Homepage Archive - February 2023 (page 1)

Tuesday the 7th

Ohm's Law Quiz - How's Your E=IR?

All but two of these circuits in this "How's Your E=IR? Quiz" can be analyzed by inspection, without even needing a calculator or writing down equations, because the component, voltage, and current values given are integer ratios that make the math easy. It appeared in a 1969 issue of Popular Electronics magazine. You might end up with an order-of-magnitude error when mentally calculating milli, kilo, etc., but your base number will be correct. Numbers 8 and 10 are a bit trickier. Your approach might be to rearrange the schematic to create more recognizable series and/or parallel component configurations. For number 8, I ended up writing equations for the three circuit loops and solving the simultaneous equations because I did not see the balanced bridge configuration. However, my mesh equations yielded I_25Ω = 0 mA. Be careful with number 10 to not assume...

Please Thank RF & Connector Technology for Their Support

Providing full solution service is our motto, not just selling goods. RF & Connector Technology has persistently pursued a management policy stressing quality assurance system and technological advancement. From your very first contact, you will be supported by competent RF specialists; all of them have several years of field experience in this industry allowing them to suggest a fundamental solution and troubleshooting approach. Coaxial RF connectors, cable assemblies, antennas, terminations, attenuators, couplers, dividers, and more. Practically, we put priority on process inspection at each step of workflow as well as during final inspection in order to actualize "Zero Defects."

Wireless EV Charging Threat to AM Reception

Regular EV chargers are bad enough with power factor and harmonics issues, but the gross inefficiencies in power transfer with contactless charging will make matters even worse. Imagine a world full of them! "Consumers are eager to cut the cord on their electronics charging devices, a trend that could soon benefit drivers of electric vehicles (EVs). HD Radio developer and licensing company Xperi is seeking to raise awareness about a potential new threat to AM radio broadcast reception: the proposed introduction of wireless power transfer systems for electric vehicle charging, or WPT-EV, that use switching frequencies that generate harmonics in the lower AM band. Xperi recently filed comments about this concern in response to a notice of inquiry at the FCC about radio receiver performance. It hopes to raise awareness and also believes its HD Radio technology can be of help. Interference to AM from unintentional radiators including low-cost switching power supplies in EVs is a concern..."

YL News and Views

I wonder why today's editions of the ARRL's QST magazine does not have a column dedicated to the "YL" (Young Lady, or female in general) contingent of the amateur radio realm? Ham radio, as most - if not all - historically male-dominated hobbies has fairly significant outreach efforts to try attracting women into activities. My Model Aviation magazine has a monthly column written by a lady whose enthusiasm for model airplanes equals that of most males - and she's funny to boot! - but it is not dedicated to female modelers. If there is a girl or woman present at a competition, she is almost guaranteed to receive coverage in the form of a photograph and/or mention in an article. Any lack of other-than-male participation these days can only be attributed to a lesser degree of interest by other than males. Could there really be a difference between men and women (in general) after all?

EMI Issues Caused by Structural Resonances

"Has it happened to you? When troubleshooting an electromagnetic interference (EMI) issue, you've tried various combinations of components and saw the signal of interest reduced. But another frequency signal unexpectedly raised above the limit line. Or, you introduced a chassis plane on your printed circuit board (PCB), only to find the radiated emissions became much worse instead of getting better. These are typical cases of 'tuning the resonances of a circuit.' Most EMI emissions are related to structural resonances. Structural resonances are also one of the main reasons that electromagnetic compatibility (EMC) can be mystifying. Unknowingly, engineers often spend days and months tuning the resonances of a circuit by adding passive elements such as inductors and capacitors. Sometimes, they are lucky enough to finally arrive at a combination that would give them a pass. But most of the time, solutions are hard to find. A tremendous amount of work has been done on the subject of structural resonances. Two practical case studies are  presented to demonstrate methods to identify, locate, and fix EMI issues that are associated with structural resonances. EMC engineering often requires problems to be resolved..."

Electronics Themed Comics

It's time for little levity. These electronics-themed comics from a 1944 issue of Radio-Craft magazine have an electronics theme, so you can claim looking at them is work-related since you might use one for your next conference or project status presentation. Some of the concepts are utterly foreign to contemporary readers, like user-serviceable electronics apperati [sic] and radio sets that receive over-the-air signals with analog information modulated on the carrier. Radio was still somewhat of a novelty to much of the public, and "radio can do anything" memes were common in comics. I took the liberty of colorizing them. There is a list of many more similar comics at the bottom of the page in case you haven't seen them yet. Enjoy.

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

/jobs.htm">RF 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...

Thanks Once Again to everythingRF for Long-Time Support!

Please 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.

Monday the 6th

Spiral Conical Antennas

Using modern blazing speed computers and sophisticated programs, designing and analyzing something as complex as a spiral conical antenna is child's play - and many school-age children actually do it. It wouldn't surprise me if there is a phone app capable of performing such tasks. However, back in 1960 when this article appeared in Radio-Electronics magazine, a lot of intuition, guesswork, and trial and error on physical models was necessary to model and parameterize the spiral conical antenna shown on the cover. This particular antenna resonates at 14 MHz with a 1.25:1 VSWR, however across the 7-17 MHz intended bandwidth the VSWR can be as high as 6:1. Surprisingly, an image search for spiral conical antenna radiation patterns did not turn up much. This paper from the International Center for Radio Astronomy Research is about the best I could find...

Thanks Again for Windfreak Technologies' Continued Support!

Windfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project.

Zenith Models 5R080 & 5R086 Schematic & PL

Here are the schematic and parts list for Zenith model 5R080 and 5R086 radio/phonograph combos, from a 1947 issue of Radio News magazine. It must have been a fairly popular set because many have been sold on eBay; in fact, that's where I got the photos shown here. The schematic page from the Sam's Photofact also came from an eBay listing. Note where it says that unless otherwise noted, all resistors values are ±20%. I suppose when your phonograph turntable uses a metal chain drive mechanism, precision isn't a huge concern. 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; that's why I keep a running list of all the data sheets I find to facilitate searches...

The Future of Automation at Digi-Key

This story on the Supply Chain Connect website caught my attention because of the photo of the huge new Digi-Key building in Thief River Falls, Minnesota (about as far north you can go in the USA). "Join us as we explore the latest development in supply chain automation when we visit Digi-Key's newly opened, 2.2 million-square-foot, PDCe in Thief River Falls, Minnesota. After the ribbon is cut, we learn how one of the 10 largest warehouses in the country plans to accelerate into the next decade. We sit down with Digi-Key leadership, including Vice President, Order Fulfillment at Digi-Key, Chris Lauer, to talk about new areas of growth and the implementation of technology that pushes the envelope of supply chain automation. We answer questions like: What are the challenges that come with shipping 13.4 million products to more than 857,000 customers each year in 180 countries..."

How's Your Math?

If you are just starting out in the realm of electronics or maybe just need a little freshening up of your basic math skills, this rather extensive article from a 1942 issue of QST magazine is just what you need. Author Dawkins Espy does a really nice job of laying out the basics of algebraic operations, Ohm's law, trigonometry, and logarithms. Examples are provided for each category. In this day of calculators doing all the hard work of calculating logs, antilogs, and trig functions, it does even seasoned veterans at electronics calculations a bit of good to do a quick read-through to knock off cobwebs in the gray matter. How long has it been since you have seen tables of sine, cosine, and tangent values and/or tables of logarithms? Not long enough, you say?

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

/jobs.htm">RF 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...

Thanks to Wireless Telecom Group for Their Support!

The Wireless Telecom Group, comprised of Boonton, Holzworth, and Noisecom, is a global designer and manufacturer of advanced RF and microwave components, modules, systems, and instruments. Serving the wireless, telecommunication, satellite, military, aerospace, semiconductor and medical industries, Wireless Telecom Group products enable innovation across a wide range of traditional and emerging wireless technologies. A unique set of high-performance products including peak power meters, signal generators, phase noise analyzers, signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable noise generators.

Sunday the 5th

Chinese Spy Balloon Finally Shot Down

As of September 16, 2022, if I fly my radio-controlled model airplane, helicopter, or drone even an inch off the ground anywhere in the U.S. without having a specially designed and certified electronics device - at my expense - broadcasting identification and position data ("Remote ID of Unmanned Aircraft"), I can be fined and/or jailed and/or have my equipment confiscated by the U.S. government. The stated justification is concern for safety of property, persons, and national security. However, if a country established as a military and economic threat to the U.S. flies a huge uncontrolled (other than by altitude in air currents) aircraft burdened by maybe 1000 pounds of equipment, including batteries, from coast to coast across populated areas, no action is taken. Here is a video of the Chinese balloon finally being shot down over the ocean after it was allowed to collect and relay data, and even possibly release pathogens over wide areas for days (NOAA HYSPLIT trajectory). Here's Trump impersonator Shawn F. with his take on the Chinese spy balloon debacle. Another victory for China!

Electronics Theme Crossword for February 5

This custom RF Cafe electronics-themed crossword puzzle for February 5th 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.

Get Your Custom-Designed RF Cafe Gear!

This 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...

Many Thanks to KR Electronics for Long-Time Support!

KR 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.

Friday the 3rd

Carl & Jerry: Going Up, Up, Up

Thanks to Mr. Ferrous Steinka for submitting this commentary on the episode of Carl & Jerry appearing in the March 1955 issue of Popular Electronics. "Radio and television waves are reflected in the same way as light waves. As both light and radio waves are forms of electromagnetic waves, they are both subject to the same basic laws and principles. Visual examples of light reflection are everywhere from specific mirrors to flat reflective surfaces like glass, polished metal and the like. So too, radio waves can experience reflection. Conducting media provide the optimum surfaces for reflecting radio waves. Metal surfaces, and other conducting areas provide the best reflections, so the story below is feasible and within the known technology at the time. The use of a highly directional Yagi antenna would have been very important because without it the reflected waves would have been inverted (out of phase) with the normal signals, thereby reducing the overall received signal..."

Antennas & Microchips Blur Line Between Science and Sci-Fi

"Sophisticated antenna arrays paired with high-frequency wireless chips act like superpowers for modern electronics, boosting everything from sensing to security to data processing. In his lab at Princeton, Kaushik Sengupta is working to expand those powers even further. In recent years, Sengupta's lab has designed antenna arrays that help engineers make strides toward peering through matter, boosting communications in canyons of skyscrapers, putting a medical lab on a smart phone, and encrypting critical data with electromagnetic waves instead of software. In a new article in Advanced Science, Sengupta's research team presented a new type of antenna array based on the paper-folding art of origami. The shape-shifting array, designed like a folded paper box called a waterbomb..."

Voices in the Mail

This 1956 Popular Electronics magazine article reports on the very earliest form of voice mail - recording a message on a reel-to-reel tape deck, placing it in an envelope, and snail mailing it to its recipient. Sure, it was slow, but unless you were under surveillance for some suspected crime, there was just about zero chance that some government agency was going to hear your private message. I had forgotten about it until reading this, but I remember that back in the 1960s, my father bought an el cheapo tape deck for our family and one for his parents, who lived in Buffalo, New York. My parents and four sisters and I had a pretty good time hamming it up on the tape, and looked forward to receiving a reply tape a month or two later. "Grandpa B," as we kids called him, was a real funny guy and kept us entertained for about 30 minutes with the reply tape. The exchange lasted for about a year and then our machine died (I probably broke it by opening the case and screwing with it) and then it was back to the long distance phone calls once or twice a year...

Anatech Electronics Intros 3 Filter Models

Anatech 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 filter surface mount, low loss ceramic bandpass filter models have been introduced - a 2410 MHz WiFi cavity bandpass filter with a 3 dB bandwidth of 22 MHz, a 4885 MHz cavity bandpass filter with a 50 MHz bandwidth, and a 5630 MHz WiFi cavity filter with a bandwidth of 20 MHz. 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...

1953 Radio Shack Advertisement

Against all odds, Radio Shack is still in operation today (barely). They still sell a fairly broad selection of discrete components for circuit designers and for repair and modifications. Radio Shack is and has been for a couple decades the only hometown source for parts where you can walk in off the street to get what you need, rather than order it online. Even items like a dual-gang stereo volume control potentiometer, a 2-layer, 6-position rotary switch, and a DPDT PCB-mountable relay can be had. There are nowhere near as many as there were a few years ago before all the turmoil began, but Radio Shack is still there in a pinch. This full-page Radio Shack advertisement appeared in the November 1953 edition of QST magazine, which was during the heyday of electronics DIY activity. I've written in the past of visiting the local Annapolis, Maryland, Radio Shack store with a bagful of vacuum tubes from our television set needing testing on their testing machine. There was also a Lafayette Radio Electronics store...

RF Cascade Workbook

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 2018 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. An intro video takes you through the main features...

Many Thanks to ISOTEC for Continued Support!

Since 1996, ISOTEC has designed, developed and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components and filters for wireless service providers including non-magnetic connectors for quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM RF connectors components such as power dividers and directional couplers. Off-the-shelf and customized products up to 40 GHz and our low-PIM products can meet -160 dBc with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and high-performance. Designs that are cost effective practical and repeatable.

Thursday the 2nd

Introduction to Ultrasonics

This "Introduction to Ultrasonics" article from a 1960 issue of Radio-Electronics magazine does not necessarily directly apply to RF and microwaves, but there are similarities in the circuitry and theory of generation and propagation. I was surprised to learn that ultrasonics even back then went into the low GHz realm. Any mechanical vibrations about about 20 kHz are regarded as ultrasonic. Ultrasonics can preform some of the functions of x-rays in material inspection, without the danger of ionizing radiation and extremely high voltages required to generate the rays. While working in the 1980's as an electronics technician at the Westinghouse Oceanic Division in Annapolis, Maryland, I often used an ultrasonic cleaner like the one shown here for removing flux from printed circuit board assemblies (PCA's), cable connectors, and other objects. The heated methyl-based bath solution produced a PCA with shiny solder joint totally devoid of flux residue. We were still using 60/40, Sn/Pb rosin core solder back then. We built sonar systems and components for the U.S. Navy, including transducer-equipped torpedo nose cones, sonar transducer arrays for ship hulls, and towed sonar systems...

Many Thanks to Exodus Advanced Communications for Their Support

Exodus 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.

THz Quantum Magnetic Switch at RT

"A class of nonvolatile memory devices, called MRAM, based on quantum magnetic materials, can offer a thousandfold performance beyond current state-of-the-art memory devices. The materials known as antiferromagnets were previously demonstrated to store stable memory states, but were difficult to read from. This new study, now published in Nature, paves an efficient way for reading the memory states, with the potential to do so incredibly quickly too. You can probably blink about four times a second. You could say this frequency of blinking is 4 hertz (cycles per second). Imagine trying to blink 1 billion times a second, or at 1 gigahertz, it would be physically impossible for a human. But this is the current order of magnitude in which contemporary high-end digital devices, such as magnetic memory, switch their states as operations are performed. And many people wish to push the boundary a thousand times further, into the regime of a trillion times a second, or terahertz. The barrier for realizing faster memory devices may be the materials used..."

Now! Use Gift Cards for Payment!

Since Elon Musk purchased Twitter and began exposing the grotesque level of bias and suppression of free speech perpetrated by social medial platforms, some people have written to say they no longer want to use PayPal when purchasing RF Cafe products. I have been agreeing to send the software immediately with a promise of payment via snail mail. On a whim, I checked to see whether Gift Cards can be sent via e-mail, and indeed they can. So, if you want an alternative to PayPal, I have posted links directly to Walmart, Lowe's, Home Depot, and Sam's Club, where the majority of my purchases are made. Of course you are also encouraged to send donations via Gift Cards. Thank you.

Radar on the Great Lakes

An article title with both "radar" and "Great Lakes" (I lived a mile from Lake Erie) in the title is sure to catch my attention, as did this. Author Norman Schorr reports on the state of the art of radar equipment and usage for the purpose of maritime navigation. Research and development, along with an ample surplus of components left over from World War II facilitated a rapid adaptation of radar to many venues. Included among its applications were airway and waterway navigation, rocket trajectory tracking, security systems, speed measurement, weather observation, and aerial mapping. It is easy to take for granted the capabilities of radar today with having the accumulated knowledge of more than half a century on our side, but pioneers in the field had to think everything up anew. I have to admit to being familiar with what a "Pliotron" was prior to reading this article (it is Irving Langmuir's high frequency version of the Audion vacuum tube)...

Keep Temperature and Humidity Under Control

Axiom Test Equipment, an electronic test equipment rental and sales company, has published a new blog post entitled "Keep Temperature and Humidity Under Control" that goes over how to select a chamber based on key specifications like size, temperature ranges and humidity. Temperature and humidity testing provide insights into whether a product or device under test (DUT) will fail or even meet required levels of performance when simulated and stimulated over extreme ranges of temperature and relative humidity (RH). Being able to control temperature and humidity provides great benefits and flexibility when evaluating the reliability of a new design or when ensuring that a product can withstand challenging operating conditions and provide the performance expected over a long operating lifetime. Requirements for a temperature or temperature/humidity chamber are typical determined by the DUT or type of DUT, such as according to its size, application, and operating environment. Learn more about the most important equipment you will need when testing temperature & humidity...

Horizontal Hamming

Here is a humorous story from a 1951 issue of QST magazine - probably not too far from being true - about a Ham operator (emphasis on "operator") who parlayed a short spat of poor health into an opportunity to get in a little rag-chewing time. The whole scenario turned out so well that he pondered afterward whether he could indulge in a bit of malingering for a repeat opportunity. So did some of the contacts he told about it while laid up. The tale didn't appear in an April edition, so it probably is on the up-and-up...

Promote Your Company on RF Cafe

New 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.

Many Thanks to LadyBug Technologies for Their Continued Support!

LadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Wednesday the 1st

Bendix Aviation Corporation

Bendix Corporation was begun in 1914 by Mr. Vincent Bendix, eventually manufacturing brakes, starters, carburetors, and other components for automobiles, trains, and airplanes. During World War II, Bendix was a major supplier of critical components, including radio transmitters and receivers and avionic instruments. As with many - probably most - big corporations, advertisements were run in many magazines in order to make sure the public knew the part their companies were playing in the effort to defeat Communism, Nazism, Socialism, and all the other "isms" worldwide seeking to subdue and destroy freedom. Bendix branched out into many areas of development and production with computers, mine detectors, inertial guidance platforms (for Saturn V and other man-carrying rockets), televisions, phonographs, kitchen appliances, and much more. I don't know if it is still the case, but back in the 1970's when I did a lot of work on my 1969 Camaro SS, the term "bendix" was a generic reference to the solenoid-actuated spur gear that coupled the electric starter to the big starter gear connected to the engine crankshaft...

Boston Dynamics' Atlas Automaton - Spooky

 Anyone involved in technology for the past decade or more is aware of the progress Boston Dynamics has made with their automatons. Early models were tethered in order to supply the amount of electrical energy required to operate. The newest models are completely self-contained and move unconstrained. If you haven't already seen it, you need to watch this video of "Atlas" as he (yep, Atlas was a male Greek god; maybe they need an "Otrera" model for equality) performs amazing acts of cognition and physical dexterity. Advances in intelligent humanoid robotics is advancing a a fairly good rate, but if you want it to really surge we need automatons released into the domestic toy and entertainment markets. If the history of drones is any predictor of the future, doing so would greatly increase research and development with a resulting feedback into commercial and military realms.

Thanks to PCB Directory for Continued Support!

The 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.

Adson Radio & Electronics Co. Advertisement

Here's another advertisement that you probably wouldn't see in a contemporary RF / microwave engineering magazine, like this one in the 1949 issue of Radio & Television News. For that matter you probably wouldn't see it on a contemporary RF / microwave engineering website ... except on RF Cafe where political correctness finds no sanctuary. Adson Radio & Electronics, an electronic components distributor, was located on Fulton Street in New York City, just a block from the 911 Memorial. The original building might well have been destroyed when "some people did something" (Saudi Arabians flew two commercial jetliners into the World Trade Center towers) in 2001...

SynthHD 10 MHz-15 GHz Dual Channel Synth Shipping

Windfreak Technologies is glad to announce that their very popular SynthHD, dual channel RF/microwave synthesizer is back in stock and shipping within 3 days of ordering. The global parts shortage made a key component hard to procure for a short while, but a dependable source has been secured. The SynthHD covers a frequency range of 10 MHz to 15 GHz in 0.1 Hz steps, with an output power of -50 dBm to +20 dBm in 0.01 dB steps. Channels are totally independent with relative phase adjustment from 0 to 360° in 0.01° steps. This allows its use in antenna beam steering applications or quadrature signal generation commonly used in image reject frequency conversion. SynthHD is useful in R&D and production applications. LabVIEW source code included. Please contact Windfreak today!

A Crystal That Amplifies

Messrs. Brattain, Shockley, and Bardeen, are credited with inventing the first working transistor per their announcement in December of 1947. This article provides what was for many people an introduction to the operational specifics of transistors. Although its crude point contact (aka "cat's whisker") emitter and collector arrangement against the doped germanium base element was still in a configuration that did not yet represent a significant challenge to the domain of vacuum tubes, people of vision recognized its superior potential. As with most technologies, progress occurred quickly and within a year the first commercial transistor was on the market. C.E. Atkins, a frequent author in Radio & Television News magazine, related this story of his own attempts to develop a transistor and offers the opinion that transistor might indeed someday replace tubes as amplifiers, oscillators, and frequency converters...

RF Cascade Workbook

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 2018 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. An intro video takes you through the main features...

Thanks to TotalTemp Technologies for Continued Support!

TotalTemp Technologies has more than 40 years of combined experience providing thermal platforms. Thermal Platforms are available to provide temperatures between -100°C and +200°C for cryogenic cooling, recirculating & circulating coolers, temperature chambers and temperature controllers, thermal range safety controllers, space simulation chambers, hybrid benchtop chambers, custom systems and platforms. Manual and automated configurations for laboratory and production environments. Please contact TotalTemp Technologies today to learn how they can help your project.

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