Homepage Archive - March 2020 (page 1)

Friday 6

What Ever Happened to TV Channel 1?

A large percentage of people today do not remember or were not alive during the days of analog over-the-air (OTA) broadcast television, so the question, "What Ever Happened to Channel 1?" is moot for them. For that matter, the standard VHF selector knob beginning with the number 2 and not 1 was probably was never a matter of concern. I do remember wondering why there was no channel 1, but it wasn't until a few years ago that I learned why that was. By that time, the Internet is full of explanations, as is the case for most information you want to know. This article from a 1982 issue of Radio-Electronics magazine lays out the answer to the question in great detail, and provides some interesting history on the development of television broadcast standards...

Transmission Lines and Coaxial Connectors

In our continuing saga Wireless Networking in the Developing World, we now turn our attention to transmission lines and coaxial connectors, where we find: The transmitter that generates the RF power to drive the antenna is usually located at some distance from the antenna terminals. The connecting link between the two is the RF transmission line. Its purpose is to carry RF power from one place to another, and to do this as efficiently as possible. From the receiver side, the antenna is responsible for picking up any radio signals in the air and passing them to the receiver with the minimum amount of distortion and maximum efficiency, so that the radio has its best chance to decode the signal. For these reasons, the RF cable has a very important role in radio systems: it must maintain the integrity of the signals in both directions...

Superconductor Transition Switches Single-Molecule Magnet

"A superconductor can switch the magnetic moment of a single-molecule magnet placed on top of it. This novel phenomenon, discovered by researchers in Italy, occurs because of quantum tunneling of magnetic spins, and might be exploited in future quantum information technologies. Single-molecule magnets are paramagnetic materials that can switch their magnetization between two states - 'spin up' and 'spin down,' for example. At low temperatures, these molecular complexes retain their magnetic state even in the absence of a magnetic field because reversing the magnetization would require them to overcome an energy barrier. This magnetic 'memory' effect could be exploited in spintronics and quantum computing applications..."

Crossword Puzzle from the December 1957 Popular Electronics

Here is a 1950s vintage crossword puzzle from Popular Electronics magazine. Unlike the weekly crosswords from RF Cafe that use only relevant technical words, this one uses some common words unrelated to electronics and science to fill in where needed. It's still a good puzzle, though. Print it out for use during your next boring meeting or 12-hour flight to China. A list of many other puzzle from Popular Electronics and Electronics World is presented at the bottom of the page. Have fun.

The Role and Trending Requirements of RF Limiters

Fairview Microwave has a new article posted on the Microwave Product Digest (MPD) website entitled, "The Role and Trending Requirements of RF Limiters in Multifunctional AESA Radar." You don't tend to see a lot of pieces on RF limiters. It begins, "In the past few years, active electronically scanned array (AESA) radar have transitioned from cutting-edge radar technology designed to be deployed on next-generation multi-role fighters, to capability and life extension systems for older aircraft and legacy radar designs. There are an increasing number of radars replaced with AESA systems, with one of the major demands being multifunctional capability to meet multi-mission and multi-role expectations for modern radar. These new expectations present substantial design difficulties, especially for the receive signal chain in a transmit/receive module driving a high number of AESA antenna elements. The design constraints of high antenna element AESA radar are further complicated when the AESA is forced into footprints catering to a previous generation of mechanical radar..."

Windfreak Technologies: USB-Powered RF Synthesizers, Mixers

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

Thursday 5

Developments in U.H.F.

Once World War II was over and the peoples of the world could breathe and start enjoying life again, television, which had just begun to take off before the war, quickly gained widespread adoption in homes. As with so many areas of technology and science, advancements in electronics and wireless communications during the war years redounded very beneficially to the TV industry. Early schemes for television combined both electronics and mechanical elements using rotating discs, vibrating mirrors, and other far-out schemes to convert electrical signals to moving pictures. Due to the small size of the first cathode ray tubes (CRTs), commonly called kinescopes at the time, light beams were launched toward physically maneuvered mirrors to steer the image onto the back of a larger glass screen - basically the first projection screen televisions ...but I digress. TV's popularity grew so fast in the late 1940s and early 1950s that the Federal Communications commission (FCC) issued a moratorium on the building of new broadcast stations until a scheme could be devised to deal with signal overlap (interference) from too closely spaced stations...

Understanding Wave Physics

Here is the electromagnetic wave section of the "Wireless Networking in the Developing World," book (open source). "Wireless communications make use of electromagnetic waves to send signals across long distances. From a user's perspective, wireless connections are not particularly different from any other network connection: your web browser, email, and other applications all work as you would expect. But radio waves have some unexpected properties compared to Ethernet cable. For example, it's very easy to see the path that an Ethernet cable takes: locate the plug sticking out of your computer, follow the cable to the other end, and you've found it! You can also be confident that running many Ethernet cables alongside each other won't cause problems, since the cables effectively keep their signals contained within the wire itself. But how do you know where the waves emanating from your wireless device are going..."

Satellite Design Applied to Superyacht

"Dutch shipbuilder Royal Huisman applied the same concurrent engineering process developed by ESA for space missions to the design of superyacht Sea Eagle II, due to become the world's largest aluminium sailing yacht when delivered to its owner this spring. This uniquely contemporary 81 m-long three-masted schooner was recently transported by barge from the company's shipyard in Vollenhove to Royal Huisman Amsterdam, where its carbon composite rig will be installed, leaving her ready for sea trials and on-board crew training..."

Z-Comm Intros Low Noise 12 GHz PLO w/Internal Reference

"Z-Communications-Low-Noise-12-GHz-PLO-Internal-Reference-3-3-3020.htm" target="_top"> Z-Communications is pleased to announce a new RoHS compliant "Z-Communications-Low-Noise-12-GHz-PLO-Internal-Reference-3-3-3020.htm" target="_top"> fixed frequency phase locked loop operating in the Ku-band. The RFS12000C-LF is a plug and play PLO which is designed to produce a fixed signal output at 12 GHz. Utilizing an internal 10 MHz reference clock, this unmatched PLO makes for simple integration into any system as no external programming is required. This simple to use RFS12000C-LF features a typical low noise performance of -72 dBc/Hz, -86 dBc/Hz, and -116 dBc/Hz at the 1 kHz, 10 kHz and 100 kHz offsets, respectively. The high performance RFS12000C-LF is designed to deliver an output power of 0۬±3 dBm while operating off a two input supply voltages...

Naval Communications

Naval communications and their communicators have always been held in high regard. Operating and maintaining sophisticated electronics equipment is difficult enough on solid ground, but doing it on the ocean with winds and waves tossing the platform (ship) relentlessly can exacerbate the problem tremendously. It is a wonder that radar systems can even be useful with the antenna constantly rotating about pitch, roll, and yaw axes while simultaneously shifting in the x, y and z axes. Sure, airborne platforms have the same sort of challenge, but their perturbations are not typically as violent, as great in magnitude, or as prolonged as a naval vessel in rough seas. For the record, I'm a former USAF radar guy so I'm not just trying to glorify my own branch of service...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. 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...

How Much Do You Really Know About Communications Electronics?

By Lou Frenzel: "How Much Do You Really Know About Communications Electronics?". "As communications wends its way into virtually every electronic product, having a solid understanding of the technology becomes essential. Here are steps you can take to achieve that goal. If you're an experienced RF communications engineer, you probably don't have to read this blog. But if you're a beginning engineer, an engineer recently assigned to a communication project, a tech manager overseeing communications engineers, or those of you who test or sell comm gear, you may want to take a look. Learning About Comm The largest sector of electronics is communications. Name an electronic product today that does NOT have some comm function..."

San Francisco Circuits: PCB Fabrications & Assembly Service

SF 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."

Wednesday 4

Bell Telephone Laboratories Punch Cards

Punch cards have been used in computer systems since the very early days of digital programming. They were probably the first form of read-only memory (ROM), come to think of it. I hate to have to admit it, but the meager computer used in my high school computer lab (circa early-mid 1970s) used punched cards. I never took the class, but stories abounded of how pranksters would shuffle a stack of punch cards while the student programmer wasn't watching and then get a good laugh when nothing worked. There are also plenty of cases where a stack was inadvertently knocked onto the floor and had to be laboriously re-ordered. IBM is the brand that comes to most people's minds when thinking about the old punched card computer systems, but other companies like NCR (National Cash Register), HP (Hewlett-Packard), DEC (Digital Equipment Corporation), and plenty of others others...

Amateur Radio Contesting for Beginners

Doug Grant (K1DG) and the ARRL just published a book titled "Amateur Radio Contesting for Beginners." While the title and cover photo suggest it is directed toward teenagers, "Beginners" encompasses people of all ages, whether veteran operators who had not competed before or relatively newly licensed guys like me who finally earned my first Ham license (Technician) in 2010 at age 51 (now Amateur Extra, BTW). "Contesting is one of the most exciting aspects of amateur radio. It's called 'radiosport' because it really is a sport – a competition to see who can contact the most stations in an allotted amount of time. Regardless of the size of your station, you can compete, too!" The book is available in softcover and Kindle formats.

The Yagi Antenna

Contributors to the Wikipedia article on the Yagi-Uda antenna credit Japanese professor Shintaro Uda primarily for the antenna's development, with Hidetsugu Yagi having played a 'lesser role." Other sources assign the primary role to Yagi. Regardless, history - and this article's author, rightly or wrongly, has decreed that this highly popular design be referred to commonly as the Yagi antenna and not the Uda antenna. I don't recall seeing advertisements for 'Uda' television or amateur radio antennas. Harold Harris, of Channel Master Corporation, does a nice job explaining the fundamentals of the Yagi antenna...

Double Slits with Single Atoms

 "Thomas Young's double-slit experiment is famous for demonstrating the principle of interference. Andrew Murray explains why it's now possible to carry out an equivalent experiment using lasers that have excited individual rubidium atoms Over the last 20 years I must have spoken to more than 400 school pupils who want to study physics here at the University of Manchester. One subject that regularly comes up at interview is Young's double-slit experiments, which clearly interest my prospective students. But when I ask them what the experiments are all about, I'm invariably told they involve using electrons to demonstrate wave-particle duality - one of the cornerstones of quantum physics. That's curious because Thomas Young performed his experiments in 1804 - long before we knew anything about electrons or the subatomic world..."

Understanding the Fresnel Zone

I ran across a really nice e-book entitled "Wireless Networking in the Developing World," which is a collaborative work by many authors, and it is published under the Creative Commons licensing scheme (a la Wikipedia). That permits reprinting with attribution. Some of the more pertinent sections will be posted here on RF Cafe. "The exact theory of Fresnel zones is quite complicated. However, the concept is quite easy to understand: we know from the Huygens principle that at each point of a wavefront new circular waves start, we know that microwave beams widen as they leave the antenna, we know that waves of one frequency can interfere with each other. Fresnel zone theory simply looks at a line from A to B, and then at the space around that line that contributes to what is arriving at point B. Some waves travel directly..."

Anatech Microwave March 2020 Product Update

"anatech-microwave-product-announcement-3-3-2020.htm" target="_top"> Anatech Microwave Company is a privately-held company founded in 2003 that focuses on supplying quality RF and microwave products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. In their March Product Update, Anatech has introduced "anatech-microwave-product-announcement-3-3-2020.htm" target="_top"> three connectorized power dividers: a DC to 4.0 GHz 8-way resistive power divider, a 1000 to 4000 MHz 2-way reactive power divider, and a 2000 to 18000 MHz 4-way reactive power divider. Custom RF power directional coupler designs can be designed and produced when a standard cannot be found, or the requirements are such that a custom approach is necessary...

Alliance Test Equipment: Used & Refurbished, Purchase & Rental

Alliance Test Equipment sells used / refurbished test equipment and offers short- and long-term rentals. They also offer repair, maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP, Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization with ability to source hard to find equipment through our network of suppliers. Alliance Test will purchase your excess test equipment in large or small lots. Please visit Allied Test Equipment today to see how they can help your project.

Tuesday 3

How the Audion Was Invented

A few days ago I mentioned that a popular early form of radio detector circuit involved the used of a flame - yes, the flame of a fire, not a romantic significant other. The subject arose in a couple articles in the January 1947 issue of Radio-Craft magazine that celebrated the 40th anniversary of Lee de Forest's Audion vacuum tube invention. This particular piece was authored by de Forest himself, who was a personal friend of Radio-Craft editor Hugo Gernsback. It is a very interesting autobiographical account of the early days of experimentation and the evolution of what eventually became the world's first mass producible signal amplifying device. You will also read that de Forest created the designation of the "B" battery for a reason he makes obvious. Also, although you have probably seen pictures of the old household type gas light fixture...

UK Unveils Post-Brexit Investment and Visa Changes to Boost Science

 "The UK government has announced a raft of measures to boost science in the country as it gets ready to leave the European Union on 31 January. They include investing £300M over five years to fund mathematical sciences, the lifting of visa restrictions on scientists coming to the UK, as well as removing the need for researchers to make 'impact' statements when submitting grant applications to UK funding councils. The boost for mathematics comes via the Engineering and Physical Sciences Research Council (EPSRC), which will invest £60m per year in the field - double what it currently spends. EPSRC says it will provide £19m towards funding PhD students for four years 'as standard' and offer five-year funding for research associates to 'compete with the U.S. and Europe'..."

AWR Design Magazine Vol 19.4

Cadence / AWR just published volume 19.4 of their monthly "AWR Design Magazine." This issue includes updates on the latest AWR software design applications, success stories, software updates, and e-learning and training tools. The feature story is titled "AWR is Now Cadence Customer." Content also includes power amplifier design tackling high peak-to-average power ratio with digital predistortion, best practices for efficient and effective planar EM simulation, and a piece on Richardson RFPD and INAF SDARS and radio astronomy...

Electromagnetism - Basic Navy Training Courses, NAVPERS 10622

After previously presenting the permanent magnet, chapter 12 of  the NAVPERS series of courses takes a look at the electromagnet. It is like a natural or artificial magnet in its attraction but unlike in its control. Its attraction is tremendous-it can hold tons of iron. But because this magnet is powered by an electric current, the magnetism can be turned on and off with the flick of a switch. Electrically-powered magnets are called electromagnets. Electromagnets come in all sizes and shapes - and do all kinds of jobs. All electromagnets use a coil of wire and a core of iron to produce their magnetism. The coil furnishes the magnetic flux and the iron concentrates it. To understand how it works, you should start with the magnetic field around a conductor. All conductors carrying current are surrounded by a field-of flux. As in the case of artificial magnets, iron filings will make this field visible. Connect a wire to a battery and dip the wire in iron filings...

Promote Your Company on RF Cafe for as Little as $45/mo.

RF Cafe typically receives 8,000-15,000 website visits each weekday and about half that on weekends. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 10,000 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. If you need your company news to be seen, RF Cafe is the place to be. Advertising begins at $45/month.

Next Generation Wi-Fi: 6 GHz Is on the Horizon

Skyworks Solutions' Wes Boyd just posted a white paper entitled, "Next Generation Wi-Fi: 6 GHz Is on the Horizon," which, as the title implies, discusses the wireless industry's motivation to more aggressively occupy the less-used 6 GHz unlicensed band. He begins, "The push to open the 6 GHz band (5.925-7.125 GHz) to unlicensed use is being driven by explosive growth in consumers' data needs, particularly from applications such as video streaming and video on-demand. The demand for data is being further bolstered by social media applications, audio platforms, and smart home devices. In addition, new and burgeoning applications such as virtual reality (VR) and augmented reality (AR) will continue to drive significant data demand into the future..."

RF Superstore: Supplier of RF & Microwave Components

RF Superstorelaunched in 2017, marking the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and microwave Industry. Pasternack fundamentally changed the way RF components were sold. Partner Jason Wright manages day-to-day operations, while working closely with Mr. Pasternack to develop RF Superstore into a world class RF and microwave component supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies, surge protectors, attenuators. Items added daily. Free shipping on orders over $99. We're leading the way again!

Monday 2

Qualcomm ultraSAW RF Filter Technology for 5G/4G

"Qualcomm Technologies, Inc. today announced the Qualcomm® ultraSAW filter technology, another groundbreaking innovation in the company's industry-leading wireless technology portfolio that builds on the company's legacy of developing breakthrough technologies and enabling new experiences and expanding the mobile ecosystem. Radio frequency (RF) filters isolate radio signals from the different spectrum bands that phones use to receive and transmit information. By achieving as much as 1 decibel (dB) improvement in insertion loss, Qualcomm ultraSAW filters offer a higher performance solution compared to competing bulk-acoustic (BAW) filters in the sub-2.7 GHz frequency range..."

How to Bend Your Own Chassis

Despite all the prefabricated, relatively inexpensive products available these days, there are still many people who like to build their own projects. Whether electrical or mechanical - or both - some sort of enclosure is usually involved. Often, you can cannibalize an existing, retired project to use its chassis or find a product at Walmart or a home improvement store that does not cost too much that you can buy just to get its enclosure. Buying a pre-formed chassis for your project can get expensive, so there are times when the best option is to obtain a piece of sheet metal (which can also be expensive) and bend it yourself. If you have never attempted such an endeavor, believe me it can be pretty challenging, especially with heavier gauge metal. It is usually best to lay out and drill / cut / punch / file as many holes as possible prior...

EDI CON CHINA Rescheduled to September 2020

"EDI-CON-China-Postponed-2-28-2020.htm" target="_top"> Following the developments of the coronavirus (COVID-19) outbreak closely and its impact on colleagues and customers in China, Horizon House announced today that "EDI-CON-China-Postponed-2-28-2020.htm" target="_top">EDI CON CHINA, May 12-13, 2020 in Beijing, China has been rescheduled for September 27 and 28, 2020 at the Chinese National Convention Center (CNCC), Beijing, China. "We express our sincere thanks to our exhibitors, sponsors, and media partners for their ongoing support of EDI CON CHINA, and we send our very best wishes to our colleagues, friends, and customers who are directly affected by the COVID-19 virus," said Ivar Bazzy, President of Horizon House, "We thank everyone for their patience as we shift to a new date for our 2020 event in the fall in Beijing...

Thanks to Transient Specialists for Continued Support!

Transient Specialists specializes in EMC test equipment rentals and carries a complete line of ESD guns, surge immunity test equipment, and EFT generators. Rentals available for military (Mil-Std 461), automotive (ISO 7637), and commercial (IEC 61000-4) EMC testing. Flexible terms, accredited calibrations and technical support on EMC testing equipment offered. Equipment consists of top EMC Test System manufacturers, including Teseq, Thermo Keytek, EM Test and EMC Partner. Contact Transient Specialists today for your ESD / EMC / RFI testing needs.

Antennas Evolve to Meet 5G Requirements

 L-Com product manager Mark Miller has an article on the High Frequency Electronics website titled "Antennas Evolve to Meet 5G Requirements." He discusses the need for active antenna systems to service the high bandwidth and high reliability mandated by 5G communications requirements. Included is a veritable cornucopia of associated abbreviations and acronyms. To wit: "It is largely believed by market research groups, industry consortiums / standards bodies, original equipment manufacturers (OEMs), academic researchers, and even consumers, that 5G technologies will offer seamless voice, data, and control services magnitudes beyond the services commonly experienced in today's metropolitan and suburban regions. It is only a common opinion that advanced antenna systems (AAS) or smart antennas (SAs), will be necessary in delivering enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC), which are considered three pillars of early 5G use cases. Upgraded antenna technologies, such as massive multi-input multi-output (mMIMO)..."

Reactel: RF & Microwave Filters of All Types

Reactel has become one of the industry leaders in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity, and waveguide designs, as well as state of the art high performance suspended substrate models. Through a continuous process of research and development, they have established a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact Reactel today to see how they might help your project.

Sunday 1

Engineering & Science Crossword Puzzle for March 1st

As with my hundreds of previous science and engineering-themed crossword puzzles, this one for March 1, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up 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, for reasons which, if you don't already know, might surprise you.

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. Some quoted items have been shortened to save space. About RF Cafe.

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