Homepage Archive - November 2019 (page 3)

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.

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Friday 22

Calculators Get Smaller, Smarter and Cheaper

Calculators Get Smaller, Smarter and Cheaper, December 1974 Popular Mechanics - RF CafeJust as most people no longer wear a wristwatch since their (practically) surgically attached smartphones can provide the time, few people bother with carrying around an electronic calculator. It's' been that way for at least a decade now. When this article entitled "Calculators Get Smaller, Smarter and Cheaper" appeared in a 1974 issue of Popular Mechanics magazine, pocket electronic calculators were still a relatively new phenomenon. Hewlett Packard had introduced their first calculator, the HP−35, just two years earlier. The first American-made pocket calculator, the Bowmar 910B, aka "The Brain," came out in late 1971/early 1972 and sold for about $240. It had only basic math functions and sported a tiny LED display. Prices fell very quickly as many companies were releasing models with more and more features. By the time of this article, calculators with basic functions could be bought for a mere $16.95 ($84.05 in 2019 money ...

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

Sponsor RF Cafe for as Little as $35 per Month - RF CafeRF 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 7,000 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, Facebook, and Twitter. If you need your company news to be seen, RF Cafe is the place to be. Banner advertising begins at $175/month ...

Applications Engineer Wanted by Triad RF Systems

Applications Engineer Wanted by Triad RF Systems - RF CafeTriad RF, located in East Brunswick, NJ, is a leader in the design and manufacture of RF SSPAs and Systems. An Applications Engineer is needed to support our customers and provide them with pre-sales technical support on our products. Tasks include working with customers and recommending suitable products based on their radio link and system requirements. The applications engineer will also work with Sales Administrators and assist them in the preparation of customer quotes. The applications engineer will also work with the test lab in establishing design test standards based on customer requirements. Skills and qualification include: Understanding of basic electronics concepts such as NPN transistors, MOSFETS, TTL logic, supply voltage, current draw, power added efficiency, knowledge of amplifier-related concepts such as gain, power output, power compression, linearity ...

The Resistor Cube Equivalent Resistance Conundrum

The Resistor Cube Equivalent Resistance Conundrum - RF CafeThis is a repeat of something I posted a decade ago, but by now millions more people have entered the electronics realm and might appreciate it. You might, too, if you didn't see it originally. You have probably seen somewhere along the line in your electronics career the resistor cube problem. The 12 edges of the cube each contain a 1 Ω resistor, and the challenge is to calculate what the equivalent resistance is between two opposing corners. It is a daunting problem using straight circuit analysis, since it requires writing and solving multiple mesh equations. There are lots of opportunities for making mistakes. One option if you had the time and facilities would be to build the model in a circuit simulator and let it determine the result. Usually, though, the cube is thrust upon you in a compromising situation, like in a job interview ...

Russian OTH Radar Now Reported to be "Everywhere"

CONTAYNER Over the Horizon Radar - RF Cafe"The latest International Amateur Radio Union Region 1 Monitoring System (IARUMS) newsletter reports the Russian "Contayner" over-the-horizon radar (OTHR) has been active in the 7, 10, 14, and 18 MHz amateur radio allocations (amateur radio is primary on 40, 20, and 17 meters). The OTHR transmissions have been 40 sweeps/second, FM on pulse, and 12 kHz wide. Additionally, IARUMS reports a significant increase in Russian military traffic using F1B, PSK, and orthogonal frequency division multiplex (OFDM) on 40, 30, 20, and 15 meters. IARUMS on November 13 reported an OTHR in northern Iran on 6.078 – 7.022 MHz, AM on pulse, 81 sweeps/second, 44 kHz wide."

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. 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!

Thursday 21

New Silvertone Radio Line, 1941 Sears Catalog

1941 Silvertone Radio Line, 1941 Sears Catalog Kirt's Cogitations #315 - RF CafeThe year was 1941 and the radio industry was going strong worldwide. Sales of receivers was hitting new highs every quarter and service shops had all the work they could handle for repair, upgrades, and installations. The radio broadcast realm was scrambling to build new studios, install transmitters and antennas, hire announcers and managers, and upgrade to keep up with the quickly evolving business. Take a look at these 24 full pages of radio-related products offered by the Sears, Roebuck Company in their Fall and Winter 1941-1942 catalog. It is typical of most radio manufacturers' catalogs of the era. For the last decade engineers had been working overtime to satisfy consumer demand for fancier cabinet designs with fancier features. So strong was public demand that people put their highest priority on acquiring the latest models (not unlike the smartphone craze of today). Then, ...

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

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 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 ...

RCA Victor Model C9-4, 3-Band Super Radio Service Data Sheet

RCA Victor Model C9-4 9-Tube 3-Band Super Radio Service Data Sheet, January 1936 Radio-Craft - RF CafeThe RCA Victor Model C9-4 is a 9-tube, 3-band superheterodyne console model radio made in the mid 1930s. A Radio Service Data Sheet for it appeared in the January 1936 issue of Radio-Craft magazine. The image of the radio was found on the RadioMuseum.org website. FM broadcasting was not in common use yet, so only AM bands and some shortwave bands were available. In fact, 1936 was the year that frequency modulation (FM) inventor Edwin H. Armstrong first demonstrated his newfangled concept that largely solved the electrical static noise problem cause by lightning, motor brushes, arcing overhead power lines ...

UK-Developed Magnet-Free Electric Motor

UK-Developed Magnet-Free Electric Motor - RF CafeThis High Density Switched Reluctance Motor (HDSRM) designed by Newcastle University's Advanced Electric Machines (AEM) could be a serious game changer to the electric vehicle industry if it proves viable. The 6-phase motor does not use permanent magnets or copper conductors, and claims to be competitive in performance with the current crop of motors that need rare earth magnets and copper wire. That represents major advantages in lower cost and independence from rare earth magnets, which now come primarily from China. Be sure to watch the video. Jolly good show, chaps!

ThinkRF Releases New Version of PyRF Development Framework

ThinkRF Releases New Version of PyRF Development Framework - RF CafeThinkRF Corporation, the leader in software-defined spectrum analysis, today announced the release of the PyRF3 Development Framework with support for version 3.0 of the Python Language Application Programming Interface (API). This latest API enables command, control and data acquisition using ThinkRF Real-Time Spectrum Analyzer platforms, including the ThinkRF R55x0 and R57x0 analyzers. The updated version ensures RF application developers can leverage the PyRF Development Framework to build custom solutions, integrate new capabilities, and develop or extend products quickly and easily. PyRF is a freely available, comprehensive development environment for wireless signal analysis, built on the Python Programming Language ...

Res-Net Microwave: Precision RF & Microwave Components

Res-Net Microwave Components - RF CafeRes-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 20

Receiving U.S. Satellite Signals

Receiving U.S. Satellite Signals, March 1958 Radio News - RF CafeIn 1958, most people were not accustomed to seeing the now-familiar maps plotting the sinusoidal courses of satellites across the face of the earth. It had only been in October of the previous year that any object other than the moon was in orbit around our home planet - that was U.S.S.R.'s Sputnik. Just as people of all ages and all backgrounds enthusiastically joined in the newfangled phenomenon of aeroplanes after the Wright Brothers flew their fragile craft at Kitty Hawk, electronics communications and scientists worldwide hopped aboard the satellite train (so to speak). This article from a 1958 issue of Radio & TV News magazine provided insight into the construction and flight characteristics of early U.S. satellites, and offered advice on how to participate in the ongoing International Geophysical Year (IGY) research effort by tuning in and reporting your signal reception characteristics. Activity was not just the domain of operators with sophisticated equipment ...

Is 5G Safe for Humans? No One Knows.

Anatech Electronics November 2019 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his November newsletter that features his short op−ed entitled "Is 5G Safe for Humans? No One Knows." The controversy over whether or not RF radiation from wireless devices - cellphones, notebook computers, tablets, smart meters, et al, is harmful to human body cells has been with us since the early 1990s, when the Wireless Revolution began. Industry standards groups have defined Specific Absorption Rate (SAR) levels for exposure that model human anatomy and cell structure in order to scientifically assess the effects of RF radiation. As with studies done with other controversial topics like tobacco and pharmaceuticals, the "truth" is as much subjective as it is objective, and the two side of the argument will never agree ...

Energy Conversion Quiz

Energy Conversion Quiz - RF CafeThis quiz from Popular Electronics magazine challenges (not too much, though) your knowledge of energy conversion in common devices. A few of them might be unfamiliar to people born after about 1990, but even so, you've probably seem them all at some point, especially if you are a regular RF Cafe visitor (meaning you're probably smart). It won't be giving anything away by telling you that item B is a heater that screws into a light bulb socket, and item F is a phonograph stylus Robert P. Balin constructed many quizzes of this kind in the 1960s and 70s. A complete list of all the Popular Electronics Quizzes is lower on this page ...

Turn on the Temperature with Thermal Test Systems

Axiom Test Equipment Blog: Turn on the Temperature with Thermal Test Systems - RF CafeAxiom Test Equipment, an electronic test equipment rentals and sales company headquartered in San Diego, has published a blog post entitled "Turn on the Temperature with Thermal Test Systems," explaining the need to properly evaluate product function across the full range of expected ambient temperature conditions. Doing so helps guarantee favorable customer experiences and online ratings, as well as reduces costs of warranty service. It begins: "Electronic device performance is sensitive to temperature, with most electronic devices and components specified according to operating and storage temperature ranges. Those ranges differ according to the type of component and application, with electronic products for industrial and military applications usually ..."

FAQs About Bus Bar EMI Filters

FAQs About Busbar EMI Filters - RF Cafe"Electromagnetic interference (EMI) can plague bus bars just like it does with cables. Here are the answers to some common questions. Do bus bars need EMI filters? Yes, they do. Just because they're large imposing structures, they can cause interference in other systems if you don't measure the EMI and take steps to get it under legal limits. In some cases, you might want to reduce EMI even further than the legal requirement to make a quiet electrical environment for your sensors or control system. EMI noise is created by any fast-changing currents, often represented by the calculus term di/dt, that is, the change of current over time. Fast-changing currents have high di/dt. If those currents ..."

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 19

Appliquéd Radio Circuits

Appliquéd Radio Circuits, May 1948 Radio-Craft - RF CafeProving once again what a visionary Hugo Gernsback was regarding science and engineering, he published in his Radio-Craft magazine this prognostication for the eventual supplanting of point-to-point wiring with printed circuit boards. Admittedly, by 1948 the electronics industry had begun to outgrow hand-wired chassis assemblies with a rats nest of wires, components, and terminal strips. It was in dire need of a new paradigm that reduced labor costs and reduced the opportunity for wiring errors. Less than a year earlier (December 1947) the trio of engineers at Bell Labs announced their transistor invention, so Mr. Gernsback knew the world was about to change significantly. Bulky transformers, vacuum tubes, and high voltage circuits would soon be relegated - at least in the consumer product realm - to the newfangled television products, so miniaturization would follow quickly. Even the smaller fingers of women on the assembly lines ...

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

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 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 ...

Skyworks Intros High-Efficiency PA for Infrastructure and Small Cell Applications

Skyworks Intros High-Efficiency Power Amplifier for Infrastructure and Small Cell Applications - RF CafeSkyworks is pleased introduce the SKY66318-11, a new addition to our family of high-efficiency power amplifiers (PA) that are designed for the stringent requirements of enterprise small cell applications. The PA offers wide instantaneous bandwidth (100 MHz) and is fully input/output matched with high gain and efficiency. On-chip active biasing circuitry is also integrated to compensate for PA performance over temperature, voltage, and process variations. The device comes in a compact 5 x 5 mm package, operates from a single 5 V power supply, and is ideal for 4G LTE and 5G NR systems from 3300 to 3600 MHz. The SKY66318-11 is also part of major transceiver reference designs ...

Hobnobbing with Harbaugh

Hobnobbing with Harbaugh, July 1970 Popular Electronics - RF CafeHere is a little electronics hobbyist humor in the form of a comic series titled "Hobnobbing with Harbaugh," compliments of Popular Electronics artist Dave Harbaugh. Citizens Band radio and dirty hippies were the topic of the day in the 1970s, so that's what you see in a couple of these comics. I got my first 23-channel CB radio (FCC mandated 40 channels in 1977) in 1976 and installed it in my 1969 Camaro SS hot rod. It required a Class D radio operator license at the time, but shortly thereafter no license was needed. The "Inventions Wanted" comic is my favorite, followed by "Mayday... Mayday!" You don't need to be an amateur radio operator to appreciate these comic strips ...

Armoring Satellites to Survive and Operate Through Attack

Armoring Satellites to Survive and Operate Through Attack - RF Cafe"Satellites do a lot of things - they help people navigate from one place to another, they deliver television programming, they search for new stars and exo-planets and they enable the U.S. nuclear deterrence strategy. But until recently, one thing they haven't done - or needed to do - is defend themselves. That may soon change. Researchers at Sandia National Laboratories launched a seven-year mission campaign this month to develop the science, technology and architecture needed for autonomous satellite protection systems. The campaign, called STARCS (Science and Technology Advancing Resilience for Contested Space), will fund dozens of Laboratory Directed Research and Development projects that focus on three critical areas ..."

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 18

Basic Electronic Counting

Basic Electronic Counting, March 1958 Radio News - RF CafeForgive me if I sound like a broken record (a scratched record, actually), but when selecting articles for posting here on RF Cafe, I like to include ones that are directed toward newcomers to the field of electronics as well as for seasoned veterans. This piece from a 1958 issue of Radio & TV News magazine entitled "Basic Electronic Counting," is a prime example in that it introduces the concept of binary numbers. We've all been there at some point in our careers. A big difference between now and when this article appeared is that in 1958, almost nobody was familiar to binary numbers, and fuggetabout [sic] octal and hexadecimal. Only those relatively few people designing and working with multimillion dollar, vacuum tube-based digital computers installed in universities, megacorporations, and government research facilities ...

Cubesat Developers Workshop

Cubesat Developers Workshop - RF Cafe"The 2020 Cubesat Developers Workshop will be held May 4 - 6 at the Cal Poly Performing Arts Center in San Luis Obispo, California. The planning team has announced a call for abstracts. All abstract and poster applications should be submitted using the online submission form on the conference website by Friday, January 10, 2020."

Exodus Advanced Communications Intros 700-6000 MHz, 100 W SSPA

Exodus Advanced Communications Intros 700-6000 MHz, 100 W SSPA - RF CafeExodus Advanced Communications' model AMP2070C power amplifier designed for broadband EMI/RFI, lab, communications and EW applications. Class A/AB linear design for all modulations and industry standards. Covers 700 MHz - 6.0 GHz, produces 100 W minimum, 50 W P1dB, 50 dB gain. Excellent gain flatness, optional monitoring parameters for forward / reflected power, voltage, current and temperature sensing for superb reliability and ruggedness. Suitable for CW, pulse and all single channel modulation standards Built-in protection circuits ...

RCA Victor Model 102 Receiver Radio Service Data Sheet

RCA Victor Model 102 4-Tube A.C.-D.C. T.R.F. Receiver Radio Service Data Sheet, January 1935 Radio-Craft - RF CafeRadio Service Data Sheets were published by various electronics trade magazines back in the early to middle decades of the last century. SAMS Photofact document sets were published on just about every appliance made, and those had much more detail than these briefs. However, for the low-budget repair shop or the do-it-yourselfer, the Radio Service Data Sheets were a godsend. I have been scanning, cleaning up, and posting all the ones I find in my vintage electronics magazine collection. See a complete list at the bottom. Many fine examples of restored vintage radios can be found on the Internet. A restored example of the RCA Victor Model 102 s appears on the RadioMuseum.com website ...

Transistors and Electronic Devices from Thread

Transistors and Electronic Devices from Thread - RF Cafe"Circuits made from thread are combined with thread-based sensors to create flexible devices. A transistor has been made from linen thread, enabling the creation of electronic devices made entirely of thin threads that could be woven into fabric, worn on the skin, or implanted surgically for diagnostic monitoring. The flexible electronic devices could enable a range of applications that conform to different shapes and allow free movement without compromising function. The thread-based transistors (TBTs) can be made into all-thread-based logic circuits and integrated circuits. The circuits replace the last remaining rigid component of many current flexible devices and when combined with thread-based sensors, enable the creation of completely flexible ..."

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks.

Copper Mountain Technologies: Vector Network Analyzers

Copper Mountain TechnologiesCopper Mountain Technologies develops innovative and robust RF test and measurement solutions for engineers all over the world. Copper Mountain's extensive line of unique form factor Vector Network Analyzers include an RF measurement module and a software application which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware via USB interface. The result is a lower cost, faster, more effective test process that fits into the modern workspace in lab, production, field and secure testing environments.

Sunday 17

Engineering & Science Crossword Puzzle for November 17

Engineering & Science Crossword Puzzle November 17, 2019 - RF Cafe For two decades, I have been creating custom engineering- and science-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. This November 17, 2019, puzzle uses a database of thousands of words which I have 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 ...