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Homepage Archive - April 2019 (page 4)

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. About RF Cafe.

Homepage Archive Pages

2020:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2019:
  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2018:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2017:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2016:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2015:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2014:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2013:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2012:  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13


See Page 1 | 2 | 3 | 4 | 5 of the April 2019 homepage archives.
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Friday 6

Electronics-Themed Comics, April 1970 Radio-Electronics

Electronics-Themed Comics, April 1970 Radio-Electronics - RF CafeWind down the week with these four electronics-themed comics from a 1970 issue of Radio-Electronics magazine. As mentioned before, radio and television technology was a big deal in the era. People hadn't been born into a world of transistorized microcircuit media devices that perform nearly every conceivable function - phone, TV, radio, computer, heart rate monitor, voice recorder, remote control, camera, compass, game, social media, etc., etc., etc. Unlike today's electronics products that typically don't break with normal use and do not require periodic alignment, folks from my demographic were used to turning on a TV or radio and having to readjust it or have it repaired ...

ARRL 'Radio Communications' Billboard Promotes Ham Radio

ARRL 'Radio Communications' Billboard Promotes Ham Radio - RF cafe"A new billboard on Interstate 40 in Tennessee promotes ARRL and Amateur Radio. Working with ARRL Product Development Manager Bob Inderbitzen, NQ1R, and Communications Manager Dave Isgur, N1RSN, ARRL Graphic Designer Sue Fagan, KB1OKW, completed a design for a the new 10 × 20 billboard, owned by ARRL Life Member Cliff Segar, KD4GT. Segar says the average daily traffic count for the area along I-40 west bound, mile marker 336, is on the order of 6 million vehicles per year ..."

Many Thanks to INSTOCK Wireless Components for Their Support!

INSTOCK Wireless Components - RF CafeINSTOCK Wireless Components designs & manufactures UHF/RF power dividers, bias tees, GPS antenna signal splitters, DC blocking L-Band splitters, high-power combiners, and current steering splitters with models in 2-way thru 64-way configurations with Type N, SMA, TNC, BNC, & QMA connectors covering frequencies from 10 MHz to 6 GHz. Custom configurations also available including mix-and-match connector options, IP67 outdoor weatherproof, rackmount, and micro-sized units. ...

FCC Seeking Communications Specialist

FCC Seeking Communications Specialist - RF CafeOpen & closing dates April 19 to May 3, 2019. Pay scale & grade GS 12 - 13. Salary $83,398 to $128,920 per year. "The FCC has announced a position opening that may be of interest to a radio amateur. The Commission seeking a Telecommunications Specialist to work at the High Frequency Direction Finding Center (HFDFC) in Columbia, Maryland. This is a full-time position. The person holding this position performs 'watch duty' and serves as a technical authority providing technical assistance and guidance to communication systems users to resolve radio interference complaints and problems. The telecommunications specialist uses radio signal analysis equipment deployed throughout the US to collect, correlate, and analyze ...

International Marconi Day 2019 is April 27

International Marconi Day 2019 is April 27 - RF cafeSome 70 stations have registered to take part in the 2019 International Marconi Day (IMD) observance on Saturday, April 27. Registered stations will operate at sites with a personal connection to wireless pioneer Guglielmo Marconi, including sites at which he set up transmitting and receiving stations. The 24-hour Amateur Radio event celebrates the birth of Marconi on April 25, 1874, and is typically held on the Saturday closest to Marconi's birthday. During IMD 2019, radio amateurs around the world will make contact with historic Marconi sites. The event is sponsored by the Cornish Radio Amateur Club, which will operate as GB4IMD. While April 27 is the day of the official celebration, some IMD special events will take place outside ...

Axiom Test Equipment: Rent, Buy, Trade & Repair

Axiom Test Equipment - RF CafeAxiom 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. Please check out Axiom Test Equipment today! ...

Thursday 25

The G-Line Antenna Lead−In

The G-Line Antenna Lead-In, April 1955 Radio & Television News - RF CafeReading this article about the G-line antenna lead−in in a 1955 issue of Radio & Television News magazine, I wonder whether the Broadband over Power Line (BPL) system designers have considered its use. According to author Leonard Lieberman, the presence of insulation over the conductor prevents or at least significantly reduces the amount of radiated energy, thus lessening not just the signal loss but also the unintentional interference with unrelated receiving equipment - such as the well-publicized impact on amateur radio. The David Bogen Company, of New York City, (now in New Jersey) marketed G-Line under under license by Surface Conduction, Inc. Current BPL systems are typically under 100 MHz, so the scheme should be applicable. The logistics of implementation ...

"Grounds" for Confusion

"Grounds" for Confusion, January 1960 Electronics World - RF CafeRobert Gary waxes philosophical on the subject of ground in his Electronics World article, "'Grounds' for Confusion." He is justified from the viewpoint of someone attempting to make sense of how something as seemingly fundamental as Earth ground is not a constant. The layman probably doesn't care. Practitioners in the electrical and electronics realms who deal only with low frequencies and short distances might occasionally be affected by differences in ground potentials, although they might not realize it is the cause of their problems. Those with more than a casual involvement (designers, installers, and maintainers as opposed to only users) in high frequencies and/or long distance signal interconnections are likely to be intimately familiar with the effects of ground potential differences. RF Cafe visitors are undoubtedly members of the latter group ...

EDI CON Online Will Reach Global Audience

EDI CON Online Will Reach Global Audience - RF CafeThe Electronic Design Innovation Conference and Exhibition (EDI CON) announced that this year, in conjunction with Microwave Journal (MWJ) and Signal Integrity Journal (SIJ), it will host an online, interactive event for high frequency and high speed design engineers on September 10-12, 2019. The interactive technical sessions will occur at no cost to attendees, and sponsors will have the opportunity to present workshops and keynote sessions as part of the daily schedule. The sessions on September 10th will focus on 5G and IoT, September 11th on radar and antennas, and September 12th on signal integrity, power integrity, and EMC/EMI. Attendees select the sessions for the online event ...

Decibels: Use with Caution

Decibels: Use with Caution - RF CafeInasmuch as new people are entering the realm of electronics all the time and are voraciously hunting for and consuming as much basic knowledge as possible, I figure this primer on decibels will be a good reference. It helps clear up one of the biggest stumbling blocks for decibels: when to use 10*log(out/in) vs. 20*log(out/in). Bob Witte has written quite a few nice articles about various aspects of electronics. "Decibels are commonly used in electronic systems that include RF, audio, and more recently, signal integrity. While many engineers already think in decibels, if you mostly work in the time domain, you may not think the same way. Because much of my background is in RF, I tend to associate the decibel with RF measurements, but the decibel began at audio frequencies defined by telephone system ..."

Compact Antenna Enables Communication Where Conventional Radios Fail

Innovative Compact Antenna Enables Communication Where Conventional Radios Fail  - RF Cafe"Scientists at the Department of Energy's SLAC National Accelerator Laboratory, have developed a new type of pocket-sized antenna that could enable mobile communication in situations where conventional radios don't work, such as underwater, through the ground and over very long distances through the air. The device emits very low frequency (VLF) radiation with wavelengths of tens to hundreds of miles. These waves travel long distances beyond the horizon and can penetrate environments that would block radio waves with shorter wavelengths. While today's most powerful VLF technology requires gigantic emitters, this antenna is only four inches tall, so it could potentially ..."

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

Centric RF microwave components - RF CafeCentric 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 ...

Wednesday 24

Radar Signature Analysis

Radar Signature Analysis, February 1967 Electronics World - RF CafeOperators didn't know how good they had it in 1967. The story talks about the nuisance of having to sift through "hundreds" of satellites, old rockets, and assorted space junk" in order to search for and track potentially threatening objects in orbit around the Earth. We're into the millions of objects in 2019, and the potential threats are infinitely larger. The article mentions the use of an AN/FPS−16 radar operating in C−band to detect and measure the returns and then the results were analyzed in an attempt to determine the character of the object. Open air test sites and anechoic chambers were used to measure the radar cross section and characteristic signature of many shapes to populate a database of recognizable returns that would help to determine whether the space object was friend or foe ...

NI AWR Webinar: Antenna Matching-Circuit Design for IoT Devices

Webinar Features NI AWR Software for Antenna Matching-Circuit Design for IoT Devices - RF CafeThe NI AWR Design Environment platform will be featured in an upcoming free webinar on Wednesday, May 15. Presented is a new technology and design methodology that uses the impedance-matching network synthesis capabilities within Microwave Office circuit design software to design the input impedance for a new generation of Virtual Antenna™ tiny antenna booster components from Fractus Antennas. This antenna technology enables a single antenna component to fit seamlessly in a printed circuit board (PCB), replacing conventional customized antennas for internet of things (IoT) and other wireless applications ...

Model Accurately Predicts Harmful Space Weather

Model Accurately Predicts Harmful Space Weather - RF Cafe"A new, first-of-its-kind space weather model reliably predicts space storms of high-energy particles that are harmful to many satellites and spacecraft orbiting in the Earth's outer radiation belt. A paper recently published in the journal Space Weather details how the model can accurately give a one-day warning prior to a space storm of ultra-high-speed electrons, often referred to as 'killer' electrons because of the damage they can do to spacecraft such as navigation, communications, and weather monitoring satellites. This is the first time researchers have successfully predicted those killer electrons across the whole outer belt region ..."

DC Motors & Generators

DC Motors & Generators, NAVPERS 10622 - RF CafeStudies of motors usually begin with the direct current (DC) type - maybe because most students have already had hands-on experiences with motors in models (cars, boats, airplanes) and/or electricity experimenter kits. They are small, cheap, and a simple flashlight battery (the ultimate in safety) makes them run. An alternating current (AC) motor requires either a direct connection to the house current or use of a step-down transformer, which still carries with it a high risk factor. This chapter of the U.S. military's Basic Navy Training Course (NAVPERS 10622) conforms to the tradition, and follows in the next chapter with AC motors and generators. While reading through the text, I ran across the unfamiliar term "kickpipe" and wondered ...

MECA Electronics: Passive RF & Microwave Components

MECA Electronics

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 ...

Tuesday 23

Air Traffic Control by Electronics

Air Traffic Control by Electronics, January 1960 Electronics World - RF CafeAir Route Traffic Control Centers, now using the acronym ARTCC rather than ARTC as used in this 1960 article, were and still are the human and computer command and control facilities responsible for safe and orderly flow of air traffic in the U.S., and a worldwide network of Area Control Center (ACC) handles everything else in a massive coordinated effort. The advent of radar during World War II and the ensuing evolution of it and electronic computers in the following years struggled to keep pace with the equally rapidly evolving aircraft design and capability. A simple control tower with air traffic controllers using binoculars and a radio mike could not handle the volume of airplanes and helicopters traversing the skies and patronizing busy terminals. Many forms of electronic navigation aids were developed including very high frequency omnidirectional range (VOR), direction finders (DF) using antenna nulling for finding radials to/from FM radio transmitter, long range navigation (LORAN) ...

VidaRF Broadband Power Dividers for 698 MHz to 2.70 GHz

VidaRF Broadband Power Dividers for 698 MHz to 2.70 GHz - RF CafeVidaRF, a manufacturer of high performance RF and microwave high performance circulators, isolators, couplers, power dividers, and other passive components, is proud to introduce a series of broadband Power Dividers covering 698 MHz through 2.70 GHz for all wireless applications from cellular through UMTS. Available in 2, 3, 4, 6 and 8-way with SMA, N, QMA or alternative connector configurations. VidaRF is focused on being a solution provider by building to customer specs and offering zero days lead time for custom parts through stock and ship program ...

Many Thanks to Nova Microwave for Continuing Support!

Nova Microwave circulators & isolatorsNova 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. Please visit Nova Microwave today ...

AC Motor Basics

AC Motor Basics, NAVPERS 10622, Chapter 16 - RF CafeChapter 16 of the "Electricity - Basic Navy Training Courses" introduces concepts of alternating current (AC) motors, their electric supply, and controls. It is part of the NAVPERS (Navy Personnel) 10622 series which is highly regarded both in and out of the military. The manuals were first written in the middle of the last century and have been upgraded a few times since then, but if you compare the sections this one on AC motors in both the original and most modern versions, not much - if anything - has changed. If you have an interest in motors and want to understand the basics of how they work both as motors and generators (AC and DC), then there is not a much better source from which to start ...

Complete Filter Design with Discrete Elements Made Easy

Complete Filter Design with Discrete Elements Made Easy - RF CafeJeffrey Kahler's "Complete Filter Design with Discrete Elements Made Easy" article on the MW&RF website reviews some of the filter design software tools currently available both as free apps from component vendors and as a subset of big-name simulator suites. Says Jeffrey, "In an era of a myriad of design tools developed to “save” the filter designer time and effort, it’s exactly time and effort that may be lost due to learning curves, cumbersome workflows, and limitations of the design process itself. Powerful design tools may thus be rendered effectively useless by any one of these problems. For example, a tool that provides powerful synthesis may fall short ..."

Drilling White Graphene to Create Artificial Atoms

Scientists Drill into White Graphene to Create Artificial Atoms - RF Cafe"By drilling holes into a thin 2-D sheet of hexagonal boron nitride with a gallium-focused ion beam, University of Oregon scientists have created artificial atoms that generate single photons. The artificial atoms - which work in air and at room temperature - may be a big step in efforts to develop all-optical quantum computing, said UO physicist Benjamín J. Alemán, principal investigator of a study published in the journal Nano Letters. 'Our work provides a source of single photons that could act as carriers of quantum information or as qubits. We've patterned these sources, creating as many as we want, where we want ..."

ConductRF: Precision & Standard Grade RF Cable Assemblies

ConductRF coaxial cables & connectors - RF CafeConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 

Monday 22

The Discovery of Radio Waves

The Discovery of Radio Waves - RF CafeAn excellent short history on "The Discovery of Radio Waves" was published by George Steber in the Jan/Feb 2019 issue of Nuts & Volts magazine. "When the concept of electromagnetic waves was first proposed around 1864, it was met with great skepticism. As a result, the idea languished for a long time. This is understandable since the foundations of the theory were complex and the conceptual ideas were at odds with physical thinking. It took several decades for a handful of dedicated persons - infatuated with the mysteries of electricity and magnetism - to finally put the theory on a solid footing ..."

Improving Object Detection with Low-Bandwidth Radar

Improving Object Detection with Low-Bandwidth Radar - RF Cafe"Researchers at Tel Aviv University have designed a new type of radar ranging system that requires virtually no bandwidth to operate successfully. This new method does not have the bandwidth limitations of traditional methods, meaning it can be used in a vast array of different applications - particularly when it comes to the automotive industry Traditionally, radar resolution was believed to be proportional the bandwidth use. Essentially, the wider available range of frequencies, the better the radar will be at detecting objects in its path. The new method devised by researchers seeks to change all that ..."

Restoring Notre−Dame Using Modern Technology

Restoring Notre Dame Using Modern Technology - RF CafeEE Times has an interesting piece on their website regarding how modern engineering methods might be used to restore the fire-ravaged Notre−Dame church to its original condition. Some interesting observations are made, one regarding how cleaning and replacing stained glass tiles will affect lighting to the 13th century conditions vs. as it was two weeks ago. Another suggests ultrasonic analysis of mortar joints to structural integrity, use of drone photos and laser measurement to construct a detailed 3D model of the building for work planning. It also suggests a call to social media for obtain as many of the millions of photographs taken by visitors from all perspectives and times of day for recreating damaged or destroyed components.

Notes on the Getter

Notes on the Getter, February 1958 Radio-Electronics - RF CafeIf you happen to be Estonian, you might think of something entirely different than most of us do when we hear the word "getter." In fact, you probably capitalize the word since it is the name of a pop singer from your country, Getter Jaani. If you are a child living in Japan, you would probably think of Getter Robo, an anime from a popular cartoon series. I, and I dare say just about everyone else that visits RF Cafe, knows getter as that silvery deposit (typically barium) that resides inside vacuum tubes for the purpose of helping to maintain the vacuum and to absorb pesky random molecules that might otherwise cause electrical noise in the circuit. This article from a 1958 edition of Radio-Electronics discusses the purpose of getter. BTW, I had never heard of either of the other two Getters due to OGS (old guy syndrome) ...

White Paper: The Future of EMC Test Laboratories

Rohde & Schwarz: The Future of EMC Test Laboratories  - RF CafeRohde & Schwarz has published a white paper entitled, "The Future of EMC Test Laboratories," which addresses the increasingly difficult to meet EMI and EMC certification requirements in today's extremely crowded electromagnetic spectrum. "The growing complexity of electronic devices within both military and commercial products has lead to a significant increase in failure rate of EMC conformance testing. Product design cycle times continue to decrease due to competitive pressure in the market. Product design companies are spending more money on multiple iterations of product EMI compliance testing at EMC test laboratories, and this comes at a significant financial ..."

Many Thanks to Res-Net Microwave for Continuing Support!

Res-Net Microwave componentsRes-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. Please check out Res-Net Microwave's website to see how they can help with your current project ...

Sunday 21

Engineering & Science Crossword Puzzle for April 21

RF Cafe Engineering & Science Crossword Puzzle April 21, 2019Since 2000, I have been creating custom technology-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. A database of thousands of words has been built up over the years and contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc. 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 ...

   
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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 typing up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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