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Homepage Archive - June 2024 (page 1)

See Page 1 | 2 | 3 | 4 | of the June 2024 homepage archives.

Friday the 7th

Solve Your Problems with Kirchhoff's Laws

Solve Your Problems with Kirchhoff's Laws, April 1962 Radio-Electronics - RF CafeNot to disrespect Gustav Kirchhoff's accomplishments, but his two eponymous laws seem so obvious that you might wonder why they even need to be stated, much less be named after someone. The equivalent for the oft-used water in a hose analogy would be as follows: (#1) The volume of water entering the common port of a manifold is equal to the sum of the water exiting all the other ports. (#2) In a closed system, the sum of the the pressure drops (e.g., constricted pipe) and pressure rises (e.g., water pump) is zero. In fairness, when Mr. Kirchhoff formulated his laws in the middle 19th century not many people were familiar with electric circuits, and instruments for making certified measurements with enough precision to validate the claims were not readily available. This 1962 Radio-Electronics magazine article introduces Kirchhoff's current law and voltage law. Remembering and applying them does make writing equations for multi-loop circuits much simpler...

Electronics-Themed Comics

Electronics-Themed Comics, January 1969 Electronics World - RF CafeHere are a couple tech-themed comics that appeared in the October 1969 issue of Electronics World magazine. I like the one with the two guys applying for a patent best. Note the size difference. Of course the mother-in-law comics are always funny. There is a huge list at the bottom of the page of links to other comics I have posted over the years. BTW, people have asked why I separate the text from the image. The answer is simple: If someone finds the image using an image search, he/she has to actually visit the webpage to get the punch line. Does that make me a bad person?

Engineering & Tech Headlines <Archives>

• U.S. Revokes Huawei Chip Export Licenses

• FCC Investigates Unauthorized Undersea Cables

463,000 Kia e-SUV Should Park Outside Pending Recall

Ofcom Plan for Hybrid Sharing of Upper 6 GHz Band

Quantum Computing Market on 17% CAGR to $1.8B in 2029


Intermodulation Distortion

Intermodulation Distortion, February 1960 Electronics World - RF CafeAudio distortion is most often expressed as total harmonic distortion (THD) as opposed to intermodulation distortion (IMD). As the name suggests, THD is a measure of harmonic power content relative to the fundamental frequency (a single tone) from which harmonics are created. IMD on the other hand, is generated from the nonlinear mixing of two or more tones, with the products being non-harmonically related to the original tones. The author's discussion of audio frequency IMD applies equally to radio frequency IMD. Intentionally generated harmonic components can enhance sound quality due to being consonant, whereas IM products create dissonant tones not directly related to the originals. Audio amplifier frequency vs. power specifications typically include the sum of total harmonic distortion and noise (THD+N), signal-to-noise ratio (SNR)...

How to Target RFCafe.com for Your Google Ads

Google AdSense - it makes good sense - RF CafeOne aspect of advertising on the RF Cafe website I have not covered is using Google AdSense. The reason is that I never took the time to explore how - or even whether it is possible - to target a specific website for displaying your banner ads. A couple display opportunities have always been provided for Google Ads to display, but the vast majority of advertising on RF Cafe is done via private advertisers. That is, companies deal with me directly and I handle inserting their banner ads into the html page code that randomly selects and displays them. My advertising scheme is what the industry refers to as a "Tenancy Campaign," whereby a flat price per month is paid regardless of number of impressions or clicks. It is the simplest format and has seemed to work well for many companies. With nearly 4 million pageviews per year for RFCafe.com, the average impression rate per banner ad is about 280k per year (in eight locations on each page, with >17k pages)...

Thursday the 6th

Fine Points of Filter Theory

Fine Points of Filter Theory, April 1962 Radio-Electronics - RF CafeSometimes one of the most interesting parts of a magazine is the Letters to the Editor. Most of the time it is composed of notes of appreciation for publishing a certain article, or appreciation for the works overall. Occasionally, a reader will sound off with a criticism of and article - some more polite than others. The magazine editor will usually give the author a chance to respond immediately after the challenge to content veracity. Such was the case in the March 1967 issue of Radio-Electronics magazine when a Zenith company engineer wrote to correct a previous article's claim regarding linear phase filter design in FM radio systems. Author Crowhusrt happened to mention in an AM-to-FM converter circuit that a Zenith scheme might not be the best approach for the application (versus a General Electric scheme). Zenith's Huenemann meant to set the record straight, but Mr. Crowhust did an admirable job defending his writing. Nerd wars...

D-Day Radio

RF Cafe website visitor Joseph B. sent me this note in regard to this 80th anniversary of the D-Day invasion:

"Below are a few links regarding D-Day (which is today). The first [Radio Comms] is a link to how radio comms were setup during the invasion, the second [Broadcasts Link] is a collection of news broadcasts on the day of the event, and the third is an article about local radio technician and baseball hero, Jim Pinder, who stormed Normandy beach carrying 52 lbs of radio equipment. Lastly, a very heartfelt "Thank you!" to all who served and to those who gave their lives.

Exodus AMP2145D-LC, 18-40 GHz, 80-W SSPA

Exodus AMP2145D-LC, 18-40 GHz, 80-W SSPA - Another Industry First! - RF CafeExodus Advanced Communications, is a multinational RF communication equipment and engineering service company serving both commercial and government entities and their affiliates worldwide. We are pleased to announce the Exodus Model AMP2145D-LC, a 18.0-40.0 GHz, 80 W Solid State Amplifier is another industry first from Exodus. Designed for Broadband EMC & Lab Testing, Mil-Std 461 (RS103) standards as well as other High-Power Applications. Exodus Model AMP2145D-LC is a compact 6U design providing outstanding power/gain flatness, Forward/Reflected power monitoring in both dBm & watts, VSWR, voltage/current and temperature sensing for superb reliability and ruggedness. Unprecedented reliability compared to TWT's, with 49 dB gain including gain control, and -20 dBc harmonics...

Hughes Research and Development Laboratories

Hughes Research and Development Laboratories, October 1955 Radio & Television News - RF CafeWhen I saw this Hughes Research and Development Laboratories employment ad in a 1955 issue of Radio & Television News magazine, I wasn't sure how to take it. The text of the ad makes no reference to the bar graph and the weird drawing. Note the "bottle" is actually a slide rule. The graph can be interpreted to indicate that the more education a person has, the less likely he is to have children. If the typical age of the respondent is in the twenties, then that might reflect how people still in school to earn a higher degree would not be having children. It might also show that people with higher degrees focus more on their careers than on having a family. If you extrapolate the graph backward, does it imply people with an Associate's degree might average 1.5 children, those with just a high school diploma have about 1.7 children, and high school dropouts average maybe 2.0 kids...

Glass Packaging for Small Footprint HF Modules

Glass Packaging for Smaller Footprint for High-Frequency Modules - RF Cafe"ED2 Corporation, a company that designs a range of products in electronics and wireless communications, has developed Advanced Glass Packaging Technology (AGPT™) that will enable heterogeneous integration of electronic components and modules. The AGPT technology is based on using Synthetic Quartz (Fused Silica) as the substrate material that exhibits excellent thermal, electrical, and optical properties. It enables ultra-small feature sizes, excellent high frequency response, allowing for tight integration and supporting fabrication as a wafer-level process, for scale and cost. The heterogeneous integration of components is facilitated..."

WWII Era Electronics Advertisements in QST

Cool Pic - WWII Era Electronics Advertisements in QST Magazine - RF CafeToday is the 80th anniversary of D-Day. Maybe it comes from having crossed the half-century Rubicon, but with increasing frequency I find myself seeking out vintage magazines to learn how the world used to be. I am a realist who has no misconceptions about how things used to be idyllic and that today is utter debauchery, but it is apparent from a lot of the publications that we surely have changed significantly in the last 50+ years - better in some ways, worse in others. Technologically we are much better off; societally, not so much. For many years I have been purchasing of WWII era QST and other electronics magazine titles listed on eBay. I do the same thing for vintage model magazines on my Airplanes and Rockets website. Selected articles and advertisements are scanned...

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...

Wednesday the 5th

What's New: May 1962 Radio-Electronics

What's New, May 1962 Radio-Electronics - RF CafeProbably most people of my era (nee 1958) had their introduction to a track ball in a bowling alley or convenience store where a Missile Command (Sega) arcade machine installed. Most machines had either pushbutton or joystick directional control, but for the fast-moving action of Missile Command, you really needed the track ball. I never got really good at it (Asteroids and Donkey Kong were my area of expertise), but the guys who were could whip that surface defense gun at lightning speed and pinpoint accuracy as the cascade of missiles came raining down from space. Their firing fingers would be a blur as they timed the barrage of shots with the track ball. Ah, those were the carefree days! A quarter was a lot to drop into a machine, but there were much more addictive, destructive, and expensive habits to consume you. This 1962 issue of Radio-Electronics reports on what would have been one of the first track ball designs. It was developed by Hughes Aircraft. The mechanism was purely electromechanical since there were no laser or even infrared diodes to use for counting light pulses through a perforated encoding disk...

Anatech Electronics Intros 3 New Filter Models

Anatech Electronics Intros 3 New Filter Models for June 5, 2024 - RF CafeAnatech Electronics offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Three new filters have been announced for June 2024 - a 2205.5 MHz cavity bandpass filter with a bandwidth of 15 MHz, a 2201.5 MHz cavity bandpass filter with a 6 MHz 1 dB bandwidth and an insertion loss of 2.0 dB, and cavity bandpass filter with a 90 MHz 1 dB bandwidth. Custom RF power filter and directional couplers designs can be designed and produced with required connector types when a standard cannot be found, or the requirements are such that a custom approach is necessary...

Electronic Analogy Quiz

Electronic Analogy Quiz, August 1960 Popular Electronics - RF CafeThis electronics analogy quiz is a little easier than many of the others created by Robert Balin and published in Popular Electronics magazine because all of the electrical and mechanical objects depicted here are very familiar. The concepts might seem trivial to those of us who have been immersed in the science for decades, but I for one can remember when first hearing these analogies how helpful they were. Not only that, but I also recall during physics and mechanics courses in college being amazed at the similarity of equations shared by electrical and mechanical processes. Wikipedia has a huge page describing many of the most familiar mechanical-electrical analogies...

Unlocking Ultra-Wideband (UWB)

Unlocking Ultra-Wideband (UWB) - RF CafeThe Yole Group has provided a comprehensive review of UWB technologies, highlighting and comparing the solutions implemented in smartphones by leading companies like Apple, Samsung (NXP), and Google (Qorvo). In the past, Yole Group conducted extensive analysis on numerous FEMs and components to provide insights into the RF market within specific flagship smartphones. Each Yole Group report focuses on a specific topic, whether it's the evolution of a particular player, a specific technology, or a comparison of flagship devices. This year, Yole Group pursues its investigation in this domain, offering various technical and cost comparisons of smartphone RFFEMs. The report, Ultra-Wideband Comparison 2024, delves into the technology and cost aspects related to UWB connectivity in consumer applications. It offers an overview of UWB technologies, comparing solutions for smartphones used by major companies...

All About Dolby

All About Dolby, June 1971 Radio-Electronics - RF CafeThis photo of Ray Dolby with one of his prototype noise reduction circuits is probably the most widely published of him and therefore the most iconic of the Dolby noise reduction system. Audiophiles of the era (and today for that matter) immediately recognize the man who took the hisses and pops out of their beloved music. I always like to keep in mind when reading articles like this one in a 1971 issue of Radio-Electronics magazine is that when it was originally published, Dolby had not yet become a household word and news of his accomplishment was just getting out. Many articles, books, and research papers have been written on how the Dolby system works. At least five of them from the groundbreaking era have been posted here on RF Cafe, so you can get some insight into the excitement. The technical term "companding" (compressing and expanding) was being seen in print for the first time. Unlike today when such signal processing...

RF & Electronics Symbols for Visio

RF Electronics Wireless Analog Block Diagrams Symbols Shapes for Visio - RF CafeWith more than 1000 custom-built symbols, this has got to be the most comprehensive set of Visio Symbols available for RF, analog, and digital system and schematic drawings! Every object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Symbols are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing...

Tuesday the 4th

What's Your EQ?

What's Your EQ?, May 1962 Radio-Electronics - RF CafeTime to put on the thinking cap again for three more "What's Your EQ?" circuit challenges, compliments of Radio-Electronics magazine in May 1962. The first is a classic "black box" type problem which, from reading its description, involves some sort of resonant circuit. that's all I'll say on that. The next, called "An Easy One?" should, by the way it is drawn, be a clue that it might be easier to solve if you re-draw it to make a familiar-looking circuit. Hint: Summons the spirit of Sir Charles Wheatstone. Just the name of the last one, "Iterative Network," is enough to induce a cold sweat. As with most of these "What's Your EQ?" problems, successful completion of a first year college circuits course is plenty to get through them. A few are better attempted by people with hands-on experience troubleshooting circuits, but don't let that scare you off...

Mac's Service Shop: Automation and the Technician

Mac's Service Shop: Automation and the Technician, July 1961 Electronics World - RF CafeOnce transistorized computers made desktop-sized systems a reality, the sure eventuality of humans being replaced by their electronic equivalents became a popular theme of media pundits. News reports and "special features" on TV at the same time scared citizens concerned for their jobs and assured them that by the year 2000, humans wouldn't need to work anymore anyway because computers and robots would be doing everything for them. The last millennium crossover occurred nearly a quarter century ago now, and looking back it is true that computers and robots have usurped a lot of what used to be done manually, but, as Mac presciently predicts in this story, along with the changeover has come a plethora of new high tech jobs both for creating and maintaining those systems. There are still many service type jobs that will never be replaced by automation, but one aspect of domestic job losses not envisioned by Mac McGregor (Frye's alter ego) is the offshoring of call service centers, doctors in Kazakhstan reading our medical x-ray and MRI images, and all the design work being done in countries most people never knew existed - using equipment...

Wireless Tracking System Improves Extended Reality

Wireless Tracking System Improves Extended Reality - RF Cafe"Engineers at the University of California San Diego have developed a new technology that has the potential to make the extended reality (XR) experience smoother and more seamless. The technology consists of an asset localization system that uses wireless signals to track physical objects with centimeter-level accuracy in real time and then generates a virtual representation of these objects. Applications of this technology range from enhancing virtual gaming experiences to improving workplace safety. The team, led by Dinesh Bharadia, a professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering, presented the technology..."

How Are Shortwaves Propagated?

How Are Shortwaves Propagated?, December 1931/January 1932 Short Wave Craft - RF CafePrior to atmospheric sounding rockets and orbiting satellites, all information gained and theories developed on the nature of Earth's upper atmosphere and its interaction with electromagnetic waves (radio in particular) were purely academic, not the result of empirical data. That is not to say the theories were wrong (although some were), just that they were incomplete. For that matter, even today there is still much to be learned and, according to an excellent article in the October 2015 issue of the ARRL's QST magazine titled "Five Myths of Propagation Dispelled", there is still a lot of misinformation being believed and promulgated about shortwaves and how they travel in the atmosphere. This work is a great testament to the level of expertise that exists in the realm of Amateur Radio, and the contributions made by it to the science world...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed...

Monday the 3rd

Electronics-Themed Comics

Electronics-Themed Comics, June 1962 Radio-Electronics - RF CafeThis quad of electronics-related comics appeared in the March 1967 issue of Radio-Electronics magazine. Their themes reflect the norms and issues of the era. If you have ever had to re-string the dial cord on a radio where the path turned a few corners and ran around three or four tuning element pulleys, then you will appreciate the comic from page 101. My most challenging dial cord adventure was on a Realistic Patrolman-50 portable radio. It was bought on eBay, and the dial cord broke shortly after I received it. Without a routing diagram, it took a bit of head scratching to get figure out the correct direction for wraps around dials and pulleys. The oscilloscope display on the page 59 comic is pretty funny...

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.

The Antenna Specialists Co.

The Antenna Specialists Co. Ad, July 1966 Popular Electronics - RF CafeHere's a gimmick that never really caught on. In the 1960's, Antenna Specialists promoted their Model M-148 Co-Ax Omni Antenna "with visual RF indicator." This 1966 Popular Electronics magazine ad is a prime example. That indicator was a neon light bulb at the tip which lit up when the transmitter was keyed on. Not only would this novel feature let you know when your transmitter was broadcasting, but it would also "guide mobiles visually to your 10-20." OK, maybe at night, but it certainly wouldn't have been bright enough during the day to even see. Alas, the feature evidently didn't impress the buying public as much as it did the designers. Maybe it had something to do with operators not wanting to waste transmitter power for the purpose of lighting a neon bulb. Oh well, nice try...

RF Analyzer Kit for Field Techs & Engineers

Bird RF Analyzer Kit for Field Technicians and Engineers - RF Cafe"Bird, recognized as the leader in RF communications, measurement and new technologies, has released an exclusive Master RF Analyzer Kit. This Master RF Kit (SK-SH-KIT) provides all the necessary equipment needed for field technicians and engineers for installation, troubleshooting, and maintenance of coaxial cable and antenna systems, and analysis of system performance. It provides coverage with the SiteHawk™ Cable and Antenna Analyzer, SignalHawk™ Spectrum Analyzer, including a power sensor, calibration combo, and an assortment of adapters and cables. Bird's Master RF Kit provides a wide frequency range..."

Spot News - Electronic Industry News

Spot News - Electronic Industry News, April 1960 Electronics World - Television broadcast stations were quickly growing in number in the post-Korean War era and the FCC needed to devise a scheme for accommodating more channels. There were only 13 channels (only 2-13 used) allocated in the VHF spectrum with 6 MHz-wide bands. Even though VHF propagates primarily in a line-of-sight mode, reflections and earth-bounce can extend the range fairly significantly, limiting density in closely spaced cities. The military refused to yield any spectrum so a decision was made to add new channels (14-83, also 6 MHz wide) in the UHF band. UHF presented its own problems with more difficult equipment manufacturing issues and higher atmospheric attenuation. It never really caught on because cable TV was being widely installed in metro areas and even into suburbs by the early 1960s. Over-the-air (OTA) transmission issues were eliminated...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated in all locations on the page! RF Cafe typically receives 8,000-15,000 visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 17,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. Your Banner Ads are displayed on average 280,000 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...

These archive pages are provided in order to make it easier for you to find items that you remember seeing on the RF Cafe homepage. Of course probably the easiest way to find anything on the website is to use the "Search RF Cafe" box at the top of every page. About RF Cafe.

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