going afterwards, what his ambitions and fortes were, which factory Mom and Aunt Rosie worked for and what they did (Auntie was riveter, maybe), who died in service to his country, blackout hours, scrap material recycling collections, all was potential fodder for enemy tacticians. Another reason for the prohibition was to free up production materials and labor for the making of military equipment. The fate of the free world depended on it - literally...

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!

Mac's Service Shop: Electronics and Car Thievery

Mac's Service Shop: Electronics and Car Thievery, October 1972 Popular Electronics - RF CafeA few interesting historical statistics were presented in this "Electronics and Car Thievery" episode of "Mac's Service Shop," which appeared in a 1972 issue of Popular Electronics magazine. One is that steering column locks first came out on 1970 auto and truck models. My 1969 Chevy Camaro did not have a steering column lock, come to think of it. Also, a year earlier (1971), one in a hundred cars in the U.S. were stolen. The aforementioned steering column lock dramatically reduced the number of stolen vehicles. Car jacking was a thing in the early 1970's, so that's not a relatively new crime - it's just that now we have video surveillance everywhere so we get to see it. This story was particularly pertinent to a couple recent experiences (not the same day) where visitors to our daughter's house locked keys in their cars...

The Aircraft-Radio Service Man

The Aircraft-Radio Service Man, October 1937 Radio-Craft - RF CafeAs a life-long aircraft enthusiast, my attention is always drawn to photos, drawings, and titles in articles dealing with any aspect - but particularly a historical aspect - of aviation. This 1937 edition of Radio-Craft magazine reported on the fledgling field of aircraft radio maintenance, and in particular the opportunities presented to radio repairmen. Aircraft electronics (aka avionics) have of course changed significantly over the last 80 years. Accordingly, maintenance has become such a highly specialized skill that other than swapping out entire pieces of equipment, relatively few facilities exist that are qualified for the task. According to the article, at the time there were a mere 5k privately owned airplanes. As of 2019, the AOPA estimated a total of around 224k private aircraft (down from 220k in 2011), with 720k currently licensed pilots (all categories) per the FAA...

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

Innovative Power Products Couplers
Exodus Advanced Communications Best in Class RF Amplifier SSPAs
TotalTemp Technologies (Thermal Platforms) - RF Cafe
Exodus Advanced Communications Best in Class RF Amplifier SSPAs

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free

 

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...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website:

AirplanesAndRockets.com