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Today in Science History

What's Your EQ?

What's Your EQ?, February 1962 Radio-Electronics - RF Cafe Here we are with another set of three "What's Your EQ?" circuit challenges, these from the February 1962 issue of Radio-Electronics magazine. As usual, those challenges provided by Jack Darr are the purview of television servicemen of the era. The photo shown of the problematic CRT display looks like a chest x-ray or maybe hieroglyphics in the dark corner of a cave, but evidently the artifacts are readily identifiable to an initiated few. The Forbidden Current Path circuit answer is not what I thought it would be. I maintain that whether my answer or the designer's answer is correct depends on the physical...

New Wireless Data Rate Record Set

New Wireless Data Rate Record Set - RF Cafe"A new world record in wireless transmission, promising faster and more reliable wireless communications, has been set by researchers from UCL. The team successfully sent data over the air at a speed of 938 Gb/s over a record frequency range of 5–150 GHz. This speed is up to 9,380 times faster than the best average 5G download speed in the UK, which is currently 100 Mb/s or over. The total bandwidth of 145 GHz is more than five times higher than the previous wireless transmission world record. Typically, wireless networks transmit information using radio waves over a narrow range of frequencies..."

Sputnik: A Brief History

Sputnik: A Brief History - RF CafeSputnik refers to the first series of satellites launched by the Soviet Union. The word "Sputnik" means "satellite" in Russian. The launch of Sputnik 1 on October 4, 1957, marked a monumental moment in human history, heralding the dawn of the Space Age and sparking a fierce technological competition known as the Space Race between the United States and the Soviet Union. This satellite, the world's first artificial one, orbited Earth at an altitude of roughly 215 to 939 kilometers and broadcast a radio signal that astonished the world, particularly in the United States, where it spurred rapid advancements in aerospace and scientific research. The successful launch of Sputnik was an achievement that was years in the making, involving a combination of visionary planning, political motives, and intensive engineering by some of the Soviet Union's top scientists.

Blog: Air Quality Measurements with Particle Counters

Axiom Test Equipment Blog: Provide Essential Air Quality Measurements with These Particle Counters - RF CafeTranscat | Axiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post entitled "Provide Essential Air Quality Measurements with These Particle Counters" that covers how particle counters can provide essential measurement capabilities that can help avoid contamination and support high manufacturing yields. These measurement tools can detect and measure microscopic particles suspended in air that can contaminate the most carefully planned manufacturing lines. Air particle counters can be designed for various...

Receiving U.S. Satellite Signals

Receiving U.S. Satellite Signals, March 1958 Radio News - RF CafeIn 1958, most people were not accustomed to seeing the now-familiar maps plotting sinusoidal courses of satellites across the face of the earth. It had only been in October of the previous year that any object other than the moon was in orbit around our home planet - that was U.S.S.R.'s Sputnik. Just as people of all ages and all backgrounds enthusiastically joined in the newfangled phenomenon of aeroplanes after the Wright Brothers flew their fragile craft at Kitty Hawk, electronics communications and scientists worldwide hopped aboard the satellite train. This article from a 1958 issue of Radio & TV News magazine provided insight into the construction and flight characteristics...

Thanks Again to LadyBug Technologies for Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Radio and Television News - Predictions

Radio and Television News, January 1969 Electronics World - RF CafeWhat were some of the top issues of the radio and television industry half a century ago? In a lot of respects, the same things that concern it today. A ready supply of service technicians was a concern that was taken seriously by the Electronics Industry Association (EIA). While there are not many local repair shops for electronics products nowadays, there is still a huge demand to techs who are willing and able to do the hard work of keeping the world's communication infrastructure operational - climbing towers, repairing cell equipment. Now, as then, good pay, job security, benefits, and respect for the job being done were at the top of...

RIGOL Introduces Oscilloscope & Generator Lines

Impressive Performance at an Impressive Price: RIGOL Introduces Oscilloscope & Generator Lines - RF CafeIn a parallel to the traditional test setup of signal generation and signal acquisition, RIGOL Technologies announced today the latest additions to its portfolio of performance measurement equipment with the introduction of the DG5000 Pro Series Generators and DHO/MHO5000 Series Oscilloscopes. The DHO/MHO5000 Series bring next-level performance to RIGOL's respected line of high-resolution oscilloscopes, while the DG5000 Pro generators do the same for the company's capable Pro Series arbitrary waveform generators...

Basic Electronic Counting

Basic Electronic Counting, March 1958 Radio News - RF CafeWhen selecting articles for posting here on RF Cafe, I like to include ones that are directed toward newcomers to the field of electronics as well as for seasoned veterans. This piece from a 1958 issue of Radio & TV News magazine entitled "Basic Electronic Counting," is a prime example in that it introduces the concept of binary numbers. We've all been there at some point in our careers. A big difference between now and when this article appeared is that in 1958, almost nobody was familiar to binary numbers, and fuggetabout [sic] octal and hexadecimal. Only those relatively few people designing and working with multimillion dollar, vacuum tube-based digital computers installed in universities, megacorporations, and government research facilities had ever dealt with digital numbers. The earliest example of powers of two I remember was back in junior high school. It had to do with a

Art of Invention Constantly Reinvented

Art of Invention Constantly Reinvented - RF cafe"Every invention begins with a problem - and the creative act of seeing a problem where others might just see unchangeable reality. For one 5-year-old, the problem was simple: She liked to have her tummy rubbed as she fell asleep. But her mom, exhausted from working two jobs, often fell asleep herself while putting her daughter to bed. 'So [the girl] invented a teddy bear that would rub her belly for her,' explains Stephanie Couch, executive director of the Lemelson MIT Program. Its mission is to nurture the next generation of inventors and entrepreneurs. Anyone can learn to be an inventor, Couch says, given the right resources and encouragement. 'Invention doesn't come from some innate genius, it's not something that only really..."

Mechanical Filters

Mechanical Filters, April 1969 Electronics World - RF CafeMechanical filters of the type described in this 1969 Electronics World magazine article are yet another example of the genius of some people. They are actually a form of electromechanical device in that the applied electrical signals are first converted into mechanical signals, followed by resonant mechanical elements that discriminate according to frequency, and finally a conversion back to an electrical signal is made. It is fundamentally the same principal as a crystal, SAW, or BAW filter, albeit each with distinctly different methods and topologies. Mr. Donovan Southworth, of Collins Radio, presents the basics of mechanical filters in this brief write-up...

Thanks Again to LadyBug Technologies for Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Electronic Test Paper

Electronic Test Paper, July 1963 Radio-Electronics - RF CafeAttempts at making an electronically printed facsimile (fax) of an original document at a location distant from the source have been around for quite a while. As mentioned by Radio-Electronics magazine editor Hugo Gernsback in this article, Samuel Morse had a crude working device for printing messages on paper even before his eponymously named code of dots and dashes became famous in 1837. A couple decades earlier, a fellow named John Redman Coxe, of Philadelphia, Pennsylvania, devised a method of electronically printing images and text on paper using a conductive solution and a direct current pile (aka battery). Dr. Coxe, a physician, is not a well-known figure in the electronics world, but in his day...

"Edge of Chaos" High-Performance Microchips

"Edge of Chaos" High-Performance Microchips - RF Cafe"Researchers have discovered how the 'edge of chaos' can help electronic chips overcome signal losses, making chips simpler and more efficient. By using a metallic wire on a semi-stable material, this method allows for long metal lines to act like superconductors and amplify signals, potentially transforming chip design by eliminating the need for transistor amplifiers and reducing power usage. A stubbed toe immediately sends pain signals to the brain through several meters of axons, which are composed of highly resistive fleshy material. These axons operate using a principle known as the 'edge of chaos,' or semi-stability, enabling the swift and precise transmission of information..."

Japanese Trade-Name Directory

Japanese Trade-Name Directory, August 1969 Electronics World - RF CafeThe January 1969 issue of Electronics World magazine published an extensive list of Japanese company trade names and their addresses. Many of them went out of business or were bought by other corporations long ago, as occurs in all countries. "Aiwa" is listed twice, but that might have been a legitimate duplication due to separate locations (BTW, I owned an Aiwa stereo at one time). My first "real" cassette tape deck was made by TEAC (founded in 1953 as the Tokyo Electro Acoustic Company) and my first "real" stereo receiver was made by Sansui. I remember the line in "Back to the Future 3" where Doc Brown, having time-travelled from 1955, makes a disparaging remark about a circuit in the DeLorean failing because of it being labeled "Made in Japan." Marty counters...

Engineering & Tech Headlines <Archives>

• ARRL Defends 902-928 MHz Amateur Radio Band

• FCC's Auto Safety Spectrum Rules

• $5M in U.S. Chips Act Money to Metrology Projects

• U.S. State Department Approves Surveillance Radar System Sale to Romania

5G Americas ITU IMT-2030 Vision for 6G White Paper

John Redman Coxe: A Short Biography

John Redman Coxe: A Short Biography - RF Cafe - RF CafeJohn Redman Coxe was a prominent American physician, scientist, and innovator born on September 20, 1773, in Philadelphia. Coxe's intellect and curiosity drove him toward an illustrious career in both medicine and early scientific exploration, which included experimentation in electrochemistry. He graduated with a degree in medicine in 1794, setting the course for his lifelong journey into medicine and early scientific innovation. Coxe broadened his approach to medicine and science, inspiring him to explore the convergence of scientific methods and practical applications. John Redman Coxe is most remembered not only for his contributions to medicine but also for his interest in experimental physics, particularly in the field of electrochemistry...

Thanks to TotalTemp Technologies for Continued Support!

TotalTemp Technologies - RF CafeTotalTemp Technologies has more than 40 years of combined experience providing thermal platforms. Thermal Platforms are available to provide temperatures between -100°C and +200°C for cryogenic cooling, recirculating & circulating coolers, temperature chambers and temperature controllers, thermal range safety controllers, space simulation chambers, hybrid benchtop chambers, custom systems and platforms. Manual and automated configurations for laboratory and production environments. Please contact TotalTemp Technologies today to learn how they can help your project.

Vibration and Shock - Nature's Wrecking Crew

Vibration and Shock - Nature's Wrecking Crew, August 1966 Radio-Electronics - RF CafeWhen I saw this 1966 Radio-Electronics magazine article entitled, "Vibration and Shock - Nature's Wrecking Crew," for some reason the first thing I thought of was "The Wrecking Crew," that anonymously played the music for a huge number of popular singers - mostly those without prominent bands of their own during the 1960s and 1970s rock-and-roll era. ...but I digress. My introduction to the potential deleterious effects of vibration on electronics was in the 1970s, with airborne receivers and servos in my radio controlled model airplanes. Even though they were transistorized, vibration from glow fuel engines could wreak havoc with potentiometers in servos and solder joints everywhere, including battery packs. I remember seeing the control surfaces jitter...

Raytheon Needs Tube Design Engineers

Raytheon Manufacturing Company Needs Vacuum Tube Engineers, July 1944 QST - RF CafeYou don't see jobs advertisements like this anymore. Here is an ad that appeared in the the July 1944 edition of QST (the American Radio Relay League's, ARRL's, monthly magazine), placed by Raytheon Manufacturing Company (now just Raytheon Company), looking for vacuum tube design, test, and processing engineers. Licensed amateur radio operators were in high demand during the war years because of their knowledge and enthusiasm for electronics and wireless communications. I hope you didn't come to this page hoping to really find a tube designer job available. Of course, there are still vacuum tubes being designed for TWTs and magnetrons, but those are few and far between...

The Carborundum Signal Detector

The Carborundum Signal Detector - RF CafeThe "carborundum" signal detector, an innovative device developed by engineer General H. H. C. Dunwoody in the early 20th century, represents a significant advancement in radio technology, particularly in the context of crystal detectors used for receiving radio signals. This device utilized the unique properties of silicon carbide, also known as carborundum, which was synthesized in the late 19th century by Edward Goodrich Acheson. The connection between Dunwoody and the material lies in the application of carborundum as a semiconductor in radio signal detection. The operational theory of the carborundum signal detector is rooted in its ability to rectify alternating current (AC) signals. When radio waves, which are essentially electromagnetic waves...

Lossless Electronics with Innovative Quantum Sandwich

Lossless Electronics with Innovative Quantum Sandwich - RF Cafe"Researchers have created a cutting-edge structure by placing a very thin layer of a special insulating material between two magnetic layers. This new combination acts as a quantum anomalous Hall insulator, significantly broadening its potential use in developing ultra-efficient electronics and innovative solar technology. A Monash University-led research team has found that a structure featuring an ultra-thin topological insulator, sandwiched between two 2D ferromagnetic insulators, transforms into a large-bandgap quantum anomalous Hall insulator. This heterostructure opens the door to ultra-low energy electronics and even topological photovoltaics..."

Printed-Circuit Laminates

Printed-Circuit Laminates, October 1969 Electronics World - RF CafeThis is another of a series of articles on printed circuit boards (PCBs) that appeared in the October 1969 issue of Electronics World magazine, reporting on the latest and greatest advances in printed circuit board technology. Already in production were rigid multi-layer laminates, flexible plastic laminates, and special-purpose laminates for hazardous duty applications. Author Norman Skow does not mention how many layers were routinely accomplished at the time. Plated-through holes were a relatively recent thing for high volume manufacturing. Of course population of PCB components was still a completely manual procedure since pick-and-place machines were still a couple decades away...

Beyond the Transistor

Beyond the Transistor, July 1963 Radio-Electronics - RF CafeThis "Beyond the Transistor" article by Hugo Gernsback, which was printed in a 1963 issue of Radio-Electronics magazine, had as its subject not the transistor in general, but specifically its potential use as a low noise, high sensitivity radio frequency signal detector. Mr. Gernsback does a useful historical review of signal detectors, beginning with Heinrich Hertz's radio detector in 1888, then progressing through Edouard Branly's 1892 coherer, Gustave-Auguste Ferrie's and Reginald Fessenden's electrolytic detector of 1903, then Greenleaf Pickard's crystal detector in 1906. Lee de Forest's early work on vacuum tubes was directed toward a signal detector, and ultimately resulted in his Audion amplifier. In 1948, Bell Laboratories' Shockley, Brattain and Bardeen...

Swirling Magnons Set to Revolutionize Computing

Swirling Magnons Set to Revolutionize Computing - RF Cafe"Researchers have developed a groundbreaking method to create more compact and energy-efficient computing devices using magnonic circuits. By utilizing alternating currents to generate and steer spin waves in synthetic ferrimagnetic vortex pairs, this new approach promises significant advancements over traditional CMOS technology, potentially leading to the next generation of computing systems. The central processing units (CPUs) in our laptops, desktops, and phones rely on billions of transistors built with CMOS technology. As the demand to shrink these devices..."

The Mystery Set

The Mystery Set, December 1934 Radio-Craft - RF CafeIn the 1930s, electricity and electronics were mysteries to most of the population. The concepts were relatively new and few had a firm grasp on the technology. That reality was exploited by Hugo Gernsback during the 1934 Electrical Exposition to challenge attendees to discover how the radio receiver sitting on the top of an empty, clear glass case was being powered. It was a clever ruse that reportedly stumped most people. The secret is revealed here in this 1934 issue of his Radio-Craft magazine. BTW, my guess is that an even smaller proportion of our current citizens would be able to figure it out, or for that matter even realize that maybe there should be a power source of some sort...

Mac's Radio Service Shop: Handling Complaints

Mac's Radio Service Shop: Handling Complaints, September 1954 Radio & Television News - RF CafeOften I have said I would like to have been born three decades earlier to have lived during the golden era of radio and TV, and owned a local service shop. Having arrived on Earth in 1958, by the time I was old enough to consider electronic servicing as a career, the industry was in full transition mode to solid state electronics. I remember the TV repair guy working in our living room with tools and test equipment spread out on the floor. Growing up in a lower middle class (or maybe it was an upper lower class) household, our television and radios (both in the house and in the old 6-cylinder Rambler) used vacuum tubes until sometime in the 1970s. Transistorized stuff was for the rich folk in the neighborhood over. Upon enlisting in the USAF in 1978, the air traffic control radar I worked on used vacuum tubes for the primary airport surveillance (ASR) radar and for the precision approach radar (PAR)...

Carl & Jerry: Slow Motion for Quick Action

Carl & Jerry: Slow Motion for Quick Action, April 1963 Popular Electronics - RF CafeOur two intrepid techno-sleuths, Carl Anderson and Jerry Bishop, are in college by now, but that does not keep them from applying their well-honed mystery solving skills to hometown situations while on spring break. The boys invoke the scientific method of Mr. R.R. Dibble, a New Zealand scientist, to help prove to county commissioners that a certain part of their critical infrastructure was in need of repair. An nth-generation farmer's observation was not proof enough, so indisputable empirical data would be needed. Real-life inventors and company's unique instruments are often incorporated into the Carl & Jerry series by John T. Frye that ran for many years in Popular Electronics...

Carl & Jerry: Two Detectors

Carl & Jerry: Two Detectors, February 1955 Popular Electronics - RF CafeListen to the Podcast! Just in time for Halloween, John T. Frye's teenage sleuths Carl & Jerry unexpectedly recorded a late-night conversation between two men where they plot how to dispose of the "body" when death occurred as a result of prolonged choking. Employing their trademark technical prowess and scheming ability, the pair sets a trap for the perpetrators and dutifully summon the authorities as they complete their nefarious act of the night before. Halloween comes into play because the recordings were made for use in creating sound effects during the reading of Edgar Allen Poe's "The Pit and the Pendulum" and "The Cask of Amontillado." This story, which appeared in a 1955 issue of Popular Electronics magazine, is a little dark compared to a typical story...

Washington Newsletter - Patent Rulings

Washington Newsletter - Patent Rulings, October 4, 1965 Electronics Magazine - RF CafeJust to remind you that patent laws are continually being monkeyed with by lawmakers and challenged in court by litigants, here is a news item from a 1965 issue of Electronics magazine reporting on a Supreme Court case brought by Hazeltine Research regarding their patent application for a microwave switch. Evidently over time the Supreme Court had been raising the bar on patent filings by requiring a higher degree of uniqueness for new inventions. The 1952 U.S. Patent Act, enacted by the U.S. Congress, simplified the terms of claims for new patents, thus making them easier to obtain, but according to critics, making new patents less valuable in the process. Now (in 1965), the Supreme court was moving itself back to ward the pre-1952 criteria. Judicial activism, anyone...

Electronic Noise Quiz

Electronic Noise Quiz, August 1962 Popular Electronics - RF CafeOK, class, put your books away and take out a pencil. Spread your chairs out because we're going to have a short test today. A collective sigh permeates the room. Remember those days? I still have nightmares over those moments, and they were decades ago for me. At least this "Electronic Noise Quiz" from the August 1962 edition of Popular Electronics won't affect your GPA. Sometimes PE's quiz illustrations are kind of hard to interpret, but this one does a pretty good job (except item 'E', but I'm not telling what it is since nobody helped me). You will need a fairly diverse background in consumer type electronics to do well, and having a few gray hairs will probably help as well. Good luck. BTW, my score was a somewhat embarrassing 80%...

Weller Soldering Gun Advertisement

Weller Soldering Guns, May 1952 Radio & Television News - RF CafeDo you think any tool company would publish an advertisement like this in today's hypersensitive environment? When Weller ran the ad shown below in the May 1952 issue of Radio & Television News magazine, nobody anywhere could have conceived of a world six decades later where the mere sight or mention of a gun would send snowflake types running for the nearest safe space (which, sadly, has a special symbol Safe Space sign - RF Cafe a la a nuclear fallout shelter). It is a little surprising that Weller still markets the tool as a soldering gun rather than, say a heavy-duty, finger-operated, palm-conforming, graspable soldering implement ;-(   Does anyone know whether soldering guns are allowed in schools these days? Zero Tolerance policies would require...

Power Supply Design

Power Supply Design, August 1945, Radio-Craft - RF CafeGood power supply design has always been key to good system function. As with so many other topics in electronics, the basics of power supply design are the same now as they were in 1945 when this article appeared in Radio-Craft magazine. We now have transistors rather than vacuum tubes, but otherwise issues of voltage regulation, current supply, ripple, and power dissipation remain. Off-the-shelf power supplies have been and are available where engineers have designed generic or special purpose units with a set of specifications which a system designer uses to integrate them into their products. Many times, though, it is necessary or preferred to have the power supply on the same circuit board or in the same enclosure as the functional part of the product, so it is up to the designer to do it all...

"Wireless" for Americans

"Wireless" for Americans, December 1955 Radio & Television News - RF CafeAuthor Lawrence Sharpe pointed in 1955 in this Radio & Television News article the potential for confusion when reading columns and advertisements written by our brothers from Across the Pond when they appeared in American electronics magazines. Most of us are familiar with valve vs vacuum tube, bonnet vs. hood (car), football vs. soccer, fag vs. cigarette, holiday vs. vacation, nappy vs. diaper, petrol vs. gasoline, torch vs. flashlight, flat vs. apartment. There are many more, but those come to mind. Read through this short list of purely electronics terms and learn that "earthed" is the same as our "grounded." One thing that surprised me was how the Brits had already adopted pico (e.g. pF) for the numerical unit of 10-12 while we were still using micromicro (10-6 x 10-6 = 10-12, e.g., μμF). Note how I omitted a comma...

Impedance Matching of Multiple Speakers

Impedance Matching of Multiple Speakers, April 1954 Radio & Televsion News - RF CafeI have five operational radios and speakers spread around my house (912 ft2, BTW) and in the basement. Only one of them is newer than 20 years old and the others are circa 1978 or earlier. AM or FM over-the-air radio is playing all day (when the el cheapo BSR turntable isn't spinning LP and 45 vinyl). In a couple instances I feed a stereo output into a mono speaker. With truly stereo-separated audio, listening to just the right (R) or left (L) channel does not do an adequate job of replicating the broadcast since often, particularly in music, the voice tends to favor one or the other of R or L. Simply tying the right and left channels together does not do the job because the low impedance of the speakers - typically 4 Ω or 8 Ω - causes noticeable distortion when doing so. The only way to achieve good sound is to use a power combiner that presents the proper impedance to each component...

Mac's Radio Service Shop: Barney is Promoted

Mac's Radio Service Shop: Barney is Promoted, May 1948 Radio News - RF CafeCertain things about John T. Frye are very apparent to the many of you familiar with techno-dramas - "Carl & Jerry" and "Mac's Service Shop" - and his many magazine articles on topics related to electronics and amateur radio: Mr. Frye has a good imagination, he is a good story teller, and he has a very deep knowledge of electronics theory, troubleshooting, repair, and practical operation. One particular aspect about him you might not know is that he spent most of his life in a wheelchair, as the result of polio. Born in 1910, John could not benefit from the polio vaccine invented by Dr. Jonas Salk in 1955. That was a mere three years before I was born. We are fortunate to live in these times when so much amazing medical research is happening to prevent, treat, and cure diseases, and while great advances have been made...

Stacked Yagi TV Antennas by Dave Jones, N1UAV

Stacked Yagi TV Antennas (Dave Jones, N1UAV) - RF CafeEvery once in a while an RF Cafe visitor writes to let me know that he or she found one of the vintage electronics magazine articles I post regularly useful. It helps to validate my efforts, which is critical for motivation to continue. A couple days ago Mr. Dave Jones (N1UAV), sent me a note about the stacked television antenna project he undertook after finding the "How to Stack TV Antennas to Increase Signal Strength and to Reduce Ghosts" article from the November 1965 issue of Popular Electronics magazine. His location about 90 miles outside of Nashville, TN, is a challenge for trying to receive a good signal from a television station from both an attenuation and multipath signal degradation perspective. Dave began with a single antenna, but was not happy with the performance. The results of adding the second antenna is amazing ...

Hi Tide in the Tweeter

Hi Tide in the Tweeter, October 1956 Popular Electronics - RF CafeBefore the current generation began destroying its hearing with smartphone earbuds, their parents and grandparents (that includes mine) destroyed our hearing with ridiculously powerful loudspeakers, often in boom boxes perched on shoulders right next to the ears (not me). The "concert hall" - or concert auditorium - experience has been long sought-after since recorded music has been available, which has only been about a century. As evidenced by the sudden increase in articles and advertisements in my growing collection of vintage electronics magazines, the early and mid 1950s saw a sudden swell of articles promoting the equally swelling supply of high fidelity (hi-fi) recording and playback equipment hitting the markets. Subjects ranging from homebuilt projects to reports of top end commercially products filled the pages each month. Television saw the same treatment in the late 1950s and early 1960s. All, of course, relied on vacuum tubes - with just enough relatively expensive semiconductors...

RCA Radio-Relay Television

RCA Radio-Relay Television, August 1945, Radio-Craft - RF CafeThe evolution of communications has been well documented both after the fact and necessarily before the fact based on the vision and determination of individuals and corporations. From grunts, hand and facial signals, and crude sketchings on cave walls to spoken and written languages. From couriers on foot and horseback, smoke signals, and light signals to wired telegraph and telephone. From wireless telegraph and telephone to television and the Internet, advancement has been continual both in large steps between the aforementioned fundamental communications venues to incremental advancements in technologies - analog to digital, vacuum tubes to semiconductors, simplex to multiplex, ever increasing access to regions of the electromagnetic spectrum from DC to light. This 1945 advertisement by RCA expounding the benefits of its recently implemented transcontinental microwave relay system was life changing at the time, but two decades later those tower networks would be supplemented and nearly replaced by satellite relay...

Carl & Jerry: Tussle with a Tachometer

Carl & Jerry: Tussle with a Tachometer, July 1960 Popular Electronics - RF CafeThis is a great example of how Popular Electronics and John T. Frye used the "Carl & Jerry" series to teach some basic electronics design principles through story telling. The same is true with his long-running "Mac's Service Shop" series of techno-dramas. In this adventure, the the two teenagers decide to build a tachometer from schematics they found in a magazine. They debate amongst themselves how the circuits works, the best way to assemble the circuit, component selection, vibration-tolerant mounting, and how to properly calibrate the tach to accurately display engine revolutions per minute (RPM). Being set in 1960, this is one of the first appearances of transistors in circuits rather than vacuum tubes. Transistors were still very mysterious - and even detested - by many electronics hobbyists and professionals, so pieces like this...

Army Studies Radio Wave Curvature

Army Studies Radio Wave Curvature, September 1956 Popular Electronics - RF CafeEarly investigations into RF signal atmospheric "ducting" was reported in this 1956-era article in Popular Electronics. Ducting effects were first noticed during World War II when Nazi broadcasts from occupied Paris were received occasionally in London. Scientists discovered that a small change in the humidity of the air near the surface has the effect of trapping radio waves, a trapping process dubbed "ducting." These waves are conducted as if they were inside of a metallic waveguide. Research by the U.S. Army Signal Corps determined a sudden temperature rise at around 50 to 200 feet above the surface appears to have the strongest effect...

Carl & Jerry: Two Detectors

Carl & Jerry: Two Detectors, February 1955 Popular Electronics - RF CafeListen to the Podcast! Just in time for Halloween, John T. Frye's teenage sleuths Carl & Jerry unexpectedly recorded a late-night conversation between two men where they plot how to dispose of the "body" when death occurred as a result of prolonged choking. Employing their trademark technical prowess and scheming ability, the pair sets a trap for the perpetrators and dutifully summon the authorities as they complete their nefarious act of the night before. Halloween comes into play because the recordings were made for use in creating sound effects during the reading of Edgar Allen Poe's "The Pit and the Pendulum" and "The Cask of Amontillado." This story, which appeared in a 1955 issue of Popular Electronics magazine, is a little dark compared to a typical story...

1953 Radio-Electronics Tech-Themed Comic

Electronics-Themed Comics, March 1953 Radio-Electronics - RF CafeIf you look through the hundreds of technology-themed comics that appeared various electronics magazines, many deal with the trials and tribulations of television repair and service. That is because in the introductory era of TVs, people were, understandably, infatuated with being able to not just hear but see what was happening in the broadcast. Radios and phonographs got a lot of coverage as well. Storylines involving a guy on the roof installing or repairing an antenna were considered particularly funny, especially if it depicted someone hanging precariously from a lead-in cable or a ladder rung. This comic addresses the all-too-common situation where sometimes a better picture was obtained using a makeshift antenna than with a bona fide, professionally designed antenna...

Mac's Service Shop: Buying and Using a Pocket Calculator

Mac's Service Shop: Buying and Using a Pocket Calculator, May 1974 Popular Electronics - RF CafeDo you remember your first calculator - electronic, that is (slide rules and abacuses don't count - actually they do, right?)? Mine was acquired sometime in the fall of 1976 during my first attempt at secondary education at Anne Arundel Community College in Maryland, where eventually, in 1987, I was awarded an Associate's degree in Engineering (which constituted the first two years of my eventual BSEE at UVM in 1989, on whose notable alumni list I am not). My name is not in AACC's list of notable alumni, either. But I digress. My calculator was a Texas Instruments model SR-50 that had a small red LED display. It cost about $100 ($445 in today's inflated money) and performed basic math with a few simple trigonometric and logarithmic functions. This edition of Mac's Service Shop, entitled, "Buying and Using a Pocket Calculator," has Mac telling sidekick Barney about the Hewlett Packard's HP-45 calculator. According to the Wikipedia entry, the HP-45 entered the market in 1973 at a list price of $395 ($2,084 today). That's the price of a high-end gamer's computer these days. Its features were about equal to my $100 SR-50 a decade later. For the budget minded calculator, he also recommended the Unicom Model 202SR...

Pearl Harbor Day Crossword Puzzle for December 7th

Pearl Harbor Day Crossword Puzzle for December 7, 2020 - RF CafeFor the sake of avid cruciverbalists amongst us, each week I create a new crossword puzzle that has a theme related to engineering, mathematics, chemistry, physics, and other technical words. This December 7th Pearl Harbor Day crossword puzzle has a few words and clues relating to the surprise attack in 1941. As always, the 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!!!

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