Homepage Archive - November 2021 (page 2)

See Page 1 | 2 | 3 | 4 of the November 2021 homepage archives.

Sunday the 14th

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."

Science Terms Crossword Puzzle for November 14th

Science Terms Crossword Puzzle for November 14th, 2021 - RF CafeThis technically themed crossword puzzle for November 14th contains only clues and words are directly to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other science 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!

Saturday the 13th

Many Thanks to KR Electronics for Long-Time Support!

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.

Friday the 12th

Microwaves Part V - Waveguide

Microwaves Part V - Waveguide, September 1949 Radio-Electronics - RF CafeAlthough the subtitle of Part V of the 1949 Radio−Electronics magazine "Microwaves" introductory series in refers to Special Sections of Waveguide Are Employed as Transformers, author Palmer is discussing not impedance transformers but physical configuration transformations. That includes in-between rectangular, circular, and oval cross-sections, in-between waveguide and coaxial cable, and rotary joints. Signal injection and extraction via stubs are also covered. He provides a high level introductory description of how microwave frequency waveguide works without delving into the scary mathematics required to design the components...

Teledyne e2v HiRel Intros TDGD271 and TDGD274 Drivers for GaN FETs

Teledyne e2v HiRel Announces Availability of New TDGD271 and TDGD274 Drivers for GaN FETs - RF CafeTeledyne e2v HiRel today announced availability of a pair of new isolated gate drivers ideally suited for driving GaN power parts used in a wide variety of power supply, dc/dc converter, battery management systems (BMS), Point−of−Load (POL) modules and motor control applications. The TDGD27x isolated gate drivers utilize silicon isolation technology, supporting up to 2.5 kVrms. This technology enables industry leading common-mode transient immunity (CMTI), tight timing specifications, reduced variation with temperature and age, better part-to-part matching, and 100% AC/DC testing at −55°C to 125°C...

Topological Insulator Design Makes 30 Lasers Emit as 1

Topological Insulator Design Makes 30 Lasers Emit as 1 - RF Cafe"An array of 30 vertical cavity surface emitting lasers (VCSELs) has been made to behave as a single coherent light source for the first time, paving the way for large-scale, high-power applications that were previously out of reach for this popular class of laser. The design of the new array draws on concepts from the field of topological insulators, and its developers are now working with industrial partners to refine the technology for use in medical devices and communications networks. VCSELs are the most common lasers in the world, routinely used in application areas ranging from portable phones and optical communications to instrumentation, manufacturing, sensing and even facial recognition. Like other lasers, they contain a gain medium in which light is generated and emitted..."

Say You Saw It in QST

Say You Saw It in QST, December 1933 QST - RF CafeIn the early 1930s, QST magazine (ARRL's monthly publication) usually ran a line at the bottom of every page in the back half of each issue that said, "Say You Saw It in QST - It Identifies You and Helps QST." They even got the capitalization correct (all lower case short prepositions and conjunctions, but I digress). The December 1933 edition was a bit different, however, in that all the left-hand pages had the message translated into one of fourteen different languages while the right-hand pages used English. I deemed that discovery cool enough to scan and post here. Since the only languages I speak with any fluency are English and Pig Latin...

R&S, OpenWorks Prove Counter UAS Tech at NATO TIE

Rohde & Schwarz and OpenWorks Prove New Counter UAS Technology at NATO TIE Exercise - RF CafeRohde & Schwarz and OpenWorks have collaborated to prove a new high performance and autonomous 3D detection and tracking system for use in counter unmanned aerial systems (C-UAS) missions. Integrated through the new SAPIENT standard protocol and tested at the NATO Technical Interoperability Exercise (TIE) event in De Peel Airbase in the Netherlands, the solution combines the proven R&S ARDRONIS drone detection solution with the recently released SkyAI Autonomous Optical technology. Rohde & Schwarz and OpenWorks successfully prove C-UAS solution during NATO Technical Interoperability Exercise. NATO TIE will evaluate how the latest autonomous C-UAS sensors interact, using a new "plug and play" standard called SAPIENT, with the latest command and control systems and decision engines; ultimately testing performance against escalating UAS threats...

Victimized by a Record Moocher

Victimized by a Record Moocher, November 1958 Popular Electronics - RF Cafe"A record 'Moocher' is one of the lowest forms of human life. He has no particular habitat but can be found wherever there is a record owner." So says Norman Van Tubergen in this 1958 Popular Electronics magazine article. Anyone who grew up in the record player era, or for that matter the 8-track tape or cassette tape era has known (or has been) such a moocher. This is the person who was always asking to borrow your music media either for listening to on his personal equipment or for copying onto his own tape (cassette or reel-to-reel). He rarely ever bought any of his own music, but was more than happy to generously re-lend his copies to fellow Moochers, and of course he never had anything you might want. The modern-day equivalent is the person who is always bugging you to let him/her copy your music file that you either paid for as a download or purchased in CD/DVD format...

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.

Many Thanks to Amplifier Solutions Corporation (ASC) for Continuing Support!

Amplifier Solutions Corporation (ASC) - RF Cafe ASC designs and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers for low, medium and high power applications using gallium nitride (GaN), gallium arsenide (GaAs) and silicon (Si) transistor technologies. ASC's thick film designs operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up to 20 GHz.

Thursday the 11th

Raytheon Vacuum Tubes

Raytheon Vacuum Tubes, June 1945 Radio-Craft - RF CafeMost aviation enthusiasts upon hearing the name Pan American "Clipper" thinks of the large four-engined amphibious airliner. There were other models of the Clipper, however, including the Douglas DC−4, the Lockheed Constellation, and the Boeing 377. The latter appear to be the early concept model depicted in this 1945 Raytheon vacuum tubes promotion in Radio−Craft magazine. Raytheon was a major supplier of electronic components, equipment, and systems for the military and government throughout World War II. Manufacturers came to trust and rely on the big-name companies for high quality and dependable components. By the time this advertisement appeared, Germany had recently signed an unconditional surrender, and Japan was only a few months away from total defeat. Sadly, many of the familiar names from the era have either been acquired by foreign firms (and usually renamed) or have gone out of business due to poor management decisions (usually from failing to keep up with changing times)...

Gain Medium Boosts Sonic Crystal "Saser"

Gain Medium Boosts Sonic Crystal "Saser" - RF CafeYou are familiar with the laser and maser. Meet the the "saser." "Researchers in China and Spain have succeeded in making a saser - the equivalent of a laser for sound waves - by adding a gain medium to artificial acoustic materials known as sonic crystals. The new saser could have applications in medical ultrasonics and non-destructive materials testing, among other areas. Gain media (also known as active media) are commonplace in optics and are a crucial part of lasers. However, they have not really been employed for sound waves before, explains Johan Christensen, an expert in acoustic metamaterials at the Universidad Carlos III de Madrid. In a laser, the gain medium typically consists of a material such as a semiconductor, doped crystal or glass surrounded by a highly reflective optical cavity. By stimulating electrons within this medium to release energy due to collisions with photons in the cavity..."

First Over-the-Horizon TV Bridge

First Over-the-Horizon TV Bridge, November 1957 Radio & TV News - RF CafeIn the days before satellite communications (Telstar I, c1962), long-range television broadcasts relied on an extensive (and expensive) series of line-of-sight microwave towers. Each site had land ownership and maintenance expenses, so there was an incentive to streamline operations. Development of an over-the-horizon relay system enabled a reduction in sites and streamlining of operations - at least in theory. History shows that these installations must not have provided the improvement needed to implement them on a larger scale than that reported here. Nowadays, the proliferation of cellphone towers for ubiquitous coverage of wireless telecommunications has proven that huge numbers of individual sites can be profitable given a large enough customer base. You can scarcely go anywhere anymore without being able to spy a cell tower sticking out over the landscape...

Veterans Day 2021: A Pittance of Time

Veterans Day 2016 (Snoopy copyright) - RF Cafe This is my annual Veterans Day tribute. On November 11 (the 11th day of the 11th month), at 11:00 am (the 11th hour), we observe 2 minutes of silence in honor of countrymen who "gave the last full measure of devotion." A Pittance of Time is performed by Canadian citizen Terry Kelly (he went blind at an early age). It was written after an experience he had on Veterans Day in 1999. It is done in the finest Celtic tradition.

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!

Many Thanks to LadyBug Technologies for Their Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Wednesday the 10th

Lady Television Engineer

Lady Television Engineer - Cover Story, November 1949 Radio-Electronics - RF CafeThere is no denying that in 19th and 20th Century America and most other industrialized countries, non-white males dominated the academic, commercial, and industrial design and service workforce. Societal norms were much different in those times, and the truth is most women did not desire to enter into the "professional" market. Many performed low skill labor and assembly functions, serving an essential yet less demanding role in providing goods and services for the world. This 1949 "Lady Television Engineer" story appearing in Radio−Electronics magazine celebrated Tex Barbarite as a ground-breaking and glass-ceiling-breaking woman in the commercial television broadcast industry. As was common in the era, Ms. Barbarite's public platform was used to give encouraging insight into her path to success - not to complain and dwell on resistance met in her effort. BTW, would it be politically incorrect to point out, as evidenced by the complaints of others, that it was mostly White males who envisioned and created the most of the modern world...

Many Thanks to Exodus Advanced Communications for Their Support

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

Topological Insulator Design Makes 30 Lasers Emit as 1

Topological Insulator Design Makes 30 Lasers Emit as 1 - RF Cafe"An array of 30 vertical cavity surface emitting lasers (VCSELs) has been made to behave as a single coherent light source for the first time, paving the way for large-scale, high-power applications that were previously out of reach for this popular class of laser. The design of the new array draws on concepts from the field of topological insulators, and its developers are now working with industrial partners to refine the technology for use in medical devices and communications networks. VCSELs are the most common lasers in the world, routinely used in application areas ranging from portable phones and optical communications to instrumentation, manufacturing, sensing and even facial recognition. Like other lasers, they contain a gain medium in which light is generated and emitted..."

Superconductor State of Matter Involves Cooper Pairs

Superconductor State of Matter Involves Cooper Pairs - RF Cafe"Cool a material below its superconducting transition temperature and you'd expect it to start conducting electricity without resistance and expelling magnetic fields. But an international group of physicists has found that a certain kind of iron-based material doped with negative charges does the opposite at around the same temperature - producing spontaneous magnetic fields and retaining resistance when chilled. The researchers say that the results point to a new state of matter in which electrons flow in correlated groups of four, rather than two. According to the Bardeen-Cooper-Schrieffer (BCS) theory, superconductivity occurs when electrons get together to form what are known as Cooper pairs..."

Radio Broadcasting Stations

Radio Broadcasting Stations, September 1932 Radio News - RF CafeThe Federal Communications Commission (FCC) claimed in 2013 to be receiving more than 30,000 applications per year for commercial broadcasting licenses. That covers the gamut from AM and FM to television, Low Power FM, Low Power TV, translators and booster stations, as well as some non-commercial stations for educational purposes. Inexpensive, turnkey broadcast station equipment make entry into the realm very affordable. Accordingly, there are many stations vying for space in a very crowded section of the electromagnetic spectrum. Contrast that to the year 1932 list of broadcasting station in the U.S. which was able to fit onto a single page of the Radio News magazine - about 500 to 600 in number. Interestingly, the wavelengths are expressed in meters, at a time when metric units were rarely used in the U.S...

Sparton Model 60 Short-Wave Converter Radio

Sparton Model 60 Short-Wave Converter Radio Advertisement, April 1932 QST - RF CafeNot everyone is into radio history, so items like this advertisement for Sparton Radio's Model 60 Short-Wave Receiver which appeared in the April 1932 issue of QST will not invoke much or any interest. On the other hand, there is a large contingent of hobbyists and professionals who enjoy seeing these historical snapshots of the places from whence we have come technically. Products like radios, kitchen appliances, automobiles, etc., were constructed very robustly with metal, wood, and fabric. No cheap plastic will be found anywhere, but maybe not for the reason you think - plastic as we know it today had not entered the commercial marketplace yet. In fact, many "modern" plastic formulas and processes were a closely held military secrets until the end of World War II.

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...

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.

Tuesday the 9th

Electronics Themed Comics

Electronics Themed Comics, July 1946 Radio-Craft - RF CafeBoth of these vintage electronics-themed comics, which appeared in a 1946 issue of Radio−Craft magazine, have a unique feature. The first is one of the very popular (then and now) "Radio Term Illustrated" comics where a reader suggested a way to relate a common term or phrase to a situation in the technical realm which can be similarly interpreted. In this case the subject is a "dynamic speaker." It is a form of a double entendre. The other comic mocks the use of "handie-talkies" as a prop for abetting an unlawful act. In this same issue is an article entitled "Inside the Handie-Talkie" that is sort of a reverse engineering exercise on what was a relatively new technology from the recently ended World War II era. This cartoon was considered profound enough to warrant an editorial remark by the magazine...

Remote Control Weapons

Remote Control Weapons, August 1944, Radio-Craft - RF CafeWorld War II brought about the first wireless remotely controlled weapons. Prior to radio technology, bombs and missiles needed to either be within a distance serviceable by detonation wires, or were set off using mechanical or electrical timers. Both of those methods required the operator to gain access to the target area at a time relatively close to when the attack was to occur. Army battalions did have warheads with spooled wires attached that enabled them to control the time of detonation and even in some instances some degree of steering, but range was limited. Wireless technology enabled weapons to be delivered and controlled over great distances. Missiles could be directed enroute and bombs could be planted practically anytime and anywhere to await a signal when appropriate. Hugo Gernsback wrote a short op-ed...

General Electric Announces Split into 3 Companies

Flashing Red Light - RF Cafe

General Electric Announces Split into 3 Companies - RF CafeAnother great American company is feeling the pain of a diminishing national dominance in world markets. General Electric just announced it will break into three separate companies - energy, health care and aviation. I place the blame on both management and labor. Management in this "woke" era puts far too much emphasis on very costly political correctness, selling IP to foreign interests, and bending over to politicians' whims while labor (union and non-union) has permitted and even abetted the outsourcing of jobs and offshoring of manufacturing. This has been happening for a few decades, and the country has paid severely for it. Consider all the stalwart century-old manufacturing and retail companies gone, acquired by foreigners, or otherwise minimalized: Westinghouse, RCA, Bell, Pontiac, IBM, Motorola, Oldsmobile, Sears Roebuck, Firestone - even Budweiser is now based in Belgium. The list is huge. Will the last founding American company please turn out the lights on the way out?

New Dimension in Magnetism and Superconductivity

New Dimension in Magnetism and Superconductivity - RF Cafe"An international team of scientists from Austria and Germany has launched a new paradigm in magnetism and superconductivity, putting effects of curvature, topology, and 3D geometry into the spotlight of next-decade research. The results are published in Advanced Materials. Traditionally, the primary field in which curvature plays a pivotal role is the theory of general relativity. In recent years, however, the impact of curvilinear geometry has entered various disciplines, ranging from solid-state physics to soft-matter physics to chemistry and biology; and giving rise to a plethora of emerging domains, such as curvilinear cell biology, semiconductors, superfluidity, optics, plasmonics and 2D van der Waals materials. In modern magnetism, superconductivity and spintronics, extending nanostructures into the third dimension has become a major research avenue..."

Introduction to Wave-Generation and Wave-Shaping

Introduction to Wave-Generation and Wave-Shaping - RF CafeUpon completion of this chapter, you will be able to: 1. State the applications of a resonant circuit. 2. Identify the conditions that exist in a resonant circuit. 3. State and apply the formula for resonant frequency of an AC circuit. 4. State the effect of changes in inductance (L) and capacitance (C) on resonant frequency (fr). 5. Identify the characteristics peculiar to a series resonant circuit. 6. Identify the characteristics peculiar to a parallel resonant circuit. 7. State and apply the formula for Q. 8. State what is meant by the bandwidth of a resonant circuit and compute the bandwidth for a given circuit. 9. Identify the four general types of filters. 10. Identify how the series- and parallel-resonant circuit can be used as a bandpass or a band-reject filter...

Admiral "Aeroscope" Midget Sets Radio Service Data Sheet

Admiral "Aeroscope" Models 161-5L, 162-5L and 163-5L Midget Sets Radio Service Data Sheet, August 1939 Radio-Craft - RF CafeFor many years I have been scanning and posting Radio Service Data Sheets like this one featuring the Admiral "Aeroscope" 161−5L, 162−5L, and 163−5L Midget Set models which appeared in a 1939 issue of Radio−Craft magazine. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. Some websites offer to sell this information, but often what is shown here is enough to get an old radio working again since most times both schematics and alignment steps are included. I keep a running list of all data sheets to facilitate a search...

Many Thanks to Withwave for Continued Support!

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

Monday the 8th

Tuning on the U.H.F.

Tuning on the U.H.F., June 1945 Radio-Craft - RF CafeAlthough this "Tuning on the UHF" article refers to a specific radio band popular for "shortwave listening," the information therein is generally applicable to any band. It appeared in a 1945 issue of Radio-Craft magazine, at a time predating widespread ownership of television, where instead of watching the boob tube many people enjoyed tuning in broadcast stations from across the country and across the globe. Radio was still a mysterious and magical thing. A tapped coil, variometer, permeability tuner, standard coil-condenser, and General Radio butterfly tuner are possible methods for any frequency typically used...

What to Do with a Tape Recorder

What to Do with a Tape Recorder (until the hi-fi arrives), February 1963 Popular Electronics - RF CafeRemember tape recorders? They were a big deal in 1963 when these comics appeared in Popular Electronics magazine, but they began going the way of the typewriter about three decades ago when solid state voice recorders hit the market, but now smartphones with sound recording have made even those devices seem outdated. In fact, when my daughter's house burned down a few weeks ago, all of the on-site conversations with the insurance adjuster, fire marshal, and housing contractors were recorded to ensure an accurate account of what was said by all parties. In North Carolina, law does not require you to apprise other parties taking part of the conversation that they are being recorded, so long as the person doing the recording is an active participant in the conversation (aka "one-party consent"). But I digress... back to the tape recorder era. These four comics were drawn by Mr. Bill Hutchinson back when not only...

Practical Electric Airplanes Decades Away

Practical Electric Airplanes Decades Away - Airplanes and Rpockets"Electric Airplanes Won't Make Much of a Dent in Air Travel for Decades to Come. Reason: Batteries are nowhere near able to sustain wide-body airliners over flights measuring in the thousands of kilometers. Exaggeration has become the default method for news reporting, and the possibility of commercial electric flight has been no exception, with repeated claims that these new planes will utterly change how we live. In 2017, Boeing and JetBlue funded Zunum Aero, a U.S. company that promised nothing less than transforming air travel with short-haul electric planes capable of carrying 12 people - and doing it by 2022. Two years later Boeing declined to continue funding the project. At the Paris Air Show..."

Meteor Detection by Amateur Radio

Meteor Detection by Amateur Radio, July 1947 QST - RF CafeThe 1940s and 1950s was an era of much advancement in our knowledge of Earth's upper atmosphere and its affects on radio communications - both good and bad as reported by this 1947 issue of QST magazine. Industry, government, academic, and amateur groups all played major roles in conducting experiments and publishing findings for the interested community to share and build upon. Still today a huge amount of research is being carried out to better understand how the various layers of the atmosphere - from ground level to space - are affected by extraterrestrial influences. A year ago I posted an article, along with a bit of editorializing, from the July 1958 edition of Radio-Electronics entitled..."

WWV/WWVH Scientific Modulation Working Group

WWV/WWVH Scientific Modulation Working GroupWebsite visitor Rick L. wrote to say, "I was listening to WWV this morning in order to coordinate all my clox throughout the QTH here in Taxconsin (sic) and caught the announcement on this:" WWV/WWVH Scientific Modulation Working Group. "NIST is participating in a new project to study the ionosphere and its effects on high frequency (HF) radio propagation. As part of the WWV/WWVH Scientific Modulation Working Group, radio stations WWV and WWVH will each broadcast test signals once per hour that will allow operators using a type of software defined receiver (SDR) to record the signal data at their location and upload it to a central server for analysis..."

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

/jobs.htm" target="_top"> Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable /jobs.htm" target="_top">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 PCB Directory for Continued Support!

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


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