RF Cafe Homepage

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...

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.

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...