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Today in Science History

Electronics-Themed Comics

Electronics-Themed Comics, January 1962 Radio-Electronics - RF CafeI have written before about the love-hate relationship a lot of the buying public had with television and radio repair shops and repairmen - similar to car owners and mechanics. Lots of jokes and skits (what today is termed a "meme") were created back in the heyday of in-home entertainment to make light of the situation. These four electronics-themed comics from a 1962 issue of Radio-Electronics magazine are typical examples. The one from page 111 alludes to an issue that would almost never be seen today on a TV, unless maybe the AC power supply was on the fritz. A composite analog broadcast signal contained vertical and horizontal sync[ronization] components which...

3D-Shield Electronics from ESD

3D-Shield Electronics from ESD"Electrostatic discharge (ESD) protection is a significant concern in the chemical and electronics industries. In electronics, ESD often causes integrated circuit failures due to rapid voltage and current discharges from charged objects, such as human fingers or tools. With the help of 3D printing techniques, researchers at Lawrence Livermore National Laboratory (LLNL) are 'packaging' electronics with printable elastomeric silicone foams to provide both mechanical and electrical protection of sensitive components. Without suitable protection, substantial equipment and component..."

TV and Radio Repair Featured in "Dragnet"

Television and Radio Repair Featured in "Dragnet" - RF Cafe Video for EngineersMr. Bob Davis, a seemingly endless source of little known and/or long forgotten historical radio and television technical trivia, apprised me of this short segment from the 1960s Dragnet television series, starring Sgt. Joe Friday. It features a guy, who turns out to be a ... well, I won't spoil it for you ... who proudly professes his thirty year career as a radio repairman. "...started back in the days of the old Crosleys, Atwater-Kents, Farnsworths. Those were real radios, well built, well designed. Nothing cheap about any of them. They didn't have transistors in those days, just tubes as big as light bulbs. That meant heavy chassis, heavy transformers, and we didn't fix them by simply slapping in a new part, either. We fixed the old parts. I wish...

Square-Corner UHF Reflector Beam Antenna

The Square-Corner Reflector Beam Antenna for Ultra High Frequencies, November 1940 QST - RF CafeA new word has been added to my personal lexicon: "sphenoidal." Author John Kraus used it to describe the wedge shape of a corner reflector. The Oxford Dictionary defines "sphenoid" thusly: "A compound bone that forms the base of the cranium, behind the eye and below the front part of the brain. It has two pairs of broad lateral "wings" and a number of other projections, and contains two air-filled sinuses." This "square corner" configuration - essentially a "V" shape, is shown to exhibit up to 10 dB of gain while being relatively (compared to a parabolic reflector) insensitive...

General Relativity

Spacetime Distortion General Relativity - RF CafeAlbert Einstein's general theory of relativity, published in 1915, fundamentally reshaped the way scientists understand gravity, space, and time. It extended his 1905 special theory of relativity, which described how the laws of physics are consistent for all observers in uniform motion and how light's speed is constant in a vacuum. However, the special theory did not address accelerating reference frames or gravitational forces. Einstein's general theory tackled these limitations by proposing that gravity is not a force in the traditional sense, but rather a curvature of spacetime caused by mass and energy. This profound insight would alter the course of 20th-century physics, influencing cosmology, black hole theory...

Memristor Analog Switching Neuromorphic Computing

Memristor Analog Switching Neuromorphic Computing - RF Cafe"The growing use of artificial intelligence (AI)-based models is placing greater demands on the electronics industry, as many of these models require significant storage space and computational power. Engineers worldwide have thus been trying to develop neuromorphic computing systems that could help meet these demands, many of which are based on memristors. Memristors are electronic components that regulate the flow of electrical current in circuits while also 'remembering' the amount of electrical charge that previously passed through them. These components could replicate the function of biological..."

Reflections on the News

Reflections on the News, February 1969 Electronics World - RF CafeReading through the news items in the vintage electronics magazines provides a mixture of important historical facts and figures along with some predictions on the future of the industry. Some of the predictions turn out to be amazingly accurate, even though in retrospect they might seem obvious. Take, for example, Sylvania VP Dr. Robert Castor's foresight about how, "the future growth of the semiconductor industry lies in a major switch from the production of individual components to solid-state subsystems that can be used as building blocks in electronic designs." "Well of course," you might be temped to say; however, at the time there were still significant hurdles to overcome related to material purity, wafer size, photolithography...

Many Thanks to Reactel for Their Long-Time Support!

Reactel Filters - RF CafeReactel has become one of the industry leaders in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity, and waveguide designs, as well as state of the art high performance suspended substrate models. Through a continuous process of research and development, they have established a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact Reactel today to see how they might help your project.

Electronics in 2012 AD

Electronics in 2012 AD, October 1962 Radio-Electronics - RF Cafe2012 came and went more than a decade ago. The date was 50 years in the future back in 1962 when Radio-Electronics magazine editor Hugo Gernsback asked industry leaders to cogitate on possibilities of the state of electronics in 2012. Let's see how they did. One guy predicted our communications would be in the 100 THz to 1,500 THz band, using 2 decimeter antennas. Nope. Another believed we would be communicating with aliens on a regular basis. A military dude partly hit the mark by predicting 2- and 3-year-olds would be sitting in front of "televideo screens" (cellphones) learning Esperanto and "other basic studies." Bell Labs believed most audiovisual material, along with commerce, would be done electronically; i.e., the World Wide Web. I'm not quite sure how to interpret the IT&T guy's prediction of replacing microwave space transmission with light wavelength waveguide transmission. Seems bassackward to me...

The Phone Scam Gram

The Phone Scam Gram - RF CafeHere is a unique approach to discouraging scam callers. A lot of scam calls are themselves AI, so can one AI detect and aviod another? "Gangster Granny! Meet Daisy: O2's new weapon against scammers. O2 has unveiled its new, unique weapon in its fight against scammers: Daisy, an AI-powered assistant designed to keep fraudsters talking and waste their time. As part of Virgin Media O2's 'Swerve the Scammers' campaign, Daisy's mission is to distract scammers with realistic, rambling conversations, helping protect potential victims while raising awareness about fraud. Her lifelike conversations, peppered with stories about family or hobbies like knitting, have kept fraudsters on the line for up to 40 minutes..."

Special Relativity

Special Relativity - RF Cafe

Albert Einstein's special theory of relativity, a milestone in physics, transformed our understanding of space, time, and energy (mass). The theory, published in 1905, stemmed from Einstein's efforts to resolve inconsistencies in classical physics, specifically between Newtonian mechanics and electromagnetism as formulated by James Clerk Maxwell. By reconceiving space and time as interconnected and relative to the observer's frame of reference, Einstein established a framework that had profound implications for science and technology. To understand how this groundbreaking idea emerged, one must consider...

Werbel 2-Way Splitter for 500 MHz to 26.5 GHz

Werbel Microwave 2-Way Power Splitter for 500 MHz to 26.5 GHz - RF CafeWerbel Microwave's Model WM2PD-0.5-26.5-S is a wideband 2-way in-line power splitter covering of 500 MHz to 26.5 GHz with excellent return loss, low insertion loss, and high isolation performance. With ultrawideband performance, amplitude balance is typically 0.24 dB and phase unbalance is typically 2.6°. Insertion loss is low for the bandwidth, coming in at a typical 1.2 dB above 3 dB splitting loss. Return loss 16 dB typical. Isolation 18 dB typical. The device is precision-assembled and tested in the USA...

RCA Institutes Career Opportunity

RCA Institutes Ad, June 1969 Electronics World - RF CafeIf you wanted a career as an electronics technician at the end of World War II, the world was your oyster - so to speak. Electronics and communications trade magazines and publications like Mechanix Illustrated and Popular Science ran a plethora of ads monthly that offered unlimited opportunity to men seeking a career servicing the burgeoning market of postwar technological marvels. Even though the enclosures were not yet being marked with "No user serviceable parts inside," that fact was most people were not qualified - nor did they want - to monkey with the guts of radios, televisions, and other household appliances... (I provide a simulation to show the true zener diode circuit output)...

Electronics-Themed Comics

Electronics-Themed Comics, February 1962 Radio-Electronics - RF CafeTake time out of your busy workday to look at these three electronics-themed comics from the February 1962 issue of Radio-Electronics.. The page 32 comic reminds me of sometime in the late 1970s while working as an electrician (prior to enlisting in the USAF) when I was doing side jobs, and a guy had me wire up a receptacle for his big 25" screen (CRT) which he had mounted in a wall, with the chassis sticking out the back. It was in an upstairs room in a Cape Cod style house with lots of room behind the wall. He was a "man cave" pioneer with a full suite of high quality audiovisual equipment - even a Betamax machine! The page 81 comic exhibits the irony that would have existed in the day if American-made electronics equipment had been promoted in Japan, which they probably were not. In 1962, Japanese...

No Video for Satellite Direct-to-Cell

No Video for Satellite Direct-to-Cell - RF CafeAdmittedly, I mostly posted this because of the drawing. "While direct-to-cell (D2C) satellite communications were a big topic at the recent Brooklyn 6G Summit, the technology is already here, well before 6G's anticipated 2030 arrival. Apple and Google already offer D2C emergency messaging, and Starlink, T-Mobile and others are anticipated to follow. D2C satellite communications will be well established when 6G arrives. The 3GPP froze a 5G specification for Non-Terrestrial Networks (NTN) in Release 17 in March 2022, which means that NTN-compatible chips and components should be available now or soon. SpaceX has reduced the cost..."

Electricity & Physiology

Electricity & Physiology, January 1971 Popular Electronics - RF CafeThe subtitle of this article from a 1971 issue of Popular Electronics magazine, "From Quackery to Speculation to Programmed People," could to some extent still be applicable even though the author evidently meant to put an end to the "quackery" and "speculation" part of it. Indeed, a lot of advancement has been made in the fields of electrostimulation of weak or/or paralyzed muscles, healing of certain types of soft and hard tissues, suppressing sporadic muscle twitching and epileptic seizures, and other malady diagnosis and relief. Specifically tuned microwave frequencies have proven useful in healing and symptom relief as well. As with most articles on medical procedures, I cringe at some...

Anatech Intros 3 Filter Models for November

Anatech Electronics Intros 3 New Filter Models for November 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 C-band cavity bandpass filter models have been added to the product line, including a 4994 MHz BPF with a 50 MHz bandwidth, a 4950 MHz BPF with a 10 MHz bandwidth, and a 5785 MHz BPF with a 100 MHz bandwidth. 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...

Engineering & Tech Headlines <Archives>

• 5G Is 42% of Fixed Wireless Access (FWA) in 2024

• Robert Dennard, DRAM Pioneer, Dies at 91

• TSMC's Energy Demand Drives Taiwan's Geopolitical Future

• Semiconductor Packaging Market on 5.6% CAGR 'Till 2028

• Altering Asteroid Trajectories with Nuclear X-Rays

Albert Einstein: A Short Biography

Albert Einstein: A Short Biography - RF CafeAlbert Einstein, one of the most renowned physicists in history, was born on March 14, 1879, in Ulm, in the Kingdom of Württemberg, part of the German Empire. His father, Hermann Einstein, was an engineer and salesman who ran an electrochemical factory, and his mother, Pauline Koch, managed the household and supported her son's education. Einstein had one sister, Maja, who was born in 1881 and with whom he had a lifelong close relationship. Einstein's extended family included several relatives who would play various roles in his life, both personally and professionally. His early family life was comfortable, though his parents moved frequently as they sought economic stability. Hermann Einstein's business ventures had varying success, and eventually, the family moved to Italy in 1894...

Rotary Stepping Switches

Rotary Stepping Switches - They're Everywhere, December 1967 Radio-Electronics - RF CafeHere is the second part of a series of articles about stepping switches appearing in 1967 issues of Radio-Electronics magazine. A standard (at the time) dial rotary phone was used as a familiar example in the part one. It delivers a single pulse for each number / letter set from 1, 2 (ABC), 3 (DEF), through 9 (WXY), 0 (Operator). On some phones, you can hear the clacking of the switch contacts as the spring-loaded dial rotates from the selected number back to home position. The stepping action as the result of dialing occurs at the telephone system switching and call routing equipment at central locations. There, stepping switches increment with each pulse received, and when the full number of pulse sets have arrived, the circuit is complete and the call put through to ring the phone...

2024 ARRL Field Day Results Published

2024 ARRL Field Day Results Published - RF Cafe"Results are published, and the numbers are in. They paint a picture of a very active 2024 ARRL Field Day. Nearly 1.3 million contacts were reported during the 24-hour event. That is up from 2023's 1.25 million contacts. That's likely indicative of the continued rise of Solar Cycle 25 leading up to the event, but more people also participated this year. Entries were received from all 85 ARRL and Radio Amateurs of Canada (RAC) sections, as well as from 27 different countries from outside the US and Canada. 'It is encouraging to see a rise in participation year to year,' said ARRL Contest Program Manager Paul Bourque, N1SFE. 'ARRL Field Day is amateur radio's premier event, and the hams turned out for it..."

Einstein Expounds on His New Theory

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

Exodus AMP2103P-LC, 0.5–3.2 GHz, 1 kW Pulse SSPA

Exodus AMP2103P-LC, 0.5–3.2 GHz, 1 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 AMP2103P-LC, dual-mode (CW & pulse) amplifier covering 800 to 3200 MHz. 1000 watt peak pulse power, or 500 watts CW. Ideal for automotive pulse/radar EMC-testing & commercial applications. Pulse widths to 560 μsec, duty cycle to 10%, 60 dB gain, and outstanding pulse fidelity. Monitoring parameters for forward/reflected power in watts and dBm, VSWR, voltage, current, and temperature, with unprecedented reliability and ruggedness in a compact 7U chassis...

Sally, the Service Maid

Sally, the Service Maid: The Case of the Silent Speaker, April 1944 Radio-Craft - RF CafeSally Mason was the soldering iron-wielding heroette (heroine sounds too much like the narcotic) of Nate Silverman's "Sally, the Service Maid" series that ran in Radio-Craft magazine during the years of World War II. As I noted in the previous episode, many of the nation's women were left behind to run their husband's, father's and/or son's electronics sales and repair businesses when they went off to save the world from aggressive Communists, Socialists, Maoists, Nazis, and other nasty types. Some of those ladies had already become very adept at troubleshooting, component replacement, and aligning radio and television sets, while some were left to learn at the School of Hard Knocks. Sally's father, Gus Mason...

Thanks to Crane Aerospace & Electronics for Their Support!

Crane Aerospace & Electronics - RF CafeCrane Aerospace & Electronics' products and services are organized into six integrated solutions: Cabin Systems, Electrical Power Solutions, Fluid Management Solutions, Landing Systems, Microwave Solutions, and Sensing Components & Systems. Our Microwave Solution designs and manufactures high-performance RF, IF and millimeter-wave components, subsystems and systems for commercial aviation, defense, and space including linear & log amplifiers, fixed & variable attenuators, circulators & isolators, power combiners & dividers, couplers, mixers, switches & matrices, oscillators & synthesizers.

Electronic Navigation in Flight

Electronic Navigation in Flight, August 1962 Radio-Electronics - RF CafeThe AN/MPN-13|14 mobile radar system I worked on while enlisted in the U.S. Air Force was designed and fielded around the time this Electronic Navigation in Flight article appeared in a 1962 issue of Radio-Electronics magazine. It had been upgraded a few times by 1979 when I was in Air Traffic Control Radar Repairman technical school at Keesler AFB, Mississippi; however, the original system did not featured a Doppler capability. The fully RF analog system could not provide air traffic controllers with speed data, but it did use physical mercury delay lines to provide a stationary target (ground, and to some degree, rain, clutter) cancellation by inverting and summing a real-time radar...

Why Color-TV Makers Worry

Anxiety Amid Affluence: Why Color-TV Makers Worry, December 27, 1965 Electronics Magazine - RF CafeDecisions, decisions, decisions. As the title states, color television manufacturers were, in 1965 when this Electronics magazine article was published, finding themselves between a rock and a hard place, as the saying goes, regarding a change from vacuum tubes to transistors. The buying public (aka consumers) had mixed emotions about the newfangled semiconductors based at least partly on bad information about transistors. Transistors had been designed in various circuits for a decade and a half and were gaining rapidly in performance and reliability. The price was coming down, but as reported here, still cost $5 to $10 apiece compared to a $1 vacuum tube. Company management needed to decide whether to delay implementing the new engineering and production methods required to deal with transistors...

The 1st Virtual Meeting Was in 1916

The 1st Virtual Meeting Was in 1916 - RF Cafe"At 8:30 p.m. on 16 May 1916, John J. Carty banged his gavel at the Engineering Societies Building in New York City to call to order a meeting of the American Institute of Electrical Engineers. This was no ordinary gathering. The AIEE had decided to conduct a live national meeting connecting more than 5,000 attendees in eight cities across four time zones. More than a century before Zoom made virtual meetings a pedestrian experience, telephone lines linked auditoriums from coast to coast. AIEE members and guests in Atlanta, Boston, Chicago, Denver, New York, Philadelphia, Salt Lake City, and San Francisco had telephone receivers at their seats so they could listen..."

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...

Solid State Electronics - The Spacistor Et Al

Solid State, August 1967 Popular Electronics - RF CafeThe monthly "Solid State" column in Popular Electronics reported on all the wonderful new germanium- and silicon-based devices being prepared for the brave new world of electronics. It is a good resource for historical research. For instance, did you know that the unijunction transistor was originally going be called a "double-base diode?" How about a feeble attempt to integrate solid state and vacuum tubes by incorporating a "semiconductor cold cathode" to replace the standard 6.3 V or 12.6 V heated cathode for supplying an electron source? Have you ever heard of a "spacistor?" A 1957 edition of "Proceedings of the IRE" published a paper by Pucel and Statz titled, "The Spacistor, A New Class of High-Frequency Semiconductor Devices." The summary statement says..."

How to Target RFCafe.com for Your Google Ads

Google AdSense - it makes good sense - <em>RF Cafe</em>One aspect of advertising on the RF Cafe website I have not covered is using Google AdSense. The reason is that I never took the time to explore how - or even whether it is possible - to target a specific website for displaying your banner ads. A couple display opportunities have always been provided for Google Ads to display, but the vast majority of advertising on RF Cafe is done via private advertisers. That is, companies deal with me directly and I handle inserting their banner ads into the html page code that randomly selects and displays them. My advertising scheme is what the industry refers to as a "Tenancy Campaign," whereby a flat price per month is paid regardless of number of impressions or clicks. It is the simplest format and has seemed to work well for many companies. With nearly 4 million pageviews per year for RFCafe.com, the average impression rate per banner ad is about 225,000k per year (in eight locations on each page, with >17k pages)...

'

USAF Charles Pritt Info on MPN-14 & TPN-19 Radars

Note from Charles Pritt re MPN-14 and TPN-19 radars from the USAF 3rd MOB - RF CafeFellow USAF radar technician Charles Pritt checked in with a plethora of info and photographs about his time in the 3rd MOB (aka 3CCG or 3rd Combat Communications Group). Says Charles: "I attended Technical training at Keesler, from April to September 1973, for Radar Repair. My first assignment after Technical school was to the 1837th E&I squadron at Yokota AB, Japan starting in October 1973. Since we were not supporting a daily operational radar system and the only time we worked on Radar was when we went on TDY, we usually just sat around the office, talking, drinking coffee or studying radar books for our promotions..."

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 ...

Electronics-Themed Comics

Electronics-Themed Comics, November 1947 Radio-Craft - RF CafeDo you detect any (probably unintended) irony in the page 76 comic from a 1947 issue of Radio-Craft magazine? It shows a husband and wife shopping for a new radio and has the husband telling the salesman, "I don't care if it is FM - I want one that plays in the P.M.!" I'll let you think on it for a moment. As with many of the comics that appeared in the magazine, the scenarios were suggested by readers. The other comic played on the common music programming schedule that included times of "dinner music," "evening music," etc. If you like these comics, then you'll appreciate the huge list at the bottom of the page of others with tech themes.

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...

How to Target RFCafe.com for Your Google Ads

Google AdSense - it makes good sense - <em>RF Cafe</em>One aspect of advertising on the RF Cafe website I have not covered is using Google AdSense. The reason is that I never took the time to explore how - or even whether it is possible - to target a specific website for displaying your banner ads. A couple display opportunities have always been provided for Google Ads to display, but the vast majority of advertising on RF Cafe is done via private advertisers. That is, companies deal with me directly and I handle inserting their banner ads into the html page code that randomly selects and displays them. My advertising scheme is what the industry refers to as a "Tenancy Campaign," whereby a flat price per month is paid regardless of number of impressions or clicks. It is the simplest format and has seemed to work well for many companies. With nearly 4 million pageviews per year for RFCafe.com, the average impression rate per banner ad is about 225,000k per year (in eight locations on each page, with >17k pages)...

American Telephone and Telegraph from a 1917 Saturday Evening Post

American Telephone and Telegraph from the August 11, 1917, The Saturday Evening Post - RF CafeThe American Telephone and Telegraph Company (AT&T) was founded as part of the Bell Telephone System to build a nationwide wired, long distance communications service. When this advertisement was printed in a 1917 issue of The Saturday Evening Post magazine, many American households still did not have a telephone installed, and most of those that did subscribed to "party line" hookups. Party lines were a service sharing agreement whereby multiple users were connected to the same telephone number and agreed to share the line. The upside was a discounted phone bill, but the downside was the any other member of the "party" could listen in on your conversation. I remember back in the 1960s when our house had a party line. My sister and I (both preteens) would sometimes carefully pick up the phone receiver and listen in hopes of ...

Transistor Topics: Semiconductors Other Than Transistors

Transistor Topics: Semiconductors Other Than Transistors, March 1958 Popular Electronics - RF CafeIn March of 1958 when this article appeared in Popular Electronics, learning of semiconductor devices other than transistors was usually new to experienced professionals as well as to hobbyists. Vacuum tubes still dominated electronic products in the day. Companies like General Electric, Sylvania, and RCA were the pioneers for development of Zener diodes, photodiodes, SCRs, thyristors, etc. Relatively simple compounds like selenium, germanium, silicon, and lead and cadmium sulphides were used. The exotic witch's brew of elements in modern semiconductors - particularly those used to photovoltaics - were likely not even envisioned in 1958. This article discusses some of "new" devices using simple compounds...

Heathkit 19" Color Television Kit in Christmas 1982 Catalog

Heathkit 19" Color Television Kit Christmas 1982 Catalog - RF CafeIf you are shopping for a new television set and are willing to spend $500, you can get a fully assembled and ready to play Samsung 55" 4K UHD LED Smart TV with Alexa Built-in, or maybe a Vizio 50" 4K UHD LED Smart TV (UHD = 3,840px x 2,160px = 8,294,400 px^2). The same $500 in 1982 got you a 19" CRT with 525 horizontal scan lines (only 480-490 actually visible), but theoretically an infinite number of points across each line due to the analog nature of the signal. Come to think of it, an argument could be made that the old CRT displays had a higher resolution than the UHD modern digital TV (infinite versus 8.3 million, respectively). Ditto for the total number of color levels - infinite for analog versus 16.8 million for digital (8 bits per color = [28]^3). Fully assembled and ready to play 19" TVs could be bought in 1982 for about the same price, so the motivation for going to the trouble of building your own set was mostly pride and personal satisfaction...

Electronics-Themed Comics, Radio & TV News

Electronics-Themed Comics, June and July 1952 Radio & Television News - RF CafeAn age-old meme is used in the first of these vintage electronics themed comics from Radio & Television News magazine. It shows a husband attempting to repair some domestic device (a TV in this case) in order to avoid being ripped off by a professional repairman. I'm guessing that the use of the term "gyp," which is a pejorative referring to gypsies, would not be allowed in today's politically correct environment. In order to "get" the other comic, you need to know about the stacked plates used in selenium and copper-oxide type rectifiers that preceded silicon and germanium semiconductor models. Electronics magazines of the era published many articles about selenium rectifiers...

Current-Carrying Capacity of Wires

The Laboratory Page: Current-Carrying Capacity of Wires, December 1940 January 1941 National Radio News - RF CafeAs mentioned in an earlier article, National Radio Institute (NRI) was one of the first companies to exploit the burgeoning field of electronics in the early part of the last century. They invested heavily in facilities and resources for producing educational material for both classroom and correspondence courses. Up until sometime in the early 1990s when throw-away electronics and almost total offshore manufacturing became the rule rather than the exception, there were always large advertisements in magazines offering to rescue floundering career seekers with promises of untold opportunities and riches from servicing radios, televisions, home appliances, and more. That is not to say the courses were not valuable - they were...

Clean Layout Technique

Clean Layout Technique, August 1965 Popular Electronics - RF CafeUsually an article about clean layout techniques would be about printed circuit board layout; however, this one refers to chassis layout. Having built many electronics chassis in my days as an electronics technician (prior to earning an engineering degree), I have a great appreciation for a professional-looking job. Some of the work done by hobbyists that appear in magazines like QST, Nuts & Volts, and the older titles like Poplar Electronics looks pretty darn nice - both for kits and homebrews. It's a short article, but worth a quick look...

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...

RF Cafe Quiz #69: RF Electronics Basics

RF Cafe Quiz #69: RF Electronics BasicsThis RF Electronics Basics quiz targets those of you who are newcomers to the world of radio frequency (RF) electronics, but seasoned vets are welcome to give it a go as well. People have reported using material from these quizzes as fodder for interviewing potential candidates. All quizzes are multiple choice and answers are provided...

RF Cafe Engineering Crossword Puzzle w/Weekly Headlines February 18

RF Cafe Engineering Crossword Puzzle w/Weekly Headlines February 18, 2018At least 10 clues with an asterisk (*) in this technology-themed crossword puzzle are pulled from this past week's (2/12 - 2/16) "Tech Industry Headlines" column on the RF Cafe homepage (see the Headline Archives page for help). For the sake of all the avid cruciverbalists amongst us, each week I create a new technology-themed crossword puzzle using only words from my custom-created related to engineering, science, mathematics, chemistry, physics, astronomy, etc. Enjoy...

Swan Electronics Frequency Counter

Swan Electronics Frequency Counter, November 1976 QST - RF CafeSwan Electronics was another of the many electronics equipment companies that was started in the founder's garage - literally - and built a loyal customer following in their areas of specialty. Probably the most famous example is Bill Hewett and Dave Packard's garage (known affectionately among enthusiasts as "The HP Garage"). As evidenced by this RF frequency counter advertisement in QST magazine (six pages worth), Swan manufactured a line of products for the radio amateur including transceivers, antennas, and a few pieces of test equipment. Swan Electronics merged with Cubic Corporation in 1967. Information on this frequency counter and some of the other accessories sold by Swan Electronics can be found on this Swan Virtual Museum website...

The Real Inventor of Wireless

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

Mac's Radio Service Shop: Intermittents Still Pursue

Mac's Radio Service Shop: Intermittents Still Pursue, February 1949 Radio & Television News - RF CafeMac McGregor, owner of Mac's Radio Service Shop, can always be counted on to provide his apprentice technician, Barney, with a lesson from his own life-long attendance at the School of Hard Knocks. Barney is your stereotypical young buck whose level of seriousness needs occasional alignment, just as do the radio and television sets he services. In this episode, I can't find where Mac actually solved the intermittent electrical condition believed to be causing the problem - weird. The "Mac's Radio Service Shop" series ran in Radio & Television News magazine for many years prior to a similar electronics story series called "Carl & Jerry" that appeared in Popular Electronics. Both were created by consummate storyteller John T. Frye.

Electronics-Themed Comics from May 1947 Radio-Craft

Electronics-Themed Comics, May 1947 Radio-Craft - RF CafeMany topics of the electronics-themed comics which appeared in Radio-Craft were suggested by the magazine's readers. Staff artists like Frank Beaven turned those suggestions into cartoons. For a while there was a special feature called "Radio Term Illustrated" where, as the name suggests, terms like "Signal Generator" and "High Potential" are rendered in farcical form. These four comics, two of each type, appeared in a May 1947 issue of Radio-Craft. I have to admit that even with my familiarity with vintage electronics memes I do not get the Television "Organ" comic (yes, I understand the organ grinder, but not how it applies to TV).

Tone Modulator for R-C from April 1958 Radio-Electronics

Tone Modulator for R-C from April 1958 Radio-Electronics Magazine - RF CafeDeclaring any kind of straight LC tank circuit to be high stability is a bit of a stretch when compared the Q available simply by adding a crystal, even in 1958. Tone modulation was an early method for achieving remote control of model airplanes, boats, and cars. The number of channels with these tone modulation systems is two times the number of modern proportional systems in that moving the rudder left took one channel and moving it right took another. Up and down elevator likewise took two channels. Therefore, this four channel system is only two channels by today's terminology. Technology evolved into fully proportional ...

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...

The Radio Month

The Radio Month, December 1949 Radio-Electronics - RF Cafe"The Radio Month" was a regular feature in Radio-Electronics magazine in the late 1940s and early 1950s. It contained news items from around the industry and across the world. The entire two pages are included in the included scan, but a couple items in particular stand out that are worth mentioning. The first is announcing the soon to be available rectangular cathode ray tubes (CRT) for television. Until then, the actual CRTs had round faces even though the displayed image was rectangular. A 4:3 aspect ratio was the standard, which required the tube diameter to be roughly 25% larger than the horizontal size of the picture. In fact, that is how TV display sizes came to be rated by their "diagonal" dimension rather than the picture width, and the standard stuck even after rectangular tubes were available. For instance, the 4:3 aspect ratio conveniently produces a diagonal length of 5 (the 3:4:5 triangle), where the hypotenuse...

Keying the Crystal Oscillator

Keying the Crystal Oscillator, May 1941 QST - RF CafeThere is still a lot of vintage ham radio equipment in use both by the original owners and by newcomers who buy the equipment at Hamfests and on eBay. User's manuals are hard to come by, since they often were separated from the original gear a long time ago. Knowing how to operate, repair, and align everything properly is still necessary, especially as the airwaves get ever more crowded and the FCC gets more serious about prosecuting violators. Old editions of QST are the perfect resource for locating such information. This article covers some of the basics of oscillators - tritet types in particular - used for CW keying. The tritet oscillator gets is name from having been designed originally to efficiently generate third and fourth harmonics, per James Lamb's June 1933 QST article "A More Stable Crystal Oscillator of High Harmonic Output." ARRL members can download the article...

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