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New & Timely

New & Timely, December 1969 Radio-Electronics - RF CafeThe December 1969 issue of Radio-Electronics magazine's "New & Timely" column reported that at the National Electronic Association conference, technicians reported burns and eye damage caused by X-radiation from color TV sets under repair. Night vision scopes for commercial use were introduced by Raytheon, suitable for law enforcement, industrial security, and nature study. A joint U.S.-Indian plan planned to beam TV directly to millions of Indian villagers via a stationary applications satellite in 1972. The French Atomic Energy Commission used a superpowerful laser to create minute thermonuclear explosions, fusing deuterium...

Anatech Intros 3 New Filter Models for April 

Anatech Electronics Intros 3 New Filter Models for April 2025 - 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 filter models have been added to the product line in April, including a 5500 MHz WiFi cavity bandpass filter, a 3437-3537 MHz ceramic duplexer filter, and a 1425 MHz cavity bandpass filter. 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 Electron Microscope

The Electron Microscope, May 1955 Popular Electronics - RF CafeThis article published in a 1955 issue of Popular Electronics magazine is a really good primer on the history and working principles of the electron microscope. It also explains why such a device is needed; i.e., why an optical microscope cannot do the job when really high levels of magnification are required. As object dimensions are spaced at distances near to or less than the optical wavelength being observed, it becomes impossible to resolve into separate features. Accordingly, when observing at the upper end of the visible light spectrum at around 400 nm, under ideal conditions you would not be able to clearly discern two feature less than about 800 nm apart. Current (2019) CMOS gate thicknesses run about 5 μm, so visible light cannot be used to image those structures. Another resolution limiting factor is aperture size, which, depending on the wavelength causes diffraction patterns of two objects to overlap...

Pacific T.V. Vacuum Tube Supply

Pacific T.V. Vacuum Tube Supply - RF CafeIf you are a seasoned vintage electronics equipment aficionado, restorer, hobbyist, etc., then you most likely already have your own list of supply sources for vacuum tubes. Contrary to what others might think, there is still a healthy stock of tubes available from private websites like Pacific T.V. (hat tip to Bob Davis), as well as collective sites like eBay, Facebook Marketplace, Craigslist, and vintage electronic equipment forums. Prices for common tubes are surprisingly low if you shop around. If you need an output power amplifier for a commercial radio station, be prepared to shell out major wampum, though. Many NOS (new old stock) varieties in original boxes can be had, as well as used tubes. Most have been tested for specification compliance.

Westinghouse Wartime Products

Westinghouse Wartime Products, May 1943 Popular Mechanics - RF CafeWestinghouse is yet another bulwark company of America's foundational industrial age, beginning in the late 19th Century. George Westinghouse founded eponymously-named company, Westinghouse Electric & Manufacturing Company, in 1886, during the time he was working with Nikola Tesla (I wonder whether any of the current-day anti-Tesla nimrods are stupid enough to vandalize NT statues and monuments?) to institute a commercial electrification infrastructure. Mr. Westinghouse began his life of fame and fortune with a locomotive air brake design. During World War II, Westinghouse's many locations designed and manufactured many types of products to facilitate troops in all Theaters of Operation. This 1943 issue of Popular Mechanics magazine carried a full-page...

What's Your EQ?

What's Your EQ?, January 1963 Radio-Electronics - RF CafeThis set of three circuit analysis challenges appeared in the January 1963 issue of Radio-Electronics magazine. Readers, staff, and even come companies submitted the "What's Your EQ?" (EQ = Electronics Quotient) content. As an example of the latter, Cleveland Institute of Electronics provided "Draw the Waveform." Don't let the diode vacuum tube deter you from the puzzle. Just mentally replace the tube with a solid state diode symbol with the anode at the top where the tube's plate (anode) is shown. The negative element of a tube is called the cathode, same as the solid state diode. "Capacitor Charge" is easy enough. "Another 2-Box Light"...

2025 UK Engineering Salary Survey

2025 UK Engineering Salary Survey - RF Cafe"Despite increasingly intense competition for skills across all sectors of industry and a growing appetite amongst engineers for a new challenge, engineering salaries appear to have stagnated over the past 12 months. This is just one of the key findings of The Engineer's tenth annual salary survey, which is published in full on The Engineer's website in a new interactive digital format. Attracting responses from 621 engineers working across 12 different sectors, this year's survey was carried out between December 2024 and January 2025. As ever, the results provide a fascinating insight into UK engineering salaries and how engineers are feeling about their careers..."

Television and Sound

Television and Sound, January 1963 Radio-Electronics - RF CafeIn this 1963 issue of Radio-Electronics magazine, editor Hugo Gernsback reflects on the early days of television, noting that the first regular daily TV broadcast began on August 13, 1928, over radio stations WRNY and W2XAL, which were associated with his former publication, Radio News. Initially, these broadcasts were silent, featuring only moving images the size of a postage stamp, and it wasn't until 1931 that TV broadcasts included sound. Gernsback critiques the slow progress in improving the audio quality of television receivers, pointing out that despite advancements in high-fidelity and stereo audio technology, most TV sets still lacked these features due to regulatory restrictions by the FCC. He expresses hope that recent petitions to the FCC...

Exodus AMP20081, 80-1000 MHz, 500 W SSHPA

Exodus AMP20081, 80-1000 MHz, 500 W SSHPA - RF CafeExodus Advanced Communications, is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. Exodus' model AMP20081 high power solid state power amplifier (SSHPA) is ideal for broadband EMI-Lab, communications, and EW applications. Class A/AB linear design accommodates all modulations & industry standards. It covers 80-1000 MHz, producing 600 W nominal, with a 500 W P1dB and 56 dB minimum gain. Excellent flatness, optional monitoring parameters for forward/reflected power, VSWR, voltage, current & temperature sensing for superb reliability and ruggedness...

Electronics-Themed Comics

Electronics-Themed October 1944 & May 1945 Radio-Craft - RF CafeIn that these comics from Radio-Craft magazine have an electronics theme, you can claim looking at them is work-related. The themes of the comics reflect common scenarios of the 1944-1945 era in which they were published, but with not much modification can be applied to today's environment. People will always expect more features from products, will be critical of everything presented to them, and will want to haggle for the best deal from the used camel salesman. You might consider using one of them for your next conference or project status presentation. There is a list of many more similar comics at the bottom...

World's 1st Quantum Entanglement Communications Service

World's First Quantum Entanglement Communications Service Offered by QentComm - RF CafeIn a groundbreaking announcement that will forever transform global communications, QentComm®©™ (Quantum Entanglement Communications) has unveiled the world's first commercially viable quantum entanglement communication system. Dubbed QeG®©™ (Quantum entanglement Generation, pronounced kwee-gee), supplementing the traditional 4G, 5G, and 6G nomenclature, this revolutionary technology eliminates the limitations of traditional radio-based systems, delivering instantaneous, unlimited connectivity across any distance without reliance on satellites, cell towers, or fiber optics. Under the leadership of Kirt Blattenberger, QentComm (pronounced kwent-kahm) has created a system that defies conventional physics by utilizing quantum entanglement for real-time, secure communication between devices anywhere in the universe - including here on Earth...

Carl & Jerry: Secret of Round Island

Carl & Jerry: Secret of Round Island, March 1957 Popular Electronics - RF CafeIn this "Carl & Jerry" technodrama from a 1957 issue of Popular Electronics magazine, the two boys start out enjoy a casual day of kite flying, using a homebrew radio-controlled camera attached to the kite to capture an aerial view of Round Island in a lake. After successfully taking a picture, they develop the film and discover two men and an odd setup on the island. Curious, they return the next day, find a hidden tunnel, and stumble upon an illegal liquor still. As you might expect, the teens run into a heap of trouble when the moonshiners nab them. Using their combined ingenuity and knowledge of communications methods common to Ham radio operators of the era, contact was made and help was on the way. Read about Carl and Jerry's exploit and exactly what it was that saved the day - and their hides!

Ham Radio Students at DSES Radio Telescope

Amateur Radio Students Visit DSES Radio Telescope - RF Cafe"In late January 2025, 17 students and staff members from Las Animas High School (LAHS) in Colorado visited the Deep Space Exploration Society Radio Telescope (DSES) located at the Plishner Radio Astronomy and Space Sciences Center near Haswell, Colorado. They also got an introduction to amateur radio. 'This first field trip visit of high school students reflected the dreams of Michael Lowe, former DSES board president, who sought to create a center for radio astronomy and space science education in southeast Colorado,' said DSES President Myron Babcock, KL7YY..."

Old World Standards Breaking Through

Old World Standards Breaking Through, April 1966 Popular Electronics - RF CafeMaking format changes to magazines after many years of an established standard always ruffles the figurative feathers of a significant portion of regular readers. Two magazines I read monthly, Model Aviation and QST, recently underwent a format change - both of which I considered very nice. However, reader comments in the aftermath showed a few who were not impressed. Popular Electronics magazine in 1966 made announcements regarding plans to adopt some of the newer base units for physical measurements, including this one for beginning to use "Hertz" (Hz), along various numerical prefix forms, instead of "cycles per second" (cps). The editors give sound reason...

Harold Beverage of the Eponymously Named Antenna Type

Harold Beverage of Eponymously Named Antenna Type, August 1944, Radio-Craft - RF CafeThe Beverage Antenna, very familiar to amateur radio operators, is a simple but efficient, highly directional, non-resonant antenna that consists of a single straight wire of one or more wavelengths that is suspended above the ground. It is orientated parallel to the direction of intended reception. One end is terminated to ground through a resistor, and the other is connected to the receiver. The following quote comes from the patent (US1,81,089) text: "In accordance with theoretical considerations, if an antenna were to be freely suspended and if the surface of the earth constituted a perfectly conducting parallel plane, current waves would travel through...

Dear Mr. Fips: 30-Day Record Response

Dear Mr. Fips: 30-Day Record Response, June 1961 Radio-Electronics - RF CafeThis letter was sent to Hugo Gernsback, publisher of Radio-Electronics magazine, in response to the "30-Day Record Response" article penned by noted scientist and inventor Mohammed Ulysses Fips. In it, Stephen A. Kallis, Jr. heaped laud upon the "Most Revered and Esteemed Fips" for his long-term recording device (remember, 1961 was many decades before microminiature terabyte memory and microprocessors) were available, and chastises Mr. Gernsback for evidently calling into question the authenticity of the recorder. Kallis, a self-proclaimed stereo enthusiast, bolsters Fips' case by citing "A Proposed Listening Area," by the Institute of Synergistic Statics Proceedings...

Ulano Masking Films - Rubylith

Ulano Masking Films, December 27, 1965 Electronics Magazine - RF CafeRaise your hand if you're old enough to remember doing printed circuit board layout using Rubylith tape. My hand is up. Back in the early 1980s, I did prototype PCB designs in an engineering development lab at Westinghouse Electric's Oceanic Division. Most of it was for analog and RF substrates that would be photographically reduced in size for use with bare integrated circuit die and surface mount passive components (Rs, Ls, and Cs), upon which I would later epoxy-mount those components and wire-bond everything using 1-mil gold wire. However, there were projects where full-size leaded components were used on a through-hole PCB that used not only the Rubylith tapes but also sheets with special electronics shapes for solder pads around the holes for components leads, ground and power planes, board-edge connectors...

Mind-Bending Quantum Phase Flip

Mind-Bending Quantum Phase Flip - RF Cafe"Quantum systems don't just transition between phases - they do so in ways that defy classical intuition. A new experiment has directly observed these dissipative phase transitions (DPTs), revealing how quantum states shift under carefully controlled conditions. This breakthrough could unlock powerful new techniques for stabilizing quantum computers and sensors, making them more resilient and precise than ever before. A new frontier phase transitions, like water freezing into ice, are a familiar part of everyday life. In quantum systems, however, these transitions can be far more extreme, governed by principles like Heisenberg's uncertainty..."

DX Hams Do Get Around

DX Hams Do Get Around (November 1940 Boys' Life Article) - Airplanes and RocketsIn this November 1940 issue of the Boy Scouts Boys' Life magazine, amateur radio operators, or "hams," are described as having the ability to communicate across vast distances, connecting far-flung locations such as Goulds, Florida, Cali, Colombia, Cairo, Kenilworth, England, Bombay, and Brisbane. These operators, licensed by the Federal Communications Commission, engage in various activities such as talking to distant stations, participating in contests, and providing emergency communication during natural disasters. With call letters assigned by international treaty, these stations use a combination of code and phone to make contact, exchanging reports and QSL cards. The Radio merit badge was first offered in 1918 and has been...

Thanks Again to ConductRF for Continued Support!

ConductRF coaxial cables & connectors - RF CafeConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 

Electronic Razor

Electronic Razor, April 1962 Radio-Electronics - RF CafeThe date approacheth when, according to Western customs, every body needs to stand a vigil against the attempt of another body to make him or her a fool. That date is of course April 1st, aka, April Fools' Day. Many of the technical magazine we grew up with - and some still today - engage in the ruse. Innovator and publisher Hugo Gernsback, who's long list of accomplishments includes this Radio-Electronics magazine, often contributed his own wit to the April editions. The usual scheme is to make the article just authentic enough to be possibly real, while including features outrageous enough to clue the read that he is being "had." Experienced subscribers knew that the Mohammed Ulysses Fips byline was sure to deliver an April Fools delight. Here, Mr. Fips expounds on the newfangled "Electronics Razor..."

Photon Entanglement Miniaturizes Quantum Computers

Photon Entanglement Miniaturizes Quantum Computers - RF Cafe"Quantum computing has long struggled with creating entangled photons efficiently, but a team of researchers has discovered a game-changing method using metasurfaces - flat, engineered structures that control light. By leveraging these metasurfaces, they can generate and manipulate entangled photons more easily and compactly than ever before. This breakthrough could open the door to smaller, more powerful quantum computers and even pave the way for quantum networks that deliver entangled photons to multiple users..."

Waveguide Temperature Rise

Temperature Rise in Rigid Waveguide, January 17, 1964 Electronics Magazine - RF CafeHere is a chart you don't see every day - "Temperature Rise in Rigid Waveguide." The company, Engineering Antenna Systems, of Manchester, New Hampshire, that published the chart in a 1965 edition of Engineering magazine, does not exist anymore. They were probably bought by someone else, but I could not even find an honorable mention of them in a Google search. Given the very low attenuation of properly sized and installed waveguide, it is hard to imagine a temperature rise of 500°F; however, when megawatts are pumped into it even a couple tenths of a decibel of attenuation per 100 feet results in a lot of power loss. Noted is how attenuation - and therefore temperature rise - is greater for frequencies at the lower end of the waveguide's operational range. Temperature rise numbers are for natural convection in free air...

everything RF Interviews Ernest Werbel

everything RF's Interview with Ernest Werbel from Werbel Microwave - RF CafeHere is an inspiring interview of Werbel Microwave's Ernest Werbel - a case of pulling oneself up by one's own bootstraps --- everything RF recently interviewed Ernest Werbel, the Chief Design Engineer of Werbel Microwave. He is from Livingston, NJ, and got his associates in EE Technology, at County College of Morris. Ernest completed his Bachelors in Electronics and Computer Engineering Technology from NJ Institute of Technology. He founded Werbel Microwave in 2014. Q. Can you tell us about Werbel Microwave? When did you start the company and how has it evolved over the years? Ernest Werbel: Firstly, thank you for the opportunity to participate in the everything RF community. I appreciate everything that Raghav and his team have done for us since the beginning, getting our products listed on everything RF and featuring our products in the email blasts... As a child and teen in the 90s, I was always interested in electronics. When I was very young, a radio was a magical box with a voice. Later, when my grandparents passed in '97, my parents and I were cleaning out their home in Brooklyn. Among other things were many old and broken consumer electronic items...

Have You Seen Him?

Have You Seen Him?, April 1935 Short Wave Craft - RF CafeToday we have missing persons notices printed on milk cartons and computer-aged pictures of missing kids on bulletin boards at Walmart, and of course the Internet with all its various forms of publicity. In 1935, evidently, an electronics magazine was a proper venue for placing a missing person ad. At the time there was no convenient and accessible way for family members to reach out to a nationwide audience other than to place ads in magazines and/or newspapers in remote locations. I thought it odd to see such a placement in this edition of Short Wave Craft magazine, but considering the aforementioned, doing so is entirely reasonable for a worried family. I wonder how much it cost to place the notice? It's heartbreaking, really...

Engineering & Tech Headlines <Archives>

• 2025 Tech Jobs Expected to Take Off

• Semiconductor Industry Faces a Seismic Shift

• 76% of News Consumers Still Use AM/FM

• FCC Spectrum Rules to Support Advanced Flight Technologies

• Radio Attracts High Purchasing Power Consumers

Turn Your Vertical Antenna into a Rotatable Beam

Turn Your Vertical Antenna into a Rotatable Beam (QST) - RF CafeI'm always aware of the old saying that it is better to remain silent and thought a fool, than to open your mouth and remove all doubt, but I'll take the risk here. The ARRL's QST magazine has for decades in the April issue published at least one unannounced "April Fool" item. I think I found at least two for 2025. While enthusiastically reading "Turn Your Vertical Antenna into a Rotatable Beam," (p60), it didn't occur to me that this was the April issue, and I was in awe of Jay Kolinsky's (NE2Q) intuition and creativity in devising a scheme to get directivity from his standard vertical whip antenna. By sliding a carbon fiber tube with a narrow slit along the length over top of the antenna, a 14 dB increase was realized in the direction of the slit. NE2Q has named his invention the Loof Lirpa Slot (LLS). What's in a name - Juliet?. Is a patent in the works?
CW Corporation of America's "Snappy Training Key" - RF CafeThe other suspect is the CW Corp. of America's "Snappy Training Key," reported on page 95 by Ellwood Brem (K3YV). You need to log in to read the articles, or borrow a hard copy from a Ham friend.

Today in Science History

Today in Science History - RF Cafe

Radio Term Illustrated - "Cross" Modulation

Radio Term Illustrated - "Cross" Modulation, December 1939 Radio News - RF CafeHere is another of the "Radio Term Illustrated" type of comic, which appeared in the December 1939 issue of Radio News magazine. The DXing Hams can get a bit animated when trying to squeeze the last picowatt out of a long distance contact. I'm not sure why the guy is depicted as a country hick when for certain there were plenty of polished city slickers who resorted to the same antics. A big list of other electronics-themed comics is at the bottom of the page, many of which contain other of the "Radio Term Illustrated" style.

For the Record: Popular Electronics Announcement

For the Record: Popular Electronics Announcement, August 1954 Radio & Television News - RF CafeRadio Amateur News began life in July 1919, then changed its name a year later in July 1920 to Radio News. In August 1948 the title was again changed to Radio & Television News, then shortened to Radio & TV News in May 1959. Publication continued through April 1959. The next month's issue (May 1959) was entitled Electronics World, with Radio & TV News as a subtitle, and ran through December 1971, when it merged with Popular Electronics. Popular Electronics began publication as a new magazine in October 1954 and printed its final issue in October 1982. The next month it became Computer & Electronics, which continued until April 1985. From May 1985 through January 1989 it was called Hands-on Electronics. Believe it or not, in January 1990...

Radio Data Sheet 333 for General Electric Model 100

Radio Data Sheet 333 General Electric Models 100, 101, 103 and 105, March 1946 Radio-Craft - RF CafeIt has been a while since posting on of these Radio Data Sheet 333 that often appeared in vintage electronics magazines like Radio-Craft. This one is for General Electric Radio Models 100, 101, 103 and 105. The RadioMuseum.org website has a very nicely restored General Electric Model 103 radio. Per their description: "The General Electric 103 is an AC/DC operated 5 tube BC band receiver. The BC band frequency tuning range is 540-1600 kHz. Has built-in loop antenna with provisions for connecting an external antenna. The following models use the same schematic and chassis but have different cabinets..." A few Model 100 versions show up on eBay in case you might be interested in acquiring one...

How Intermodulation Distortion (IMD) Results from Nonlinearity

Intermodulation Distortion, February 1960 Electronics World - RF CafeAudio distortion is most often expressed as total harmonic distortion (THD) as opposed to intermodulation distortion (IMD). As the name suggests, THD is a measure of harmonic power content relative to the fundamental frequency (a single tone) from which harmonics are created. IMD on the other hand, is generated from the nonlinear mixing of two or more tones, with the products being non-harmonically related to the original tones. The author's discussion of audio frequency IMD applies equally to radio frequency IMD. Intentionally generated harmonic components can enhance sound quality due to being consonant, whereas IM products create dissonant tones not directly related to the originals...

Microwaves - Receiving and Transmitting Antennas

Microwaves - Receiving and Transmitting Antennas, December 1949 Radio-Electronics - RF CafeThis is the eighth and final installment on a "Microwaves" series of articles in Radio-Electronics magazine by author C.W. Palmer. Each part is a stand-alone tutorial that does not rely on previous parts to be useful. Unlike most of the preceding articles that dealt in one way or another with waveguide, this final one concerns "receiving and transmitting antennas for microwave communication." It touches lightly on various types of antennas, field patterns, impedance matching, and applications. If you've been around for a while, you've likely seen it all before, but there are some nice photos of antennas designed and deployed by Bell Telephone Laboratories for their nationwide microwave telephone relay network. Bell Labs has done a lot of ground-breaking research in all aspects of communications technology...

Getting Feedback Straight

Getting Feedback Straight, March 1958 Radio-Electronics - RF CafeFeedback has been widely misunderstood by many electronics enthusiasts, even those who have a fairly extensive background in circuit design (that which does not involve feedback). In fact, there have been instances of articles being printed in magazines like Popular Electronics, Radio-Electronics, etc., where the authors got relatively simple feedback equations wrong due to improper summing of nodes, necessitating a correction in a later issue based on reader feedback (a convenient and appropriate word for this comment). This article discusses feedback in audio circuits to avoid distortion, but the concepts apply to any frequency of operation. It is possible in many cases to implement seat-of-the-pants feedback schemes successfully, but if you need a specific response and guaranteed stability...

Raytheon Numerical Indicator Tubes and Data Display Devices

Raytheon Numerical Indicator Tubes and Data Display Devices Advertisement, November 15, 1965 Electronics Magazine - RF CafeBefore there were side-view neon numerical indicator vacuum tubes there were top-view neon numerical indicator vacuum tubes. Nixie tubes and pixie tubes were featured in "Readouts and Counter Tubes" in the October 1959 issue of Electronics World magazine. At the time, most were top-view designs whose size was restricted by the diameter of the tube (typically about 0.8"). Switching to a side-view format did not enable the overall width to increase much, but the aspect ratio permitted taller displays with characters that appear as normally seen (rather than being squashed in height). This advertisement in a 1965 issue of Electronics magazine for numerical indicator tubes from Raytheon were likely some of the first side-view models available from any manufacturer...

Reader Letter: Waveguide

Reader Letter: Waveguide, May 4, 1964 Electronics Magazine - RF CafeThis letter submitted to Electronics magazine by reader Fred Standish really should have been saved for the next April issue. He writes concerning an attempt to mathematically describe the three-port circular-to-rectangular waveguide transition for the pictured configuration. If I remember correctly, the first time I saw that optical illusion was sometime in the early 1970s. The drawing showed Alfred E. Neuman (the red-haired, freckled-faced "Me Worry? guy from Mad magazine) attempting to don a pair of pants (a triplet of pants in that case?) sewn to resemble the three-legged configuration - known unofficially as the "Impossible Trident." I was in my early teens at the time and though it was awfully clever. After doing a little research, I found that the first instance of the Impossible Trident in Mad magazine was on the cover of the March 1965 issue ...

Hi-Fi Quiz

Hi-Fi Quiz, October 1955 Radio & Television News - RF CafeHere is a quick Hi-Fi Quiz for all you audiophiles out there. Although it appeared in a 1955 issue of Radio & Television News magazine, save for question #10 all of Q's and A's still apply to today's equipment. Even that one can be easily guessed. Q4 might seem a bit foreign, but think of the "groove" type as applying to 78, 45, or 33-1/3 rpm platters and you'll do OK. Question #7 could be a baffler (pun intended - you'll see how) were it not for one obviously invalid option that it takes an RF guy (or gal) to recognize its inanity. Good luck. BTW, I missed Q1, but should have known better.

Engineering & Science Crossword Puzzle for May 19

Engineering & Science Crossword Puzzle May 19, 2019 - RF CafeThis week's crossword puzzle will keep you busy for a while. Since 2000, I have been creating custom engineering- and science-themed crossword puzzles for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out on whether or not this type of mental challenge helps keep your gray matter from atrophying in old age, but it certainly helps maintain your vocabulary and cognitive skills at all ages. A database of thousands of words has been built up over the years and contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure...

Hytron's Master Tube Tester

Hytron's Master Tube Tester, October 1944 Radio News - RF CafeFounded in 1921 in Salem, Massachusetts, Hytron Corporation started out making vacuum tubes, then after being bought by CBS in 1951 they moved into the realm of semiconductor production. This story from a 1944 issue of Radio News magazine extolled the virtues of Hytron's Master Test Station for its ability to quickly and accurately measure a wide variety of tubes. Auto-ranging voltage regulators, parallax-free meters with auto-ranging scales, safety fusing, and easy servicing were among it notable features. To me, a parallax-free meter is one with a mirror behind the needle used to assure the operator is looking straight-on at the scale, but in this case it meant the array of meters was arranged in a semi-circle so that the operator was naturally looking perpendicular to the meter faces from a fixed vantage point. The level of automation no doubt reduced measurement errors...

GE Model M-49 Radio-Phonograph Restoration by Jeff B.

General Electric Model M-49 Radio-Phonograph - RF CafeRF Cafe visitor Jeff B. of Beverly, MA, sent me these photos of his General Electric Model M-49, 4-tube radio-phonograph, dual-wave superheterodyne set that he is going to restore to working order. It appears to be in extremely nice condition for a 1930s era unit. He found the Radio Service Data Sheet from a January 1935 issue Radio-Craft magazine that I posted back in October 2016. These are now the only images of the M-49 anywhere I can find on the Internet...

Engineering & Technical Headlines Crossword Puzzle for September 22

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

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...

Fastest Electronic Device: Josephson Junction

Josephson Junction - Fastest Electronic Device, May 1973 Popular Electronics - RF CafeThe Josephson effect was predicted in 1962 by British physicist Brian David Josephson. It postulated the possibility of a resistance-less path for electrical current across an extremely thin insulator sandwiched between two superconductors. Dr. Juri Matisoo, of IBM, is credited with building the first Josephson junction switch in 1967, demonstrating sub-nanosecond switching times. Back in the day, superconducting materials, like graphene, were resources available only to well-funded research establishments like major corporations, universities, and government facilities. Now, anyone with an interest can order both...

Homepage Archives for March 2023

Homepage Archives for March - RF CafeHomepage Archives for March 2023. Items on the RF Cafe homepage come and go at a pretty fast rate. In order to facilitate fast page loading, I keep the size reasonable - under a megabyte (ebay, Amazon, NY Times, etc., are multiple megabytes). New items are added at the top of the content area, and within a few days they shift off the bottom. If you recall seeing something on the homepage but now it is gone, fret not because many years I have maintained Homepage Archives.

Introduction to Wave-Generation and Wave-Shaping

Introduction to Wave-Generation and Wave-Shaping - RF CafeUpon completion of this chapter, you will be able to: 1. State the applications of a resonant circuit. 2. Identify the conditions that exist in a resonant circuit. 3. State and apply the formula for resonant frequency of an AC circuit. 4. State the effect of changes in inductance (L) and capacitance (C) on resonant frequency (fr). 5. Identify the characteristics peculiar to a series resonant circuit. 6. Identify the characteristics peculiar to a parallel resonant circuit. 7. State and apply the formula for Q. 8. State what is meant by the bandwidth of a resonant circuit and compute the bandwidth for a given circuit. 9. Identify the four general types of filters. 10. Identify how the series- and parallel-resonant circuit can be used as a bandpass or a band-reject filter...

A $25,000 Sundial from Motorola?

A $25,000 Sundial?, December 1971 Popular Electronics - RF CafeIn 1970, engineers at the Hamilton Watch Company introduced the world's first solid state electronic digital watch called the Pulsar Time Computer. It went on sale commercially two years later, just a few months after this article appeared in the December 1971 issue of Popular Electronics magazine. Motorola created this "$25,000 Sundial," which represents the research and development cost of the LED clock display that the company predicted would one day lead to an inexpensive wristwatch. Maybe they hadn't seen the The Tonight Show show where it made its debut in 1970. The Pulsar Big Time watch retailed for $295 in 1972, which in 2018 is the equivalent of $1,777 (per the BLS Inflation Calculator). That's about three times the cost of the top end Series 4 Apple Watch today, and all the Pulsar watch could do was tell time...

RF Cafe Engineering Crossword Puzzle w/Weekly Headlines for August 5

RF Cafe Engineering Crossword Puzzle w/Weekly Headlines August 5, 2018 - RF CafeFor 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 list related to engineering, science, mathematics, chemistry, physics, astronomy, etc. At least 10 clues with an asterisk (*) in this technology-themed crossword puzzle are pulled from the past week's (7/30 - 8/3) "Tech Industry Headlines" column on the RF Cafe homepage. 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 directly related to this puzzle's theme, such as Hedy Lamar or the Bikini Atoll, respectively. Enjoy!...

Old World Standards Breaking Through: Reader Response

Old World Standards Breaking Through - Reader Response, August 1966 Popular Electronics - RF CafePopular Electronics reader Frederic D. Barber, Jr., was having none of the newfangled designations for standard physical units as reported in the April 1966 issue. He, and evidently many others, was not ready to accept the replacement of terms such as cycles per second (cps) with Hertz (Hz), or seemingly any other change that included honoring a person by using his/her name. We don't know whether...

Veterans Day Tribute 2020

Veterans Day Tribute 2020 - RF CafeThe eleventh hour of the eleventh day of the eleventh month - November 11th, at 11:00 am - that is when the armistice (cease fire) began in 1918, unofficially ending World War I. This music video Veteran's Day tribute is by Canadian citizen Terry Kelly. It was written after an experience he had on Veterans Day in 1999. Terry went blind at an early age, but has excelled as an athlete and a musician. "A Pittance of Time" is done in the finest Celtic tradition. Per the U.S. Department of Veteran Affairs website: "World War I – known at the time as 'The Great War' - officially ended when the Treaty of Versailles was signed on June 28, 1919, in the Palace of Versailles outside the town of Versailles, France. However, fighting ceased seven months earlier when an armistice, or temporary cessation of hostilities, between the Allied nations and Germany went into effect on the eleventh hour of the eleventh day of the eleventh month. For that reason, November 11, 1918, is generally regarded as the end of 'the war to end all wars...'"

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