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"It's amazing the extent to which we know very little." - Wendy Johnson, U. of MN

Today in Science History

Tech Industry Headlines

Tech Industry Headlines - RF Cafe- Archive -

• GSMA Says Some 5G Auctions Artificially Inflating Spectrum Prices

• Supreme Court Rules to Allow Apple Antitrust Suit

WhatsApp Hacked Installed Spyware on People's Phones

Defense Software Budget May Get Streamlined in 2020

• Everything You Need to Know About LoRa and IoT

• Apple to Change Antenna Structure in 2019 iPhones

Amazon Machines Pack Orders, Replace Jobs

• Facebook Co-Founder Say It's Time to Break up the Monopoly

• With New 5G Revenues Come Security Concerns 

For the Record: Technological Revolution

For the Record: Technological Revolution, May 1955 Radio & Television News - RF CafeThe problem of and concern about our country's youngsters seemingly not being overly interested in pursuing technical career paths is a theme often heard in the tech news media and workplaces. As our world grows increasingly automated and everything from light bulbs to telephones and automobiles are so packed with "no user serviceable parts inside," there seems to be little motivation for an otherwise potential budding tinkerer to take stuff apart to discover what makes it work. In the "old days" like, say, 1955, products were much more accessible to kids' curious nature and explains why fostering the next crop of engineers, scientists, and technicians took care of itself. You might think so, but alas, the dilemma evidently persists with each succeeding generation ...

What are the 8 Most Important Oscillator Specs?

What are the 8 Most Important Oscillator Specs? - RF CafeJim Holbrook has a useful guide on the Microwaves &  RF website entitled, "What Are the 8 Most Important Oscillator Specs?" It begins: "What’s the first thing you think of when selecting electronic components? Chances are it’s the processor or something else central to the system. The timing component may be the last thing on your mind, even though the clock provides the heartbeat that all signals in the system depend on. Selecting these essential timing components may appear to be a straightforward process, but one must consider a number of factors that affect system performance. So, what are the most important specifications and considerations? Here's a short rundown of the top oscillator parameters ..."

Quiz on AC Circuit Theory

Quiz on AC Circuit Theory, December 1970 Popular Electronics - RF CafeHere is a fairly simple quiz on AC circuit analysis. If you are not already comfortable with adding series and parallel circuits containing resistors, capacitors, and inductors, you will appreciate the simple formula presented that will keep the sweat level down ;-) . An even simpler form that solves explicitly for the four variables are as follows:
VTotal = √ [(VL - VC)2 + VR2]

VR = √ [(VT)2 - (VL - VC)2]

VL = VC + √ [VT2 - VR2]

VC = VL - √ [VT2 - VR2]

    OK, pick up your pencils... now ...

Altum RF Announces Opening of Eindhoven, Netherlands Office

Altum RF Announces Opening of Eindhoven, Netherlands Office - RF CafeAltum RF, a supplier of high-performance millimeter-wave to digital semiconductor solutions for next generation markets and applications, announces the opening of its Eindhoven, Netherlands office located on the campus of Eindhoven University of Technology. "Opening an office on this university campus gives us the strategic advantages of access to top engineering talent and to leading-edge electrical engineering research and development," stated Greg Baker, Altum RF CEO. "We work closely with electrical engineering research groups and collaborate with other start-ups to develop ground-breaking technology, so this location is ideal for our company. There is also an excellent source of high-tech talent in this region, which is important for our expansion ..."

Changing the Light Bulb on a 1,500' Tower - A Drone's-Eye View

Changing the Light Bulb on a 1,500' Tower - RF CafeBack in 2012, I posted a video of the PBS "Frontline" show (Cell Tower Deaths) that highlighted the dangers cell tower climber technicians face while working for very low wages. Other news stories since then have reported on new regulations from OSHA and other agencies that have helped make the safety issue better, but I haven't seen anything on whether the pay has gotten any better. There are lots of videos and photos online of tower climbers all over the world, but this one showing tower climber Kevin Schmidt making the ascension to the very top of the now inactive KDLT TV analog broadcast antenna near Salem, SD, is unique in that the recording was made from a drone platform. It has more than 12 million views. Capturing this kind of video requires a drone with a wireless live feed so the pilot ...

Hams Help Trace "Mystery" Signal Disrupting Keyless Entry Devices

Hams Help Trace "Mystery" Signal Disrupting Keyless Entry Devices - RF CafeThis is pretty amazing: "A recent article in The New York Times reported that many garage door openers and keyless vehicle entry fobs in an Ohio town near Cleveland mysteriously stopped working. While the article invoked The X-Files and hinted initially that a NASA research center somehow could be involved, the cause was not so much mystifying as arcane. 'Garage door repair people, local ham radio enthusiasts, and other volunteer investigators descended on the neighborhood with various meters,' the May 4 article by Heather Murphy recounted. 'Everyone agreed that something powerful was interfering with the radio frequency that many fobs rely on, but no one could identify the source ..."

Windfreak Technologies: USB-Powered RF Synthesizers, Mixers

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

How the J-K Flip-Flops

How the J-K Flip-Flops, January 1969 Radio-Electronics - RF CafeAn alternate title for this article that appeared in a 1969 issue of Radio-Electronics magazine could have been, "How to Build a J-K Flip-Flop." Author Leonard Geisler takes the reader through a step-by-step assembly of a functional J-K flip-flop using a collection of 1- 2- and 3-input NAND gates. The 1-input NAND, in case you are wondering, is used as an inverter. The piece reads like an in-depth first-semester electrical engineering technician course textbook. In the process of building the J-K, an R-S (reset/set) flip-flop is described. Nowhere does Geisler offer an explanation of from where the "J" and the "K" input labels come. According to electrical engineer Sourav Bhattacharya blog, it was Dr. Eldred Nelson of Hughes Aircraft who first coined the term J-K flip-flop ...

Generating Multiple Phase Coherent Signals – Aligned in Phase and Time

Generating Multiple Phase Coherent Signals - RF CafeTesting multi-antenna systems such as phased array or beamforming antennas requires a test system capable of providing multiple signals with constant phase relationships between them. The coherent test signals must have a specific or definable phase difference (relative phase) and definable amplitude. Some of the challenges for such a test system include compactness, phase control capability and simplicity in handling. In particular, phase stability between the channels is of importance. This Generating Multiple Phase Coherent Signals–Aligned in Phase and Time application note explains how to generate phase coherent signals. It details what to consider and how to configure the test setup ...

Acorns in Microwave Antenna

Acorns in Microwave Antenna - RF Cafe Video for EngineersThis you need to see. The full story behind this video is unknown, but supposedly customers were complaining about poor reception associated with the Bear Creek Road microwave station somewhere in northern California. Upon inspection, the technicians discovered a small hole in the radome. When the cover was pulled away, according to the video somewhere between 35 to 50 gallons of acorns spilled out. You can see the bulge in the radome before emptying. The tech probably thought the water drain hole was clogged and it was full of water. From a National Geographic story: "Walter Koenig, a senior scientist with the Cornell Laboratory of Ornithology, says he's pretty sure the the acorn woodpecker ..."

Glass Semiconductors Developed

Glass Semiconductors Developed, January 1969 Radio-Electronics - RF CafeThe term "ovonic" - a fairly unfamiliar word these days - appeared in the May edition of Radio-Electronics, in an article entitled, "All About Ovonics," just a few months after this news item ran in the January issue (which I posted last month). Ovonics is a portmanteau of "Ovshinsky" (from Stanford R. Ovshinsky, the inventor) and "electronics." Read the "All About Ovonics" article for a deeper dive into the subject. The big deal, which turned out to be not a big enough deal, was the use of amorphous "glassy" compounds as semiconductors rather than the standard crystalline silicon structures. Maybe someday an enterprising genius inventor type will give a rebirth to the concept ...


USAF Test of SHiELD Laser Weapon

Air Force Test of SHiELD Laser Weapon - RF Cafe"The Air Force said it successfully shot missiles out of the sky with a ground-based laser system that it plans to make small enough to fit on its aircraft. The Self-Protect High Energy Laser Demonstrator Advanced Technology Demonstration Program, or SHiELD , conducted the tests on April 23, an Air Force Research Laboratory statement said Friday. 'The successful test is a big step ahead for directed energy systems and protection against adversarial threats,' said Maj. Gen. William Cooley, AFRL commander. 'The ability to shoot down missiles with speed-of-light technology will enable air operation in denied environments.' During the tests at White Sands Missile Range, N.M., the laser system engaged and shot down multiple air-launched missiles in flight. It was not immediately clear whether the laser ..."

San Francisco Circuits: PCB Fabrications & Assembly Service

San Francisco CircuitsSF Circuits' specialty is in the complex, advanced technology of PCB fabrication and assembly, producing high quality multi-layered PCBs from elaborate layouts. With them, you receive unparalleled technical expertise at competitive prices as well as the most progressive solutions available. Their customers request PCB production that is outside the capabilities of normal circuit board providers. Please take a moment to visit San Francisco Circuits today ...

Cunningham on R/C: Edsel Murphy's Law

Cunningham on R/C: Edsel Murphy's Law, March 1972 R/C Modeler - Airplanes and RocketsOne of the monthly columns in R/C Modeler magazine, written by Chuck Cunningham, entitled "Cunningham on R/C," that reported on the current state of radio control, which had only fairly recently evolved into fully solid state, proportional control systems. Anyone involved in electronics is painfully familiar with the weird kinds of issues that crop up in complex circuits that operate in hostile environments. The March 1970 issue contained part of an article authored by D. L. Klipstein, Director of Engineering, Measurement Control Devices, entitled, "Murphy's Law: The Contributions of Edsel Murphy to the Understanding of the Behaviour of Inanimate Objects.*" Only a few of the items were printed in Cunningham's column, but I managed to locate ...

For Safety's Sake

For Safety's Sake, December 1966 QST - RFCafeThis is a story with a lesson learned by the author and thousands of others ever since electric power appliances and tools first became available. Fortunately, his Ham buddy was not permanently harmed, but even today with all the effort put into educating the public, people continue to use ungrounded (2-wire type, or with the ground prong removed) extension cords in conjunction with 3-wire power cords on tools and end up electrocuting themselves (or somebody else). I've told the story before about a friend of mine from high school who shortly after graduation was making a piece of furniture in a garage that had a damp dirt floor, and was electrocuted to death by the metal-framed circular saw that had no ground connected. Nowadays we often have power provided by a GFCI ...

Axiom Test Equipment Blog: Keeping Self-Driving Vehicles on the Road

Axiom Test Equipment Blog: Keeping Self-Driving Vehicles on the Road - RF CafeAxiom Test Equipment, an electronic test equipment rentals and sales company, has published a blog post entitled, "Keeping Self-Driving Vehicles on the Road," which discusses the technical and test requirements for the mm-wave radars and optical wavelength Lidar systems used for precise, fast-acting sensing and processing. Sophisticated test equipment is required for development, all of which Axiom Test Equipment can provide on a sale or lease basis. Self-driving cars, also known as autonomous vehicles, are literally right down the road. These electronically guided vehicles of the future will be built with advanced driver assistance system (ADAS) hardware and software, using several different technologies to detect and track other cars, pedestrians, and objects on the road and steer the vehicle ...

A Real-Life RoboCop Is in Your Future

A Real-Life RoboCop Is in Your Future - RF CafeI assume the "real" RoboCop won't be sporting a hokey helmet and will handle inclement weather interfaces. This concept is actually a good idea based on how dangerous traffic stops have become for police officers. "The new cop robot was created to make police stops and arrests safer for everyone. We have all been stopped by a cop a few times and it is never a pleasant experience. However, according to Reuben Brewer, a Senior Robotics Research Engineer in SRI International's Applied Technologies and Science Department (ATSD), it can even be a downright dangerous one. According to the video's description ...

Slingshot Flying Pig Accelerometer

Slingshot Flying Pig Accelerometer - RF CafeMy daughter, Sally, in addition to owning and operating a very successful horse riding school named Equine Kingdom Riding Academy, has a rather large eBay store she uses as a venue for selling items purchased at the local Goodwill "Bins" store. She often buys vintage toys with electronics features - sometimes working and sometimes not. A properly functioning vintage toy, be it a stuffed animal or a game of some sort, can make a huge difference in the resale price. When that is the case, she sends them home with me to attempt a repair. Many times the problem is corroded contacts from leaky batteries. A dental pick and some isopropyl alcohol usually solves the problem. When that doesn't work, it's time to open 'er up for a deeper look. Over the years I have found problems ranging from dirty activation switches to broken wires ...

Alliance Test Equipment: Used & Refurbished, Purchase & Rental

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

All About Dolby

All About Dolby, June 1971 Radio-Electronics - RF CafeThis photo of Ray Dolby holding one of his prototype noise reduction circuits is probably the most widely published of him and therefore the most iconic of the Dolby noise reduction system. Audiophiles of the era (and today for that matter) immediately recognize the man who took the hisses and pops out of their beloved music. I always like to keep in mind when reading article like this one in a 1971 issue of Radio-Electronics magazine is that when it was originally published, Dolby had not yet become a household word and news of his accomplishment was just getting out. Many articles, books, and research papers have been written on how the Dolby system works. At least five of them from the groundbreaking era have been posted here on RF Cafe, so you can get some insight into the excitement. The technical term "companding" (compressing and expanding) was being seen in print for the first time ...

Microwave Journal Releases Comprehensive Microwave Basics Library

Microwave Journal Releases Comprehensive Microwave Basics Library - RF CafeMicrowave Journal has developed and published an enhanced Microwaves Basics section online. This comprehensive library is based on content from the books "Microwaves and Wireless Simplified," by Thomas S. Laverghetta and "Handbook of RF, Microwave, and Millimeter-Wave Components," by Leonid A. Belov, Sergey M. Smolskiy and Victor N. Kochemasov, both published by Artech House, plus "Mixer Basics Primer: A Tutorial for RF & Microwave Mixers," by Ferenc Marki & Christopher Marki of Marki Microwave. If your work involves microwave or wireless communications technology or you just want to brush up on your technology basics, the Microwave Basics Library provides a good understanding of key concepts ...

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Copyright: 1996 - 2024
    Kirt Blattenberger,

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 Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

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