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Homepage Archive - February 2023 (page 3)

See Page 1 | 2 | 3 | 4 | of the February 2023 homepage archives.

Tuesday the 21st

A Major Revolution in Electronics Is Shaping

Microelectronics: A Major Revolution in Electronics Is Shaping, February 1960 Radio-Electronics - RF CafeHugo Gernsback (1884-1967) was a Luxembourgish-American inventor, writer, editor, and publisher who is often referred to as the "Father of Science Fiction." Gernsback was also an inventor and entrepreneur, and was awarded many patents, including for early television systems. He founded several companies, including the Gernsback Publications, which published a variety of magazines that included this one, Radio-Electronics, and its predecessor, Electronics World, and before that, Radio Craft. Mr. Gernsback was undeniably qualified to pontificate and prognosticate on the future of the electronics industry, as he does in his February 1960 editorial in Radio-Electronics magazine...

King Breakout Boards

King Breakout Boards Launches Innovative Micro-D and Nano-D Breakout Board and Boxes Product Line - RF CafeKing Breakout Boards, a leading provider of electrical integration and test solutions, has announced the launch of its new line of Micro-D and Nano-D Breakout Board and Boxes. The new product line is designed specifically to meet the needs of engineers and technicians in a range of industries, including telecommunications, aerospace, defense, and medical. With a focus on Satellite Flatsat Integration & Test bench setups. The new Micro-D and Nano-D Breakout Boards and Boxes are designed to meet Mil-dtl-83513 and Mil-dtl-32139 specifications, ensuring high quality and reliable performance. The product line is offered in standard pin counts of 9, 15, 21, 25, 31, & 37 with contacts available as Pins or Sockets, making it easy for users to find the right solution for their needs. The new Breakout Boards and Boxes offer a range of benefits, including increased reliability, improved performance, and cost savings. The boards are made of high-quality materials and are designed to be user-friendly, allowing for easy and intuitive setup and use. "We are thrilled to announce the launch of our new Micro-D and Nano-D Breakout Board...

Electronics World Crossword Puzzle

Electronic Crossword Puzzle, April 1963 Electronics World - RF CafeResearch has shown over and over again that engaging in mental exercise is a good way to stave off senility in old age. Playing musical instruments, writing software, working crossword puzzles, and other types of activities that require logic, physical dexterity, and memory recall are often cited as examples. There is no guarantee these things will prevent or even delay cerebral atrophy, but why take a chance? Work this crossword just to make sure. Disclaimer: I am not a doctor and am not prescribing this challenge as a remedy for potential future imbecility, daftness, tendency to dodder, mental infirmness, or senescent gray matter accumulation, nor do I suggest that starting now will reverse any of these symptoms you might already exhibit. This electronics-themed crossword puzzle appeared in the April 1963 issue of Electronics World magazine. If you really like crossword puzzles and crave more, please see my weekly RF Cafe crossword puzzles...

"Perfect" Atom-Thin Materials

"Perfect" Atom-Thin Materials - RF Cafe"Their method could enable chip manufacturers to create transistors for the next generation using materials besides silicon. Adhering to Moore's Law, the number of transistors on a microchip has doubled annually since the 1960s, but this growth is expected to reach its limit as silicon, the foundation of modern transistors, loses its electrical properties when devices made from it dip below a certain size. Enter 2D materials - delicate, two-dimensional sheets of perfect crystals that are as thin as a single atom. At the scale of nanometers, 2D materials can conduct electrons far more efficiently than silicon. The search for next-generation transistor materials therefore has focused on 2D materials as potential successors to silicon..."

Firestone-Stewart-Warner Model R1332 5-Tube Auto Radio

Firestone-Stewart-Warner Model R1332 5-Tube Auto Radio Service Data Sheet, March 1936 Radio-Craft - RF CafeThis Radio Service Data Sheet for the Firestone-Stewart-Warner Model R-1332 automobile radio schematic appeared in the March 1936 issue of Radio-Craft magazine. I could not find any images of the R-1332 version, but evidently the equivalent was the Stewart-Warner Model R-133, for which I did manage to locate a photo. Back in the day, installing a radio in your car or truck was no simple matter. It came as as least three separate components - the receiver, which mounted under a seat or in the trunk, a tuner which mounted in or under the dashboard, and an antenna that often times consisted of a wire loop strung under the auto chassis, forming a loop. Some auto radio models had the power supply in a separate chassis, which also mounted under a seat or in the trunk...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000 or so symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing. Check them out!

Many Thanks to Exodus Advanced Communications for Their Support

Exodus Advanced Communications - RF CafeExodus Advanced Communications is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. Power amplifiers ranging from 10 kHz to 51 GHz with various output power levels and noise figure ranges, we fully support custom designs and manufacturing requirements for both small and large volume levels. decades of combined experience in the RF field for numerous applications including military jamming, communications, radar, EMI/EMC and various commercial projects with all designing and manufacturing of our HPA, MPA, and LNA products in-house.

Monday the 20th

The Wavelength Factor, Part I

The Wavelength Factor Part I, February 1952 QST - RF CafeAt long last, I finally acquired the February 1952 issue of QST magazine, which contains Part 1 of the three-part "The Wavelength Factor" article series. Author Yardley Beers covers a lot of ground (pun intended) regarding selection of the best transmitter, receiver, and antenna type for the intended purpose, including fixed-to-fixed and/or fixed-to-mobile communications. Part 2 focuses on propagation, modulation, and receivers. Finally, Part 3 covers choice of frequency bands for civil defense and UHF...

Many Thanks to KR Electronics for Long-Time Support!

KR ElectronicsKR Electronics has been designing and manufacturing custom filters for military and commercial radio, radar, medical, and communications since 1973. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop, equalizer, duplexer, diplexer, and individually synthesized filters for special applications - both commercial and military. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Please visit their website today to see how they might be of assistance. Products are designed and manufactured in the USA.

Mystery Burst Transmission in the HF Ham Bands

Mystery Burst Transmission in the HF Ham Bands, Kirt's Cogitations #349 - RF CafeA couple days ago, website visitor Bill P. wrote from his location in the western mountains of North Carolina to ask whether I have any information on a mysterious burst transmission he has been picking up in the 10- and 12-meter bands (28.000 to 29.700 MHz and 24.920 to 24.930 MHz, respectively) that "only appears when the bands are open." The signal has appeared intermittently for more than ten years. He included a link to a demodulated audio file of the captured signal. It sounds like a series of bursts at the same frequency. I do not recall ever having heard it. Probably the best method for determining the source of a broadcast is to perform a spectral analysis of the demodulated signal to discover its constituent parts. I used a free audio analyzer package called WavePad, by NCH Software. The screen shot below quantifies a few of the primary parameters. It consists of 63 bursts at approximately 24 ms intervals. Each burst appears to be a CW signal of about 1,280 Hz (780 μS), although looking at the spectral waterfall most of the content appears to be in 1,100 Hz realm...

U.S.A. Calling

U.S.A. Calling, December 1942 QST - RF CafeAlthough the Japanese attack on Pearl Harbor on December 7, 1941, was a complete surprise and shock to the nation, that fact that the United States would eventually be drawn officially into World War II was well known. The amateur radio community had begun talking about the potential impact on radio communications hobbyists earlier in the year, as evidenced by articles printed in QST and other magazines. Within a couple weeks of Congress declaring war, all unauthorized transmissions from Ham stations were terminated in order to prevent both intentionally and unintentionally conveyance of information that could proves useful by the enemy. Along with being a patriotic bunch that were eager to help defeat Axis powers, they also loved their hobby and willingly (in most instances) made critical components of their equipment available for battlefield use. Items such as meter movements, tuning capacitors, and even energy storage cells (lead-acid batteries) were needed for troops on the ground, at sea, and in the air. The American Radio Relay League (ARRL) devoted a lot of print space to promoting an attitude of service and sacrifice, as with this article...

IPP-7093, 2-8 GHz, 90-Degree Hybrid Coupler

Innovative Power Products IPP-7093, 2-8 GHz, 90-Degree Hybrid Coupler - RF CafeInnovative Power Products (IPP), with more than 30 years of experience designing & manufacturing RF & microwave passive components, presents our latest 90-degree hybrid coupler, model IPP-7093, that operates over the full 2 to 8 GHz band. The IPP-7093 handles 50 watts CW in a Surface Mount package that is only 1.21 x 0.20 x 0.177 inches. The IPP-7093 will combine two signals for up to 50 watts CW of total input power. Its Insertion Loss is less than 0.80 dB, its Amplitude Balance is less than ±0.65 dB, its Phase Balance is less than ±8 degrees, VSWR is less than 1.40:1, and it provides greater than 15 dB of Isolation. The IPP-7093 is available for commercial and military use, and in a RoHS compliant version.

Carl & Jerry: Anchors Aweigh

Carl & Jerry: Anchors Aweigh, July 1956 Popular Electronics - RF CafeJust the other day I saw a greeting card with a sailboat on the front with the words "Anchors Away," on it. It does not seem to haven been meant to be a pun on "anchors aweigh;" the card writer didn't know any better. This episode of "Carl & Jerry" has our teenage Ham radio operators and electronics hobbyists running a newly built model tugboat powered by a steam engine and navigated via a radio control system. As is always the case, no activity of the pair goes without drama of some sort. Author John T. Frye used his writings to present technical topics within the storyline, both in the "Carl & Jerry" series here in Popular Electronics and his earlier "Mac's Radio Service Shop" series that appeared in Radio & Television News editions in the 1940s and 1950s...

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 (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Many Thanks to Withwave for Long-Time Support!

Withwave RF & Microwave Components - RF CafeWithwave manufactures an extensive line of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch, board edge, panel mount), calibration kits (SOLT), a fully automated 4-port vector network analyzer (VNA) calibrator, between- and in-series connector adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes & probe positioner. Special test fixtures for calibration and multicoax cable assemblies. Frequency ranges from DC through 110 GHz. Please contact Withwave today to see how they can help your project succeed.

Sunday the 19th

Electronics Theme Crossword Puzzle for February 19th

Electronics Theme Crossword Puzzle for February 19, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for February 19th contains words and clues which pertain strictly to the subjects of electronics, mechanics, power distribution, engineering, science, physics, astronomy, chemistry, etc. If you do see names of people or places, they are directly related to the aforementioned areas of study. As always, you will find no references to numbnut movie stars or fashion designers. Need more crossword RF Cafe puzzles? A list at the bottom of the page links to hundreds of them dating back to the year 2000. Enjoy.

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 (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Please Thank Lotus Communication Systems for Their Support!

Lotus Communication Systems Modular RF/Microwave Components - RF CafeLotus Communication Systems began in 2009, setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex Country, Massachusetts. Lotus is committed to highest quality and innovative products. Each RF/microwave module meets exceedingly high standards of quality, performance and excellent value, and are 100% MADE IN USA. Lotus' RF/microwave products cover frequency band up to 67 GHz. Lotus also offers an COTS shield enclosures for RF/microwave prototyping and production. All products are custom designed. We will find a solution and save your time and cost. Lotus has multiple 4 axis CNC machines and LPKF circuit plotters. In stock, 1-day free shipping.

Friday the 17th

Whatever Happened to Atwater Kent?

Whatever Happened to Atwater Kent?, July 1969 Popular Electronics - RF CafeI have to admit that when presented with the Atwater Kent Award upon graduation from the University of Vermont in 1989, I had no idea who the fellow was. It wasn't until years later I read the name in IEEE's Spectrum magazine article (this one is from a 1969 issue of Popular Electronics) and learned he was a radio designer and manufacturer. In the course of publishing the RF Cafe website, Atwater Kent's name appears on occasion in Radio Data Service Sheets like this Model 776 in the June 1936 issue of Radio-Craft magazine. According to this article entitled "Whatever Happened to Atwater Kent?," that was the year he shut the doors of his extremely profitable business because he refused to give in to union thugs attempting to organize his employees. If you are not familiar with the history of Mr. Arthur Atwater Kent, then this story is one you will appreciate. He was one of the relatively few entrepreneurs who managed to thrive during the Great Depression years...

Did USAF Shoot Down Amateur Radio Balloon over Canada? 

Did USAF Shoot Down Amateur Radio Balloon over Canada? - RF CafeRF Cafe visitor Lynn L. sent me a link to this article on the RTL-SDR.com website - an amateur radio resource for users of the RTL-SDR computer dongle that is a software defined radio scanning receiver based on the RTL2832U IC. It is widely used by Hams for thousands of experimental communications projects, in conjunction with HDSDR computer software (which I happen to use). One such application is high altitude weather and long distance (Dx) communications when carried aloft by a Pico Balloon, "which involves the use of mylar helium party balloons to launch small solar powered payloads that are only a few grams in weight. They typically transmit low power WSPR at HF frequencies and can only transmit whenever there is sufficient solar power available. Amateur radio or SDR hobbyist stations around the world can pick up these transmissions... Well built balloons can totally circumnavigate the globe several times over several months before degrading." Using NOAA wind models and known position data, operators of K9YO-15 believe it is the $100 "UFO" downed by a $400k Sidewinder missile over the Yukon. I will say, though, it is impressive that a Sidewinder can hit such a diminutive target!

IPP Success with "Lean" and "Six-Sigma" Programs

Innovative Power Products Celebrates Success of Lean and Six-Sigma Programs - RF CafeInnovative Power Products (IPP), with more than 30 years of experience designing & manufacturing RF & microwave passive components, is proud to report having ended 2022 with a product return rate of less than 0.16% for the year. Over the past year, IPP has been investing heavily to implement "Lean" and "Six-Sigma" practices, including company-wide training for all employees. Thank you to our team and our vendors for the excellent quality and thank you to our customers who trust us to deliver to the highest expectations. Lean quality control is a systematic approach to quality management that aims to eliminate waste, defects, and errors in a production or manufacturing process. Six Sigma quality control is a data-driven approach to quality management that focuses on minimizing defects and variability in a production or manufacturing process...

National Company Advertisement: Inductor Bank Switches

National Company Advertisement: Inductor Bank Switches, May 1939 QST - RF CafeNational Company, a major manufacturer of radio components, ran a very long series of advertisements in QST magazine that were in a format more reminiscent of a short essay than a company promotion. This installment for the May 1939 edition was number 63 (I have one numbered 224 from December 1952). Subjects ran the gamut from technical innovations from the company's research and development laboratory to social and political issues relevant to electronics technicians, hobbyists, students, and engineers. Here, company president James Millen explains the research and motivation for developing a new inductor switching arrangement for band switching. Advice from active amateur radio operators was included in the process. James Millen was a prominent radio engineer and designer who worked for several companies throughout his career, including National Company, which was a major manufacturer of amateur radio equipment in the U.S., from the 1930's through the 1980's. During his time at National, Millen designed and developed a wide range of amateur radio equipment, including transmitters, receivers, tuners...

China's Hypersonic Generator for Power-Hungry Weapons

China's Hypersonic Generator for Power-Hungry Weapons - RF Cafe"Scientists in Beijing say they have developed a generator that can turn hot gas moving at hypersonic speeds into an intense electric current capable of powering futuristic weapons. The electricity produced could be used to charge military lasers, microwave weapons, rail guns and other pulsed energy weapons, according to the team led by assistant researcher Zhang Xiaoyuan with the Institute of Mechanics under the Chinese Academy of Sciences. According to the researchers, the technology could also be used for civilian purposes, such as devices for producing nuclear fusion energy or to send a burst of strong SOS signals in an emergency. The reusable air defence system that could protect China from hypersonic weapons. The device produced more than 10 times the power..."

I.F. Coil & Transformer Design

I.F. Coil & Transformer Design, April 1932 Radio-Craft - RF CafeThe use of intermediate frequency (IF) coils and interstage coupling transformers were a major feature of vacuum tube based receivers. Both served the dual purpose of impedance matching and frequency selectivity. Resistive losses in the relatively large passive components required careful attention to matters that affect signal sensitivity, especially in the front end where losses add significantly to the overall noise figure. This article appeared in an early 1930s edition of Radio-Craft magazine at a time when superheterodyne receivers were just coming into popularity and were a new challenge for many designers because of the variable frequency oscillator...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeNew Scheme rotates all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000 website visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 16,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. 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.

Thanks to PCB Directory for Continued Support!

PCB  Directory - RF CafeThe leading website for the PCB industry. PCB Directory is the largest directory of Printed Circuit Board (PCB) Manufacturers, Assembly houses, and Design Services on the Internet. We have listed the leading printed circuit board manufacturers around the world and made them searchable by their capabilities - Number of laminates used, Board thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing, fabrication, assembly, prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.

Thursday the 16th

Electronics "B" Quiz

Electronics "B" Quiz, July 1969 Popular Electronics - RF CafeThis Electronics "B" Quiz by the Popular Electronics magazine's quizmaster Robert Balin appeared in the July 1969 issue. Most of his quizzes are fairly easy to score well on, some are pretty darn difficult, and some are a cinch. This one falls into the latter category. That said, I could not get item #2, and honestly even after seeing the answer at the bottom of the page, it still doesn't seem familiar. Don't let the sketch for item #1 throw you because it shows a vacuum tube; just mentally substitute a FET. Item #6's answer is not "bulb;" it refers to the base type. You'll need some familiarity with color TV analog signals to get item #9. If you don't know about color TV signals, then calculate your score as [number correct]/9*100%....

Some Thoughts on the Balloon Fiasco

Chinese Spy Balloon Fiasco, Kirt's Cogitations #348 - RF CafeLike a lot of Americans (and presumably some Canadians), I was amazed to watch as a Chinese spy craft as large as a couple school busses was permitted to drift over the country from Alaska to South Carolina. It was laden with sophisticated sensors (optical?, radio frequency?, audio?) and communications equipment, powered by huge PV arrays. A detailed reverse engineering effort of an intact, possibly functional inspection could determine the system architecture, electronic component types, software / firmware, mechanics, optics, battery technology, etc., including where they came from and who built them. A lot of information can be gleaned from such an investigation. We are just now being informed that the military knew of the craft from the time it was launched off the coast of China. We are also now told that Biden* was not apprised of the situation until it had been spotted over Montana by civilians and photographed with a cellphone. Then, officials said bringing it down over populated areas was too risky, even though there was ample opportunity to do so while it was over unpopulated areas in Alaska and Canada. In fact, it could probably have been brought down over land gradually via controlled deflation rather than blowing it out of the sky with a Sidewinder missile. The payload equipment would then have been more readily accessible and intact for inspection. Prior to learning the balloon was being tracked even before it flew over the U.S., we were told that NORAD and all other radars missed it...

I Equals E over R

I Equals E over R, August 1932 Radio-Craft - RF CafeWhoa, it's a good thing I read these articles prior to publishing them, lest some soul unfamiliar with this topic be lead to the wrong conclusion! Keep in mind that this article was written in 1932, prior to the development of the quantum mechanical model of the atom, but on the other hand, Ernest Rutherford and Niels Bohr developed their model in 1913, so the relevant information was available. The Rutherford-Bohr model of the atom suggested a nucleus comprised of positive masses called protons, each of which carries a charge of +1 unit, and neutrons with no net charge. Surrounding the nucleus were orbiting masses called electrons, each of which carries a charge of -1 units. Accordingly, the net charge of an atom was the sum of protons and electrons, with unionized atoms having a net charge of 0 (zero). Neutrons, carrying no charge, have no effect on the overall atomic charge. Modern science says quarks, three of which make up each proton and neutron, have individual charges of +1/3, -1/3, +2/3, or -2/3, thereby determining the particles' net charges...

Offline Turbines at Wind Farms Kept Warm by Diesel Generators

Offline Turbines at Wind Farms Kept Warm by Diesel Generators - RF CafeThis sort of thing happens all over the place, and the public is rarely made aware of it. I'm a big supporter of alternative energy sources, electric cars, etc., but I resent the gas-lighting and outright lies put out by government, academia, and industry regarding the "greenness" of it all. "Dozens of giant turbines on Scotland's windfarms have been powered by diesel generators, the Sunday Mail can reveal. Scottish Power admitted 71 of its windmills were hooked up to the fossil fuel supply after a fault developed on the grid. The firm said it was forced to act in order to keep the turbines warm during very cold weather in December. But a whistleblower has told the Sunday Mail the incident is among a number of environmental and health and safety failings.'" Amongst other problems reported is "over 4000 litres of [hydraulic] oil leaked from hydraulic units on turbines and sprayed over the countryside." Also does 95% availability seem good to you? That's 57.6 minutes out of every 24 hours...

Anatech Electronics Intros 3 Filter Models

Anatech Electronics Intros 3 Filter Models for Mid February 2023 - 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 filters have been announced - a 2020-2080 MHz / 2200-2260 MHz cavity duplexer with a 1.0 dB insertion loss, 836.5 MHz / 881.5 MHz cavity duplexer with a 1.0 dB insertion loss, LTE Band 12 cavity duplexer with a 1.2 dB insertion loss. Custom RF power filter and directional couplers designs can be designed and produced with required connector types when a standard cannot be found, or the requirements are such that a custom approach is necessary...

Ford-Philco Radio Model FT9 Auto Radio

Ford-Philco Radio, Model FT9, 6-Tube Auto-Radio Receiver Radio Service Data Sheet, April 1936 Radio-Craft - RF CafeThis Radio Service Data Sheet covers the Ford-Philco radio model FT9, 6-tube auto-radio receiver. It appeared in a 1936 issue of Radio-Craft magazine. Most - if not all - electronics servicemen had subscriptions to these magazines because they were a ready source of not just these service sheets, but because of the extensive articles offering advice on servicing radios and televisions. In fact, many electronics manufacturers had a policy of supplying service data only to bona fide shops. Thumbnail photos at the left came from a Ford-Philco FT9 radio on eBay. A large list is included at the bottom of the page of similar documents from vintage receiver schematics, troubleshooting tips, and alignment procedures. They were originally published in magazines like this one, Radio and Television News, Radio News, etc. I scan and post them...

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, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

Please Visit Empower RF's Website in Appreciation of Their Support

Empower RF Systems - RF CafeEmpower RF Systems is the technological leader in RF & microwave power amplifier solutions for EW, Radar, Satcom, Threat Simulation, Communications, and Product Testing. Our air and liquid cooled amplifiers incorporate the latest semiconductor and power combining technologies and with a patented architecture we build the most sophisticated and flexible COTS system amplifiers in the world. Solutions range from tens of watts to hundreds of kilowatts and includes basic PA modules to scalable rack systems.

Wednesday the 15th

Bell Telephone Laboratories - Jacques Bernoulli

Bell Telephone Laboratories - Jacques Bernoulli, February 1960 Radio-Electronics - RF CafeBeing one of the world's premier communications technology companies, Bell Telephone Laboratories (aka Bell Labs) engineers and scientists relied heavily on mathematics for its accomplishment. It comes as no surprise, then, that one of their full-page promotions in a 1960 issue of Radio-Electronics magazine celebrated the accomplishments of mathematician Jacques Bernoulli, a Swiss mathematician who, along with his brother Jean Bernoulli, was instrumental in the development of calculus and the application of mathematical principles to various fields. Jacques Bernoulli was born into a family of mathematicians in Basel, Switzerland, and showed an early aptitude for mathematics. He studied at the University of Basel and then went on to study in Italy, France, and the Netherlands. In 1687, he became a professor of mathematics at the University of Basel, where he remained until his death...

The Wives and Mothers of Radio Amateurs

The Wives and Mothers of Radio Amateurs, August 1931 QST - RF CafeHow well received do you think this social concept would be in today's easily offended world: "To bring together socially the Wives and Mothers of Dallas Radio Amateurs; to promote mutual sympathy, counsel, and interest in our husband's and our son's hobby; and with a realization that theirs is an outstanding, fascinating, far-reaching and educational hobby, it is our desire to further their interests in whatever way may present itself." It would be roundly criticized as a backward, misogynistic, 1930-era mindset intended to subject women to yet another form of domestic slavery beyond housekeeping and child rearing - no doubt thought up by a man. Anyone thinking so would be right in one aspect: It was a 1930s-era idea. However, The Wives and Mothers of Radio Amateurs was the brainchild of and orchestrated by wives and mothers who genuinely desired to foster the productive and educational radio communication hobby of their husbands and sons. Some even eventually joined in themselves. The ARRL then, as today, expends much effort attempting to proselytize women and girls into the hobby not as moral support but as licensed operators. In fact, according to the YLRL (Young Ladies' Radio League)...

Many Thanks to Aegis Power Systems for Their Continued Support!

Aegis Power Systems - RF CafeAegis Power Systems is a leading supplier of AC-DC and DC-DC power supplies for custom and special applications. Aegis has been designing and building highly reliable custom power supplies since 1995. They offer a complete line of switch mode power supplies and power converters for a variety of markets including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft, EV, telecom, and embedded computing applications. Design and manufacture of custom power supply solutions to meet each customer's exacting specifications. Please visit Aegis Power Systems today.

Space-Based Solar Power

Space-Based Solar Power - RF Cafe"For about as long as engineers have talked about beaming solar power to Earth from space, they've had to caution that it was an idea unlikely to become real anytime soon. Elaborate designs for orbiting solar farms have circulated for decades - but since photovoltaic cells were inefficient, any arrays would need to be the size of cities. The plans got no closer to space than the upper shelves of libraries. That's beginning to change. Right now, in a sun-synchronous orbit about 525 kilometers overhead, there is a small experimental satellite called the Space Solar Power Demonstrator One (SSPD-1 for short). It was designed and built by a team at the California Institute of Technology, funded by donations from the California real estate developer Donald Bren, and launched on 3 January - among 113 other small payloads - on a SpaceX Falcon 9 rocket..."

Dividing Networks

Dividing Networks, December 1949 Radio & Television News - RF CafeDividing network is another name for a crossover network used to separate and direct parts of the audio frequency band to specific speakers - bass, midrange, and tweeter, for example. It is the audio equivalent of a diplexer or multiplexer filter in the RF and microwave realm. As with many other aspects of consumer electronics, there was a time when many audiophiles chose to design and/or build their own crossover networks for home-built speakers. Although never really a bona fide audiophile, I did design and build my own custom speaker cabinets and the crossover network. The woodwork was done at the woodshop at Robins Air Force Base while I was serving in the USAF as an Air Traffic Control Radar Repairman (not an air traffic controller). I don't know if it is still the case, but back then most large bases had hobby and craft establishments for woodworking and metalworking, ceramics, artistic painting, and even electronics benches. To the left is the only photo I have of one of the speakers, which have since been sold. My units each had three speakers and a homemade L-C crossover network. Admittedly, no real science went into the electrical design; I adjusted the inductor and capacitor values until everything sounded "about right"...

Post Your Engineer & Technician Job Openings on RF Cafe for Free

/jobs.htm">Engineering Job Board - RF CafeRF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable /jobs.htm">job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

Many Thanks to Anatech Electronics for Long-Time Support!

Anatech Electronics logo - RF CafeAnatech Electronics (AEI) manufactures and supplies RF and microwave filters for military and commercial communication systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter and cable assembly products are published in our website database for ease of procurement. Custom RF filters designs are used when a standard cannot be found, or the requirements dictate a custom approach for your military and commercial communications needs. Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please visit Anatech today to see how they can help your project succeed. 

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