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Homepage Archive - April 2020 (page 3)

See Page 1 | 2 | 3 | 4 | of the April 2020 homepage archives.

Friday 6

Quartz Crystal Etching

Quartz Crystal Etching, May 1954 Radio & Television News - RF CafeIf you are going to write an article about etching crystals for radio frequency circuits, having a last name like Gene Brizendine's couldn't be much better. It just sounds like a mineral or a compound (benzidine, etc.). Amateur radio operators have for a long time adjusted the resonant frequency of their crystals by either grinding or chemical etching. Mr. Brizendine recommends etching as a more controllable method that does not reduce the quality of the crystal like improper grinding can do. Ammonium bifluoride is mentioned as the etchant. It is said to have cost about $1/pound in 1954, and sells on Amazon today for about $23/pound. According to the BLS Inflation Calculator, $1 in 1954 is the equivalent of about $9.60/pound in 2020, so the price has gone up considerably - not sure why. Of course it could be that the modern solution is more concentrated than that used by the author...

Morse Code in "Western Union" Song

Morse Code in the "Western Union" Song, Kirt's Cogitations #318 - RF CafeThe other day a song entitled "Western Union" played on my local over-the-air oldies radio station. It was released by the group The Five Americans in 1967. I've heard it many times before, but it finally occurred to me that the use of Morse code-like symbols in the refrain made it a perfect candidate for a spot here on RF Cafe. The full lyrics of "Western Union" can be found at the bottom of the page, but notice the "Dah-Dit-Dah-Dit-Dah" repeats in the refrain. Even though I'm a licensed (as of 2010) Ham, my shameful (according to some veterans) status as a post-Morse-code era did not require demonstration of code proficiency. As such, my lack of a Morse code deciphering ability required that I rely on an online translator for considering what the code might be. Depending on how you separate the dits and dahs, the string of characters can be interpreted as TETET (- . - . -), TAA (- .- .-), KA (-.- .-), NK (-. -.-), CT (-.-. -) or other combinations, none of which seem to mean anything in particular...

Many Thanks to San Francisco Circuits for Continued Support!

San Francisco CircuitsSF Circuits' specialty is in the complex, advanced technology of PCB fabrication and assembly, producing high quality multi-layered PCBs from elaborate layouts. With them, you receive unparalleled technical expertise at competitive prices as well as the most progressive solutions available. Their customers request PCB production that is outside the capabilities of normal circuit board providers. Please take a moment to visit San Francisco Circuits today. "Printed Circuit Fabrication & Assembly with No Limit on Technology or Quantity."

3D Smith Chart Now Free to Students

3D Smith Chart Now Free to Students - RF CafeAndrei Muller and his associates are now offering their revolutionary 3D Smith Chart free to university students. The 3D Smith Chart tool is a completely reconfigurable and very easy to install software program operating in Windows and programmed in Java for high frequency engineering. The 3D Smith Chart tool includes starting 2019 negative capacitance and frequency display, added to the previous negative resistance features. The tool contains two modes: Analysis Mode (S-parameters Touchstone files based) and Design Mode - Both include 2D and 3D Smith Charts in Z/Y (impedance / admittance) versions. Slide shows and videos are provided, along with a detailed description and instructions. 3D Smith Chart literally adds a whole new dimension to impedance and admittance analysis by transforming a plane into a sphere, thereby exposing information not visible in Phillip H. Smith's original version (itself a game changer). For the free trial version please contact them via the Contact form or on 3dsmithchart@gmail.com !

Odyssey Technical Solutions Needs an RF Repair Technician II

Odyssey Technical Solutions Needs an RF Repair Technician II - RF CafeOdyssey Technical Solutions, with more than 60 employees in our new 32,000 ft2 facility in Round Rock, Texas, and having done 50,000 repairs, is showing no signs of slowing down. In fact, we currently have openings for qualified RF Repair Technicians. Procedures and processes developed over many years are designed for repeatable success in our repairs and to give our customers a high level of confidence that we will do it right the first time. Our employees bring a variety of experiences to our company, which has helped us grow by incorporating their experiences into what we do. Meeting and exceeding customer expectations is the top priority for Odyssey, our goal is to provide the highest quality repair each and every time. With legendary customer service helping to drive customer satisfaction on a daily basis...

ERZIA: Microwave & mm-Wave Modular Amplifiers

ERZIA Technologies - RF CafeERZIA serves critical aerospace and defense missions by designing and manufacturing RF, microwave, and mm-wave amplifiers, integrated assemblies operating from low frequencies up to 100 GHz, and by providing high reliable satellite communications. The company was founded in 2002 to become a worldwide reference of advanced engineering, performance, reliability and ruggedness. Their catalogue of standard amplifier modules comprises more than 100 different models, having also a high capacity of customization for amplifiers and integrated assemblies. Some of products have space heritage and are used in aerospace, commercial, military and scientific systems, having a wide range of final applications.

Thursday 5

The Ground Plane Grows Up

The Ground Plane Grows Up, May 1954 Radio & Television News - RF CafePrior to the advent of personal computers and handy-dandy antenna design software like EZNEC, determining the effects of varying parameters - element spacing, angles and length, ground plane distance and extent, feedpoint impedance, the presence of conductive structures, etc. - it was necessary to make a series of often complex mathematical calculations and ultimately perform real-world measurement. Huge amounts of time would be invested in the design and verification process. It has been know for a long time that the distance an antenna sits above a ground plane has a significant effect on the radiation pattern - particularly the vertical pattern. The information provided in this 1954 Radio & TV News magazine article undoubtedly required many hours to assimilate and required someone (author William Harrison) with a lot of knowledge in the science/art of antennas. While some empirical testing is still needed for critical applications, in most cases these days the results of computer simulations suffice...

Copper Mountain Technologies RF Basics Webinar

Copper Mountain Technologies RF Basics Webinar - RF CafeCopper Mountain Technologies (CMT) will be presenting a free "RF Basics Webinar." This webinar will touch on the basic concepts which underlay the operation of a Vector Network Analyzer. What does it really measure? What are the key components? What are its limitations? How does one compare one analyzer to another? What are the key specifications? We'll take a brief look at the evolution of VNA design over the years to understand how a state-of-the-art VNA is USB based without an embedded operating system. The viewer should come away with an intuitive understanding of VNA operation and how best to use this important measurement tool. It will be taking place on Wednesday, April 29, 2020, at 10 AM EST.

Intuitive Machines Announces 2021 Moon Mission

Intuitive Machines Announces 2021 Moon Mission - RF Cafe"Intuitive Machines, under contract to carry NASA science instruments to the moon on a privately-developed robotic spacecraft, said this week its first commercial lunar mission will target landing in October 2021 near a deep, narrow valley named Vallis Schröteri. The startup company, based in Houston, announced Monday the landing site for its first lunar landing mission. Vallis Schröteri is located in on the upper left part of the moon's near side, as viewed from the northern hemisphere on Earth. Scientists think the channel-like valley, or rille, has volcanic origins. The rille, also known as Schröter's Valley, likely formed from a collapsed volcanic lava tube..."

China Bears Down on Protecting State Secrets

Dr. Murray Scot Tanner (lawfareblog.com image) - RF CafeAuthor Murray Scot published a piece a couple years ago entitled, "Tanner Beijing's New National Intelligence Law: From Defense to Offense," on the Lawfare website (for the record, Lawfare is not a conservative website by any stretch of the imagination). Its content is relevant in regard to the worldwide pandemic of a killer virus that originated in Wuhan, China. He states in part: "China's National Intelligence Law, enacted on June 27 with unusual speed and limited public discussion, is a uniquely troubling milestone in Beijing's four-year-old campaign to toughen its security legislation." Further, "The law also perpetuates the Xi Jinping leadership's narrative that all foreign contacts should be regarded as suspicious; that Chinese citizens engaged in such contacts do so at the risk of surveillance and harassment by their own government; and that the Chinese Communist Party-state is now strong enough to call for intelligence cooperation even from foreigners doing business in China." Remember this when you try to get N95 masks.

Anatech Electronics April 2020 Newsletter

Anatech Electronics April 2020 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his April newsletter that features his short op−ed entitled "5G SARS-CoV-2 Conspiracy Theories Abound," which would be funny if it wasn't so serious. In the past couple weeks I have posted news items about crazies in Europe who have been setting 5G cell towers - or sometimes any cell tower - on fire after an article from Belgian newspaper Het Laatste Nieuws published an article by Dr. Kris Van Kerckhoven entitled, "5G is life-threatening and no one knows it." An Internet search turns up scores of stories: BBC, Forbes, The Verge, Business Insider, Twitter thread. Also included in the newsletter are a few headlines including stories about the big money shelled out by carriers for millimeter-wave spectrum, autonomous vehicles, 5G and Iot, and TracFone being investigated for fraud...

Triad RF Systems: RF/Microwave Amplifiers and Amplifier Systems

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.

Wednesday 4

How to Break the 10-Words-Per-Minute Code Barrier

How to Break the 10-Words-Per-Minute Code Barrier, July 1974 Popular Electronics - RF CafeWhen you think about it, the speed at which a human being is able to accurately copy Morse code is limited by the same kinds of processes that limit the speed at which binary data can be sent between electronic transceivers (modems). Noise introduced into the signal at both the transmitting and receiving ends or in the transmission path connecting the two, degrades the ability of the receiver (electronic and human) to discern between a "1" and a "0." It can take the form of electrical or audio interference and distortion. Phase noise in the electronic realm is sort of the equivalent of an irregular sending human hand that cannot maintain equal dwell times for dits and dahs, thus making the recognition of characters error-prone. The operational speed of circuitry on an electronic assembly can also limit the speed at which Morse code can be copied similar to how a particular person's gray matter can limit his comprehension speed...

Commercial Satellite Boom May Threaten National Security

 Commercial Satellite Boom May Threaten National Security - RF Cafe"The mass building and deployment of commercial satellites is likely to bring about serious threats to U.S. national security and global interests, as fellow countries quickly work to expand their stakes in space, a new study published by researchers with the Institute of Defense Analyses (IDA) has revealed. Published in the National Defense University's Joint Forces Quarterly, the study noted that while the spike in satellites will help to better inform US service members across the board during military operations, the build-up will also have some drawbacks. 'The effects of proliferated constellations will not be confined to the commercial sector. The exponential increase in the number of satellites on orbit will shape the future military operating environment in space,' reads the study..."

NanoVNA Portable Vector Network Analyzer

NanoVNA Portable Vector Network Analyzer - RF Cafe Cool ProductPhil Salas, AD5X, published an extensive review of the NanoVNA vector network analyzer in the May 2020 issue of the ARRL's QST magazine. Unfortunately, the article is not available to non-members, but if you are a member or know someone who is, it would be worth reading. He compared measurements by the NanoVNA with those obtained using an Array Solutions VNAuhf, which yielded very favorable results. There are many knock-offs of the NanoVNA available, which is typical since most of these low-cost, high-performance electronics devices are built using widely available block-level components that make replication relatively easy. Variations in the quality of coaxial connectors, internal batteries, switches, etc., can and often does make a big difference in the quality and ruggedness of the equipment you buy. Firmware and support software can vary significantly as well. It's a roll of the dice to some extent...

On the Very Highs

On the Very Highs, July 1944 QST - RF Cafe"Our first complete column devoted to the subject [of v.h.f. and u.h.f. signal variation], presenting material similar to that which follows, was withheld from publication at that time in compliance with censorship." That is an amazing statement from a time when almost any form of technical information that was not already public knowledge was withheld for the sake of the war effort. Nothing that might even remotely give the enemy an edge, and consequently possibly harm our troops, got past the government censors at the War Department. Most citizens and even media editors willingly complied. Compare that with today's 5th column traitors at most of the media outlets that not only can't wait to publish information that will aid and abet our country's enemies, but have been known to manufacture stories in order to make the U.S. look bad...

Southwest Antennas Omni-Directional 4x4 MIMO Antennas for Aircraft

Southwest Antennas Omni-Directional 4x4 MIMO Antennas for Aircraft, Helicopters, and Large UAV Systems - RF CafeSouthwest Antennas, a leader in rugged RF and Microwave antenna products and accessories for tactical radio systems, is pleased to announce the release of two new antennas to meet the demand for multi-port MIMO antenna solutions for medium range aircraft performing ISR missions. These antennas are built off of Southwest Antennas' existing, field-proven MIMO antenna technology with design improvements specifically for these new mission requirements. Our engineering team has added a new flange mount base for secure mounting, in addition to reinforcing the antennas for the higher altitude and airspeed achieved by medium range military turboprop aircraft that are commonly used for surveillance, patrol, search and rescue, and transport operations. With a conservative airspeed rating of up to 374 MPH these MIMO antennas...

everythingRF: Their Name Says It All

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 265,628 products from more than 1380 companies across 313 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.

Tuesday 3

Early Digi-Key Advertisement

Digi-Key Advertisement, July 1974 Popular Electronics - RF CafeWaaaay back in the mid-1980s when I first became aware of Digi−Key, it was one of the relatively few electronics component suppliers that had a large on-hand stock of commonly used parts and provided fast shipping. Places like Newark Electronics and Allied Electronics also provided good service, but Digi−Key usually offered lower prices than the others. By the 1990s, I was placing orders at least weekly during circuit design projects. Digi−Key was founded in 1972 in Thief River Falls, Minnesota - the town that for many years often had the country's lowest recorded daily temperature. This 1/4-page advertisement appeared near the back of a 1974 issue of Popular Electronics magazine. By the mid-1990s, their multipage ads in electronics magazines were proliferating like today's Harbor Freight ads. Here's a bit of trivia I just learned: The company's name is a reference to the "Digi−Keyer Kit," a digital electronic keyer kit that founder Ronald Stordahl developed and marketed to amateur radio...

Gin & Tonic (of Quinine) Factoid

Gin & Tonic (of Quinine) Factoid - RF CafeHydroxychloroquine has been in the news a lot as a historically safe virus combatant. Its origins reach back to the 1700s in the form of quinine as a malaria treatment. Paradoxically, U.S. medical "experts" avoid the topic, urging patience until a big-pharma solution is available (at big $$$ per dose). Regardless of which side of the debate you fall on, you might be interested to know that the "tonic" part of the popular "gin and tonic" mixed drink was a tonic of quinine. It was mixed with gin by soldiers to mask the horrible taste of the quinine because they avoided consuming it in raw form, preferring to risk infection. And now you know... The Rest of the Story.

Many Thanks to Nova Microwave for Continuing Support!

Nova Microwave Circulators & Isolators - RF CafeNova Microwave is a leader in technically differentiated electronic and radio frequency Ferrite Circulators and Isolators that connect, protect and control critical commercial and military wireless telecommunications systems. Our staff is dedicated to research and development of standard and custom design quality Ferrite Circulators and Isolators from 380 MHz to 26.5 GHz. Available in single or multi-junction topographies, the Nova Microwave product line of is specifically designed for use in varied environmental and temperature extremes. 

Japan Short-Wave Phone to America Open

Japan Short-Wave Phone to America Open, March 1935 Short Wave Craft - RF Cafe"Tokyo is now a next-door neighbor-thanks to the magic of short-waves." That statement was made in a 1935 edition of Short Wave Craft magazine after the American Telephone and Telegraph (AT&T) company completed its wireless phone (voice) link between the U.S. and Japan; which is the first 'T' in AT&T. Most people today would probably have a hard time guessing that the second 'T' in AT&T stands for 'telegraph.' Its surprising that the name has not been changed to reflect the outdated-ness. Western Union sent its final telegraph in 2006. Another news headline a couple years ago reported on India sending its final official telegraph message...

Steering UAVs Clear with Digital Circuit Testing

Steering UAVs Clear with Digital Circuit Testing - RF CafeAxiom Test Equipment, an electronic test equipment rentals and sales company headquartered in San Diego, has published a blog post entitled "Steering UAVs Clear with Digital Circuit Testing." This blog is the second in a series of three planned articles that will take a closer look at the global fascination with UAVs and how they are used, whether for farming or for warfare, and some of the best test tools that can be applied to ensuring the best UAV performance possible. The OQ-2A, one of the first remote-controlled target drones produced in the U.S., was made by the Radioplane Company owned Hollywood actor Reginald Denny. Norma Jeane Mortenson, aka Marilyn Monroe, was discovered there. "Drones and unmanned aerial vehicles (UAVs) are being used in a growing number of commercial, civil, industrial, and military applications. They are currently used for many security and surveillance task...

Odyssey Technical Solutions Needs an RF Repair Technician I

Odyssey Technical Solutions Needs an RF Repair Technician I - RF CafeOdyssey Technical Solutions, with more than 60 employees in our new 32,000 ft2 facility in Round Rock, Texas, and having done 50,000 repairs, is showing no signs of slowing down. In fact, we currently have openings for qualified RF Repair Technicians. Procedures and processes developed over many years are designed for repeatable success in our repairs and to give our customers a high level of confidence that we will do it right the first time. Our employees bring a variety of experiences to our company, which has helped us grow by incorporating their experiences into what we do. Meeting and exceeding customer expectations is the top priority for Odyssey, our goal is to provide the highest quality repair each and every time. With legendary customer service helping to drive customer satisfaction on a daily basis...

KR Electronics: RF & Microwave Filters

KR ElectronicsKR Electronics designs and manufactures high quality filters for both the commercial and military markets. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop and individually synthesized filters for special applications - both commercial and military. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Please visit their website today to see how they might be of assistance. Products are designed and manufactured in the USA.

Monday 2

Vintage Electronics-Themed Comics

Vintage Electronics-Themed Comics, April & September 1947 Radio-Craft - RF CafeHere are a couple more electronics-themed comics from vintage Radio−Craft magazines. Artist Frank Beaven, who created a huge number of comics and advertisements (e.g., Eveready batteries, Zippo lighters) for technical and other types of publications (Saturday Evening Post, New Yorker, Esquire), did both of them. Beaven must have a fan base since many examples of his drawings are offered for sale on eBay. Most of his comics credit reader suggestions as the basis for the subject. I have to admit to not really "getting" the gag in the top comic. Maybe Sinatra's voice strained the frequency response of simple tabletop radios of the day. The bottom comic is one of a series entitled "Radio Terms Illustrated," in this case "High Potential." I'll be posting a few others in the coming months...

Berkeley Nucleonics Academy Continuing Education Program

Berkeley Nucleonics Academy Continuing Education ProgramBerkeley Nucleonics Corporation (BNC - like the connector) offers several short courses on RF, Test & Measurement, and Nuclear technology to allow students and technical staff entering the field to quickly develop a basic understanding of the principles involved. BNC Academy's online learning is a popular way to maintain currency in your field while not requiring time away from critical project activities. Courses may be completed online and are supplemented with downloadable materials. Titles such as "RF Boot Camp," "Demystifying Phase Noise Measurements," and "Nuclear Radiation 101" are among the offerings. Completion certificates are issued and onsite training is also available. It is possible to look at previews of upcoming courses on BNC Academy right now.

Subminiature Magnetic Amplifiers

Subminiature Magnetic Amplifiers, December 1957 Radio & TV News - RF CafeMagnetic amplifiers (aka "mag amps") use a property of saturated core inductors (saturable reactors) to obtain signal amplification via a transformer-type plus diode-assisted voltage multiplication. Magnetic amplifiers were preferred over vacuum tube amplifiers in some circuits because they do not require a high bias voltage, are generally smaller in size, are quite robust and are practically immune to microphonics. Their biggest limitation is bandwidth. The high number of turns in the core provides a lot of interwinding capacitance so the self-resonant frequency is in the low megahertz range. Additionally, the need for the magnetic amplifier reactor to operate in a saturated condition further imposed a limit on the frequency response. Even today, there are some critical applications that exploit the fool-proof and ultra high reliability nature of the magnetic amplifier. This article goes into the details of operation both as amplifiers and as bistable multivibrators...

Calvin's Father Explains the Country Shutdown Philosophy

Calvin & Hobbes Bridge Weight Limit (Watterson) - RF Cafe

This has always been one of my favorite Calvin & Hobbes comic strip episodes. Calvin's father, a patent attorney, is famous for providing zany explanations to Calvin's inquiries about physics, astronomy, and other science subjects which he knows nothing about. Here, Calvin asks how weight limits are determined for bridges. His father's answer seems a perfect analogy to what politicians are doing to our economy today in response to the Wuhan Virus pandemic. I'm surprised this comic has not been a "viral" meme on social media websites - which maybe it is but I wouldn't know since I do not visit them, so I'll take credit for it. IMHO, the shutdowns are entirely unnecessary except in the worst areas. "You never let a serious crisis go to waste. And what I mean by that it's an opportunity to do things you think you could not do before." - former Chicago mayor...

5G: Sorting Fact from Fiction

5G: Sorting Fact from Fiction - RF CafeIn spite of "5G" having been in the news for nearly a decade, many (maybe most) people do not really know what it is. 5G is not simply faster 4G; it is a whole new paradigm if ubiquitous wireless interconnectivity of everything at data speeds formerly achievable only with wired systems. Pasternack has an article on the Microwave Product Digest (MPD) website entitled, "5G: Sorting Fact from Fiction," that helps clarify the subject somewhat. As is often the cases - and its not a bad thing - the article is partly an infomercial for Pasternack products. It begins, "So much has been written about 5G that it's impossible for mere mortals to form their own conclusions about what it will actually achieve. Although it's far too early to know for sure, this hasn't stopped the continuing deluge of marketing hype throughout the industry promising something for everyone. In the hope of providing some clarity on these issues, this article addresses some of the primary areas of confusion..."

Innovative Power Products: RF & Microwave Passive Components

Innovative Power ProductsInnovative Power Products (IPP) has over 30 years of experience designing & manufacturing RF & microwave passive components. Their high power, broadband couplers, combiners, resistors, baluns, terminations and attenuators are fabricated using the latest materials and design tools available, resulting in unrivaled product performance. Applications in military, medical, industrial and commercial markets. Take a couple minutes to visit their website and see how IPP can help you today.

Sunday 1

Radio & Radar Engineering Crossword Puzzle for April 19

Radio & Radar Engineering Crossword Puzzle April 19, 2020 - RF CafeApril 19 commemorates a special birthday here at RF Cafe as explained in 39 and 74 Across. You can calculate her age by solving these two equations in two unknowns: Her Age = Her Year of Birth - 1902, and My Age = Her Year of Birth - 1900. Actually, you don't need to know my age to solve the first equation. This tech-themed crossword puzzle contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have personally built over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia...


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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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