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Homepage Archive - October 2023 (page 3)

See Page 1 | 2 | 3 | 4 | of the October 2023 homepage archives.
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Sunday the 22nd

Electronics Themed Crossword Puzzle October 22nd

Electronics Themed Crossword Puzzle October 22nd, 2023 - RF CafeAs with my hundreds of previous engineering and science-themed crossword puzzles, this one for October 22nd uses only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over more than two decades. Many new words and company names have been added that had not even been added to the world's technical lexicon when I started in the year 2002. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you. The technically inclined cruciverbalists amongst us will appreciate the effort. A full list of all RF Cafe crosswords is at the page bottom. Enjoy!

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. 

Friday the 20th

Hobnobbing with Harbaugh - Key Clicks and Mike Splatter

Hobnobbing with Harbaugh - Key Clicks and Mike Splatter, December 1961 Popular Electronics - RF CafeTGIF, right? Here are a few of Dave Harbaugh's Ham radio related comics from the December 1961 issue of Popular Electronics magazine to help wind down the week. From the time Popular Electronics began publication in October 1954, it dedicated a lot of print space to amateur radio and to radio controlled modeling. A lot of self-deprecating humor accompanied special features by various artists and story writers. Carl Kohler contributed many humor columns under the McWatts series and his domestic antics while attempting to appease "Wife friend." A fairly common topic of Ham radio comics is having a wife discover her husband has been carrying on communications with a "YL" (young lady); one such theme is included here. Being the December edition, of course there is a Christmas-themed comic as well. With the Khrushchev comic (remember the era), I'm not sure whether the red-faced Harbaugh is meant to indicate his rage while arguing with a Commie, or to represent his conversation with a "Red." Also common in the day was the nuclear war threat with a popular practice of building...

How Resistors Are Made

How Resistors Are Made, March 1935 Radio-Craft - RF Cafe

Resistors, probably the most common electronic components in existence, have undergone significant evolution since first being mass produced in the late 19th century. Amazingly, less than two centuries have passed since the concept of electrical resistance was first published in 1827 by Georg Simon Ohm, a German physicist. As with most products of the era, and well into the 20th century, resistor manufacturing involved a degree of human labor. Resistors found in your grandparents' old vacuum tube radios were most likely measured and sorted, and the colored value markings painted by the hand of a human worker. This "How Resistors Are Made" article from a 1935 issue of Radio-Craft magazine provides a look at the early manufacturing process long before salt-grain size surface mount resistors. Note the photo showing an operator manually painting color code dots on the resistor body. One of America's earliest and largest resistor manufacturers...

Electronic Sensor the Size of a Single Molecule

Electronic Sensor the Size of a Single Molecule - RF Cafe"Piezoresistors are commonly used to detect vibrations in electronics and automobiles, such as in smartphones for counting steps, and for airbag deployment in cars. They are also used in medical devices such as implantable pressure sensors, as well as in aviation and space travel. In a nationwide initiative, researchers have developed a piezoresistor that is about 500,000 times smaller than the width of a human hair. Dr. Darwish said they had developed a more sensitive, miniaturized type of this key electronic component, which transforms force or pressure to an electrical signal and is used in many everyday applications. 'Because of its size and chemical nature, this new type of piezoresistor will open up a whole new realm of opportunities for chemical and biosensors, human-machine interfaces, and health monitoring devices,' Dr. Darwish said..."

American-Bosch Model 430T 5-Tube 3-Band Superhet Radio

American-Bosch Model 430T 5-Tube 3-Band Superhet. Radio Service Data Sheet, January 1936 Radio-Craft - RF CafeThe American-Bosch model 430T is a 5-tube, 3-band superheterodyne table 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 to the left 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 noise problem...

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...

Many Thanks to Amplifier Solutions Corporation (ASC) for Continuing Support!

Amplifier Solutions Corporation (ASC) - RF CafeAmplifier Solutions Corporation (ASC) is a manufacturer of amplifiers for commercial & military markets. ASC designs and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers for low, medium and high power applications using Gallium Nitride (GaN), Gallium Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility in the town of Telford, PA. We offer excellent customer support and take pride in the ability to quickly react to evolving system design requirements.

Thursday the 19th

Ultrasonics

Ultrasonics, December 1961 Popular Electronics - RF CafeUltrasonics as a cleaning method was a big thing in industry long before this article appeared in a 1961 issue of Popular Electronics magazine, but as with microwaves (for other than broadcasting), ultrasonics was beginning to move into domestic, medical, and small business applications. If you are not familiar with the capabilities of ultrasonics, Ken Gilmore will enlighten you on methods for cleaning air, measuring fat content in tissue, cleaning extremely small mechanical components, meat tenderizing, ship hull barnacle prevention, and other such things. My first exposure to ultrasonic cleaning was while at Westinghouse Oceanic Division in Annapolis, MD, where we had an ultrasonic vat filled with methyl chloroform (1,1,1, trichloroethane) for degreasing and defluxing electronics assemblies. We got it in 55-gallon drums. The methyl chloroform was heated to enhance its cleaning action, and there was a pipe surrounding the perimeter of the open top that had cold water running through it which caused the evaporated solution...

Reconfigurable Field-Effect Transistor and Memory Device

Reconfigurable Field-Effect Transistor and Memory Device 2D Heterostructure - RF Cafe "Transistors are crucial components of most electronics on the market today, including computers, smartphones, wearables and numerous other devices. These components, generally based on semiconducting materials, are designed to switch, detect and amplify current inside devices, controlling the flow of electricity inside them during their operation. As conventional transistors are reaching their highest possible performance, electronics engineers have been working on alternative transistor designs that could be promising for future applications. Using different materials and arranging these materials in unique ways, engineers hope to enhance the performance of transistors, reduce their size or enable unique functions. Reconfigurable field-effect transistors (FETs) are an emerging class of transistors that could help to reduce the complexity of electronics, by combining different functions in a single device. Specifically, these programmable transistors could combine the characteristics of unipolar n- and p-type semiconductors..."

Lens-Like Antenna: Low Noise, Less Space

Lens-Like Antenna: Low Noise, Less Space, February 28, 1964 Electronics Magazine - RF CafeElectronics magazine is very different from all the other vintage electronics magazines I have used in the past. Electronics is much more focused on military, space, and fundamental research. New issues were published bi-weekly by McGraw-Hill from 1930 until 1988. About half the editions had two to three times as many pages as the other half, with most of the extra pages being advertisements. The publishers must have made a fortune on advertising revenue. My guess is that the vast majority of the companies appearing in the early 1960s issues I bought on eBay do not exist anymore, having either gone out of business or having been acquired by bigger companies. The article presents a very interesting rhombic antenna concept. Someone had his thinking cap on real tight when dreaming up the radio wave focusing scheme described. A "high speed computer" was used for simulations prior to building the prototype. Its key objective was to drastically reduce the amount of acreage needed to obtain performance akin to rhombic layouts. The FAA funded the project citing a need for reliably receiving intercontinental air traffic control information...

Anatech Electronics Intros 3 Bandpass Filters

Anatech Electronics Intros 3 Filter Models for October 18th, 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 for October 2023: a 2205.5 MHz cavity bandpass filter with a bandwidth of 15 MHz and power handling of 25 W, a 2201.5 MHz cavity bandpass filter with SMA Female connectors and a 6 MHz bandwidth, and a 2201.5 MHz cavity bandpass filter with a 6 MHz bandwidth and an insertion loss of 2.0 dB and handles 10 W of power. 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...

Japanese Push for Technical Leadership

Japanese Technology - The New Push for Technical Leadership , December 13, 1965 Electronics Magazine - RF CafeIf the December 13, 1965, edition of Electronics magazine had a theme, it was undoubtedly reporting on the current state of Japanese technology. The cover photo is a shot of microwave antennas dominating Tokyo's skyline. Japanese technology companies worked hard to overcome the largely undeserved negative connotation that a "Made in Japan" label carried in the day. Do you remember the scene in the movie "Back to the Future Part III" where Doc, having traveled back in time from the 1950s, is trying to fix his DeLorean time travel car and discovers a burnt out circuit and claims, "No wonder this circuit failed, it says made in Japan?" Marty, who travelled from the 1980s, replied, "What do you mean doc, all the best stuff is made in Japan." There is no denying the Japanese people succeeded at their goal...

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 Centric RF for Their Continued Support!

Centric RF microwave components - RF CafeCentric RF is a company offering from stock various RF and Microwave coaxial components, including attenuators, adapters, cable assemblies, terminations, power dividers, and more. We believe in offering high performance parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power levels from 0.5-500 watts are available off the shelf. We have >500,000 RF and Microwave passive components we can ship you today! We offer Quality Precision Parts, Competitive Pricing, Easy Shopping, Fast Delivery. We're happy to provide custom parts, such as custom cables and adapters, to fit your needs. Centric RF is currently seeking distributors, so please contact us if interested. Visit Centric RF today.

Wednesday the 18th

News Briefs, August 1964 Radio-Electronics

News Briefs, August 1964 Radio-Electronics - RF CafeHave you heard of the term "neutrodon?" Not me, until it appeared in this 1964 issue of Radio-Electronics magazine's "News Briefs" section. A neutrodon is a neutralizing capacitor used in vintage tuned radio frequency (TRF) radios based on triode tubes - called neutrodynes - invented by Dr. Louis Alan Hazeltine. The capacitors cancel out the Miller capacitance of high gain vacuum tubes. He founded Hazeltine Corporation, which is now owned by BAE Systems (British Aerospace Electronics - it's amazing how many of our technology companies are owned by foreign companies). Also reported is Dr. Alexander de Seversky, designer and manufacturer of World War I combat biplanes and monoplanes, experimenting with a model "ion-powered craft" - the "Ionocraft" - that floated on a stream of electrons from an emitter grid located below it. Although no details were given, he claimed the craft could fly to altitudes of 60 miles. That height would place the Ionocraft within the ionosphere, where I'm guessing the ambient charges would wreak havoc with the navigation / propulsion system...

Memristor Semiconductor Building Block

Memristor Semiconductor Building Block - RF CafeUh-oh, I wonder if  dummkopf Tim H., who keeps writing to call me an idiot for claiming memristors are real, will crawl out of his hole again for this story? "The world's first fully system-integrated memristor chip has been unveiled by a team of Chinese scientists who believe it could not only make artificial intelligence smarter, but also more time and energy efficient. While the semiconductor has yet to leave the lab setting, it could allow for the development of AI that is capable of more human-like learning, which could have implications for the way smart devices and autonomous driving work, according to the researchers. 'Learning is highly important,' for edge intelligence devices, the research team from Tsinghua University said in their study released in the journal Science on September 15, referencing devices that process data internally with technology like AI..."

Frequency Modulation in Tomorrow's Set

"Frequency Modulation" in Tomorrow's Set, September 1935 Radio-Craft - RF CafeEdwin Armstrong, often referred to as Major Armstrong due to his commission in the U.S. Army Signal Corps, came up with a working scheme for wideband frequency modulation (FM) in the early 1930s. He did not, as believed by many, invent FM. Narrowband FM was explored in the 1920s as a replacement to amplitude modulation (AM) in hopes that it would eliminate the susceptibility to static that AM suffered, but no significant improvement was achieved. When this article was published in Radio-Craft magazine 1935, it was a mere two years after Armstrong was awarded patents for his wideband FM system. AM was still the scheme used by all commercial broadcast stations primarily because receivers were not being manufactured yet. On January 1, 1941, the Federal Communications Commission (FCC) allocated a band of 40 channels spanning 42–50 MHz for FM broadcasting. Radio station WSM-FM (W47NV) in Nashville, Tennessee, becoming the first fully licensed commercial FM station...

Bremer-Tully Model 7-70 Radio Service Data Sheet

Bremer-Tully Model 7-70 and 7-71 Radio Service Data Sheet, January 1930 Radio-Craft - RF CafeJanuary 1930 was very shortly after the major stock market crash in October of the previous year, so a lot of people suddenly were not motivated to buy unnecessary creature comfort items - like radios. Many of the smaller manufacturers were forced out of business accordingly. Fewer and simpler designs seemed to dominate the surviving market for a couple years as the economies of the world slowly recovered. America was not alone in the financial doldrums. Just about the time things were rolling along merrily again, a short-tempered little guy with a funny mustache decided he wanted to rule over all of Europe, starting a war that would eventually cause nations to dedicate manufacturing facilities and materials for radios (and many other things) to weapons production. Non-military radio production was suspended from 1942 through 1945. After that, electronics for all manner of entertainment grew exponentially. The photo of the Bremer-Tully Model 7-70 radio was found on the RadioMuseum.org website. It looks like a very basic tabletop configuration...

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 ConductRF for Continued Support!

ConductRF coaxial cables & connectors - RF CafeConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 

Tuesday the 17th

What is It? - A Question Bee in Photographs

What is It? - A Question Bee in Photographs, June 1941 Popular Science - RF CafeEverybody likes a "What Is It?" type picture quiz - especially if the results are not being graded. These eleven photos were published in a 1941 issue of Popular Science magazine, along with suggestions for what they might be. All except two are commonplace items which should cause no difficulty for most RF Cafe visitors. My experience is that the kinds of people who read magazines like Popular Science, Mechanix Illustrated, and Popular Mechanics are both self-educators and "doers" who regularly indulge in science (astronomy, weather, propulsion), mechanics (cars and trucks, mowers, washing machines, motors), chemistry (solvents, lubricants, coatings), and all the tools and gadgetry that go along with them. A couple items here are somewhat antiquated, but anyone older than about forty to fifty years old have likely seen and/or own them. Bon chance...

Mac's Service Shop: Biological Effects of Electrical Shock

Mac's Service Shop: Biological Effects of Electrical Shock, May 1973 Popular Electronics - RF CafeHere is a timeless subject for anyone routinely subject to exposed high voltages. Most RF Cafe visitors already know that technically, it is the amount of electric current through the body that determines severity of electric shock, not the voltage. However, we also know that voltage does play a role because a certain voltage, per Ohm's law, is needed to induce a commensurate current. The body's resistance is determined primarily by perspiration (salt and water) and the path between contact points (e.g., across adjacent skin areas or hand-to-hand via the heart). MIL-STD-883 and JEDEC* have decided that the proper Human Body Model (HBM) for testing semiconductor survivability when subject to high voltages is 1.5 kΩ. I could not find out how that value was determined...

New Dawn for Directed Energy Weapons

New Dawn for Directed Energy Weapons - RF Cafe"We live in an increasingly gray zone and asymmetric world, where coercive actions must be effective against near-peer adversaries and non-state actors alike. Ukraine is largely a drone war, while the U.S. and allies struggle to supply much costlier conventional weapons. China is modernizing its forces with a ferocity too few Americans appreciate, spanning land, air, sea and space capabilities, as well as electronic and information warfare. At home, our citizens and infrastructure face looming threats from attritable systems. As sobering as these perils are, the U.S. already has the means to achieve step changes in mission effectiveness and deterrence, using directed energy (defined as concentrated beams of electromagnetic energy). Legacy military applications mostly focused on jamming communications and face barriers to achieving more comprehensive effects. Today, thanks to five years of dramatic advances in directed energy, we stand at a pivotal moment, as high-power microwave capabilities enter the spotlight. Directed energy will define the next era of defense..."

Allied Radio's Knight Model E10913 Tabletop Radio

Allied Radio Corp., Knight Model E10913 Radio Service Data Sheet, January 1939 Radio-Craft - RF CafePhotographs of some - maybe even most - of the vintage vacuum tube radios are difficult or even impossible to find online. This Knight Model E10913 tabletop radio manufactured by Allied Radio Corporation is an example. When I post these Radio Service Data Sheets from magazines like Radio-Craft, I always attempt to find a photo of a restored radio or at lease a one in decent condition. Websites like The Radio Attic and Radio Museum have large inventories of photos, schematics, and sometimes a description and company history. eBay and Etsy are also a good place to look. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. Accordingly, a running list of all data sheets is at the bottom to facilitate a search. Most radio service shop technicians were able to troubleshoot and align these simple sets without any kind of documentation.

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...

Thanks to Copper Mountain Technologies for Continued Support

Copper Mountain TechnologiesCopper Mountain Technologies develops innovative and robust RF test and measurement solutions for engineers all over the world. Copper Mountain's extensive line of unique form factor Vector Network Analyzers include an RF measurement module and a software application which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware via USB interface. The result is a lower cost, faster, more effective test process that fits into the modern workspace in lab, production, field and secure testing environments. 50 Ω and 75 Ω models are available, along with a full line of precision calibration and connector adaptors.

Monday the 16th

How to Repair Your Electric Clock

How to Repair Your Electric Clock, December 1954 Popular Electronics - RF CafeGreat minds think alike, as the old saying goes. Back in 2021, my 1970s-era General Electric Model 7-4305C roll-down number clock-radio began making a high pitch grinding noise. It is powered by a small, pancake AC synchronous motor. After looking on eBay for a replacement motor, I discovered that they were commonly selling for $20-$50, which is more than I paid for the radio. On a whim, I decided to try drilling a small hole in the top of the motor case and injecting a couple drops of 3-in-1 motor oil (there was no way to safely open the case. The motor body was rotated a few times to distribute the oil inside. I did not cover the hole since it was purposely drilled in the top. When I plugged it back in, the noise was gone, and to date has not returned. To my amazement, when perusing my hard copy of the December 1954 issue of Popular Electronics magazine a few days ago, I ran across this "How to Repair Your Electric Clock" article! The author did exactly the same thing I did, except he covered the hole he made. I couldn't believe it...

Espresso Engineering Workbook™ for Excel - 10.16.2023

RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeOhm's Law Calculator in RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeThe newest release of RF Cafe's spreadsheet (Excel) based engineering and science calculator is now available - Espresso Engineering Workbook™. Among other additions, it now has an Ohm's Law Calculator. Note that the Spurious Product Calculator has been removed because its large number of calculations slowed down the spreadsheet too much. Since 2002, the original Calculator Workbook has been available as a free download. Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is also provided at no cost, compliments of my generous sponsors. The original calculators are included, but with a vastly expanded and improved user interface. Error-trapped user input cells help prevent entry of invalid values. An extensive use of Visual Basic for Applications (VBA) functions now do most of the heavy lifting with calculations, and facilitates a wide user-selectable choice of units for voltage, frequency, speed, temperature, power, wavelength, weight, etc. In fact, a full page of units conversion calculators is included. A particularly handy feature is the ability to specify the the number of significant digits to display. Drop-down menus are provided for convenience. Now that a more expandable basis has been created, I plan to add new calculators on a regular basis...

What Do You Know About Resistors?

What Do You Know About Resistors?, April 1974 Popular Electronics - RF CafeOK, I am ashamed to admit that with just a quick guess I thought Rx in question 6 would be 180 Ω rather than the correct value of 20 Ω. I knew the ratio of 150 Ω to 50 Ω (3:1) would be the same as for 60 Ω to Rx, but stupidly went the wrong way. In order for the bridge to be balanced, the voltage division between the left and right arms of the bridge had to result in the voltages on both sides of the meter to be 0 V. I did manage to get the equivalent resistances of Q8, 9, and 10 right, though, by re-drawing the circuits (Hint: it helps a lot to number the nodes and resistors when doing so). Q10, by the way, is similar to the resistor cube problem I demonstrated a method for solution back in 2010 (wow, that long ago?!)...

Arvin-Ford 17-A Radio

Arvin-Ford 17-A Radio Schematic, June 1935 Radio-Craft - RF CafeArvin, a subsidiary of Noblitt-Sparks Industries, was a brand of car radios and audio equipment that was popular in the 20th century. Founded in the 1930s, Arvin quickly established itself as a leader in the field of automotive sound systems. Known for its quality and reliability, Arvin's products were widely used by American consumers and became synonymous with in-car entertainment. At a time when radio was still a relatively new technology, Arvin's car radios stood out for their compact size and ease of use. They were well-designed and offered a range of features, including AM/FM tuning, volume control, and push-button tuning. Arvin also offered a range of other audio products, including home radios and portable speakers, that were well-received by consumers. This schematic for the Arvin-Ford 17-A Automotive Radio was published in the June 1935 issue of Radio-Craft magazine. The image is representative of an Arvin car radio of the era...

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 weekdayRF 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...

Thanks Once Again to everythingRF for Long-Time Support!

everything RF Searchable Database - RF CafePlease take a few moments to visit the everythingRF website to see how they can assist you with your project. everythingRF is a product discovery platform for RF and microwave products and services. They currently have 267,269 products from more than 1397 companies across 314 categories in their database and enable engineers to search for them using their customized parametric search tool. Amplifiers, test equipment, power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers, power supplies, and everything else. Please visit everythingRF today to see how they can help you.

Sunday the 15th

Electronics Theme Crossword for October 15th

Electronics Theme Crossword Puzzle for October 15th, 2023 - RF CafeThis week's electronic-theme crossword puzzle for October 15th sports an electronics theme. This being the 15th day of the month, many of the words begin and/or end with the letter "O." Clues for words containing "O" are marked with an asterisk (*). All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny, Hedy Lamarr, or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

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...

Thanks Again for RIGOL Technologies' Continued Support!

RIGOL Technologies (electronics test equipment)RIGOL Technologies is transforming the Test and Measurement Industry. Our premium line of products includes digital and mixed signal oscilloscopes, spectrum analyzers, function / arbitrary waveform generators, programmable power supplies and loads, digital multimeters, data acquisition systems, and application software. Our test solutions combine uncompromised product performance, quality, and advanced product features; all delivered at extremely attractive price points. This combination provides our customers with unprecedented value for their investment, reduces their overall cost of test, and helps speed time to completion of their designs or projects.

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