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Today in Science History

Can We Ever Go to the Stars?

Dr. Wernher von Braun Lays the Cards on the Table (AI generated image): Can We Ever Go to the Stars?, July 1963 Popular Science - RF CafeWhen I read this account of relativistic space travel by Dr. Wernher von Braun in a 1963 issue of Popular Science magazine, I was a bit dubious about numbers he presented because they seemed to me to assume a fixed value of relativistic speed during the entire round trip. It is an example of the Twin Paradox. Time dilation, as predicted by Einstein's theory of Special Relativity, is barely noticeable at 10% the speed of light (0.1c), and is not really significantly noticeable until around 30% the speed of light (0.3c), so I suspected that maybe he had simplified the answer. His space ship example reached that speed at 3½ months with a steady 1 G acceleration rate. Not wanting to go to the effort of figuring it out for myself, I asked ChatGPT 4.0 to assess the article and render an opinion...

Semiconductor Trends for 2025

Semiconductor Trends for 2025 - RF CafeHere are eight predictions for the semiconductor industry in 2025, per the IDC (International Data Corporation). "1: Memory is expected to grow by more than 24%, mainly driven by the increasing penetration of high-end products such as HBM3 and HBM3e with HBM4 expected to be introduced in H2. Non-memory is expected to grow 13%, driven by demand for advanced node ICs for AI servers, high-end mobile phone ICs, and WiFi7. 2: Asia-Pacific IC design market will grow 15% as inventory levels stabilize, personal devices demand picks up, and AI computing extends to a wide range of applications. 3: Under the traditional Foundry 1.0 definition..."

xTelevision in Space

Television in Space, August 1965 Electronics World - RF CafeA mere five years elapsed from the time Echo, a gas-filled metallized plastic sphere that passively reflected radio signals back to Earth, was launched and the time that 35 television cameras had been launched into space. The Space Race was at a fever pitch. Although the Ruskies beat us in being the first to launch both an active satellite (Sputnik) and a man (Yuri Gagarin) into space, America's deep pool of intellectual resources, consisting of both native scientists and many of the world's top scientists who chose to flourish in freedom here rather than oppression behind the Iron Curtain, fostered the advantage that in short order established the United States as the leading super power both in space and on terra firma. TIROS satellites began providing real-time visual data on the Earth's weather in 1960. Not only were cameras transmitting images of the Earth...

The Christmas Equation

The Christmas Equation - RF CafeAn RF Cafe visitor sent this equation to me a few years ago. It can be found all over the Internet (including here), but I cannot determine a definite origin. Mathematicians claim that math can explain everything in the universe, which is not quite true. It can't for example, explain why my next-door neighbor is a junk hoarder. This Christmas equation does not appear to begin with a particular application; it looks like something from a set of textbook end-of-chapter problems. Even if you don't celebrate Christmas, it provides a secondary benefit by demonstrating rules for the manipulation of logarithms and exponents along with basic algebraic rearrangements of terms...

A Christmastide Muddle

A Christmastide Muddle, January 1930 Radio-Craft - RF CafeMerriam-Webster defines Christmastide as "the festival season from Christmas Eve till after New Year's Day or especially in England till Epiphany." In 1930 when this article appeared in Radio-Craft magazine, most likely everyone knew what Christmastide was, but not so much today. While reading and scanning vintage magazine articles throughout the year, I set aside ones specific to holidays like Christmas, Thanksgiving, Halloween, etc., and post them during their respective seasons. This story is about the trouble caused by a well-meaning but unqualified family member attempting to fix a radio that wasn't broken by gifting dear old Dad a Balkite trickle charger (radiomuseum.org has one) for his battery-powered radio set. It also mentions using a potato to test the DC polarity of a power supply or battery...

Flying Saucers - Myth or Fact?

Flying Saucers - Myth or Fact?, November 1964 Radio-Electronics - RF CafeHere is a very timely article entitled, "Flying Saucers - Myth or Fact?," which appeared in a 1964 issue of Radio-Electronics magazine. The recent rash of unidentified flying objects over parts of New Jersey, Wright-Patterson AFB, and a few other key locations has resurrected an interest in whether "UFOs" exist. Despite hundreds of reports of what appear to be large drones, the government insists they are not U.S. or foreign military equipment. They specifically do not deny that they belong to some U.S. government agency - like Homeland Security, FBI, CIA, etc. Conjecture that they are "nuke-sniffing" drones searching for missing fissionable material. Regarding UFO video recordings, have you noticed how with all the high tech cameras out there that there has never been a clear, up-close picture of one? Those glimmering "orbs" in videos is clearly the planet Venus in the evening sky right now...

Engineering Salary & Career Survey 2024

Engineering Salary & Career Survey 2024 - RF CafeSalaries trend up for electrical and electronics engineers in 2024 per this Electronic Design magazine survey -- mine has been going down for years :{ "In a tight labor market, skilled engineers continue to have leverage when negotiating salaries and pushing for bonuses and other perks. In 2024, the median income of electronics engineers and other tech professionals who responded to the survey is in the range of $125,000 to $149,999. The survey revealed that slightly more than 20% of engineers expect to earn between $150,000 and $199,999, excluding bonuses, overtime pay, and other earnings over and above their base salary...

Yagi–Uda Antenna

Yagi–Uda Antenna - RF CafeThe Yagi–Uda antenna,, often referred to simply as the Yagi antenna, was developed in the late 1920s by Japanese engineers Hidetsugu Yagi and Shintaro Uda at Tohoku University in Sendai, Japan. The primary motivation for their work was to design a highly directional antenna capable of efficiently transmitting and receiving radio waves over specific frequencies. This need arose as radio communications technology was rapidly advancing, with an emphasis on improving signal strength and selectivity for applications in research and burgeoning communication systems. Mssrs. Yagi and Uda sought to enhance the performance of basic dipole antennas by creating an array that exhibited improved directivity and gain. ..

Electronic Crossword

Electronic Crossword, July 1961 Electronics World - RF CafeMargaret LeFevre created a handful electronics-themed crossword puzzles for the July 1961 issue of Electronics World magazine. Crosswords have been around for at least two centuries and come in many formats from having both x- and y-axis symmetry to symmetry about only one axis or even no symmetry at all. They can be square, rectangular, or have special shapes. This particular one has partial symmetry about the y-axis. Note that it is composed of two isolated regions with no open path between the regions. If you enjoy working crossword puzzles, there are plenty more which I have posted from electronics magazines, plus I have...

Engineering & Tech Headlines <Archives>

• Kids Can Talk to Santa via Ham Radio

Cellphone Radiation Linked to Brain Cancer

• EU Gives €127M Funding Boost to 6G Research

• Q3 Foundry Revenues up 27% Y-o-Y

TSMC Panics When Identified Huawei Chip Maker

Electronic Failures in Space

Electronic Failures in Space, April 1964 Radio-Electronics - RF CafeBy the time editor Hugo Gernsback wrote his "Electronic Failures in Space" article for the April 1964 issue of Radio-Electronics magazine, half a decade had passed since the official end of the International Geophysical Year (which was actually 18 months long). Much new knowledge had been gained and theories confirmed regarding the environment electronics would be exposed to not just while above the atmosphere, but also while passing through it. Oh, and the extreme vibration and acceleration during the launch and boost phases to get into space were no piece of cake to accommodate, either. Fortunately, a lot of immensely smart and dedicated people worked out the bugs one by one, and we have arrived at a vastly advanced...

MESFETs on Single Crystal Aluminum Nitride

MESFETs on Single Crystal Aluminum Nitride - RF Cafe"Arizona State University (ASU) in the USA reports on high-voltage aluminum nitride (AlN) metal–semiconductor field-effect transistors (MESFETs) on single-crystal AlN substrates. The researchers claim their work as the first report of 'AlN transistors via homoepitaxial growth on native substrates.' The team comments: 'The devices showed good saturation and pinch-off behavior with high maximum Ids, gm and on/off ratio compared with AlN-on-sapphire devices without complicated contact layers.' AlN has the highest breakdown electric field, 12MV/cm..."

Semiconductor Boules

Semiconductor Boules - RF CafeThe history of growing semiconductor boules is a cornerstone of modern electronics, marking advancements in material science and technology that have propelled numerous industries. Boule growth processes have their roots in the early 20th century, when researchers first sought to create pure semiconductor materials for experimental purposes. Initially, materials such as germanium (Ge) and silicon (Si) were used, with silicon ultimately becoming the most prevalent due to its superior properties and availability. Germanium was the first material used extensively in semiconductor applications, as its electronic properties made it suitable for early transistor designs. The Czochralski process, developed in 1916, was adapted for germanium and later silicon. This method, involving the slow pulling of a seed crystal from molten material, remains fundamental to boule growth today. Silicon's dominance...

Side-Looking Radar Imagery

Side-Looking Radar Imagery, August 1965 Electronics World - RF CafeSide-looking airborne radar (SLAR) started out using a narrow beam formed by reflectors, like traditional radars, as opposed to the synthetic aperture type most often used today. Both types of side-looking radars rely primarily on the physical movement of the airborne platform for effective azimuthal scanning rather than steering the beam either mechanically or electronically. This 1965 Electronics World magazine article represents early versions which used "real aperture" antennas. Modern computer-controlled synthetic aperture radar beams can be segmented and directed off-axis for detected...

How to Build a Crossover Network

How to Build a Crossover Network, March 1968 Radio-Electronics - RF CafeDid I ever bore you with my experience building a crossover network for a set of medium power speakers (about 100 watts each) when in the USAF? Too bad I didn't have this "How to Build a Crossover Network" article from a 1968 issue of Radio-Electronics magazine handy. I'll spare you the details, but the era was 1979, and I was in tech school at Keesler AFB studying to be an Air Traffic Control Radar Repairman. Being amped up (pun intended) with electronics theory with both semiconductor and vacuum tube circuits, I was looking to cobble together a nice amplifier and a set of speakers. Back in the day, it was possible to buy the components...

Immersion Silver Surface Finish

San Francisco Circuits: Immersion Silver Surface Finish - RF CafeSan Francisco Circuits, a premier provider of leading edge technology printed circuit boards, has published a new article on the Immersion Silver Surface Finish process, also known as immersion Ag. It is an RoHS compliant (lead-free) PCB surface finish offering exceptional flatness and cost efficiency. This surface finish is particularly well-suited for fine-pitch components and can replace Immersion Gold over Electroless Nickel (ENIG) in many applications. Unlike ENIG, Immersion Silver applies directly to copper without requiring a diffusion barrier. It's an excellent choice for applications that must avoid magnetic...

Electronics-Themed Comics

Electronics-Themed Comics, July 1961 Electronics World - RF CafeHere are a couple high tech comics for your enjoyment from the pages of the July 1961 edition of Electronics World magazine. I'm guessing the joke in the page 72 comic is that unknown parts were/are generically referred to as "Brand X," so hopefully that would bring in customers who couldn't identify components (which the repairman probably could). The page 94 comic is yet another play on the huge popularity of home hi-fidelity (hi-fi) sound systems of the day. Amplifiers still used vacuum tubes so building speaker driver circuits that could handle hundreds of watts was easy to do. Finding speakers to handle that power (and getting neighbors to tolerate...

"Merry Christmas and Happy New Year" Around the World

How to Say, "Merry Christmas and Happy New Year," Around the World: Kirt's Cogitations™ #367 - RF CafeIn case you are wondering, here is how you would write "Merry Christmas and Happy New Year" in the world's most prominent languages. While not everyone celebrates the birth of Jesus, most recognize the holiday spirit during what we call the Christmas Season. This image includes the same hopeful and grateful message to everyone. Thanks to all of you who has helped make RF Cafe a success since 1999!

RF Cafe Podcasts

RF Cafe PodcastsAt the prompting of others, I decided to give podcasting a try. Having been advised that I have a face for radio and a voice for print, there was some hesitation on my part. However, there have been many fine articles published in vintage electronics magazine that people might be willing to listen to when there is no opportunity or desire to read them. Regular features such as "Carl & Jerry," "Mac's Radio Service Shop," editorials by the great Hugo Gernsback, and other types that do not contain images which need to be referred to in order to get the gist of the content, are prime targets for podcast listening. If the podcasts prove to be popular enough, I will expand to a paid subscription...

Many Thanks to KR Electronics for Long-Time Support!

KR ElectronicsKR Electronics has been designing and manufacturing custom filters for military and commercial radio, radar, medical, and communications since 1973. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop, equalizer, duplexer, diplexer, and individually synthesized filters for special applications - both commercial and military. State-of-the-art computer synthesis, analysis, and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Update: KR Electronics has been acquired by NIC, where KR Electronics' legacy of quality and innovation will continue to thrive, offering the same trusted products and services under NIC's leadership. For over three decades, NIC has delivered high-quality component performance and reliability, ensuring the successful deployment and operation of our clients' mission-critical solutions. Designed and manufactured in the USA. Please visit NIC today to see how we might be of assistance.

What's Your EQ?

What's Your EQ?, July 1962 Radio-Electronics - RF CafeAnother triplet of electronics circuit challenges here for you from a 1962 issue of Radio-Electronics magazine - a resistor network, a voltage divider, and a delayed switching circuit. As is usually the case with the resistor network, rearranging the circuit branches into a more familiar configuration simplifies its analysis. That is a good general rule when analyzing any circuit - rearrange and break down into recognizable subcircuits. The series circuit is about as simple as it gets, but knowing about how an ammeter is constructed helps. The Delayed Switching challenge is a little misleading in its description since the proposed solutions does use a vacuum tube duo diode (aka dual diode or full-wave diode) as part of the power supply circuit, although...

QST Christmas Covers

QST Christmas Covers, Kirt's Cogitations #324 - RF CafeAs our traditions are besieged by malcontents determined to denigrate, impugn, and ultimately erase memories of holidays and events that have meant so much to families and friends, I feel compelled to resist the movement by documenting parts of the past that will cause us to wax nostalgic over our cherished traditions. Intimidation and violence is part of the strategic calculus; we have seen it in spades in 2020, and 2021 promises to be even worse. The Cancel Culture might eventually win out with the complicity of government agents both elected and unelected, but I'm not going down without a fight. Here is a collection of twentieth century, December issue QST magazine covers with Christmas themes that will no doubt be familiar to many of you. Finding them was more difficult...

John T. Frye: A Short Biography

John T. Frye: A Short Biography - RF CafeJohn T. Frye, born on March 14, 1910 and passing on January 31, 1985, was a celebrated author, electronics enthusiast, and technical writer whose work left an indelible mark on the world of radio and electronics. According to historical records, he was stricken with polio as an infant, which left him physically disabled and confined to a wheelchair. Despite this early adversity, Frye demonstrated extraordinary perseverance and creativity, becoming one of the most prolific and beloved contributors to technical literature during the mid-20th century. John T. Frye's career as a writer began to flourish in the 1940s and 1950s, when he penned numerous articles, instructional guides, and serialized stories that combined entertainment with education. Among his most iconic works were the Carl & Jerry stories, which ran for many years in Popular Electronics magazine...

Drones Shut down Wright-Peterson AFB

Drones Shut down Wright-Peterson AFB - RF Cafe"Unknown drone activity forced one of the U.S.'s most critical military installations to shut down for several hours late Friday evening and Saturday morning, officials confirmed. The incident prompted heightened security measures and temporarily halted operations at Wright-Patterson Air Force Base in Ohio. Home to the 88th Air Base Wing, Wright-Patterson is one of the largest and most strategically important bases in the U.S., tasked with advanced research, intelligence, and operations. Unauthorized drone activity in military airspace poses significant risks, from espionage to safety hazards. In audio recordings by the Air Force Base air traffic control, which were shared online, an operator can be heard saying they are diverting 'over base' air traffic..."

What is Q?

What is Q?, October 1963 Electronics World - RF Cafe"Q" is an often used term to describe the electrical "quality" of a circuit or component, and for the most part anyone engaged in the conversation (verbally or via reading) understands the concept. However, having a firm grasp on the technical ramifications is required if you happen to be a circuit or system designer and need to conform to certain specifications. "Q" can be good or bad, depending on your needs. If, for example, you need a narrowband receiver to reject adjacent signals or you are designing a high stability and spectrally clean oscillator, then you want all the "Q" you can get. On the other hand, if your goal is to receive a spread spectrum signal or generate white noise across some bandwidth, then a lower "Q" is what...

Please Thank IPP for Their Long-Time Support!

Innovative Power ProductsInnovative Power Products has been designing and manufacturing RF and Microwave passive components since 2005. We use the latest design tools available to build our baluns, 90-degree couplers, directional couplers, combiners/dividers, single-ended transformers, resistors, terminations, and custom products. Applications in military, medical, industrial, and commercial markets are serviced around the world. Products listed on the website link to detailed mechanical drawings, electrical specifications, and performance data. If you cannot find a product that meets your requirements on our website, contact us to speak with one of our experienced design engineers about your project.

The Dit Makers

The Dit Makers, August 1966 Popular Electronics - RF CafeA lot of innovation went into perfecting telegraph keys. The earliest keys were the familiar "straight key" tapping type where the operator uses a single finger to close a set of contacts that "keyed" the transmitter for a burst of RF energy. The length of each "dit" or "dah" was determined by the operator's dwell time. It didn't take long for someone to improve on the scheme by designing keys that assured an adjustable, constant length for a dit or a dah. Poor quality transmitters with lousy rising and falling edge signatures at the beginning and end, respectively, of a CW pulse made matters worse. Constant length bursts make it easier for...

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, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers" Smith chart design. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. My graphic has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. I only make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way to help support RF Cafe. Thanks...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated in all locations on the page! RF Cafe typically receives 8,000-15,000 visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 17,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. Your Banner Ads are displayed on average 225,000 times per year! 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. If you need your company news to be seen, RF Cafe is the place to be...

The Decibel: AWG Wire Size Rule of Thumb

The Decibel: AWG Wire Size Rule of Thumb, October 1931 QST - RF CafeIn 1931, QST reader John H. Miller, Electrical Engineer, of the Jewell Electrical Instrument Company, wrote to the editor regarding the story "What Is This Thing Called Decibel?," by James L McLaughlin and James J. Lamb, which appeared in the August issue of that year. Mr. Miller wished to inform (or remind) readers that the American Wire Gauge system for assigning sizes to wire cross-section ratios closely follows a decibel (i.e., logarithmic) relationship. Applying his information: A 28 AWG solid wire has a cross-section of 160 circular mils, so at 3 sizes larger, 25 AWG should be 320 circular mils. In fact, it is 320 circular mils. A 12 AWG solid wire has a cross-section of 5,630 circular mils, so at 3 sizes larger, 9 AWG should be 13,060 circular mils, and it is 13,090 circular mils. That verifies the 3 dB per three differences in gauge for two cases using small and large wire sizes. What about, say, 5 dB for 5 wires sizes in difference? Using 28 AWG again as a reference, a 5 dB increase in size for 28-5=23 AWG wire should be about...

The Real Inventor of Wireless

The Real Inventor of Wireless, October 1965 Popular Electronics - RF CafeCredit for being the first to accomplish any notable feat, whether in sports, medicine, science, aviation, etc., is constantly being challenged. Some contestations are worthy of consideration based on documented facts, while others can be readily dismissed as crockery. Gustave Whitehead, per anti-Wright Brothers zealots, made the first powered airplane flight. The Vikings landed in America centuries prior to Columbus - supposedly. Many stories have been written claiming that Dr. Mahlon Loomis, a dentist, beat Guglielmo Marconi in the wireless communications race by using a system of kites that took on a charge from overhead clouds. A keying device opened and closed a conductive path to ground for effecting the Morse code...

RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Kill Those Harmonics

Kill Those Harmonics, October 1960 Popular Electronics - RF CafeHere is a short tutorial on how to construct a ¼-wave stub "trap," or filter to attenuate even-order harmonics from transmission lines. It applies whether the transmission line is feeding an antenna or is a section of copper foil running on a microwave substrate. Author Kent Mitchell (W3WTO) discusses both an open stub and a shorted stub. In case you are not familiar with how quarter-wave transmission lines stub work, a short at the far end appears as an open circuit where the stub connects to the main transmission line, and an open stub line appears as a short circuit. That is because there is a 180° phase shift at the end of the shorted stub and a 0° phase shift at the end of the open stub. Therefore, there is a total of 360° (i.e., 90°+180°+90°=360°, equivalent to 0°) with the shorted ¼-wave stub so it has no effect where it attaches to the main transmission line. The open stub experiences no phase shift...

More Tricks and Treats with Versatile Tarzian Tape

More Tricks and Treats with Versatile Tarzian Tape, October 1962 Popular Electronics - RF CafeHonestly, I don't remember why I scanned this advertisement for Sarkes Tarzian recorder tape that appeared in a 1962 edition of Popular Electronics magazine. Maybe it was to illustrate how far personal recording technology has come in the half century since the ad ran. Today's recorders are in the form of a very small digital device the size of a pack of gum (or any smartphone can be used), and not only is the miniature recorder capable of storing longer sessions, but the quality of the recording is almost certainly better. The cost of a digital recorder is about the same in inflated dollars as a spool of tape was in 1962...

Comics with an Electronics Theme, March 1967 Popular Electronics

Comics with an Electronics Theme, March 1967 Popular Electronics - RF CafeHere are a couple more electronics-themed comics from the March 1967 issue of Popular Electronics magazine for your TGIF enjoyment. The comic on page 100 especially appeals to me since I am finishing the installation of a Channel Master CM-5020 antenna. It has been a long time since I installed a traditional style TV antenna - about 40 years ago when I put a Radio Shack antenna on the roof of my mother's house. The entire 109" long by 100" wide antenna, including mounting hardware, weighs only 11.5 pounds and presents a wind resistance of 30 pounds. This is Channel Master's best antenna...

Quasi-Peak Detector Measurements

Quasi-Peak Detector Measurements (Cris Schulze) - RF CafeRF Cafe visitor Cris Schulze saw the Design News article I linked to titled, "EMI Emissions Testing: Peak, Quasi-Peak, and Average Measurements," and has given permission to reprint his brief response to it (originally posted on LinkedIn). The included notebook image includes an excerpt from Wikipedia's quasi-peak detector page, and he illustrates a block diagram of the test chain with de Forest's audion circuit that provides the fast rise-time and slow fall-time that characterizes it. A table of actual test data compares quasi-peak measurements to average measurements...

Are Modern Military Radars Infallible?

Are Modern Military Radars Infallible?, September 1971 Popular Electronics - RF CafePrior to the availability of high speed semiconductor circuitry, there was not enough computational power available - particularly in airborne platforms - to perform a significant amount of real-time signal processing in radar systems. Analog methods were available to do things like stationary target cancellation (moving target indication, MTI) and noise reduction to eliminate clutter on the plan position indicator (PPI, aka radar scope), range and azimuth blanking of selected regions of the scan, signal discriminators and integrators, and false target elimination via pulse repetition rate (PRR) and pulse repetition interval (PRI). There was nothing, really, in the older vacuum tube based systems to derive a target profile based on radar cross section (RCS) and signal vector (amplitude and phase) processing. This 1971 article reported on what was at the time information about very new technology that was just being...

Washington Newsletter, October 18, 1965 Electronics Magazine

Washington Newsletter, October 18, 1965 Electronics Magazine - RF Cafe1965 was the beginning of America's involvement in Vietnam. A mere decade had passed since the end of the Korean War (or "conflict" if you prefer), and the Department of Defense had not done much to modernize the military since then. Unlike with World War II when U.S. factories were turning out military aircraft, ships, and ground vehicles ahead of formal involvement, Congress was not interested in making headlines with news of war machines. The "Washington Newsletter" feature of this October 1965 issue of Electronics magazine reported on, among other military-related items, the U.S. Air Force's plans to phase out the venerated B-52 Stratofortress bomber by sometime in the 1970s. Here it is half a century later and the B-52...

All About IC's: Integrated Circuit Families

How IC's Work: Integrated Circuit Logic Families, September 1969 Radio-Electronics - RF CafeThis is part 4 of the "All About IC's" series that appeared in Radio-Electronics magazine in 1969, where author Bob Hibberd discusses the various types of integrate circuit (IC) families. He is not referring to TTL and CMOS with divisions into small scale integration (SSI), medium scale integration (MSI), large scale integration (LSI), and very large scale integration (VLSI) like we have today. Back in 1969 the IC world was still evolving through basic circuit structures like diode-diode logic (DDL), diode-transistor logic (DTL), resistor-transistor logic (RTL), direct-coupled transistor logic (DCTL), etc. What seems obvious now needed to be learned and dealt with then. It is like struggling with a homework problem and being able to look at the answer worked out in the back of the book where the solution then looks obvious...

The Futuramic Antenna

Futuramic Antenna by Channel Master, October 1952 Radio-Electronics - RF CafeYou're not going to find much information about the "Futuramic Antenna" by doing an Internet search. I had never head of such an antenna before seeing this article about it in the October 1952 issue of Radio-Electronics magazine. Although it was the trade name of a design by Channel Master, the authors (company engineers) claim it is a variation of a Yagi antenna which provides a much wider bandwidth by stacking multiple antennas and phase adjusting them in a combiner. The story takes place in the era shortly after the FCC ended a freeze on new television broadcast station licenses (1948) because channel assignments in the spectrum were being changed and UHF channels added, rendering some older equipment in need of modification or replacement. The effort was a model of bureaucratic chaos...

Why Not a Ham License Just for Ladies?

Why Not a Ham License Just for Ladies?, December 1967 Popular Electronics - RF CafeIn this saga of YL (young lady) and OM (old man) Ham radio operators, General license holder Carole H. Allen elucidates, with a touch of humor, the woes beset upon women pertaining to repairing radio equipment. Mrs. Allen's lament is in fact not the treatment of women participating in the communication aspect of Ham radio, but the reluctance of men to allow them to engage in the technical aspects of the electronic equipment. From an operator standpoint, guessing the gender of the Ham on the other end of the signal can be nearly impossible, particularly with CW (Morse code). Poor transmission quality can make phone (voice) determination of YL or OM difficult sometimes as well. Back in the 1960s it was not possible to simply surf to the FCC's Universal License System website...

Phase Noise Reference Page Added

Phase Noise Explanation & Equations - RF CafePhase noise measurements quantify the short term stability of a frequency source. That is because phase and frequency are mathematically related by a differential function [ω(t) = dΦ(t)/dt] so they are directly connected. Phase noise also includes amplitude instability due to atomic scale effects like FM flicker noise (1/f3), white noise (1/f2), PM flicker noise (1/f), and possibly even voltage supply noise (typically discrete spurs). When the frequency source is used as a local oscillator in a frequency converter (up- or down-), the amount of instability (jitter) is modulated onto the transmitter or received signal. While not usually a major concern in analog systems, in high speed digital communication systems phase noise can degrade the ability of the receiver to correctly determine the difference between a "1" and a"0." That is because...

Crystal Diodes in Modern Electronics

Crystal Diodes in Modern Electronics, January 1952 Radio & Television News - RF CafeDiode characteristics and their applications have not changed fundamentally since this article was published in 1952. Sure, the die are smaller, power handling and frequency range has increased, package styles are greatly expanded, and the cost per unit is way down, but if you are looking for some basic diode information, you will find it here in this 4th installment of a multi-part series in Radio & Television News magazine. Don't let the vacuum tubes in schematics scare you off and think that it makes the story irrelevant for today's circuits. For purposes of illustration substitute a transistor's collector (or drain) for the tube's plate, a transistor's base (or gate) for the tube's screen grid, and a transistor's emitter (or source) for the tube's cathode...

Plug Ugly Eliminator

Plug-Ugly Eliminator, May 1946, Radio-Craft - RF Cafe"Plug-Ugly Eliminator" could refer to a couple possible devices. One might be some sort of cover for hiding electrical cords and plugs where the go into a wall socket. It might also be a move decorative type plug than the standard kind on the end of a line cord. What the Plug-Ugly Eliminator actually is, is an overly complex contraption allowing a radio listener to turn off a radio for a predetermined amount of time when "commercial announcements in which he may have no interest or which may even be offensive to him" begins playing. The "Plug" part of the name is another name for a commercial. Maurice Kay's Plug-Ugly Eliminator, which appeared in the May 1946 issue of Radio-Craft magazine, is another items where if had occurred in an April edition, you might think you were being pranked for April Fools. The drawing certainly has the characteristics of a Rube Goldberg creation...

New Bell Telephone

New Bell Telephone, February 1953 Radio-Electronics - RF CafeSomeone sent me a link to a viral video of a group of teenagers (aka "Millennials") attempting to use an old school dial type telephone. Two things are notable. #1: They do not remove the handset from the cradle prior to dialing. #2: One of them asks whether it is necessary to let the dial spin all the way back to rest before dialing the next number. It's really not their fault since except for in dusty old places like my house, finding a dial phone is difficult. Many historians have commented that two innovations most responsible for America's greatness in the last century were the interstate highway system (for moving goods) and the telephone system. Bell Telephone Labs engineers designed phones and all the equipment that connected them to be simple, highly functional, robust, and to have...

May 27 RF Cafe Engineering Crossword Puzzle w/Weekly Headlines

RF Cafe Engineering Crossword Puzzle w/Weekly Headlines May 27, 2018At least 10 clues with an asterisk (*) in this technology-themed crossword puzzle are pulled from this past week's (5/21 - 5/25) "Tech Industry Headlines" column on the RF Cafe homepage. For the sake of all the avid cruciverbalists amongst us, each week I create a new technology-themed crossword puzzle using only words from my custom-created related to engineering, science, mathematics, chemistry, physics, astronomy, etc. You will never find among the words names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You might, however, see someone or something in the exclusion list who or that is directly related to this puzzle's theme, such as Hedy Lamar...

Tunnel Diodes

Tunnel Diodes, July 1969 Electronics World - RF CafeA decade after tunnel diodes were first invented by Nobel Laureate Leo Esaki, grand plans for the unique device never played out. Predictions included its use for computer solid state memories to replace magnetic core arrays. Tunnel diodes benefitted from the aura surrounding their exploitation of the quantum mechanical tunnelling phenomenon, which had a futuristic ring to it. Conventional diodes, having a relatively wide depletion region, require the current carriers (electrons and holes) to overcome a potential hill in traveling from the valence band to the conduction band of energies. Since high doping levels are used in the tunnel diode, a narrow depletion region is formed at the junction. This allows electrons...

RCA Victor Models 54Bx Radio Data Sheet

RCA Victor Models 54B1, 54B-N, 54B2, 54B3 Radio Data Sheet 335, May 1946, Radio-Craft - RF CafeSometimes finding an existing instance of one of the vintage radios is difficult or impossible. The RCA Victor Model 54Bx portables are an exception. Plenty can be found for purchase on eBay as this is written, as was a 54B1, 54B3, and a 54B4. I did a capture of some of the listing images for a Model 54B2, and had Archive.org story a copy for once the eBay site deletes it. In the internal photos, all four miniature vacuum tubes (3S4, 1S5, 1R5, 1T4) can be clearly seen. Note also in the photos you can see where, per the alignment procedure, rubber bands have been place around the tubes in order to keep them from moving. The extremely cramped space required particular attention to the routing of interconnect wires...

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