Homepage Archive - March 2020 (page 4)

Friday 27

Constant-Resistance Network Inductor Design

In this Radio & Television News magazine article, author Jack Gallagher derives a formula for the number of turns of wire to wind on a form of given dimensions for a parallel constant-resistance network. He argues that although commonly used formulas like that of Wheeler provide the number of turns needed to achieve a desired value of inductance, it does not predict the size of cross-sectional shape of a coil form that results in an optimal configuration. His work applies to audio frequency divider networks like those used for speakers to steer specific frequency ranges to a woofer, midrange, and tweeter trio; hence the need for "constant resistance" (e.g., for standard 8 Ω or 16 Ω speakers). By the way, in case you are not familiar with the annotation in older electronics articles, "mhy" is microhenries, and "s.c.c." is...

Notable Tech Quote: Concerning "Wavicles"

"Matter was neither particle nor wave, but a bit of both - a wavicle." - Ian Stewart, in "In Pursuit of the Unknown: 17 Equations That Changed the World," 2012, regarding the dual nature of light as covered in the chapter on Schrödinger's equation for wave functions. BTW, the real term used is "wave–particle duality," which is a quantum mechanical principle stating that all matter–energy has both a wave and a particle nature. The wave behavior of light is exhibited in its ability to be diffracted at a sharp edge. It is the particle nature which accounts for the photoelectric effect.

NEW - RF & Electronics Symbols for Visio

With 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...

Drone Radar Database Made Public for UAV Hunters

"A database of drone radar cross sections has been made public to help those developing countermeasures. 'We measured drone radar cross sections at multiple 26-40 GHz mm-wave frequencies to better understand how drones can be detected, and to investigate the difference between drone models and materials in terms of scattering radio signals,' said researcher Vasilii Semkin of VTT Technical Research Centre of Finland. 'We believe that our results will be a starting point for a future uniform drone database. Therefore, all results are publicly available along with our research paper..."

11 Ways Engineers Are "Kung Flu Fighting"

Ok, the real title on the Interesting Engineering website is, "11 Ways Engineers Are Helping out to Fight Against the Pandemic." Individuals and companies (comprised of individuals) are responding to the COVID-19 crisis in an utterly amazing manner. Except for grandstanding politicians and agenda-driven, hateful media types, many of our fellow Earthlings are working tirelessly to provide a way out of this present surreal crisis, and in the process are developing new knowledge and technology that will benefit us during "the next big thing." Others do what they can do by honoring precautionary rules of sanitation and separation. Admittedly, the exercising of extreme governmental powers worries me a bit as limits of citizens' willingness to comply are tested. One American politician famously recommended, "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." Here is the original 1974 "Everybody Was Kung Fu Fighting" song (I was in 10th grade). Be careful.

Prize Winners for Best "YL" Photos

In an effort to promote entry of women and girls into the amateur radio hobby, Short Wave Craft magazine ran a few contests for Best "YL" Photos. Amazingly - and maybe there are still instances of it today - many (if not most) of the YLs featured had built their own equipment. In 1935, most people built their own equipment, so that is not too surprising. The winner for this month was a 16-year-old young lady (i.e., "YL") who in fact built her rig. Another winner was an 83-year-old grandma who was born before Marconi, Maxwell, and Hertz did their best work! The third winner was a girl who earned her Ham license at age 6, which back in the day required sending and receiving 5 words per minute (WPM) in Morse code. BTW, according to the Bureau of Labor Statistics' (BLS) Inflation Calculator says $5 in 1935 is the equivalent of $94.41 in 2020 money...

Anatech Electronics: Off-the-Shelf and Custom RF & Microwave Filters

Anatech 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. 

Thursday 26

U.H.F. Fringe Antenna Installations

Multiple path transmission, diffraction around obstacles, absorption by foliage, and reflection from moving objects have always been challenges to the wireless system designer and/or user. Whether it concerns communications between a WiFi router and a notebook computer, a cellphone and a tower, an FM radio with a broadcast station, or deep space probe with an earth station, all of the aforementioned mechanisms must be dealt with to some degree. Although in a different way, even transmissions within a waveguide or coaxial cable deal with those same issues - reflections and the resulting standing waves have the same effect as multipath in terms of vectorially additive versions of the same original signal. Signal degradation issues can usually be overcome when all components are performing within specifications, by having knowledge potential causes, and then assessing the situation at hand. Of course an insufficient signal power from the transmitter, too-high Friis-determined atmospheric path loss, and inadequate receiver sensitivity under ideal conditions...

ConductRF Performance Flexible RF Cables to 18 GHz

"ConductRF-Performance-Flexible-RF-Cables-3-25-2020.htm" target="_top"> ConductRF LSA series of Low Loss, Performance flexible "ConductRF-Performance-Flexible-RF-Cables-3-25-2020.htm" target="_top"> RF cable assemblies, provide microwave system designers with a versatile solution for most applications. Here we offer customers a solution for 0.086" diameter cable that facilitates greater flexibility and handling or, 0.141" diameter that exploits the same great performance but with almost half the loss. Connector options include SMA, Type-N, TNC & SMP that provide excellent VSWR between DC and 18 GHz, also solutions for MCX & SMB are available in a wide array of configurations. These assemblies are built using our own double shielded, FEP jacketed cable, that was developed specifically for performance solutions. With shielding effectiveness exceeding 90 dB through 18 GHz, these cables minimize the threat of cross-talk effect. ConductRF guarantees its performance through 100% factory test prior to shipping. Additional options are also available...

Methods to Increase Channel Capacity in RF Data Links

Triad RF Systems' Steve Barthelmes, Patrick Sherlock, and Ken Andrew  published a Technical Brief article entitled, "Methods to Increase Channel Capacity in RF Data Links," in Microwave Product Digest. "As can be seen, increasing the robustness of RF links is a tricky business, however, there are multiple weapons in one's toolkit to increase capacity and combat RFI. MIMO is a radio technology that is taking hold worldwide. This wireless technology increases the channel capacity of the system while improving the reliability of the link. High gain antennas and tracking technologies can be employed, however, the mobile aspects of many RF links (UxV systems) do not always allow for the size, complexity, and sensitivity trade-offs that come along with them. BDAs can be employed, in conjunction with these other technologies, or alone, to increase the link margin of systems that are underperforming, however, there is a modest cost and power trade-off..."

How Did Dilbert Get His Name?

Do you know how engineering whipping boy Dilbert came to be called by that name? Per Scott Adams, while working at Pacific Bell he ran an informal name-the-comic-strip-engineer contest from his cubicle. A guy named Mike Goodwin suggested Dilbert. "I ended the contest immediately and declared Mike the winner," says Adams. It sounded perfect. Years after the comic strip had become syndicated, Mike commented that he believes the name idea might have come from seeing his father's old WWII aviator comics with "Dilbert the Pilot." DtP was a screw-up, invented by Navy artist Robert Osborn, whose purpose in life was to illustrate the wrong way of doing things so that real pilots wouldn't make the same mistakes. The name was funny then, as it is funny now. BTW, Dilbert is a variant of Delbert meaning nobly famous. During the War, "dilbert" became a synonym for "blunder" for Navy pilots. The Navy even produced an aviator safety film titled, "Don't Kill Your Friends," featuring Dilbert the Pilot...

Verizon Demos Peak Speeds of 4.2 Gbps on Live 5G Network

"Verizon, along with Samsung Electronics Americas, Motorola Mobility, and Qualcomm Technologies, have teamed up to demonstrate 5G peak speeds of 4.2 Gbps on a live 5G network. Using carrier aggregation, a technology that combines multiple channels of spectrum to provide greater efficiency for data sessions transmitting over the wireless network, the four companies combined eight separate channels of mmWave spectrum to achieve the multi-gigabit speeds on Motorola's upcoming flagship smartphone. Adam Koeppe, Senior Vice President of Technology Planning at Verizon commented that they are continuing to expand the 5G Ultra Wideband network, built to enable unique and transformational experiences for their customers. They continue to innovate and introduce advanced technologies on their 5G network that will help them reach 'never seen before' mobile capabilities..."

Res-Net Microwave: Precision RF & Microwave Components

Res-Net Microwave has a complete line of precision RF & microwave components including attenuators, terminations, resistors, and diode detectors for commercial, military, and space applications. Products range from the small flange type to large 2,000 watt connectorized power attenuators and/or terminations at frequencies up to 26.5 GHz. In-house photo etch and laser trim capability. The company is a leader in development and production of the films required for these type of RF/microwave components. Please check out Res-Net Microwave's website to see how they can help with your current project.

Wednesday 25

Mac's Service Shop: Zenith's 1973 Color Line

Those of us who have been around for six or more decades have lived through two evolutions of video display types - raster scanned cathode ray tubes (CRTs) and digitally pixelated light-emitting diode (LED) and liquid crystal (LCD) displays. Unlike with the latter display types that improved in color depth, picture resolution and display size, the former had effectively a fixed resolution of horizontal lines (525 vertical steps - only 484 visible, actually, due to blanking). That meant for CRTs, designers needed to find ways to make images appear in-focus while also looking continuous on larger screens. Doing so involved cleverly adjusting the size and spacing of fluorescent color dots on the picture tube face while also using special metal masks between the electron gun and the tube. A lot of research that included panels of people rendering opinions...

You Know You're an Engineer If…

...You Watched These Movies and TV Shows as a Kid. The Design News website likes to run these "You Know You're an Engineer If..." things, and usually they're pretty good. This one, of course, has me waxing nostalgic. "Here are some of classic engineering and robot movies and TV shows from the 1950s and 1960s. Every kid who grew up to be an engineer loved robots. The love of science fiction and robots seems to follow closely on the heels of the fascination with dinosaurs. Some of these movies were scary for a kid, like the deadly robot in The Day the Earth Stood Still. Others were lovable, like Robbie the Robot in Forbidden Planet. Some were terrifying in a more realistic way, such as HAL in 2001 a Space Odyssey..."

FQXi: Is Reality Digital or Analog?

Each year the Foundational Questions Institute (FQXi) holds an essay contest inviting writers to submit missives addressing the question chosen by the FQXi board as being particularly thought-provoking. In their words, "FQXi catalyzes, supports, and disseminates research on questions at the foundations of physics and cosmology, particularly new frontiers and innovative ideas integral to a deep understanding of reality, but unlikely to be supported by conventional funding sources." The 2011 question was "Is Reality Digital or Analog?" Scientific American magazine, being one of three partners, published the runner-up entry in the December 2012 issue: University of Cambridge professor of theoretical physics professor David Tong's paper argues that the world is in fact fundamentally analog. Professor Tong actually tied for second place, but for some reason SciAm does not tell us whether the other second place paper supported an analog or digital viewpoint...

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

RF 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 (of course a gratuity will be graciously accepted). 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...

Cubic Receives $5.1B Tactical Communication Contract from the U.S. Army

"Provider of integrated solutions for transportation and defense C4ISR, Cubic Corporation has announced that their Cubic Mission Solutions (CMS) business division has been selected as one of the awardees to compete under the U.S. Army for Global Tactical Advanced Communication Systems (GTACS II) Indefinite Delivery/Indefinite Quantity (IDIQ) contract vehicle. The contract has a ceiling of $5.1 billion, with a five-year base, one five-year option period and a Firm Fixed Price, Cost Plus Fixed Fee and Cost No Fee contract, in support of the Program Executive Office Command, Control and Communications-Tactical (PEO C3T), and Project Manager Tactical Network (PM Tactical Network)..."

Axiom Test Equipment: Rent, Buy, Trade & Repair

Axiom Test Equipment allows you to rent or buy test equipment, repair test equipment, or sell or trade test equipment. They are committed to providing superior customer service and high quality electronic test equipment. Axiom offers customers several practical, efficient, and cost effective solutions for their projects' TE needs and is committed to providing superior customer service and high quality electronic test equipment. For anyone seeking a way to offload surplus or obsolete equipment, they offer a trade-in program or they will buy the equipment from you. Some vintage items are available fully calibrated. Please check out Axiom Test Equipment today!

Tuesday 24

Westinghouse Tubes Contest w/Mickey Mantel

Other than vaguely recognizing the name, do Millennials know who Mickey Mantel was? Maybe hard-core Yankees fans of all ages still know. My having been born in 1958, the kids in my neighborhood watched "The Mick" playing on TV, witnessing real-time some of his final 536 career home runs being hit. When this two-page Westinghouse advertisement appeared in a 1954 issue of Radio & Television News magazine, he was only beginning in his forth season in Major League Baseball (MLB), which ran through 1968. The promotion was for a contest where servicemen who bought Westinghouse vacuum tubes submitted a witty response for the comic showing a housewife (that's what we called them back then) asked the poor bloke who fixed her TV set, "All that money to replace this little tube?" It was a line heard day in and day out...

The Urgent Need for a U.S. Space Force

Just as in the Gulf War air superiority was credited for minimizing damage to bodies and structures on the ground, so will space superiority be essential to surviving global threats on the ground. A strategically sufficient space system of communications and retaliatory weapons will be key to maintaining peace (at least physically if not financially). Gen. Steven Kwast, USAF, ret., has an opinion piece posted on the High Frequency Electronics website titled "The Urgent Need for a U.S. Space Force," with useful professional insight. "The following is adapted from a speech delivered on November 20, 2019, at Hillsdale College's Allan P. Kirby, Jr. Center for Constitutional Studies and Citizenship in Washington, D.C., as part of the AWC Family Foundation lecture series. In June 2018, President Trump directed the Department of Defense to 'begin the process necessary to establish a space force as the sixth branch of the armed forces..."

De Forest Radio Company Yukon Territory Ad

The Klondike / Yukon Gold Rush is generally credited with opening up the Alaskan territory to exploration and habitation. Gold was first reported in August of 1896, just three decades prior to this advertisement in a 1931 issue of QST magazine by the De Forest Radio Company extolling its domination of the region with radio communications stations. Company founder Lee De Forest was very successful in exploiting the virtues of his famous Audion amplifier tube. A back-handed swipe is taken at Government installations that used "whatever tubes the Government has..."

Mass Teleworking Causes Spike in DOD Network Attacks

"The Defense Department's networks have seen an uptick in cyberattacks this past week, and officials want to restrict the use of commercial streaming services, such as YouTube, as much of its workforce goes remote in response to the coronavirus pandemic. The U.S. is grappling with the COVID-19 pandemic with many companies and government agencies calling for telework. But it's a twofold challenge for DOD, which has 37 reported cases, as it tries to meet device demands and keep down network vulnerabilities. Essye Miller, the principal deputy CIO for DOD, said the organization's networks experienced a surge in cyberattacks as more employees were pushed to work remotely if possible..."

rfLyncs Antenna Testing Services

rfLyncs proprietor and chief engineer Steve Ledingham contacted me about listing his company's services on the RF Cafe applicable Antenna Vendor pages. He specialized in RF hardware, wireless systems and antenna design for over 20 years in commercial, medical, military and aerospace industries. rfLyncs provides custom antenna design, on-site antenna testing, wireless and RF design consultancy services for IOT and M2M devices. Experts in GPS, WiFi cellular, LTE connected devices. We help you meet or exceed your user requirements in a cost effective way by providing custom antenna design, antenna selection and integration, antenna test services, and RF & wireless hardware design. rfLyncs is located in Greater Boston area of Massachusetts. Please check out rfLyncs to see how Steve's expertise might help your project.

Centric RF: Attenuators, Adapters, Cable Assemblies, Power Dividers

Centric RF is a company offering from stock various RF and Microwave coaxial components, including attenuators, adapters, cable assemblies, terminations, power dividers, and more. We believe in offering high performance parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power levels from 0.5-500 watts are available off the shelf. Order today, ship today! Centric RF is currently looking for vendors to partner with them. Please visit Centric RF today.

Monday 23

New Stunts with Short Waves

As with many relatively new technologies, the exuberance over radio peaked quickly once the benefits of communications over long distances without the need for wires was realized by the public. After a couple decades a lot of "authorities" began pontificating about how all the useful applications of radio waves had been discovered and that any new innovation would be merely incremental improvements in existing technology. Novel circuits for minimizing static over the radio or maybe building more powerful transmitters for longer range were the only concepts within reach of their limited imaginations. Similar phenomena occurred for those who thought airplanes would always have two (or more) wings and that automobiles would never be faster than a train. This 1935 issue of Short Wave Craft magazine reported on the beginnings of investigations into the use of radio waves for heating...

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...

Smart Transformers Play a Major Role in Smart Grid

"Developing a smart grid that has online components will mean opening up the network to potential cyberattacks. But the risk may be warranted to see the electrical grid and its related systems brought into the modern age. It's rather evident that collectively, the energy industry must make some optimizations to the conventional power grid. There are many questions and concerns - both ethical and security-focused - about implementing smart and IoT-related technologies. Implementing a smart grid with online components will mean opening up the network to potential cyberattacks. That said, the risk may be worth it to see the electrical grid and its related systems brought into the modern age. The particulars are still being worked out, at least on a grand scale..."

After Class: Ground, Ground, and Grounded

"Ground is ground the world around." That's a saying that I have often heard Ham radio operators say aloud and in writing. In a general sense, it's true, but on a local level grounds can vary widely from location to location, even within a few hundred feet. It is true both for direct current and low frequencies and for frequencies in to the GHz regions. It has to do with the conductivity of the soil and/or rock in the area as well as the amount of moisture and other elements in the ground. Antenna guys like to run conductive (usually copper) "radials" out from the mounting pole or tower in order to create a sufficient local reference ground, and electric power distribution engineers often need to salt the ground around substations with ionic compounds in order to create sufficient conductivity to provide a safe grounding system...

Modeling Antennas Installed in the Presence of Large Platforms

This article on the Microwaves & RF website entitled, "Algorithms to Antenna: Modeling Antennas Installed in the Presence of Large Platforms," deals with large conductive solid surfaces and meshes (e.g., towers and steel beam buildings) in the near field. Even with today's powerful PC platforms, solving the huge matrices involved in method of moments (MoM) simulations can take a significant amount of time. That's not so bad once an accurate model has been confirmed, but during the "guesstimate" stage running validation simulations can suck up a lot of time. "To consider the effects of an electrically large platform, a physical-optics (PO) solver helps provide you with a good result without a large increase in simulation time." Sure, it's an infomercial for Mathworks, but then a large portion of these magazine articles are, and they are extremely valuable.

MECA Electronics: Passive RF & Microwave Components

Since 1961, MECA Electronics has designed and manufactured an extensive line of RF & microwave components for in-building, satellite, radar, radio, telemetry, mobile radio, aviation & ATC. Attenuators, directional & hybrid couplers, isolators & circulators, power dividers & combiners, loads, DC blocks, bias-Ts and adapters & cables. MECA has long been the 'backbone' of high performance wired and air-interfaced networks such as in-building applications, satellite communications, radar, radio communications, telemetry applications, mobile radio, aviation & air traffic communications.

Sunday 22

Notable Tech Quote: WHO on COVID-19

This was a Tweet put out by the World Health Organization on January 14, 2020: "Preliminary investigations conducted by the Chinese authorities have found no clear evidence of human-to-human transmission of the novel coronavirus (2019-nCoV) identified in Wuhan China." Since Twitter posts have a way of disappearing when proven embarrassing, that hyperlink goes to an archived Google page. For some reason Archive.org is not able to save Twitter pages (I tried to force a save, but it failed). President Trump initiated the travel ban on January 31, 2020 (and caught heck for it), two weeks prior to WHO's infamous Tweet telling the world not to worry.

Engineering & Science Crossword Puzzle March 22

This March 22, 2020, 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, 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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