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Homepage Archive - November 2022 (page 2)

See Page  1 | 2 | 3 | 4 of the November 2022 homepage archives.
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Monday the 14th

Survey of Transistor Development

Survey of Transistor Development: Part 3, November 1952 Radio News - RF CafeMr. B. N. Slade, of the Tube Department of Radio Corporation of America, wrote a series of articles on transistor development for three 1952 issues of Radio & Television News magazine. Consider that it was only four years earlier, a few days before Christmas, that Messrs. Bardeen, Brattain, and Shockley announced their game-changing invention of the point contact transistor. Already a plethora of commercial transistors were on the market for incorporation into new electronic products. At the time, germanium was still the semiconductor of choice, although silicon was gaining ground in laboratories. This article covers the three basic transistor circuit topologies of common emitter, common base, and common collector, which are analogous to vacuum tube circuits using common cathode, common grid, and common plate topologies, respectively. Operation up to around 200 MHz was obtainable...

Thanks Again for Windfreak Technologies' Continued Support!

Windfreak TechnologiesWindfreak 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.

NYC Residents Complain About "Ugly" LinkNYC 5G Poles

NYC Residents Complain About "Ugly" LinkNYC 5G Poles - RF CafeYeah that's a serious issue. After all, would you want one of those "ugly" poles being the last thing you see before getting pushed in front of a subway train, getting mugged in broad daylight, or OD'ing on a fentanyl-laced pill? It seems to me NYC residents have a lot more to worry about than how more free stuff is being provided to them. "The idea is to provide free and equitable telecom and connectivity services, but LinkNYC is getting dinged for aesthetics and the placement of 32-foot structures around the streets of New York City. Some residents are calling them eyesores. Others are worried about safety due to their placement. 'No one asked us about the design or where they should go. We have notes,' said a Brooklyn neighborhood group on Facebook. As The New York Times wrote last weekend, the 'towers' are part of LinkNYC efforts to install about 2,000 Link5G poles over the next several years in an effort to help eliminate the city's 'Internet deserts.'' A prior attempt to cover the city with Wi-Fi connectivity didn’t come to pass..."

After 50 Years, Digital Voices Speak Again

IEEE: After 50 Years, Digital Voices Speak Again - RF CafeHave you ever seen one of these? I haven't. This type of flexible vinyl record used to be a popular way for magazines to incorporate audio extras according to this IEEE Spectrum magazine article entitled, "After 50 Years, Digital Voices Speak Again." Says Stephen Cass: "'Ali Baba knew how men buy lime.' 'The beach is dry and shallow at low tide.' 'Few thieves are never sent to the judge.' These cryptic sentences - and more than a dozen like them - were contained in a 1973 issue of IEEE Spectrum. But unless you happen to have a perfectly preserved physical copy you would never know they existed. It is impossible for any other reader to locate them, even using the IEEE Xplore digital library. The reason for their ongoing absence is that they never actually appeared in print. Instead, they were encoded in the grooves of a phonograph record bound inside the magazine. And there they would have stayed without a chance conversation and assistance from some very capable librarians and archivists." This Eva-Tone Soundsheet entitled "Sounds from Space" can be heard on YouTube (others, too)...

General Electric Model 219 Tabletop Radio

General Electric models 219, 220, and 221 Tabletop Radio, November 1946 Radio News - RF CafeWhen searching the Internet for examples of General Electric models 219, 220, and 221 tabletop radios, all I could come up with for the 219 is a picture from a Sam's Photofact sheet. A really nice GE model 220 is now for sale on eBay (see screenshots below). The phenolic cabinets were very nice, being a simulated wood grain pattern and color. A GE model 221 also happens to be for sale right now. The November 1946 issue of Radio News magazine had the schematic and parts list for the three radios, but no textual description. To the left is a full-page ad from a 1946 issue of The Saturday Evening Post magazine which included the GE model 220 tabletop radio. 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...

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. The file format is XML so everything plays nicely with Visio 2013 and later...

Many Thanks to Reactel for Their Long-Time Support!

Reactel Filters - RF Cafe

Reactel has become one of the industry leaders in the design and manufacture of RF and microwave filters, diplexers, and sub-assemblies. They offer the generally known tubular, LC, cavity, and waveguide designs, as well as state of the art high performance suspended substrate models. Through a continuous process of research and development, they have established a full line of filters of filters of all types - lowpass, highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact Reactel today to see how they might help your project.

Sunday the 13th

Electronics Themed Crossword for November 13th

Electronics Themed Crossword Puzzle for November 13th, 2022 - RF CafeHere is your custom made Electronics Themed crossword puzzle for November 13th, 2022. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only words and clues related to electronics, electricity, radio, radar, 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 or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

RF & Electronics Stencils for Visio

RF & Electronics stencils for Visio r4 - RF CafeWith more than 1000 custom-built stencils, this has got to be the most comprehensive set of Visio Stencils available for RF, analog, and digital system and schematic drawings! Every stencil symbol has been built to fit proportionally on the included A-, B-, and C-size drawing page templates (or use your own page if preferred). Components are provided for system block diagrams, conceptual drawings, schematics, test equipment, racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1 scale so that measurements can be made directly using Visio built-in dimensioning objects. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Many Thanks to Aegis Power Systems for Their Continued Support!

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

Friday the 11th

Mac's Electronics Service: Intermittent Roundup

Mac's Electronics Service: Intermittent Roundup, November 1962 Electronics World - RF CafeJust about anyone who has done a fair amount of troubleshooting on electrical and/or electronics equipment has experienced the frustration (to put it mildly) of trying to identify the source of an intermittent problem. As Mac points out in this "Mac's Electronics Service: Intermittent Roundup" story from a 1962 issue of Electronics World magazine, the causes can be electrical, mechanical, or thermal. A combination of two or all three might even be cohorts in making your life miserable. If poor power cord or battery connections are not the culprit, then I typically start exercising switches and twisting knobs in search of any one of them causing an unexpected change in the functionality. Following that, I'll open the device and sniff and look around for obvious failures. Next comes unplugging and plugging back in all the internal connectors (multiple iterations) in case a contact is contaminated. If no joy is produced by that point, it's time to pull out the DMM and start checking easily determined voltages from power supplies...

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

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

Nominate a Colleague for IEEE Major Award

Nominate a Colleague for IEEE Major Award - RF CafeAn IEEE "Major Award" is up for grabs. Maybe this is the year RF Cafe finally gets recognition for its decades of contributions. Any Major Award I might get would be akin to the Leg Lamp in A Christmas Story ;-)  Says IEEE: "Each year IEEE pays tribute to technical professionals whose outstanding contributions have made a lasting impact on technology and the engineering profession for humanity. The IEEE Awards program seeks nominations annually for IEEE's top awards—Medals, Recognitions, and Technical Field Awards—that are given on behalf of the IEEE Board of Directors. You don’t have to be an IEEE member to receive, nominate, or endorse someone for an award..."

Return of the Prodigal Ham

Return of the Prodigal Ham, February 1955 Popular Electronics - RF CafeHere is another article about a "prodigal" Ham who returned to amateur radio after about a 30-something year respite, per this 1955 Popular Electronics magazine. Author Charles Meistroff's previous experience had been with surplus World War I - yes that's WWI! He must have been in Heaven to be able to now get his hands on all the new-fangled equipment now (then) available on the World War II surplus equipment market! I don't know if the military is still making surplus equipment available like they did even up through Korea and Vietnam. There must be some great stuff from the Middle East wars if it is circulating within the surplus market. Then again, other than ruggedness factors, most commercial equipment is as good or better than MIL-SPEC stuff...

Salary & Career Survey: Continuing Education

2022 Salary & Career Survey: Continuing Education - RF CafeMicrowaves & RF magazine just released the results of their 2022 Salary & Career Report: Continuing Education. It is one category of the overall survey. This pathetic statement (not MRF's fault) begins the report, "Our survey indicates that fear of contracting disease is no longer the big barrier to continuing education that it was in 2020 and part of last year." It is yet another reminder of the misanthropic COVID scam perpetrated upon the entire world by a relative handful of powerful bureaucrats and politicians... but I digress. The main takeaways are that lack of time the most limiting factor in continuing education. Work-life imbalance rates up there, too, compounded by long commutes. Company support (or lack thereof) is a limiting consideration; 27% said they get no form of reimbursement of time off for continuing education...

Western Electric, 1945 Saturday Evening Post

Western Electric Ad from the August 25, 1945, Saturday Evening Post - RF CafeHere is an advertisement by Western Electric from the August 25, 1945, edition of the Saturday Evening Post magazine. As with many of the advertisements of the era, this ad refers to the company's contribution to the war effort during WWII. "How communications help tighten the ring," accompanies a map of the Japanese islands. All forms of battlefield and shipboard communications benefitted from the innovations of Western Electric scientists, engineers, and assembly line workers. These days Western Electric manufactures special purpose audio frequency vacuum tubes and amplifiers to use them. They're not cheap. Back in 1945, Western Electric was a major manufacturer of telephone and telegraph equipment for Bell Telephone, Western Union, and America Telephone & Telegraph (AT&T). Dr. Lee de Forest, inventor of the Audion amplifier tube, worked for Western Union...

Veterans Day 2022: A Pittance of Time

Veterans Day 2016 (Snoopy copyright) - RF Cafe This is my annual Veterans Day tribute. On November 11 (the 11th day of the 11th month), at 11:00 am (the 11th hour), we observe two minutes of silence in honor of countrymen who "gave the last full measure of devotion." A Pittance of Time is performed by Canadian citizen Terry Kelly (he went blind at an early age). It was written after an experience he had on Veterans Day in 1999. It is done in the finest Celtic tradition.

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 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 Berkeley Nucleonics for Continued Support!

Berkeley Nucleonics Corp - RF CafeBerkeley Nucleonics Corporation (BNC) is a leading manufacturer of precision electronic instrumentation for test, measurement, and nuclear research. Founded in 1963, BNC initially developed custom pulse generators. We became known for meeting the most stringent requirements for high precision and stability, and for producing instruments of unsurpassed reliability and performance. We continue to maintain a leadership position as a developer of custom pulse, signal, light, and function generators. Our designs incorporate the latest innovations in software and hardware engineering, surface mount production, and automated testing procedures.

Thursday the 10th

Carl & Jerry: Dog Teaches Boy

Carl & Jerry: Dog Teaches Boy, February 1959 Popular Electronics - RF CafeIn his usual manner, John T. Frye uses this "Dog Teaches Boy" episode of Carl & Jerry technodrama story to present a lesson in electronics. A method for cooking hotdogs using the standard 117-volt household supply was used to admonish the reader regarding necessary conditions for electrocution. Maybe it's from being so familiar with working around electricity for many decades, but the comment about some people believing that 117 volts can't kill you seems incredible. I do have to take exception to the claim that switching the neutral wire along with the "hot" wire is a safer way of doing things. The National Electric Code prohibits doing so except under certain very specific conditions. The reason is because the neutral, being connected to the same point electrically as the ground in the circuit breaker panel, should always be connected so that any current present has a low impedance path. Most people have no idea how electrical systems work, and I have known people who believed that you can only get shocked from the hot wire. The fact is...

Please Thank IPP for Their Long-Time Support!

Innovative Power ProductsInnovative Power Products (IPP) has over 35 years of experience designing & manufacturing RF & microwave passive components. Their high power, broadband couplers, combiners, resistors, baluns, terminations and attenuators are fabricated using the latest materials and design tools available, resulting in unrivaled product performance. Applications in military, medical, industrial and commercial markets are serviced around the world. Products listed on website link to detailed mechanical drawings that contain electrical specifications as well as performance data. Please take a couple minutes to visit their website and see how IPP can help you today. 

Chart of Radio Symbols

Chart of Radio Symbols, March 1935 Radio-Craft - RF CafeThis Chart of Radio Symbols would make a nice wall poster for your office, lab, or Ham shack. It has a nice vintage look to it - because having been scanned from a 1935 edition of Radio-Craft magazine, it is a true vintage relic. Although it would look great in its gray scale format, importing it into a graphics program and adding a little color would really jazz it up. A bit of brown would provide an aged sepia look, or you could go all out and custom color each square (I created one for you). Click on the image to have the high resolution version display for printing...

Braiding Enables Antenna Fabrication for Next-Gen Devices

Braiding Enables Antenna Fabrication for Next-Gen Devices - RF Cafe"Antennae that work at frequencies needed for next generation phones and wireless devices can be fabricated with a machine developed in the U.S. These devices will require antennae that work at tens of gigahertz but making them will require braided filaments of about one micrometer in diameter. Now a team of researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) has developed a simple machine that uses the surface tension of water to grab and manipulate microscopic objects, offering a potentially powerful tool for nanoscopic manufacturing. The research is published in Nature. 'Our work offers a potentially inexpensive way to manufacture microstructured and possibly nanostructured materials..."

Anatech Intros 3 Filter Models for November 2022

Anatech Electronics Intros 3 Filter Models for November 2022 - 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 filter models have been introduced - an 849 MHz cavity bandpass filter with a 5 MHz bandwidth, a DC-1440 MHz / 2200-2500 MHz LC diplexer, and a 20 MHz LC highpass filter with a 1.5 dB insertion loss. Custom RF power filter and directional couplers designs can be designed and produced with required connector types when a standard cannot be found, or the requirements are such that a custom approach is necessary...

High-Q Tank Circuit for Ultra-High Frequencies

High-Q Tank Circuit for Ultra-High Frequencies, September 1939 QST - RF CafeWhen I see that mechanical drawing of an oscillator tank circuit, the cross-section of a screw-on type automotive oil filter comes to mind. Ham radio operators who build their own equipment have never shied away from tackling leading-edge, technically challenging projects. Indeed, many Amateurs have pioneered radio circuit, antenna, and propagation concepts that were later adopted by military and commercial concerns. One of the first examples was the relegation of hitherto believed to be unimportant shortwave frequency bands for amateur radio use. Quite unexpectedly, Hams quickly took up the challenge and exploited the unique long range communications capabilities possible due to atmospheric channeling and reflection phenomena. This 1939 QST magazine article features coaxial resonant cavities used to construct high-Q oscillators. While the title says "Ultra-High Frequencies," the highest frequency mentioned is for 1¼ meters, that is around 240 MHz, which according to today's spectrum assignments doesn't quite reach into the 300 MHz to 3 GHz realm...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeNew Scheme rotates all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000 website visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 12,000 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. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be.

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

Amplifier Solutions Corporation (ASC) - RF Cafe 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.

Wednesday the 9th

The Counter as a Test Instrument

The Counter as a Test Instrument, November 1962 Electronics World - RF CafeA few years ago I was in a second-hand shop in Erie, Pennsylvania, and happened to spot a Hewlett-Packard model HP 5212A Electronic Counter stashed in a cardboard box with a bunch of other electronic stuff. It was a little dirty, but otherwise appeared to be in pretty good condition. I took it to the counter and asked the lady what she'd take for it, and we agreed on $15, provided when I plugged it in the front panel display would light up and no smoke came from the chassis. It did and it didn't, respectively. Once at home, I fired it up and ran some functional tests on it, and all seemed to be working properly. After performing some major clean-up to nearly like-new condition, I decided it should go to someone who could put it to good use, so it went up for sale here on RF Cafe. Believe it or not, the best offer received was $125. It deserved more respect than that, but the guy was a collector of vintage test equipment, so at least it went to a loving home. This 1962 "The Counter as a Test Instrument" article in Electronics World magazine article shows both the HP 5212A (300 kHz) and the HP 5243L (500 MHz) electronic counters...

Artemis Moon Rocket Launch Set for November 14th

Artemis Moon Rocket Launch Set for November 14th - RF CafeAll the world's astronauts have been launched to the ISS via the communist, America-hating countries of Russia and China since the Space Shuttle program shut down in 2011 (with no standby replacement capability). "NASA's moon rocket is back on the pad for another launch attempt, following more repairs. The 322-foot rocket departed its hangar in the middle of the night and completed the 4-mile trip shortly after sunrise Friday. NASA is aiming for a launch attempt on Nov. 14, sending an empty crew capsule around the moon and back in a dramatic flight test before astronauts climb aboard in a couple years. Forecasters are keeping their eyes on potential tropical weather that could interfere. It is NASA's biggest step yet to get astronauts back on the moon by 2025. The space agency is nearing the 50th anniversary of its last human moon landing: Apollo 17 in December 1972..."

How to Make Power Transformer Substitutions

How to Make Power Transformer Substitutions, April 1959 Popular Electronics - RF CafePower transformers have not changed too much since this article was appeared in a 1959 issue of Popular Electronics magazine. Efficiencies might be up a bit, and maybe sizes down, but other than that, the equations and implementation methods are about the same. True, you will not find a lot of new transformers with secondaries that sport vacuum tube filament and plate voltages, but their equivalents for ±15, ±12, ±5, etc. are out there. 60 Hz transformers are of course most common here in the U.S. (50 Hz in Europe), and 400 Hz is a common frequency for military equipment (ships, aircraft, tanks, etc.), but I was surprised to learn that 25-cycle (25 Hz) power was at one time common near hydroelectric plants. Niagara Falls, in Buffalo, New York, was one of the first to adopt 25 Hz, in part because of a belief that the AC motors used in nearby industrial applications would be more reliable at lower commutator frequencies (see "25-Hz at Niagara Falls - end of an era on the Niagara Frontier"). Other frequencies such as 8-1/3 Hz, 16-2/3 Hz, 25 Hz, 33-1/3 Hz, and 41-2/3 Hz were proposed. As you might expect, a lot of politics and corporate battling played into the final decision...

CETECOM Launches RF Automotive Experience Lab

CETECOM Launches 1st-Ever RF Automotive Experience Lab - RF CafeCETECOM, a global company providing automotive test and certification services, announces the first-of-its-kind Automotive Experience Lab (AEL). This innovative testing center, which opens on November 1, 2022 in Silicon Valley, is designed as a proof-of-concept lab for automotive application testing in a simulated environment. CETECOM, with more than 25 years experience in testing and certifying RF devices, leads the project, which will enable automotive engineers to validate component-level hardware designs during the HIL phase. With early access to cutting-edge test equipment, automotive application teams can significantly reduce design time, saving development costs and getting their product to market more quickly. CETECOM is offering one free four-hour session in the lab, which includes a consultation with CETECOM experts and training...

High Tech Comics

High Tech Comics, November 1944 Radio-Craft - RF CafeA wee bit of levity in the form of comics is good for the soul on a busy workday. Good humor, it is said, contains a degree of truth in it, and this group from vintage editions of Radio-Craft magazine is no exception. One of the comics in particular struck a chord with me - the one with the table model radio where the serviceman is speaking on the phone with his customer. The first familiar feature is the shape of the radio and the removed rear cover; it reminds me of my Tesslor R-601S. The second thing is the dead bugs. Just like a stray cat will climb into your car's engine compartment on a bitter cold day in search of heat, so will bugs be drawn to a heat source such as that provided by an electronic appliance filled with warm, glowing vacuum tubes - they might have liked the brightness as well. I remember well removing the backs of radios and TVs to find carcasses of bug colonies scattered around the electronics chassis. A couple years ago I bought a Snoopy and Woodstock telephone from the 1960s to restore. Although it was not a heat generator, the components were covered with tiny spots of bug excreta both on the outside and on the inside...

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

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

Many Thanks to Exodus Advanced Communications for Their Support

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

Tuesday the 8th

Auto-Sembly of Miniature Military Equipment

Auto-Sembly of Miniature Military Equipment, July 1951 Electronics Magazine - RF CafeAccording to this "Auto-Sembly of Miniature Military Equipment" article from a 1951 issue of Electronics magazine, the U.S. Army Signal Corps first experimented with chemically photo-etched printed circuit boards (PCBs) in 1949. Someone there got the idea from seeing the way nameplate manufacturers created similar signs for doors, desks, equipment nomenclature plates, etc. The authors wrote numerous articles* in numerous magazines over about a five year period on the Auto-Sembly process whereby leaded components are inserted into substrate through-holes, and then dipped into a solder bath as a complete assembly. Some history on the research is provided regarding photoresist compounds, etching mixtures, parameters of copper traces based on foil thickness and width (resistance, current handling), and other critical items. RF impedance measurement are not discussed since at the time only low frequency (DC, audio, and control signals) was involved on PCBs. It is a very interesting read...

"Conductive Play-Doh" Could Herald New Materials

"Conductive Play-Doh" Could Herald New Materials - RF Cafe"A team in the U.S. has created a material that is pliable like plastic but conducts electricity like a metal, shifting the foundations of how we think about conductivity. Discovered by researchers at the University of Chicago, the material's molecular structure is jumbled and disorderly, suggesting it should be a poor conductor. Good conductors are generally made up of straight, closely packed rows of atoms or molecules, allowing electrons to easily flow through the material. A conductive material without these properties challenges a fundamental principle of conductivity and could signify a paradigm shift in materials science. The work is published in Nature..."

Poll: Do You Use Twitter for Business?

Do you use Twitter for business purposes? - RF Cafe Twitter PollFor a few years I have avoided using Twitter because it had become a platform both overtly and covertly moderated by global censors with a one-sided political agenda. Now that Elon Musk had taken the reigns, I'll give it another try. Webmastering (a verb I just created) RF Cafe takes a lot of time, and adding content to Twitter is not a zero-effort task, but I'm willing to contribute some effort to it if people find it useful. A few of the recent homepage posts have been added already, and I also created this poll to test the response. Please take a moment to cast your vote.

Lissajous Had a Figure for It

Lissajous Had a Figure for It, March 1957 Popular Electronics - RF CafeOld sci-fi movies were famous for displaying Lissajous patterns on oscilloscopes in hopes of portraying a futuristic look. The first time I hooked up signals to the x and y axes of a scope and played around with the frequencies and amplitudes, I was mesmerized by the patterns and the fact that it was me creating them. Of course that was 30-something years ago when I was first getting into electronics and electricity, but even today it's a cool thing to do. In a typical, male-dominated, Chauvinistic manner, this article from the March 1957 edition of Popular Electronics magazine delves into the subject of Lissajous patterns. The author dares to compares men's attraction to curvaceous o-scope figures to a similar attraction to curvaceous women. Can you imagine the hateful feedback the editor of a current magazine would receive if something like this slipped...

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

Many Thanks to Withwave for Long-Time Support!

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

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PCB Directory (Manufacturers)
Copper Mountain Technologies (VNA) - RF Cafe

Innovative Power Products Passive RF Products - RF Cafe

Windfreak Technologies Frequency Synthesizers - RF Cafe