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Click here to read about RF CafeView the YouTube RF Cafe Intro VideoKirt Blattenberger ... single-handedly redefining what an engineering website should be.

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(Seize the Day!)

5th MOB:
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My daughter Sally's horse riding website

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- Welcome to the RF Cafe Website -
"Successful technology is invisible. It gets out of the way and lets us live our lives." - Amber Case of Geoloqi

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Newest Posts on RF Cafe Forums

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RF Cafe Visitor & Page View Count Climbing - Thanks !

Visitor & Page View Count Climbing - RF CafeThanks to everyone for the explosive growth of RF Cafe's visitor and page view number in the last year! In 2015 the number of website Visits has grown by about 10%, while the number of Page Views has grown about 300%. That means visitors like you are now spending more time looking at multiple pages once you arrive here. RF Cafe has more than 10,000 unique pages covering a wide variety of engineering and science topics, most of which can be useful to all levels of hobbyists, technicians, students, engineers, managers, and even people with a casual interest in science. I always welcome your comments, suggestions, and contributions. The RF Cafe Forum is available if you prefer that venue for participation (registration not required).

What to Expect When You're an Expert

What to Expect When You're an Expert (IMS ExpertServices) - RF Cafe"You may be the expert in your field, but if you fail to understand how the rules on admissibility of expert testimony may affect your opinions and testimony, you jeopardize your role as an expert. If the court excludes your testimony, all your hard work is for naught and you lose your opportunity to be the expert in front of the jury." IMS ExpertServices is now offering a new whitepaper, What to Expect When You're an Expert. It is the first in a series of whitepapers and presents strategies on how to conduct your expert witness business with an eye toward the rules on admissibility of expert testimony throughout the litigation process. The information ...

Men Who Have Made Radio
E. F. W. Alexanderson

Men Who Have Made Radio - E. F. W. Alexanderson, September 1930 Radio-Craft - RF CafeThe name Ernst Frederick Werner Alexanderson (1878-1975) might not seem overly familiar to you, but he is credited with designing the first high frequency alternator for transmitting longwave audio modulation over long distances. His device preceded the spark and arc type transmitters that infamously spewed harmonics and noise all over the spectrum and were therefore a great nuisance when broadcast at high power levels. It was a relatively (for the time) narrowband scheme that permitted more stations to be co-located in a given service area. He went on the develop one of the first successful television projectors as well. Read a short biography on Mr. Alexanderson in the "Men Who ...

Six-Inch Radio Waves

Six-Inch Radio Waves, January 1930 Radio-Craft - RF Cafe2.1 GHz (5.6-inch, or 14 cm wavelength) radio waves were an almost totally unexplored realm in 1930, with it and higher frequencies being the domain of theoretical research laboratories. Signals generators capable of producing much more than a few hundred megahertz were rare even in commercial applications. As reported here, centimeter-length electromagnetic waves were "according to the theories of Barkhausen and Kurz, [the] result of purely electronic vibrations, whose frequency was determined only by the operative data of the tube and was not dependent on any internal or external oscillation circuit." A half-wave receiving antenna picked up the transmitted signal with a simple diode detector to enable, after ...

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Ultra High Definition TV to Exceed
330M Units by 2019

Ultra High Definition TV Sets to Exceed 330M Units by 2019 - RF Cafe"TV manufacturers could have a very good holiday season, and the good times likely will continue through 2019. Sales of 4K or Ultra High Definition (UHD) TV sets will exceed 330M units by the end of 2019... However, while the price of those sets has fallen sharply and likely will continue to fall, a report released this month by the Natural Resources Defense Council contended that new UHD models use on average 30% more energy than their HD predecessors." AGW warriors  would be committing sacrilege by owning one of these ...

ARDX V1.3 Arduino Experimentation Kit

ARDX V1.3 Arduino Experimentation Kit - RF CafeCyber Monday is just four days away, so why not use it as an excuse to buy yourself or significant other (wife, husband, teenager, college student) an introductory kit of components to join in on the Arduino craze? Per the sales pitch: "13 circuits to explore microcontroller basics. Covering LEDs, transistors, motors, integrated circuits, pushbuttons, variable resistors, photo resistors, temperature sensors & relays. Comes with an Arduino Uno (the latest Arduino) prototyping bundle to make constructing your circuits and future projects easy. Printed copy of the Arduino Experimenter's Guide."

Notable Quote: Lawrence Krauss

"What Einstein Got Wrong" September 2015 Sciam - RF Cafe"For most of us, the times when we go astray are happily forgettable. In Einstein's case, even the mistakes are noteworthy." - Lawrence M. Krauss, in What Einstein Got Wrong, appearing in the September 2015 issue of Scientific American.

RF Application Engineer Needed by e2v

RF Application Engineer Needed by e2v - RF Cafee2v is looking for an RF Applications Engineer that will support high performance RF IC products and Broad Band Data Converters. This position will provide application support for RF switches, mixers, PLLs, DSA, and prescalers in challenging environments for defense an space systems. High speed data converters with industry leading performance will also be a key focus. The position will also require the candidate to take the lead role in assessing and understanding Aerospace and Defense Electronics customers' system requirements and provide guidance to the R&D teams to develop successful semiconductor products. This position provides a unique opportunity to support current and new cutting edge technology that supports some of our nation's fundamental defense programs ...

The "Neon" Interference Problem

The "Neon" Interference Problem, October 1935, Radio-Craft - RF CafeBefore there was radio, it really didn't matter much how much electromagnetic energy at any frequency was spewed into the air and into electric wires as long as the amplitude was not great enough to physically damage affected equipment. There was no need for an FCC or unintentional radiation limit regulations. It was not long after radio came along that the presence of electromagnetic interference (EMI) made itself painfully obvious due to its presence on audio as static. Motor brush arcing, electrical atmospheric phenomena (lightning, meteors), switching on and off of circuits, intermittent connections, nearby radio spurious emissions, high voltage transformers, and in this case, neon lighting were among ...

Please Welcome Alliance Test
Equipment as My Newest Supporter!

Alliance Test EquipmentAlliance Test Equipment, located in Webster, Massachusetts, is a leading source of quality used/reconditioned test & measurement equipment. Please Welcome Alliance Test Equipment as My Newest Supporter!- RF CafeAlliance Test sells used & refurbished test equipment, offering short-and long-term rentals. They also purchase your excess test equipment in large or small lots, and do repair, maintenance and calibration. Alliance Test offers products from many manufacturers available at prices discounted up to 80% off manufacturer list price.

Engineering & Science Crossword
Puzzle for November 22, 2015

Engineering & Science Crossword Puzzle for November 22, 2015 - RF CafeFor the sake of avid cruciverbalists amongst us, each week I create a new crossword puzzle that has a theme related to engineering, mathematics, chemistry, physics, and other technical words. You will never be asked the name of a movie star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). Enjoy!

Simple Radio Mathematics
for the Service Man

Simple Radio Mathematics for the Service Man, September 1930 Radio-Craft - RF CafeIncluded in this first of a series of the 'Simple Mathematics for the Serviceman' series that ran in Radio-Craft is another 'cheat sheet' full of oft-used formulas. It begins with basic Ohm's law, resistance, inductance, and capacitance, then builds from there. What was valid in 1930 is still valid in 2015. See October 1930 for the next installment that includes yet another handy-dandy cheat sheet of formulas ...

Visions of 1946

Visions of 1946, December 1936, Radio-Craft - RF CafeDecember is traditionally the issue for magazines to sum up accomplishments of the ending year and make predictions for the next year. Radio-Craft was no exception, but in 1936 they went ten steps farther and prognosticated a decade into the future - all the way to 1946! It is actually a tongue-in-cheek reprint from Pathe News magazine. However, note the drawing of 'professor teaches 2 million pupils,' where he is instructing via television and the railroad company boss checking in on the conductors en route via wireless teleconferencing. It might have seemed like a pipe dream in 1936, but now it is commonplace. Not only do we now have live classroom broadcasts, but millions of YouTube videos of instruction for performing ...

Electrons Always Find a Quantum Way

Electrons Always Find a Quantum Way - RF CafeScientists from the University of Basel in Switzerland have demonstrated for the first time how electrons are transported from a superconductor through a quantum dot into a metal with normal conductivity. This transport process through a quantum dot had already been calculated theoretically in the nineties, but scientists at the University of Basel have now succeeded in proving the theory with measurements. Transport properties such as electrical conductivity play ...

2016 Obamacare Cost for RF Cafe

2016 Obamacare Cost for RF Cafe - RF CafeIt looks like again in 2016 Melanie and I will be without health insurance because of the prohibitive cost of the misnamed Affordable Care Act (aka Obamacare). Not only will we have no insurance, but we will be taxed at a rate of 2.5% of our Modified Adjusted Gross Income (MAGI*) for opting out. Our expected MAGI of about $60,000 amounts to $1,500 being added to our standard income tax - which already includes paying the full amount of the Social Security tax**. What follows is a brief synopsis of our decision-making rationale. Bear in mind while reading that tens of thousands of Americans are making similar decisions nowadays. Prior to 2014, we had ...

Nuvitron's Vintage Nixie Clock

Nuvitron's Vintage Nixie Clock - RF CafeJust in time for holidays for the Nixie tube aficionado who appreciates a fine wooden chassis and 'authentic' vintage, heretofore unused Nixies is Nuvitron's Vintage Nixie Clock (clever name). Says them, "With brand new, unused Nixie tubes that were rescued from exile in long abandoned basements in Eastern Europe, the vintage Nixie tube clock imparts a warm glow from within its beautiful, handmade, Art Deco enclosure. Each clock casing takes over 30 hours to create and a lifetime to admire. Make yourself appear cooler than you actually are with this super cool Nixie tube clock." Now, if anyone is still trying to figure out what to get me for Christmas ... (hat tip to Electronics Weekly, where I learned of it)

Pasternack Waveguide Mixers Operate
for Ka, Q, U, V, E & W Bands

Pasternack Waveguide Frequency Mixers Operate Across Full Ka, Q, U, V, E & W Millimeter Wave Bands - RF CafePasternack, a leading provider of RF, microwave and millimeter wave products, adds new millimeter wave (mm-wave) waveguide frequency mixers available in six down-conversion and six up-conversion models that cover full Ka, Q, U, V, E, and W bands. Designs utilize high performance GaAs Schottky Barrier Beam Lead Diodes in balanced configurations that require a +13 dBm LO drive and display low levels of conversion loss ...