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Today in Science History

Charles Babbage: A Short Biography

Charles Babbage: A Short Biography - RF CafeCharles Babbage, born on December 26, 1791, in London, England, was one of the foremost mathematicians and inventors of the 19th century, best known for his pioneering work on the concept of a programmable computer. He was the son of Benjamin Babbage, a banker, and Betsy Plumleigh Teape, who hailed from a relatively affluent family. His upbringing was comfortable, allowing him access to an education that would later foster his intellectual pursuits. His father's wealth enabled Charles to attend some of the finest schools of the time, although his formal education started somewhat later than usual due to early childhood illness. Babbage's schooling began at a local academy in Alphington and later at the King Edward VI Grammar School in Totnes, Devon. He was a highly curious child...

Preventing Another Europa Clipper Transistor Panic

Preventing Another Europa Clipper Transistor Panic"Yesterday, NASA successfully launched the Europa Clipper, the largest spacecraft the agency has ever built for a planetary mission. Clipper is now successfully on its multi-year journey to Europa, bristling with equipment to study the Jovian moon's potential to support life - but just a few months ago, the mission was almost doomed. In July, researchers at NASA found out that a group of Europa Clipper's transistors would fail under Jupiter's extreme radiation levels. They spent months testing devices, updating their flight trajectories, and ultimately adding a warning “canary box” to monitor the effects of radiation as..."

Printed-Circuit Technology

Printed-Circuit Technology, October 1969 Electronics World - RF CafeThe October issue of Electronics World magazine included many articles written by printed circuit board (PCB) industry leaders regarding the state of the art. Multi-layer PCB technology was still in its infancy at the time, with most prototype and production boards being 1- or 2-sided. As with the switch from vacuum tubes to transistors, there were hold-outs who resisted the change to PCBs - for good reason in some cases. A list of advantages and disadvantages is presented both for and against, respectively, use of printed circuit boards. One of the biggest advantages to point-to-point wiring (i.e., in the PCB disadvantage list) was that circuit modifications in production was more easily accommodated, unless the change was simply...

FM Antennas for Better Listening

FM Antennas for Better Listening, February 1962 Radio-Electronics - RF CafeAlong with the advent of FM (frequency modulation) radio came an entirely new variety of antenna shapes and configurations, compared to primarily a simple long, straight wire for AM (amplitude modulation) radio antennas. Amateur radio operators (Hams) of course had been designing, tuning, and using such antennas (as FM) for decades, but the average radio listener was facing a whole new world of options for getting the most out of his receiver. It is not that AM radio cannot benefit by similar antenna configurations, it is just that the relatively long wavelength of AM station frequencies (540 to 1,700 kHz) compared to FM station frequencies (88 to 108 MHz) represents a two-order-of-magnitude...

Beyond Moore's Law: Revolutionary Hot Carrier Transistors

Beyond Moore's Law: Revolutionary Hot Carrier Transistors - RF Cafe"Researchers have developed a novel graphene-germanium hot-emitter transistor using a new hot carrier generation mechanism, achieving unprecedented performance. This advancement opens new possibilities for low-power, high-performance multifunctional devices. Transistors, the fundamental components of integrated circuits, encounter increasing difficulties as their size continues to shrink. To boost circuit performance, it has become essential to develop transistors that operate on innovative principles. Hot carrier transistors, which harness the extra kinetic energy of charge carriers, offer the potential to enhance transistor speed and functionality..."

Electronics-Themed Comics

Electronics-Themed Comics, August 1969 Electronics World - RF CafeWhen this was originally published, it was Labor Day in the USA, so most people were off work (which seems antithetical to the "labor" part of the holiday name). For those unfortunate enough to be at work, here is a bit of vintage electronic comic relief from a 1969 Electronics World magazine for your office-bound condition. Actually, during my years of working for someone else, I used to work the holidays (except Christmas) if I could get another day off instead. With very few managers around, those of us at work would enjoy what we termed "IPV," or "In-Plant-Vacation." Very little work got done on those days, and lunches and break-times were pretty long. I was always surprised the scheme never caught on more widely...

AMP2074P-2KW, 1.0–2.5 GHz, 2 kW Pulse SSPA

Exodus AMP2074P-2KW, 1.0–2.5 GHz, 2 kW Pulse SSPA - RF CafeExodus Advanced Communications, is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. We are pleased to announce the model AMP2083P-2KW solid state pulse amplifier (SSPA) is designed for Pulse/HIRF, EMC/EMI Mil-Std 461/464 and radar applications in the C-band, 4.0-8.0 GHz frequency band. Providing superb pulse fidelity and up to 100 μsec pulse widths. Duty cycles to 6% with a minimum 63 dB gain. Available monitoring parameters for Forward/Reflected power in watts & dBm, VSWR, voltage, current, temperature sensing for outstanding reliability and ruggedness in a compact...

Making Picture Tubes

Picture Tubes, May 1955 Popular Electronics - RF CafeBy the time most of us who even remember cathode ray tubes (CRTs) were first introduced to them, the technology and manufacturing processes had been pretty much perfected - especially for the standard 525-line (or 625-line outside the U.S.) resolution type. The National Television System Committee (NTSC) published a standard for black and white (B&W) television in 1941 and then for color in 1953. This "Picture Tubes" article in a 1955 issue of Popular Electronics provides a look inside a CRT manufacturing plant at General Electric. For some reason the photos in the magazine were very poor quality (maybe for secrecy). If you want one of the best explanations I have ever seen on how a TV picture scan is implemented, check out this video entitled What is 525-Line Analog Video? If you don't understand raster scanning after watching it, you never will. You might be surprised to learn that there were not actually 525 lines of picture information...

News Briefs

News Briefs, March 1962 Radio-Electronics - RF CafeThe March 1962 "News Briefs" feature in Radio-Electronics magazine was chock full of interesting developments. Space flight was a big deal in the day, not that it isn't today, but the difference is everything about it was new then. Fundamental technology was in the process of being developed, and then continual improvements would be made during the ensuing decades until we get to where we are today with a permanent presence of men in orbit, interplanetary science probes, space-borne telescopes, Earth environment sensors, and space weapons, and thousands of active communications satellites. The sky is awash with manmade objects. In other news, satellite TV was quickly gaining in capability (including live transmissions and, gasp, "Living Color" per NBC)...

Direct Conversion vs. Heterodyne vs. Superheterodyne

Direct Conversion vs. Heterodyne vs. Superheterodyne - RF CafeThe distinction between direct conversion, heterodyne, and superheterodyne receivers represents a significant evolution in radio technology. Each type of receiver plays a crucial role in the development of modern communications, and their invention marks important milestones in the history of radio engineering. To understand these differences, we will explore the invention history, technical descriptions, and practical implementations of each type, including their inventors, patents, and notable applications. A direct conversion receiver (also known as a "zero-IF receiver") represents the simplest type of radio architecture. It was first conceptualized in the early 20th century as a way to simplify radio designs by eliminating the intermediate frequency (IF) stage...

Taming Transients

Taming Transients, July 1963 Electronics World - RF CafeDealing with the problem of lightning strikes was of concern long before electronic equipment needed to be protected from its effects. Fires that were the result of lightning have always been a problem in nature, but they were really catastrophic to civilization once cities crowded with close-quartered wooden buildings became the norm. Benjamin Franklin observed that when the many lightning-induced fires of Philadelphia were sparked (pun intended), it was almost always the tallest structures in the area that were hit. Those fire often spread to neighboring buildings and burned down entire city blocks. It was a devastating and frequency...

Next-Gen Electronics Fail at Lower Temps

How Next-Gen Electronics Fail at Lower Temperatures - RF Cafe"By observing spintronic magnetic tunnel junctions in real-time, researchers found these devices fail at unexpectedly low temperatures, offering valuable insights for improving future electronic designs. Next-Generation Electronics Degradation A new study led by researchers at the University of Minnesota Twin Cities is providing new insights into how next-generation electronics, including memory components in computers, breakdown or degrade over time. Understanding the reasons for degradation could help improve efficiency of data storage solutions. The research is published in ACS Nano, a peer-reviewed scientific journal and is featured on the cover..."

Arthur C. Clarke: A Biography

Arthur C. Clarke: A Biography - RF CafeArthur C. Clarke's writings and contributions to science are vast and influential, intertwining his imaginative narratives with profound scientific concepts. Clarke is credited with proposing the idea of geostationary satellites in a paper he published in the October 1945 issue of Wireless World magazine. Titled "Extra-Terrestrial Relays: Can Rocket Stations Give Worldwide Radio Coverage?," he described the concept of using a network of geostationary satellites to provide global radio coverage. Geostationary satellites are satellites that orbit the Earth at the same rate as the Earth rotates, so they appear to stay in the same place in the sky relative to a fixed point on the Earth's surface. This makes them ideal for telecommunications and broadcasting, as they can provide constant coverage of a particular area without the need for multiple satellites or complicated ground infrastructure...

What's Your EQ?

What's Your EQ?, July 1961 Radio-Electronics - RF CafeHere we go with three new "What's Your EQ?" challenges from the July 1961 issue of Radio-Electronics magazine. Readers submit the problems, which typically involve creating a circuit to perform a specified function, or determining how a given circuit works. The first of these is more of a puzzle, since the author shows you how to go about arriving at the answer. Since incandescent light bulbs are not overly familiar to a lot of people these days, it might be to the advantage of pre-Millennials who grew up using them and are acquainted with their properties. The second is an old-fashioned Black Box challenge that some readers will solve without much...

HAPS Aircraft for Stratospheric Comms

SoftBank Trials HAPS Aircraft for Stratospheric Communications - RF Cafe"Japanese operator SoftBank announced that the Sunglaider, its large-scale solar-powered uncrewed aircraft system (UAS) designed for High Altitude Platform Station (HAPS) stratospheric telecommunications, was utilized in a field trial conducted by AeroVironment and the U.S. DoD in New Mexico, the U.S. During the trial, carried out in early August, Sunglider succeeded in achieving stratospheric flight, the Japanese operator said. With a wingspan of 78 meters and the capability to carry payloads weighing up to 75kg, the Sunglider is larger than other publicly announced HAPS UAS..."

Electronics Diagram Quiz

Electronics Diagram Quiz, August 1966 Popular Electronics - RF CafeMonday (any day, for that matter) is a good day for Carl and Jerry stories, Mac's Electronics Service Shop sagas, Hobnobbing with Harbaugh, electronics-themed comics, electronics quizzes, and other forms of nerd entertainment. Here is another of Robert P. Balin's great challenges titled, "Diagram Quiz," this one from a 1966 issue of Popular Electronics magazine. Most RF Cafe visitors will easily identify eight or nine of the ten diagrams. Relatively few will be familiar with the Rieke diagram (hint: power amplifier designers will know about it). The Biasing diagram is a bit misnamed IMHO, and could cause confusion...

Anatech Has 3 New Filter Models for October

Anatech Electronics - 3 New Filter Models for October 2024 - RF CafeAnatech Electronics offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Three new ceramic bandpass filters have been announced for October 2024 - a 2275 MHz center frequency filter with a bandwidth of 250 MHz, a 2275 MHz center frequency filter with a bandwidth of 250 MHz, and a 6245 MHz center frequency filter with a bandwidth of 360 MHz. Custom RF power filter and directional couplers designs can be designed and produced with required connector types when a standard cannot be found, or the requirements are such that a custom approach is necessary.

The Operational Amplifier

The Operational Amplifier, July 1963 Electronics World - RF CafeWhen you read this 1963 Electronics World magazine article's title, I doubt you immediately assumed it would be about a vacuum tube circuit, or even one that uses discrete transistors to implement the circuit. Rather you most likely though it would be about an integrated circuit (IC). Operational amplifiers (opamp) are building blocks characterized (ideally) by their infinite input impedance, zero output impedance, infinite open-loop bandwidth and gain, zero input offset voltage, amongst other defined parameters. The first commercially produced integrated circuit (IC) opamp came to market in 1964 via Fairchild Semiconductor (the µA702, brainchild of Bob Widlar)...

The Nickel-Cadmium (NiCad) Battery

Nickel-Cadmium (NiCad) Battery (ChatGPT-generated content) - RF CafeNickel-cadmium (NiCad) batteries have a long and significant history in energy storage, with their invention attributed to Swedish engineer Waldemar Jungner in 1899. Jungner's work laid the foundation for an electrochemical power source based on nickel oxide hydroxide and cadmium, leading to the development of the rechargeable NiCad battery. It was a pioneering breakthrough because it represented one of the earliest forms of rechargeable energy storage systems. This battery technology found widespread use in various industries due to its robust performance and ability to be recharged multiple times. At its core, the chemistry of NiCad batteries involves the reaction between cadmium (the negative electrode) and nickel oxide hydroxide (the positive electrode), with potassium hydroxide as the electrolyte. During...

Electronics-Themed Comics

Electronics-Themed Comics, September 1969 Electronics World - RF CafeThese two tech-themed comics from the September 1969 issue of Electronics World magazine are pretty good. I especially like the one where the guy's wife entered his printed circuit board layout in an art contest. PCBs were just starting to gain momentum in production electronics as they replaced the old point-to-point wiring method. Also popular in that era was high fidelity stereo equipment. Owning a system with speakers that operated from 1 Hz through 30 to 40 kHz was major evidence of an audiophile's technical savvy, even though the human ear con only detect frequencies in the 30 Hz to 20 kHz range. Dogs can hear frequencies up into the 45 kHz range. Porpoises can hear up to 150 kHz. A ferret can hear from 16 Hz...

NextGen Thermal Performance Testing

Next Generation Thermal Performance Testing - RF CafeTotalTemp Technologies offers advanced and innovative methods for meeting and optimizing your thermal testing requirements. We specialize in benchtop thermal testing because small batches are typically the most cost-effective approach. We offer heat transfer by conduction with thermal platforms, forced convection as in traditional temperature chambers, combined systems, and thermal vacuum for Space Simulation. Thermal testing of Traveling Wave Tube Amplifiers and other devices with dramatically uneven power dissipation can easily be achieved with a dual zone thermal platform. Managing the heat produced by the electron gun side allows for the RF outputs side to be tested at various required temperatures. The Dual Zone Thermal Platforms allows the user to maintain safe controlling...

Engineering & Tech Headlines <Archives>

• Ham Radio Serving Southeast U.S. Recovery Efforts

• Radio "A Godsend for So Many" in Helene's Aftermath

• Estate Planning for Hams

• Intel's Woes Damaging U.S. Chip Indpendence

• Is Gen-Z Low Car Ownership a Threat to Radio? (they can't afford cars due to massive inflation - not because they don't want a car)

AMRAD: A Brief Overview and Historical Context

AMRAD: A Brief Overview and Historical Context - RF CafeAmrad, American Radio & Research Corporation, was based in Medford Hillside, Massachusetts and was founded in 1915 with funds from J. Pierpont Morgan. The company's first manager, Harold James Power, was an amateur radio enthusiast and built a research laboratory. In 1916, Amrad made its first broadcast to J. Pierpont Morgan Jr., who was aboard the ocean liner "Philadelphia." Amrad received orders for military radio equipment during World War I, but discontinued these orders after the war ended. To keep the company afloat, Amrad produced items such as electric egg beaters and cigar lighters. In 1919, Amrad was awarded a contract to make 400 SE1420 receivers, and it began advertising components for amateur radio enthusiasts...

Which Dry Battery for You?

Which Dry Battery for You?, June 1963 Radio-Electronics - RF CafeThis "Which Dry Battery for You" article is a follow-on from the previous month's "Dry Cell Battery Types" in Radio-Electronics magazine. It was a time long before the dominance of rechargeable lithium batteries. In 1963, battery-powered devices were nowhere near as widespread and diverse as they are nowadays. Hand tools like drills, saws, routers, planers, and screwdrivers got their power either from a wall outlet or the user's arm and hand muscles. Lawn mowers, grass and hedge trimmers, chain saws, and snow blowers were powered mostly by gasoline, although some models plugged into the wall. Those devices which did use batteries most often had no built-in...

Light Waves to Logic Optical Computing

Light Waves to Logic Optical Computing - RF Cafe"Researchers have developed a new architecture for optical computing called diffraction casting, offering power-efficient processing by using light waves. This method promises better integration and flexibility for high-performance computing tasks and could be used in fields like AI and machine learning. As artificial intelligence and other complex applications demand ever more powerful and energy-intensive computers, optical computing emerges as a promising solution to enhance speed and power efficiency. However, its practical application has faced numerous challenges..."

AEC: A Brief Overview and Historical Context

Atomic Energy Commission, AEC: A Brief Overview and Historical Context (ChatGPT-generated content) - RF CafeThe Atomic Energy Commission (AEC) was established in 1946 as a result of the Atomic Energy Act, signed into law by President Harry S. Truman. This legislative decision marked the United States' formal entry into managing and controlling atomic energy, a rapidly advancing field that had been essential in concluding World War II through the development and use of nuclear weapons. The AEC was conceived to handle not only military applications of atomic energy but also to develop peaceful uses, such as energy production, medical research, and industrial applications. The creation of the AEC emerged from the Manhattan Project, the secret wartime effort to develop atomic bombs. The Manhattan Project brought together prominent scientists like J. Robert Oppenheimer, Enrico Fermi, and Niels Bohr. After the war, however, the question arose...

Empower RF 8 kW, X-Band Pulsed HPA

Empower RF Systems Model 2221, 8 kW, X-Band Pulsed HPA - RF CafeEmpower RF Systems, the technology leading provider of high-performance RF amplifiers, is proud to announce the launch of the Model 2221 X-Band Pulsed High Power Amplifier. The Empower RF 2221 amplifier operates in the 9-10 GHz X-band, delivering an impressive 8000 W peak output power with long and short pulse widths. Its applications encompass radar systems, electronic warfare, HPM research, and electromagnetics effects testing. With a rugged, modular design, the 2221 offers a reliable, high-performance solution for applications demanding significant X-band power. Key Features and Specifications The model 2221 amplifier operates in the 9-10 GHz X-band frequency range, delivering an impressive 8 kW of peak pulsed output power...

The Fraudulent Technician - A Minority

The Fraudulent Technician - A Minority, May 1964 Electronics World - RF CafeAlthough not in the title as it used to be, this 1964 Electronics World magazine piece by John T. Frye is a "Mac's Service Shop" story. If Mac and Barney are the stars of the saga, then it can be none other. The story is about how the misdeeds of a few dishonest operators can taint the reputation of an entire industry - nothing new there. Barney is telling Mac about a "sting" ploy pulled by a consumer protection group whereby TV sets with a specific easy-to-troubleshoot problem introduced to see how repair technicians from a suspect company would bill the service. I'll not spoil the ending for you; however, a comment mentioned that $10 would have been a reasonable price for a house call that included the fix. According to the BLS's inflation calculator, $10 in 1964 was the equivalent of about $102 in 2024...

Unexplored Electron Gap

Unexplored Electron Gap, March 1962 Radio-Electronics - RF CafeEver the futurist, in 1962 Radio-Electronics magazine editor Hugo Gernsback was making the case for occupying millimeter- and submillimeter-wave bands. In fact, he first proposed the concept back in 1959. He refers to it as "gap between the infrared (IR) and radio regions." IR is generally understood to include wavelengths from around 750 nm (400 THz) to 1 mm (300 GHz). Gernsback cites work done by Professor Gwyn O. Jones, of Queen Mary College of the University of London, with the claim that among other advantages of millimeter-wave (mm-wave) is an ability to penetrate certain wavelength "windows" in the atmosphere where lower frequencies do not propagate efficiently, more "channels" of communications can be accommodated, smaller antennas could be used, and narrower focused transmission beams possible...

Werbel 10-Way Splitter for DC-7.2 GHz

Werbel Microwave 10-Way Resistive Power Splitter for DC to 7.2 GHz - RF CafeWerbel Microwave's WMRD10-7.2-S is a 10-way resistive splitter that covers up to 7.2 GHz with ultra-wide bandwidth. This unique design accomplishes extremely flat frequency response in a small radial package. Our unique design approach provides higher than expected isolation between outputs at far ports than would be achieved in a typical star topology. It has applications in markets such as CATV, test and measurement, and military radio. Its small size makes it easy to integrate into compact systems. Designed, assembled, and tested in the USA.

Hugo Gernsback: A Biography

Hugo Gernsback: A Biography - RF CafeHugo Gernsback, often heralded as the "Father of Science Fiction," was an extraordinary figure whose influence extended beyond the realm of speculative literature into the world of electronics, radio communication, and futurism. His life, inventions, and publications shaped not only popular science but also the practical development of radio and electronics, making him a pivotal figure in early 20th-century technological advancements. Gernsback was born Hugo Gernsbacher on August 16, 1884, in Luxembourg City, Luxembourg, to a wealthy family. His father, Moritz Gernsbacher, was a winemaker and merchant, while his mother, Bertha, came from a prominent local family. Hugo had several siblings, though details of his early family life remain somewhat obscure. From a young age, Hugo showed a strong interest in science and technology, particularly in electricity and wireless communication. He attended local schools in Luxembourg and later pursued formal education at the Technikum in Bingen, Germany...

CostQuest Gerrymanders for BEAD Biddable Locations

CostQuest Gerrymanders for BEAD Biddable Locations - RF CafeThese government programs take forever to implement, then a major portion of the money gets wasted in bureaucracies, payoffs, and misappropriations (e.g., 8 EV charging stations after spending $7.5B). "If you know CostQuest at all you probably think of it as the company that the FCC hired to clean up and refine its national broadband map. But the company is also working with state broadband offices on their Broadband Equity, Access and Deployment (BEAD) programs. To give a little background, CostQuest works with the FCC on its national broadband map. But it was also hired, separately, by the National Telecommunications and Information Administration (NTIA) to work with states..."

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...

Radio Theme Crossword Puzzle for August 29th

Radio Theme Crossword Puzzle for August 29th, 2021 - RF CafeThis Radio Theme crossword puzzle for August 29th, 2021, contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Engineering & Science Crossword Puzzle for February 23

Engineering & Science Crossword Puzzle February 23, 2020 - RF CafeAs with my hundreds of previous science and engineering-themed crossword puzzles, this one for February 23, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. 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, if you don't already know, might surprise you.

Cool Product: BridgeCom BCD-144250 Rack Mount VHF Duplexer

Cool Product: BridgeCom BCD-144250 Rack Mount (250 W) VHF Duplexer - RF CafeFor the past few months, this full-page BridgeCom advertisement has been running in the American Radio Relay League (ARRL) magazine QST. When I first saw it I though it might be one of those research laboratory hydraulic apparatuses for generating the kind of pressure found at the center of the Earth. Scientists use such devices to synthesize diamonds by compacting coal. In actuality, the four cylinders are part of the BridgeCom BCD-144250 Rack Mount VHF Duplexer. Per their website: BridgeCom Systems' BCD-144250 Duplexer for amateur and commercial applications. The BCD-144250 utilizes four high-quality cavities that results in uncompromising duplex isolation. It will handle up to 250W continuously for the most demanding applications...

Espresso Engineering Workbook™ for Excel

RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeThe newest release of RF Cafe's spreadsheet (Excel) based engineering and science calculator is now available - Espresso Engineering Workbook™. Among other additions, it now has a Butterworth Bandpass Calculator, and a Highpass Filter Calculator that does not just gain, but also phase and group delay! Since 2002, the original Calculator Workbook has been available as a free download. Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is also provided at no cost, compliments of my generous sponsors. The original calculators are included, but with a vastly expanded and improved user interface. Error-trapped user input cells help prevent entry of invalid values. An extensive use of Visual Basic for Applications (VBA) functions now do most of the heavy lifting with calculations, and facilitates a wide user-selectable choice of units for voltage, frequency, speed, temperature, power, wavelength, weight, etc. In fact, a full page of units conversion calculators is included. A particularly handy feature is the ability to specify the the number of significant digits to display. Drop-down menus are provided for convenience...

"Ravin" - an Electronics-Themed Poem

Electronics Poetry - "Ravin", September 1942 QST - RF CafeThis is yet another example of humorous - and clever - poetry written by Hams from back in the 1940s... November 1942, to be exact. It appeared in the ARRL magazine QST. As alluded to in the title, "Ravin," it is a play on Edgar Allen Poe's famous "The Raven" poem. A few other electronic-themed poems are listed on the page as well, discovered in QST and in Popular Electronics. Enjoy...

New Radio-Electronic Patents

New Radio-Electronic Patents, November 1947 Radio-Craft - RF CafeIt has been three or four decades since I have seen anything about a Lecher Line, the last time in memory being in a college lab. It might have been a physics lab, but most probably an EE lab. We used one to measure wavelengths of signals from an RF generator. The apparatus looked sort of like the one in the Wikipedia link, only just a little more modern (but not much more, being typical school equipment). This new patents report from a 1947 issue of Radio-Craft magazine has a waveguide version of a Lecher Line that supposedly was able to do more precise measurements of very short wavelengths by providing for detecting the internal wave over multiple wavelengths instead of just a single half wavelength. It was developed at Bell Telephone Laboratories...

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...

Low-Loss Coaxial Cable

Low-Loss Coaxial Cable, December 1966 QST - RFCafeWhen it comes to low loss transmission media, it's hard to beat waveguide and open wire. Open wire can exhibit less a couple tenths of a decibel per hundred feet at low frequencies, but it is very susceptible to perturbations from nearby objects, wind and moisture. Waveguide exhibits a few tenths of a decibel per 100 feet at very high frequencies, but it is expensive and difficult to work with. In the middle is coaxial cable, which for a good quality product of appropriate size, you can get very low attenuation. As with most things, you get what you pay for in coax cable. I once used really expensive Andrew (now Commscope) Heliax coax cable on an S-band radar (2.8 GHz) system that had only a little more than 1 dB/100 ft, which was necessary from a receiver noise figure requirement rather than for transmitter power efficiency. This article from QST covers some of the basics of low loss cable...

Value Engineering for the Electronics Industry

Value Engineering for the Electronics Industry, August 1967 Electronics World - RF CafeSome topics are timeless. This is one of them. The term "Value Engineering" is not so familiar these days, since ostensibly it was developed by General Electric back in the World War II era. Per Wikipedia, "Value engineering (VE) is a systematic method to improve the "value" of goods or products and services by using an examination of function. Value, as defined, is the ratio of function to cost. Value can therefore be increased by either improving the function or reducing the cost. It is a primary tenet of value engineering that basic functions be preserved and not be reduced as a consequence of pursuing value improvements ." This article from the August 1967 Electronics World was a good read then, and it is a good read in 2019...

Electronics and the IGY - Part I

Electronics and the IGY - Part I, February 1958 Radio Electronics - RF CafeThe International Geophysical Year (IGY) began on July 1 of 1957 and ran through December 31 of 1958. It was the dawn of space / high altitude flight and there was a great need to learn as much as possible about the physics of the upper atmosphere and the void of space. The USSR successfully flew their first three Sputnik satellites and the U.S. was scrambling to get Echo into orbit (finally on August 12, 1960, after the end of IGY). The Cold War was at its peak (Bay of Pigs incident was just a few years away), and the science world was looking for a way to provide a unifying tie between the planet's countries. "During this time, more than 5,000 scientists and engineers of more than 60 nations ...

Zenith TV Ad, PCBs Not Inside

Zenith TV Ad, No Printed Circuits, May 1958 Radio-Electronics - RF Cafe"PCBs? We ain't got no PCBs in our TV sets†... We don't have to give you no stinking PCBs." That is effectively what the Zenith television advertisement from a 1958 edition of Radio-Electronics told its potential customers. According to the Zenith communications department, even though their head R&D guy, Dr. Alexander Ellett, was "the daddy of printed circuit boards," they stuck with the traditional point-to-point wiring in all their TV chassis. I have to agree with them from a troubleshooting and component replacement perspective. There's nothing easier than heating a solder lug or terminal post to unwrap a leaded R, L, or C either to measure its value, isolate it from the rest of the circuit for making tests, or to replace it. There is no worry about solder splatter or bridges, overheating the PCB material to cause delamination, or lifting metal traces from the surface. There is also no issue with getting a component lead out of a plated-through hole. Yes, of course modern circuits need multilayer, high density circuit boards...

Editorial - High Life: The Bill Comes Due

Editorial - High Life: The Bill Comes DueAccording to Electronics magazine editor Lewis Young in mid-1964, the industry was entering into a slump in business opportunities. The boom times provided during the war years of WWII and Korea had resulted in, according to Mr. Young, a lax attitude toward operational strategy that led to wasteful spending and poor accountability for project results. It wasn't just the defense contractors' fault because government bureaucrats - from relatively low ranking military personnel to elected lawmakers - had (have) a habit of making sudden changes to contract requirements. Maintaining the resources needed to keep up with ever-evolving demands necessitated a lot of the excess. Fortunately, the military-industrial complex, as President Dwight D. Eisenhower dubbed it, was on the verge of being thrown another huge monetary bone - the Vietnam War. President Kennedy was already pumping lots of equipment and manpower into it, and LBJ would follow suit with vigor ...

How Did Dilbert Get His Name?

How Did Dilbert Get His Name? (Dilbert the Pilot) - RF CafeDo you know how engineering whipping boy Dilbert came to be called by that name? Per Scott Adams, while working at Pacific Bell he ran an informal name-the-comic-strip-engineer contest from his cubicle. A guy named Mike Goodwin suggested Dilbert. "I ended the contest immediately and declared Mike the winner," says Adams. It sounded perfect. Years after the comic strip had become syndicated, Mike commented that he believes the name idea might have come from seeing his father's old WWII aviator comics with "Dilbert the Pilot." DtP was a screw-up, invented by Navy artist Robert Osborn, whose purpose in life was to illustrate the wrong way of doing things so that real pilots wouldn't make the same mistakes. The name was funny then, as it is funny now. BTW, Dilbert is a variant of Delbert meaning nobly famous. During the War, "dilbert" became a synonym for "blunder" for Navy pilots. The Navy even produced an aviator safety film titled, "Don't Kill Your Friends," featuring Dilbert the Pilot...

Canada Puts Limit on R.F. Interference

Canada Puts Limit on R.F. Interference, February 1960 Electronics World - RF CafeIf you think the ISM (Industrial, Scientific, and Medical) unlicensed bands were a relatively new spectrum allocation, you might find this 1960 Electronics World news piece interesting. Individual countries generally acknowledge the ISM emissions specifications set forth by the International Telecommunication Union (ITU), which created the bands in 1947. The 900 MHz, 2.4 GHz, and 5.8 GHz WiFi bands are well known to most people. 24 GHz is gaining traction as current spectrum gets more and more crowded and high bandwidth data channels are needed. Interestingly, the first few ISM bands are integer harmonics of the lowest (6.78 MHz, center of band 1). To wit: 2 * 6.78 = 13.56 MHz (band 2), 4 * 6.78 = 2 * 13.56 = 27.12 MHz (band 3), 6 * 6.78 = 2 * 13.56 = 40.68 MHz (band 4)...

Color TV Today

Color TV Today, September 1959 Popular Electronics - RF CafeWhen color televisions hit the stores in 1954, most households could not afford one. For that matter, most households could not afford a black and white TV, either. By 1959 when this article appeared in Popular Electronics magazine, TV in general was still a novelty to most people. It is amusing to read about how much more lifelike everything would appear when broadcast in "living color." Well, duh. It's as if it never occurred to anyone that the images previously did not contain color like the real world did. I was born in 1958, and remember that my family's was last of all the households I knew of to own a color television set. We never even had a console floor model, just small tabletop pieces of junk. It was a big deal the day I, at about age 16, bought and installed a remote rotor for the rooftop antenna so we could receive more than three stations. There was no cable TV service in our neighborhood...

Interference from Left Field

Interference from Left Field, March 1970 Popular Electronics - RF CafeBy 1970, the airwaves were really getting crowded. Lots of high power commercial and military gear was online, and the radio listening public was setting new record highs every year. As such, many new sources for radio interference (RFI) were being discovered, and sometimes the problems caused went well beyond just a little noise being superimposed on top of Neil Diamond's newly released Cracklin' Rosie or the lads from Liverpool's The Long and Winding Road. Often, the interference was overwhelmingly annoying. The FCC was being flooded with complaints. Digital computers were creating a whole new type of electronic havoc, and leaky cable television cables and amplifiers caused all kinds of headaches to over-the-air sets. Rusty bolts and chain link fences in the vicinity of high power radio and TV towers - and even radar installations - manifested themselves as detectors by virtue of their nonlinear nature. I remember when people at Robins AFB, in Georgia, would sometimes complain to our radar shop because their radios would blip once every four seconds as the search radar antenna swept past their radios...

Carl & Jerry: He Went That-a-Way!

Carl & Jerry: He Went That-a-Way!, March 1959 Popular Electronics - RF CafeThis might be the first (and only) appearance of Carl's father, at least in a drawing. In this episode, John T. Frye's high-tech teen duo Carl and Jerry design and build a "polecat detector." In the process, a little drama is thrown in when a stander-by mistakenly believes he is being insulted. Even if, in spite of the detailed description by Jerry, you don't learn how a photocell-based threshold crossing circuit works, you might just learn the meaning of 'lugubriously.' Mr. Frye always worked valuable technical information into his stories about "Carl & Jerry," "Mac's Service Shop," and other regular features which appeared in electronics magazines for decades.

Filter Prototype Denormalization Page Reworked

Filter Prototype Denormalization Equations Formulas - RF CafeThis entire page has been reworked to make the denormalization of prototype lowpass filter component values much easier to understand. I have received numerous questions about the process over the years, particularly regarding the swapping of capacitor and inductor values for highpass transformations. Bandpass and bandstop transformations can be equally confusing. The original page pretty much regurgitated the kind of presentation made by many textbooks, but this new format should make amply clear the transformation from normalized lowpass component values ...

Bias T, Band Splitter and Other RF Diplexers

Bias T, Band Splitter and Other RF Diplexers - RF CafeThe following article / app note titled, "Bias T, Band Splitter and Other RF Diplexers," was submitted to RF Cafe by Bree Engineering. It is a brief introduction to and explanation of the theory and application of the named frequency selective devices. A Bias-T is frequency dependent just as much so as a band splitter or diplexer; it differentiates between DC (0 Hz) and the RF frequency. Bree Engineering Corporation was founded in 1999 and is a manufacturer of custom electronic filters, multiplexers, filter banks and other related types of components in the frequency range of 0.1 MHz to 40 GHz. Designs include Chebyshev, Bessel, Butterworth, Gaussian, transitional, elliptic-function and pseudo-elliptic-function filters in lumped element, cavity, combline, interdigital...

Men Who Made Radio - Sir Oliver Lodge

Men Who Made Radio - Sir Oliver Lodge, December 1929, Radio-Craft - RF CafeRadio-Craft magazine ran a monthly series of short articles paying tribute to some of the shakers and movers in the field of science - this time it was Sir Oliver Lodge. "While Hertz was discovering radio waves in air, Lodge was determining the laws of the corresponding activity which takes place in electrical conductors. It was Lodge who demonstrated the possibility of radio communication, experimentally, as Marconi did its commercial value - just as Henry created the telegraph and Morse made it of practical utility." See other "Men Who Made Radio" features on ...

B&K Manufacturing Co. Advertisement

B & K Manufacturing Co. Advertisement, April 1960 Electronics World - RF CafeUntil solid state electronics had supplanted the majority of vacuum tube type televisions and radios, portable tube testers were essential equipment to successful, efficient troubleshooting and repair in businesses and people's homes. Yep, believe it or not the stories told about doctors and electronics repairmen visiting homes are not just fables. I remember as recently as the 1960s having our family doctor make house calls when I or one of my fours sisters got sick. Both doctors and TV servicemen ceased the practice at about the same time - probably the result of a Brotherhood of Electronics Technicians and General Practitioners collective bargaining agreement ;-) Many column inches of editorials, articles, comics, and letters to the editor were devoted to the trials and tribulations of in-home servicemen and the experiences...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed...

Electrical Meters - Why Meters?

Electrical Meters - Why Meters? NAVPERS 10622 Chapter 18 - RF CafeEven though most electrical meters have gone to a digital format, there are still many millions of analog meter movements doing service in equipment around the world. Analog meters are especially good for when the value being reported is changing rapidly and trying to read a numerical value would be tiring or impossible. A perfect example of comparing analog to digital is the Internet speed test display used by most companies. Run this speed test from Spectrum and watch the two indicator types simultaneously. Of course many pre-electronic meters are driven by sources other than electricity; e.g., fluid flow rate pressure meters, your bathroom scale, automobile speedometers, etc. A lot of modern "analog" meter indicator needles ...

Yet More Tech-Centric Jokes

Yet More Tech-Centric Jokes - RF CafeTake a break from the drudgery with some of these tech-centric jokes, song parodies, anecdotes and assorted humor that has been collected from friends & from websites across the Internet. This humor is light-hearted and sometimes slightly offensive to the easily-offended, so you are forewarned. I have taken care to censor out "humor" with reproductive function innuendo and hateful tirades, so it is all workplace-safe. I have also tried to warn of any links that will result in audio clips so you can take appropriate precautions. As usual, there is no easy way to determine the true origin of any of these jokes. Unless otherwise noted, that prolific author "Anon" is the progenitor...

Cakes Baked in 90 Seconds - Early Microwave Oven

Cakes Baked in 90 Seconds - Early Microwave Oven, November 1951 Radio & Television News - RF CafeLittle known to most people (including moi until recently), DeForest Training School was started by DeVry University's founder Herman A. DeVry. DeVry and DeForest were DeGood DeFriends, leading DeVry to name his electronics school after DeForest. It was re-named DeVry Technical Institute in 1953. Research at DeForest Training School produced one of the first RF / microwave food baking "ovens." The prototype reported in this 1951 Radio & Television News magazine article was not at all like modern microwave ovens. There was no enclosure into which baking bowls, pans, and dishes can be inserted. Rather, electrodes were arranged at the perimeters of the special pan that in this demonstration contained cake batter. It was adapted from a process originally developed for RF induction heating of industrial materials...

Service Technicians' All-American Award Winners

Service Technicians' All-American Award Winners, February 1958 Radio & TV News - RF CafeIf you had a father, brother, uncle, grandfather, husband, or neighbor who was an electronics service technician in the days of yore, he might have been mentioned in this 1958 issue of Radio & TV News magazine highlighting General Electric's Service Technicians' All-American Award Winners. Rather than rewarding the independent businessmen for their technical prowess, the company assigned awards based on community services performed, thereby reflecting positively on both GE and the electronics service business as a whole. Each winner received a $500 check, which in 2020 money is the equivalent to about $4,500 in today's economy. The closest thing we have to the radio and television serviceman today is maybe the guys who install broadband cable and satellite dishes. Their level technical knowledge is not required to be anywhere near as deep...

Electronic Menu Quiz

Electronic Menu Quiz, August 1963 Popular Electronics - RF CafeThis Electronic Menu Quiz appeared in the August 1963 edition of Popular Electronics magazine. Robert Balin created many such quizzes for Popular Electronics over the years. It challenges you to match the common food-related term for a device with its picture. If you've been around electronics labs and/or read electronics hobbyist magazines for a while, chances are you have run across most of the terms. I suggest you click on the image to get a full-size view of the drawings to be able to see all the detail. A couple of the names I have to admit not being familiar, so they seem rather 'corny'... get it?

Inventors and Their Inventions

Inventors and Their Inventions, Kirt's Cogitations #325 - RF CafeWhen doing some research for creating a new quiz on inventors and their inventions, I decided to look for people according to their countries. I almost always do image searches since doing so does a good job of filtering out pages that merely mention the topic of interest. My first Google search was "american inventors." I expected to see the familiar faces of Thomas Edison, Henry Ford, George Westinghouse, Marie Curie, Alexander Graham Bell, George Washington Carver, Edwin Armstrong, Hedy Lamarr, Benjamin Franklin, Robert Goddard, Albert Einstein, the Wright Brothers, Samuel Morse, William Shockley, etc. Those are the names that first come to my mind, and admittedly the list is dominated by White men. Imagine my surprise when the Google search results belied my perception. Take a look at the first few pages of results to see what I mean. Next, I moved on to an image search for "canadian inventors..."

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed...

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