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"Any time the voltage 'over here' is different than the voltage 'over there,' current will flow. " - H. Ward Silver, N0AX

Today in Science History

Tech Industry Headlines

Tech Industry Headlines - RF Cafe- Archive -

• U.S. Ranks 1st in Global 5G Speeds

• Qorvo Launches World's First Dual-Band Wi-Fi 6 FEM

• SIA Pushes for Export Permits for Huawei Sales

North Korea Resumes DRM Broadcasts

Smart TVs, Smart-Home Devices Collecting Sensitive User Data

FCC Seeks to Streamline Its Hearings Process

Semiconducting Material More Affected by Defects Than Thought

Altum RF Announces RF Test Lab in Sydney, Australia

FTC vs. Qualcomm - Support Pours in for Qualcomm

Engineering & Technical Headlines Crossword Puzzle for September 22

Engineering & Technical Headlines Crossword Puzzle September 22, 2019 - RF CafeThis RF Cafe Engineering & Technical Headlines Crossword Puzzle contains at least 10 words from headlines posted on the homepage during the week of September 16 through September 20, 2019 (marked with an asterisk*). These custom-made engineering and science-themed crossword puzzles are done weekly for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. Every word and clue - without exception - in these RF Cafe puzzles has been personally entered into a very large database that encompasses engineering, science, physical, astronomy, mathematics, chemistry, etc. Let me know if you would like a custom crossword puzzle built for your company, school, club, etc. (no charge).

Basic Digital Logic Course - Part 3

Basic Digital Logic Course, December 1974 Popular Electronics - RF CafeHere is the final installment in the "Basic Digital Electronic Course" series that ran in three issues of Popular Electronics magazine. The first two parts laid the groundwork with an introduction to binary, octal, and hexadecimal arithmetic, Boolean logic, AND, OR and NOT gates, and some truth tables. Armed with those fundamentals, the authors now dive into flip-flops, encoders and decoders, debouncing circuits for switch inputs, integrated circuit (IC) types, and interconnect methods to design and build a simple digital computer with a 7-segment LED display. Don't expect too much from the computer since it was only three years earlier, in 1971, that Intel introduced the world's first integrated microprocessor - the 4-bit model 4004 central processing unit (CPU) ...

Notable Quote: Steve Ford, WB8IMY

Steve Ford, WB8IMY, Notable Quote - RF Cafe"It was made clear that I was not to touch this sacred totem, especially the threaded rods..." - Steve Ford, WB8IMY, in an article entitled, "Duplexers & Diplexers," in the October 2019 issue of QST magazine. That statement was made in regard to a cavity-tuned duplexer that was part of a Ham radio repeater installation. Mr. Ford, a monthly columnist, discusses the difference between a duplexer and a diplexer. A pull quote from the piece is, "If you're about to pay less than $100 for the device in question, it is a diplexer. If the price tag has four digits to the left of the decimal, it is a duplexer." Do you agree with that generalization? Unfortunately, the ARRL does not make the magazine articles available to non-subscribers.

PMI's September 2019 Product Announcement

Planar Monolithic Industries (PMI) September 2019 Product Announcement - RF CafePlanar Monolithic Industries (PMI) recently introduced six new products in their extensive line of RF and microwave components. Included are a successive detection log video amplifier (SDLVA) for 0.1 to 2.0 GHz; a 18 GHz, 12-BIT, vector phase shifter; a digital frequency discriminator (DFD) for 20 to 18.0 GHz, a 100 MHz amplified 8-way power divider, a 7-bit programmable attenuator for 1.0 to 18.0 GHz, a 0.1 to 50.0 GHz SP16T absorptive switch, and a Frequency Discriminator for 0.5 to 1.5 GHz. Contact PMI today for more information ...

The Rest of the Story, by Paul Harvey

The Rest of the Story... (a la Paul Harvey) - RF CafeAs a long-time Paul Harvey fan, I used to listen to his radio news broadcasts and especially looked forward to his "The Rest of the Story" pieces. It was a challenge to listen and try to figure out who or what the alluded-to person, place, or thing at the end of the the story would be. In honor of Mr. Harvey, who left this Earth in 2009, the following Smorgasbord about featured celebrity "Sam" is fashioned after his trademarked style. As is often the case with people of accomplishment, this subject's talents extended beyond the skill for which he is most known. An article in the September 2011 Smithsonian magazine inspired the research ...

Piezo-Based Approach Dramatically Shrinks VLF Antennas

Piezo-Based Approach Dramatically Shrinks VLF Antennas - RF Cafe"A research team developed VLF antennas using piezoelectric material and principles, resulting in an antenna that's far smaller than metal antennas, thus overcoming a major impediment to VLF links. While everyone is focused on RF signals in the gigahertz-plus range, it's important to remember that the other end of the electromagnetic spectrum also has its uses. However, signals in very-low-frequency (VLF) RF band present a technical dilemma: On one hand, you can't easily live with them; on the other, you can't live without them for some applications cases. The former assessment is due to their need for extremely large antennas (on the order of kilometers). The latter assessment is a result of their propagation characteristics, including Earth-hugging signals and low atmospheric attenuation, as well as their ability to penetrate seawater ... "

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.

Einstein Expounds on His New Theory - NY Times

Einstein Expounds on His New Theory, 12/3/1919 The New York Times - RF CafeOn the heels of searching for the first mention of Nikola Tesla in U.S. newspapers, I performed a similar search on Albert Einstein, again using editions available in the NewspaperArchive.com database. I was utterly surprised to find it in a 1919 issue of the The New York Times. His theory of Special Relativity was published in 1905 and his theory of General Relativity was published in 1915, so it took The NY Times four years to mention it. There is a reference to Dr. Einstein's' work on relativity in a 1915 edition of The Manitoban*, from Winnipeg, Canada. The New York Times article is an actual interview with Albert Einstein, wherein at one point it is stated that there were perhaps only a dozen people in the world at that time who understood general relativity. Interestingly, Einstein uses the term "difform motion" to describe what we now call "non-uniform motion ..."

Radar "Sidelight"

Radar "Sidelight", December 1955 Popular Electronics - RF CafeWhen I saw this photo of a man holding a fluorescent light bulb in the beam of a radar antenna, it reminded me of how we used to do the same thing on our AN/MPN-14 radar system in the USAF. The unit in the photo is a General Electric's FPS-6 height-finding radar, which operates in the S-band 2,700-2,900 MHz region. The AN/MPN-14 is a mobile ground control approach (GCA) with both an S-band airport surveillance radar (ASR) and an X-band precision approach radar (PAR). Our S-band radar had a 600 kW peak power whereas the FPS-6 put out a couple megawatts, but 600 kW was enough to light the bulb. Of course these days you would never see a company-sponsored photo of a man standing in front of a high power radar antenna with a fluorescent light bulb in his hand ...

Top 20 Countries by Number of Internet Users

Top 20 Countries by Number of Internet Users - RF Cafe Video for EngineersHere is a really interesting animation of the world's top 20 country ranked by the number of Internet users in those countries. It runs (as of this posting date) from 1990 through 2019. I have not verified the numbers used by the Animate Stats producers, but the results do not seem unreasonable. Given the the U.S. Department of Defense's research arm, Defense Advanced Research Projects Agency (DARPA), created the Advanced Research Projects Agency Network (ARPANET) that eventually became the Internet, showing the U.S. as the run-away leader in the beginning is not surprising. Around 1996, things begin to change quickly as Japan advances, but it is in 2000 when the Internet user landscape really becomes dynamic ...

1957 Auto Radios: Chevrolet

1957 Auto Radios: Chevrolet, April 1957 Radio & TV News - RF CafeApologies to Chrysler aficionados for not having similar articles for your classic automobiles, but this article from a 1957 edition of Radio & TV News only covers Chevrolet radios. Maybe someday I will acquire editions with other models. Transistors were fairly recent newcomers on the portable radio scene (on any radio scene for that matter), so you will please excuse the absence of them in most radios of the era. In fact, as evidenced by a companion article in this same edition titled "Delco's All-Transistor Auto Radio," such newfangled devices like transistors were reserved for top-of-the-line models like Cadillac's Eldorado Brougham. A move toward printed circuit boards, rather than the time-honored point-to-point wiring, was well underway, and push-button tuning ...

ConductRF Rugged Replacement VNA Cables

ConductRF Rugged Replacement VNA Coaxial Cables - RF CafePrecision Ruggedized VNA Cables from ConductRF offer RF Engineers great alternatives to costly OEM cables that are now past their best days. We have standards for applications at 18 GHz, 27 GHz, 40 GHz, 50 GHz & 70 GHz. Our torque resistant connector heads and phase stable constructions ensure great performance for many tests to come. ConductRF VNA series provides customers with reliable ruggedized solutions for Lab and Production Vector Network Analyzer testing. With options for 18 GHz, 26.5 GHz, & 40 GHz, these cables offer cost leading alternatives to original OEM VNA cable solutions. VNA Series cables are enhanced with a stainless steel spiral armor ...

Wi-Fi 6 Industry Impact Report

Wi-Fi 6 Industry Impact Report - RF Cafe"To hear technologists describe it, Wi-Fi 6 is about to transform connectivity. The next-generation Wi-Fi connectivity technology - along with the emerging 5G cellular generation - will shake up the way we connect with each other. The ability of Wi-Fi 6, or 802.11ax, to instantly route traffic - even to devices on the far reaches of very crowded networks - will also change the way we interact with our smart devices. It will even rework the way smart devices communicate with each other. But from what we've seen thus far, Wi-Fi 6 is emerging on the scene in much the same manner as previous generations of wireless technology: integrated inside the latest smartphones and laptops. And in new routers and access points that promise faster ..."

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.

The Ray of Mystery - Tesla & Röentgen

The Ray of Mystery - Tesla and Röentgen, 3/15/1986 The Warren Mail - RF CafeOn a whim, I did a search for the earliest appearance of Nikola Tesla's name in U.S. newspapers included in the NewspaperArchive.com database. This story from Mr. George Grantham Bain appeared in multiple newspapers within a few days of this March 5, 1896 edition of The Warren Times in Warren, Pennsylvania, which coincidentally is only a few miles from me here in Erie. The article reports on the role that Tesla's high voltage generators played in the development of x-ray images on fluorescent displays and on film (which Tesla termed "cathode photography"). It mentions how the term "cathode" is relatively new to the general public even though it had been around since 1832 when Michael Faraday introduced it in his work. Wilhelm Röentgen made the world's first x-ray image ...

1957 Auto Radios: Ford

1957 Auto Radios: Ford, July 1957 Radio & TV News - RF Cafe1957 was part of the heyday of the newfound radio-in-your-car craze, and the public was voraciously consuming all the high tech equipment it could afford. Rock and Roll music was on every teenager's mind and many guys for the first time were able to have their own wheels and were outfitting them with sound systems that could blast the latest works of Buddy Holley, Chuck Berry, Elvis Presley, and Fats Domino. Those machines were the first babe magnets used for cruising the strip on Saturday nights. Radio stations were popping up all over the country, enabling cross-country travel with non-stop music, news, and variety show entertainment. Ford and Chevrolet were not going to miss an opportunity, so they delved into the high end mobile radio manufacturing business ...

Thanks to QuinStar Technology for Their Support

QuinStar Technology mm-Wave Products - RF CafeQuinStar Technology designs and manufactures mm-wave products for communication, scientific, and test applications along with providing microelectronic assembly, rapid prototyping, and mass customization. Amplifiers, Oscillators, Switches, Attenuators, Circulators, Isolators, Filters, Waveguide, Antennas, Phase Shifters, Transceivers, Mixers, Detectors. QuinStar specializes in cryogenic amplifiers, circulators, and isolators. Please visit QuinStar today to see how they can help your project.

An Accurate Voltage Divider

An Accurate Voltage Divider, May 1957 Radio & TV News - RF CafeIt took me a couple passes of the explanation to comprehend the advantage of a Thomson-Varley (aka Kelvin-Varley, since Thomson and Lord Kelvin are one and the same person) switchable voltage divider compared to a standard type. At first I thought the author, Edwin Bohr, was implying that the source and load impedances would not have as great of an effect on the accuracy of the divider (and to some extent it is less sensitive), but the main advantage is that the configuration permits simple cascading stages of decade dividers to achieve essentially any degree of resolution. Both a standard series-wired type voltage divider and the Thomson-Varley need ten resistors ...

* Health Fears Prompt Swiss 5G Revolt *

Health Fears Prompt Swiss 5G Revolt - RF CafeRuh-roh. "Switzerland was among the first countries to begin deploying 5G, but health fears over radiation from the antennas that carry the next-generation mobile technology have sparked a nationwide revolt. Demonstrators against the technology are due to fill the streets of Bern later this month, but already a number of cantons have been pressured to put planned constructions of 5G-compatible antennae on ice. The technology has been swept up in the deepening trade war between China and the United States, which has tried to rein in Chinese giant Huawei - the world's leader in superfast 5G equipment - over fears it will allow Beijing to spy on communications from countries that use its products and services ..."

Basic Digital Logic Course - Gates & Circuits

Basic Digital Logic Course, November 1974 Popular Electronics - RF CafeEnglish mathematician George Boole published his "Formal Logic" syllogism system of deductive reasoning in 1847. Fellow countryman Augustus De Morgan followed on Boole's work to develop the basic combinational logic rules the AND gates, OR gates, and NOT (negation) operators. What has become known as Boolean algebra and De Morgan's theorem forms the fundamental foundation of everything related to digital logic. This second in a three-part series from a 1974 issue of Popular Electronics introduces both concepts at a beginner's level. Part 3 will present flip-flops and an overview of how all the parts come together to build a simple computer.

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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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