Hugo Gernsback - A Concise Biography
Being a big fan of
Hugo Gernsback’s technical work through his many electronics-related publications (The Electrical Experimenter, Radio Amateur News, Radio News, Radio-Craft, Short-Wave Craft, Radio-Electronics, etc.), I decided to task a couple of different AI models with conducting a deep-dive research project on all aspects of his background - family, schooling, business, finances, politics, etc. Then, I had the AI combine all results, while avoiding duplication, and filtering out “facts” that cannot be validated. A lot of websites contain Hugo Gernsback bios of varying lengths, but this, I believe, is the most comprehensive and concise. Photos were collected across the WWW…
Amateur Radio Crossword Puzzle
This custom Amateur Radio crossword puzzle contains many words particular to Amateur Radio (labeled with an asterisk *). Each week for two decades I have created a new technology-themed crossword puzzle using only words (1,000s of them) from my custom-created lexicon related to engineering, science, mathematics, chemistry, physics, astronomy, etc. You will never find among the words names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You might, however, find someone or something in the otherwise excluded list directly related to this puzzle’s technology theme, such as Hedy Lamarr or the Bikini Atoll…
How Audions Were Built
If you have never read the story of Lee de Forest’s journey from initial experiments to finally achieving success with his amplifying vacuum tube, the Audion, then you might want to take a few minutes to look over this article. It was published in a 1947 issue of Radio-Craft magazine as part of the 40th anniversary of the invention that changed the electronics world. With so many other things which are nowadays very commonplace, we tend to not think about or appreciate the ingenuity and effort that went into them. It is one thing to make incremental improvements in an existing technology, but to conceive of and created an entirely new realm of science is quite another. As with Albert…
Student’s Radio Physics Course - Series & Parallel Circuits
Not everyone who visits websites like RF Cafe is a seasoned electronics veteran. While I and most likely you, too, can do series and parallel circuit analysis (and series/parallel for that matter, possibly using Fourier or La Place transforms for reactive AC circuits) in our sleep, many are recently getting into the wonderful world of electronics who are just coming of age or have suddenly at a later point in life developed a passion for the craft. Accordingly, this article from Radio News magazine provides yet another tutorial on the fundamentals of series and parallel circuit analysis. Only resistors and basic Ohms law are covered…
Exodus AMP20005 18 – 40 GHz, 20 W SSPA
Exodus Advanced Communications presents the
AMP20005 is a solid-state RF power amplifier operating from 18.0 to 40.0 GHz with 20 W minimum power. Designed for EMI/RFI, laboratory, CW/pulse, and communication applications, the amplifier features instantaneous wide bandwidth, Class A/AB linear design, built-in protection circuits, and remote-control capabilities. Features Include * Designed for EMI/RFI, lab, CW/Pulse and all communications applications * Small form factor, rack-mounted system * Class A/AB linear design * High power advanced technology devices * Instantaneous ultra-wide bandwidth * Built-in protection circuitry…
Thévenin’s Theorem Quiz
Thévenin’s theorem stands as one of the most powerful circuit simplification tools in electrical engineering. It states that any linear, two-terminal network - no matter how complex - can be reduced to an equivalent circuit comprising a single voltage source (VTH) in series with a single resistance (RTH). To determine these parameters, engineers short all independent voltage sources, open all independent current sources, and calculate the equivalent resistance seen from the terminals. VTH is simply the open-circuit voltage across the terminals. This theorem proves invaluable when analyzing how different loads affect circuit performance, as the equivalent circuit remains unchanged…
Comics with an Electronics Theme
Here are a couple more tech-themed comics from a vintage electronics magazine (Popular Electronics). The one from page 101 reminds me again about how different the world of retail sales is today compared to just two short decades ago. Prior to the advent of online marketing and sales, you either walked into a brick and mortar (a term rarely heard before the Internet era) type store and walked out with your purchased product, or you thumbed through a catalog and placed an order either by mail or telephone. Most people opted to pay for a postage stamp rather than pay the long distance phone charge (a term rarely heard today). Free overnight or 2-day shipping from many e-stores makes…
Ward Para-Con Antenna
The word prefix “para” can mean “above and beyond” or “resembling” or “abnormal or incorrect.” Ward Products probably preferred first two be inferred by potential customers when naming their PARA-CON television antenna, although it actually is a shortening of “parabolic.” The “con” part is a shortening of “conical.” After reading the text of this full-page advertisement from a 1951 issue of Radio & Television News magazine, I’m inclined to assign the third prefix meaning of “para” to it. Then, add in the “con” part where “con” can take on either the noun form meaning of “disadvantage” or the verb form definition of “to trick or defraud,” and you get what this antenna truly represented in terms…
Transmission-Line Feed for Short-Wave Antennas
When someone with the first name of “True” writes an article about transmission line feeds for short-wave antennas, you should probably take note. This very topic has been covered in detail many times since the use of impedance-matched transmission lines have been in use (more than a century), but since there are always people new to the concept, it is good to keep introducing the topic on a regular basis.“Transmission-Line Feed for Short-Wave Antennas” appeared in a 1932 issue of QST magazine. Even in this era of prefabricated everything, it still often comes down to winding coils and adjusting cable lengths to get optimal impedance matches between transceivers and antennas…
Electrodrome: Fog and Poison Gas Dissipator
The 1934 Flying Aces magazine’s “Electrodrome: Fog and Poison Gas” article described a device invented by William Haight that allegedly used high-voltage electrostatic fields to “precipitate” fog over a radius of about 1.5 miles and, by extension, might neutralize poison gas. The concept was based on a real physical phenomenon - charged droplets and aerosols can be moved, collected, or coalesced by electric fields - but the article’s large-scale claims and Haight’s atmospheric theory do not align with modern atmospheric physics. The likely outcome was failure as a practical outdoor fog-dispersal or poison-gas-defense system. I found no credible evidence that Haight’s electrodrome was adopted by airports, the U.S. government, military…
Electronic Crossword Puzzle
This “Electronic Crossword” appeared in the September 1958 issue of Radio & TV News magazine. Its creator, John Gill, designed specialty theme crossword puzzles for many other editions of Radio & TV News and Electronics World (see the big list at the bottom of the page). He considered this crossword to be a “fooler” because he claims to include many “unusual definitions and a number of obscure words which you will have to work around if your vocabulary of ‘exotic words’ is rusty.” It really doesn’t seem so difficult to me, and anyone used to working my custom RF Cafe Crosswords will have no problem with it…
Building Your Own Audio Frequency Choke Coils
One very satisfying aspect of ‘rolling your own’ audio frequency coils (aka chokes, aka inductors), is how well the simple inductance equations match measured end results. Unless you really manage to mangle the job, if you use the right equation and are reasonably careful to observe wire size, spacing (including insulation), and core diameter, you will be amazed at how close practice matches theory. Although strictly speaking audio frequencies run from a few Hertz up to maybe 15 kHz for people with really good hearing. My experience is that similar success can be had even into the low MHz realm with just a little tuning required. It’s not until you get into the realm of self-resonance…
Heath Company: Heathkit Advertisement
Heathkit’s claim to fame was that it was able to offer user-assembled kits of high quality electronic products at a price lower than what equivalent factory assembled equivalents would cost. While that is probably generally the case, it is difficult to gauge what the relative quality really is. Some of the kits were easy to assemble for even people with little experience, but a good portion of them required familiarity with soldering and how electronics were put together. The instructions provided were very thorough, complete with photos and drawings of how each step should look. In fact, according to a 1972 installment of Mac’s Service Shop entitled “Philosophy of a Kit Manufacturer,” every Heathkit kit…
RF Cafe Quiz #92: Electric Fields
An electric field is a vector field that surrounds electrically charged particles and exerts a force on all other charged particles in the field, either attracting or repelling them. It is the fundamental manifestation of the electric force, acting as the intermediary through which charges communicate. From the static potential of a charged capacitor plate to the dynamic, wave-propagating fields of an antenna, electric fields are central to electronics, semiconductor physics, and electromagnetics. This Electric Fields Quiz explores the principles that govern these invisible forces, including the inverse-square relationship defined by Coulomb’s Law, the concept of electric potential (voltage)…
The Tecnetron: Competitor to the Transistor?
Breaking news from May 1958: “Hardly a month passes nowadays without the announcement of some ‘sensational’ new amplifying device. The great majority of these startling inventions, after their brief flurry in the popular and technical press, disappear into oblivion. But we believe that the Tecnetron, just announced in France, has a brilliant and enduring future.” Have you ever heard of a Tecnetron? I didn’t think so; neither had I before reading this article in Radio-Electronics. I guess that pretty much negates the preceding prediction. The holy grail of the Tecnetron, whose etymology in and of itself is worth reading about (it’s not what you would guess), is that its transconductance…
Simpson Electric Company Advertisement
Before the days of cheap stuff from China, the supply of most common items- particularly high technology - were the domain of relatively few companies. In some ways it was not entirely a bad thing because, at least theoretically, the economy of scale enabled larger producers to leverage bulk buying, well-equipped development labs and manufacturing equipment, and pooling of talent resources to sell quality products at a lower price. Of course it required that the company had serious competitors or monopolistic tendencies resulted in gouging - it’s human nature, unfortunately. Hewlett Packed, as much as I appreciate what the company did for electronics test equipment, had gotten…
Varian Associates Radar Illustrations by C.E.B. Bernard
Frequent RF Cafe visitor who goes by the moniker “Unknown Engineer” sent me a hyperlink to a PDF file on Amazon’s CloudFront* content delivery network (CDN - basically a file server) that contains no fewer than 17 amazing radar and vacuum tube related line drawings published by Varian Associates’ TWT Division, Palo Alto Tube Division, Solid State Division, Eastern Tube Division, Western Tube Division, Solid State West Division. These highly detailed and busy drawings were done around 1975 by British illustrator/artist C.E.B. Bernard; a search for his works did not reveal much. The events shown are fictitious, as are the accompanying hand-printed stories. Some of the puns…
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The RF Cafe Homepage Archive is a comprehensive collection of every item appearing daily on this website since 2008 - and many from earlier years. Many thousands of pages of unique content have been added since then.
Many years have passed since I sat in a college classroom to learn about transistor fundamentals. The industry had long moved past germanium transistors and was solidly into silicon. Having been formally introduced to transistors in the USAF, I was familiar with their functionality from a technician’s perspective of checking for gain, proper bias (as indicated on “educated” schematics), and determining go-no-go health by performing a front-to-back resistance measurement using an ohmmeter. Holes, energy bands, gate widths, and doping levels were first encountered in solid state physics class, however. This article does a nice job of introducing the terms and concepts at a layman’s level. I actually found the vacuum tube circuits in our radar unit easier…
Each week, for the sake of all avid cruciverbalists amongst us, I create a new technology-themed crossword puzzle using only words from my custom-created lexicon related to engineering, science, mathematics, chemistry, physics, astronomy, etc. This one for November 10, 2019 celebrates Veterans Day. You will never find among the words names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You might, however, see someone or something in the exclusion list who or that is directly related to this puzzle’s theme, such as Hedy Lamarr or the Bikini Atoll, respectively…
Just as most people no longer wear a wristwatch since their (practically) surgically attached smartphones can provide the time, few people bother with carrying around an electronic calculator. It’s’ been that way for at least a decade now. When this article entitled “Calculators Get Smaller, Smarter and Cheaper” appeared in a 1974 issue of Popular Mechanics magazine, pocket electronic calculators were still a relatively new phenomenon. Hewlett Packard had introduced their first calculator, the HP-35, just two years earlier. The first American-made pocket calculator, the Bowmar 910B, aka “The Brain,” came out in late 1971/early 1972 and sold for about $240. It had only basic math functions and sported a tiny LED display. Prices fell very quickly as many companies were releasing models with more and more features. By the time of this article, calculators with basic functions could be bought for a mere $16.95 ($84.05 in 2019 money…
This is a repeat of something I posted a decade ago, but by now millions more people have entered the electronics realm and might appreciate it. You might, too, if you didn’t see it originally. You have probably seen somewhere along the line in your electronics career the resistor cube problem. The 12 edges of the cube each contain a 1 Ω resistor, and the challenge is to calculate what the equivalent resistance is between two opposing corners. It is a daunting problem using straight circuit analysis, since it requires writing and solving multiple mesh equations. There are lots of opportunities for making mistakes. One option if you had the time and facilities would be to build the model in a circuit simulator and let it determine the result. Usually, though, the cube is thrust upon you in a compromising situation, like in a job interview…
The year was 1941 and the radio industry was going strong worldwide. Sales of receivers was hitting new highs every quarter and service shops had all the work they could handle for repair, upgrades, and installations. The radio broadcast realm was scrambling to build new studios, install transmitters and antennas, hire announcers and managers, and upgrade to keep up with the quickly evolving business. Take a look at these 24 full pages of radio-related products offered by the Sears, Roebuck Company in their Fall and Winter 1941 – 1942 catalog. It is typical of most radio manufacturers’ catalogs of the era. For the last decade engineers had been working overtime to satisfy consumer demand for fancier cabinet designs with fancier features. So strong was public demand that people put their highest priority on acquiring the latest models (not unlike the smartphone craze of today). Then,…
The RCA Victor Model C9 – 4 is a 9-tube, 3-band superheterodyne console model radio made in the mid 1930s. A Radio Service Data Sheet for it appeared in the January 1936 issue of Radio-Craft magazine. The image of the radio was found on the RadioMuseum.org website. FM broadcasting was not in common use yet, so only AM bands and some shortwave bands were available. In fact, 1936 was the year that frequency modulation (FM) inventor Edwin H. Armstrong first demonstrated his newfangled concept that largely solved the electrical static noise problem cause by lightning, motor brushes, arcing overhead power lines…
In 1958, most people were not accustomed to seeing the now-familiar maps plotting the 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 (so to speak). This article from a 1958 issue of Radio & TV News magazine provided insight into the construction and flight characteristics of early U.S. satellites, and offered advice on how to participate in the ongoing International Geophysical Year (IGY) research effort by tuning in and reporting your signal reception characteristics. Activity was not just the domain of operators with sophisticated equipment…
This quiz from Popular Electronics magazine challenges (not too much, though) your knowledge of energy conversion in common devices. A few of them might be unfamiliar to people born after about 1990, but even so, you’ve probably seem them all at some point, especially if you are a regular RF Cafe visitor (meaning you’re probably smart). It won’t be giving anything away by telling you that item B is a heater that screws into a light bulb socket, and item F is a phonograph stylus Robert P. Balin constructed many quizzes of this kind in the 1960s and 70s. A complete list of all the Popular Electronics Quizzes is lower on this page…
Proving once again what a visionary Hugo Gernsback was regarding science and engineering, he published in his Radio-Craft magazine this prognostication for the eventual supplanting of point-to-point wiring with printed circuit boards. Admittedly, by 1948 the electronics industry had begun to outgrow hand-wired chassis assemblies with a rats nest of wires, components, and terminal strips. It was in dire need of a new paradigm that reduced labor costs and reduced the opportunity for wiring errors. Less than a year earlier (December 1947) the trio of engineers at Bell Labs announced their transistor invention, so Mr. Gernsback knew the world was about to change significantly. Bulky transformers, vacuum tubes, and high voltage circuits would soon be relegated - at least in the consumer product realm - to the newfangled television products, so miniaturization would follow quickly. Even the smaller fingers of women on the assembly lines…
Here is a little electronics hobbyist humor in the form of a comic series titled “Hobnobbing with Harbaugh,” compliments of Popular Electronics artist Dave Harbaugh. Citizens Band radio and dirty hippies were the topic of the day in the 1970s, so that’s what you see in a couple of these comics. I got my first 23-channel CB radio (FCC mandated 40 channels in 1977) in 1976 and installed it in my 1969 Camaro SS hot rod. It required a Class D radio operator license at the time, but shortly thereafter no license was needed. The “Inventions Wanted” comic is my favorite, followed by “Mayday… Mayday!” You don’t need to be an amateur radio operator to appreciate these comic strips…
Forgive me if I sound like a broken record (a scratched record, actually), but when 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…
Radio Service Data Sheets were published by various electronics trade magazines back in the early to middle decades of the last century. SAMS Photofact document sets were published on just about every appliance made, and those had much more detail than these briefs. However, for the low-budget repair shop or the do-it-yourselfer, the Radio Service Data Sheets were a godsend. I have been scanning, cleaning up, and posting all the ones I find in my vintage electronics magazine collection. See a complete list at the bottom. Many fine examples of restored vintage radios can be found on the Internet. A restored example of the RCA Victor Model 102 s appears on the RadioMuseum.com website…
For two decades, 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. This November 17, 2019, puzzle uses a database of thousands of words which I have 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 village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which…
Most of us are likely familiar with the ongoing debate over whether
radiation from cellphones, Wi-Fi routers and laptop computers, cell towers, smart meters, and other such modern gadgetry is harmful to humans. It is not ionizing radiation like nuclear decay, but there are heating effects that can cause damage under the right conditions. One week news breaks from the latest organization shocking the public with proof of tissue cell damage to brain, hand, face, eyeball, and groin tissue (from laptops). The next week brings a counter report refuting apocalyptic claims of previous studies… then the cycle repeats. Early in the age of ubiquitous wireless devices, those seeking to mitigate worries of radiation argued - somewhat correctly - that enough time had not yet passed to collect statistically meaningful data. If significant harm could be proven right away, dismissing the empirical results…
Channel Master is one of the few television and FM radio antenna companies that has survived the evolution from over-the-air (OTA) broadcasting to cable-based and then Internet-based broadcasting. Up until around the end of the last century - which is incredibly two decades ago - a large number of people still relied on rooftop and set-top antennas for program reception. Airwaves continued to get more crowded both due to additional stations being built and the ambient noise level increasing due to many other lower power devices in use. An increasing number of manmade obstacles that blocked and/or reflected signals resulted in many more low signal strength pockets and areas plagued by multipath signal variability compounded the problem…