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Homepage Archive - June 2022 (page 3)

See Page 1 | 2 | 3 | 4 of the June 2022 homepage archives.

Tuesday the 21st

Altair 8800 Minicomputer

Altair 8800 Minicomputer Part 1, January 1975 Popular Electronics - RF CafeFor some reason, the January 1975 issue of Popular Electronics magazine, featuring the Altair 8800 Minicomputer construction article, seems to be the most highly prized of all editions ever published. They regularly sell on eBay for anywhere from $200 to $500, depending on the condition. If you happen to have one or find one at a yard sale, hold on to it as an investment (or mail it to me and I will hold on to it). Computers were still a sci-fi mystery type contraption to most people in the mid-1970's, and were even considered a thing to fear. Movies about evil-minded nerds hacking into critical databases and commandeering control of all aspects of life were popular, and even computers like Hal (2001: A Space Odyssey) that usurped control from its human inventors were giving the weak-hearted nightmares. Even without a CRT terminal for an interface, the Altair 8800 was a welcome and somewhat affordable ($400, equivalent to about $2,244 in 2022 money) introduction to computer hardware and programming. For that much money today, you can get a pretty high-power gaming computer setup. Notice one of the recommended applications...

Electronic Analogy Quiz

Electronic Analogy Quiz, November 1961 Popular Electronics - RF CafeIt is common in electronics courses for an analogy to be drawn between electrical and mechanical phenomena. In fact, a lot of circuit analysis methods and equations apply directly to mechanics, and vice versa. An LC (inductor-capacitor) oscillating tank circuit is akin to a spring and dashpot. Resistance of a wire is likened to skin friction of water flowing through a hose. Who among us can forget those lessons? This Electronic Analogy Quiz from the November 1961 edition of Popular Electronics magazine presents a challenge both because some not-so-familiar examples of analogies are offered, and because some are a real stretch. Therefore, don't feel too bad if you don't get a few. That's my way of saying that I didn't get all of them right ;-) Answers and explanations are at the bottom of the page...

What Is Quantum Entanglement?

What Is Quantum Entanglement? - RF CafeQuantum Entanglement is a relatively new term in the public technology world, but has been a physics concept since the days when Albert Einstein referred to to as "spooky action at a distance. With quantum computers dominating news headlines the term is seen regularly. IEEE's Spectrum magazine has an article which attempts to explain it. "When pushed to explain why quantum computers can outspeed classical computers, stories about quantum computing often invoke a mysterious property called 'entanglement.' Qubits, the reader is assured, can somehow be quantum mechanically entangled such that they depend on one another. If more detail is needed, the reader is told that entanglement links qubits no matter how far apart they are - so long as the qubits are 'coherent.' For the reader, things are far from coherent. Sure, entanglement is an important aspect of quantum computing. But what exactly is it? In a few words, entanglement is when multiple objects - such as a pair of electrons or photons - share a single quantum state..."

Clarion Replacement Chassis, Model AC-160 Radio Service Data Sheet

Clarion "Replacement" Chassis, Model AC-160 A.V.C. Superheterodyne Radio Service Data Sheet, July 1932 Radio-Craft - RF CafeThis Radio Service Data Sheet for the Clarion Model AC-160 A.V.C. Superhet radio "Replacement" Chassis, is an example of the dozens of similar schematic and alignment instruction sheets that have been posted on RF Cafe over the years. It appeared in a 1932 issue of Radio-Craft magazine. "Of the estimated 17 million radio sets now in use in the United States, the chasses of approximately 11 million are now obsolete, due to the rapid advance in receiver design." It was likely a replacement for the c1930 Model AC-60. Obtaining technical information on most things, even readily available items, prior to the Internet era was often very difficult - if not impossible. Service centers had what was need provided by manufacturers and distributors, but if you wanted to find a part number or service data on a refrigerator, radio, lawn mower, garage door opener, etc., and did not have the original paperwork, you were usually out of luck. Nowadays a Web search will quite often get you what you need thanks to people...

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...

Thanks to PCB Directory for Continued Support!

PCB  Directory - RF CafePCB 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.

Monday the 20th

53 Million TV Sets by 1960

53 Million TV Sets by 1960, July 1952 Radio-Electronics - RF CafeAccording to the statista.com website, there are about 1.72 billion television sets in the world as of 2021. Radio-Electronics magazine editor Hugo Gernsback claims there would be 53 million TV sets by 1960, eight years in the future from this 1952 issue. If so, it would represent a 300% increase over the 1952 number, which would be about 13-14 million. From 14 million to 1.72 billion is more than a 121% increase in seven decades. That's roughly a 7.1% growth (14E6 x 1.07170 = 1.70E9). How did I calculate that, you might ask? Take the 70th root of 121 = 70√121 = 121(1/70) = 1.0709. To check the answer, 1.070970 = 120.9. Consider also that the current TV set number does not include watching television shows on a computer, tablet, or smartphone. Similarly, if the number of radios in use in 1952 compared to today would not reflect the streaming radio shows listened to via the Internet. This demonstrates how when collecting statistics, the reporter needs to have enough knowledge of the big picture to either include it in the numbers, or provide a note along with the numbers explaining what the presentation's method and sources are...

Audel's Radioman's Guide Ad

Audel's Radioman's Guide Ad, September 1942, Radio-Craft - RF CafeTheodore Audel, a pen name and company name (Audel Publishers) used by Nehemiah Hawkins, published many technical handbooks covering electronics, mechanics, electric motors, mill working, carpentry, machining, plumbing, masonry, automotive, steam fitting, physical plant engineering, power generation systems, hydraulics, home appliances, oil burners, sheet metal working, refrigeration, and even gardening. I have a 1945 edition of Audels Carpenters and Builders Guide #1 that came from my grandfather, who was a carpenter. It is chock full of useful information, and I suppose the Radiomans Guide is as well. The title page quote is, "By Hammer and Hand All Things Do Stand." Do an eBay search on "audels radiomans guide" to pick up a hard copy of the original volume for just a few dollars.

June 20th is World Wi-Fi Day

June 20th is World Wi-Fi Day - RF CafeDid you even know there was such a thing as "World Wi-Fi Day?" Well, there is, and it is today, June 20th. The World Broadband Alliance has thus declared. Its website states: "Did you know there are more than 4 billion people around the world with no internet access? World Wi-Fi Day takes place on June 20th each year, and is a global initiative to help bridge the digital divide. Access to the internet provides people in developed and developing countries the opportunity to increase their economic growth, improve their social mobility and computer literacy as well as enrich their education prospects." OK, fine. Since it seems anything can have its "day," I hereby declare July 19th to be RF Cafe Day, since it was on that day in 1999 that I registered the rfcafe.com domain.

An Automatic Program Censor

An Automatic Program Censor, June 1934 Radio-Craft - RF CafeThe effort to block advertising on radio broadcasts has been going on for about as long as advertising has been in use, as evidenced by this 1934 article in Radio-Craft magazine where a "robot" advertising silencer device is presented for removing "superfluous advertising." Headlines from a few weeks ago announced Apple's program for blocking ads that appear on websites, causing a big to-do about how all the "free" content would be jeopardized since it is the advertisers who pay for the music and other programming to be delivered to the user. Without the convenience and economy of software to do the job in 1934, however, fairly complex discriminator circuits were used to detect and mute the "garrulous announcer or advertiser" between regular programming. It's pretty funny to read about how annoyed people were with the advertisements - just like today...

Removing Protective Plastic from Appliances

Removing Protective Plastic from Appliances - RF CafeThis has absolutely nothing to do with the normal RF Cafe theme, but it might come in handy for someone out there who needs to remove the protective plastic from a new appliance. We recently bought a refrigerator that came with a protective plastic film over the doors. It is applied at the factory before assembled, so the plastic is captured at the interfaces. It therefore; cannot be simply peeled off - a major pain in the posterior. A web search for advice on removal turned up all kinds of tricks - chemicals, toothpicks, fingernails - but none worked well. I then decided to try using a razor blade to run carefully along the interfaces. The plastic is very thin and soft and scores with almost no pressure. Voila! The plastic peeled right off leaving no trace or indication that it was ever there. Try it the next time you need to remove that annoying plastic - you'll be glad you did!

Sangamo Electric Company Advertisement

Sangamo Electric Company Advertisement, December 1949 Radio & Television News - RF CafeA lot of tech news websites have 3rd-party ads running that currently show an ad from a vintage magazine with a shocking title about how companies used to get away with printing images and text in advertisements that would never be tolerated today. I have seen many such ads in vintage electronics and science magazines as I scan them for useful material, and have posted a few of them on RF Cafe. Another example is this one run by the Sangamo Electric Company in a 1949 issue of Radio and Television News. As with the football team that goes by the same name, no offense was intended by the name; in fact, it was a positive portrayal of the group's attributes that was the inspiration...

Promote Your Company on RF Cafe for as Little as $40/Month

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.

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

Empower RF Systems - RF CafeEmpower RF Systems is a global leader in power amplifier solutions. Empower RF Systems is an established and technologically superior supplier of high power solid state RF & microwave amplifiers. Our offerings include modules, intelligent rack-mount amplifiers, and multi-function RF Power Amplifier solutions to 6 GHz in broadband and band specific designs. Output power combinations range from tens of watts to multi-kilowatts. Unprecedented size, weight and power reduction of our amplifiers is superior to anything in the market at similar frequencies and power levels.

Sunday the 19th

Electronics Theme Crossword Puzzle for June 19th

Electronics Theme Crossword Puzzle for June 19th, 2022 - RF CafeWith few exceptions, I, RF Cafe webmaster Kirt Blattenberger, have for more than two decades designed a custom crossword puzzle every week for the benefit of website visitors. This Electronics Theme Crossword Puzzle for was created for June 19th, 2022. All crossword puzzles use a personally built dictionary of thousands of words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword puzzle 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!

Many Thanks to Anatech Electronics for Long-Time Support!

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

Friday the 17th

Selecting the Right Radio School

Selecting the Right Radio School, July 1952 Radio-Electronics - RF CafeAlthough the details about types of electronics schools, locations, specific career goals, funding sources, etc., are a bit different today than they were in 1952 when this "Selecting the Right Radio School" article appeared in Radio-Electronics magazine, the advice offered for consideration is still applicable. You are investing a significant amount of resources - financially and commitment-wise - so the prudent approach is to do as much up-front research as possible to help assure you will not regret your decision. Of course there is always the chance that at some point you'll opt for a different career - it happens to a lot of people. One big difference these days is there is probably a lot more in the way of financial assistance available than back in the 1950s. One of the best ways then and now is to enlist in the military and take advantage of the schoolroom training and on the job training (OJT), while collecting a paycheck and having some of the best medical coverage available...

Synzen Constellation Class of Ultra-Compact Antennas at Embedded World

Synzen Constellation Class of Ultra-Compact Flexible Antennas for Small IoT Devices - RF CafeSynzen Precision Technology will be showcasing their new range of miniature FPC antennas at this year's Embedded World trade fair in Germany. The six ultra-compact flexible antennas which make up Synzen's Constellation Class of antennas feature novel and elegant design solutions that maintain superior performance, even in very small IoT devices. These antennas are perfect for asset tracking, OBDII, smart home, smart city, ISM, and wearables. Not only do they take up minimal space in modules, the antennas also display excellent coexistence, which means that you can easily integrate more than one antenna into your device. Furthermore, careful development of the range has ensured the best isolation with no out-of-band spurious resonances. Synzen's Technical Director, Chris Tomlin said: "Usually, smaller IoT devices cannot use off-the-shelf FPC antennas because of lack of clearance and/or space. So, we made a more practical range of antennas which enables quick integration without the need for expensive and time-consuming custom designs...

AT&T Flying 5G COW Drone a Game Changer

AT&T Flying 5G COW Drone - RF Cafe"Drones aren't exactly new to wireless networks, but AT&T is claiming an industry first with a 5G-driven drone launched in - of all places - a field in rural Missouri. AT&T's drone team picked the field for the April launch of its flying COW (Cell On Wings vs. the older land-based COWs, or cell on wheels) because it's so remote: no trees, no houses and no wise-cracking humans. (At least, not until they heard about it on Twitter.) Ethan Hunt, principal program manager of the AT&T Unmanned Aircraft Systems (UAS), explained in a press release that AT&T had intermittent, weak LTE signals at the flight location before they launched the 5G flying COW. 'We flew the drone up to about 300 feet, turned on the signal and it began transmitting strong 5G coverage to approximately 10 square miles,' Hunt stated. What that means is customers wit

Please Visit Triad RF Systems to Thank Them for Their Support

Triad RF SystemsTriad RF Systems designs and manufactures RF power amplifiers and systems. Triad RF Systems comprises three partners (hence 'Triad') with over 40 years of accumulated knowledge of what is required to design, manufacture, market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating amplifiers are available, in formats including tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology partner than a vendor for our line-of-sight communications product line." Please check to see how they can help your project.

Communications on the World's Greatest Airline

Communications on the World's Greatest Airline, April 1945 Radio News - RF CafeThe Douglas DC-3 revolutionized commercial air travel with its introduction in 1935, and the military version, the C-47 Skytrain (aka Dakota, aka Gooneybird), proved an invaluable workhorse for the U.S. Army Air Force during World War II. Without reliable and effective radio communications, the aircraft's success would have been much less. Companies like Bendix Radio led the way with rugged avionics that could take the harsh conditions of flight that include vibration, shock, pressure changes, and temperature variations. Replacement parts were usually not conveniently on-hand and the radio operator often needed to also be a trained electronics technician or engineer. "Necessity is the mother of invention," never proved truer than during wartime as evidenced by the many technology advances realized during the 1940s...

Anatech Electronics Webiste Down - RF Cafe Important Announcement from Anatech Electronics

Anatech Electronics logo - RF CafeTo all our customers. Anatech electronics website was cyber attacked and we had no choice but take it down since it was causing damage to other parts of our server and computer systems. Be assure that we are working diligently to remedy the problem which unfortunately will take a while sine we will have to re-construct our website. A landing page is in the works to get our visitors the essential links to communicate with us on RF and Microwave filter product needs. We appreciate your understanding and we will diligently work as usual to get you the solutions you are looking for.

Detrola Radio Advertisement

Detrola Radio Advertisement, January 1945 Radio News - RF CafeBelieve it or not, there are people who pay for vintage advertisements like these (no, I'm not trying to sell it). eBay is chock full of auctions for original pages from the old magazines that contain ads for products and services. Often, if you know where to look, you can buy the entire magazine in which a particular ad appeared for only a little more. People sometimes frame them and either hang them for decoration or present them to a parent or grandparent as a memorial to their lives. Stranger things are done. This ad for Detrola Radio appeared in the January 1945 edition of Radio News. Detrola, as the name suggests, the company was located in Detroit, Michigan...

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 Axiom Test Equipment for Continued Support!

Axiom Test Equipment - RF CafeAxiom Test Equipment allows you to rent or buy test equipment, repair test equipment, or sell or trade test equipment. They are committed to providing superior customer service and high quality electronic test equipment. Axiom offers customers several practical, efficient, and cost effective solutions for their projects' TE needs and is committed to providing superior customer service and high quality electronic test equipment. For anyone seeking a way to offload surplus or obsolete equipment, they offer a trade-in program or they will buy the equipment from you. Some vintage items are available fully calibrated. Please check out Axiom Test Equipment today!

Thursday the 16th

Coupling to 300 Ω Flat Lines

Coupling to  300 Ω Flat Lines, August 1947 QST - RF CafeAn ample supply of surplus coaxial cable after the end of World War II provided an inexpensive and easy to use form of transmission line. Not having to worry about cable routing and unintentional radiation makes transitions through walls, running along metal surfaces, and routing high power transmission lines near habitable areas a no-brainer. Issues like power handling, bend radius, and higher attenuation need more attention during the installation design phase, but that pales in comparison to coaxial cable's advantages. In this 1947 issue of the ARRL's QST magazine, author Byron Goodman addresses some of the issues Hams accustomed to using flat transmission lines (conductor pairs separated by an insulator)...

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.

DARPA Launches COFFEE Program

DARPA Launches COFFEE Program - RF CafeNow this is my kind of government program title. It took a significant effort to come up with the COFFEE name. "The Defense Advanced Research Project Agency (DARPA) has selected research teams for their COmpact Front-end Filters at the ElEment-level (COFFEE) program, which seeks to create a new class of integrable, high-frequency filters with low loss, high-power handling, and seamless uniformity. The selected teams will be led by Northrop Grumman, Raytheon, Akoustis, BAE Systems, Metamagnetics, Georgia Institute of Technology, Columbia University, Carnegie Mellon University, University of Michigan, University of Texas at Austin and University of California at Los Angeles. The COFFEE program will focus on creating an integrable filter technology to mitigate interference and maximize performance across a challenging S-band through Ku-band (i.e., 2 GHz to 18 GHz) frequency range. These filters must not only distill signals across the expansive frequency range, but do so while physically bound within an 18 GHz half-wavelength array pitch..."

Anatech Electronics June 2022 Newsletter

Anatech Electronics June 2022 Newsletter - RF CafeSam Benzacar of Anatech Electronics, an RF and microwave filter company, has published his May 2022 newsletter that features his short op-ed entitled "The Very Real Vulnerabilities of GPS," where he discusses the inherent vulnerabilities of using the satellite-based system as a primary Positioning, Navigation, and Timing (PNT) reference. The Achilles' Heel is how easily the signal can be overwhelmed and/or spoofed with local transmitters. Alternative technologies are being researched and developed, including highly accurate and robust inertial references, but to date none are as precise as GPS. In time, though, a solution will be found. Necessity is the mother of invention, as the saying goes. Also mentioned are private networks on the upswing, the fast-growing phased-array radar market, Starlink no longer being alone, and Dish and Space X duking it out...

Improve Your Television Picture

Improve Your Television Picture, August 1949 Radio-Electronics - RF CafeAnyone who used to watch television in the days when reception quality at any given time depended on whether your neighbor parked in certain spot in the driveway, or put up a big metal utility shed or even a large above-ground swimming pool, or if the air was exceptionally humid or a hammering downpour of rain or a blizzard was occurring, knows the lengths to which people would go to obtain a good picture. All sorts of tricks were used by those not familiar with engineered type solutions as shown in this 1949 issue of Radio-Electronics magazine. Whereas author Allan Lytel instructs on how to properly tune transmission lines for optimal reception (including constructing shorting stubs and tuning them with a razor blade), we uneducated (at the time) rubes resorted to adding lengths of crumpled tin foil to rabbit ears, rolling the TV (if on a stand) around the room, repositioning the 300-ohm twin lead cable from the roof-mounted antenna, and even standing or sitting in certain places in the room to affect the best picture. Yes, many of us did that, including yours truly. We didn't know why it often worked, but it did. The same goes for radio reception...

Promote Your Company on RF Cafe for as Little as $40/Month

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 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. Order today, ship today! Centric RF is currently looking for vendors to partner with them. Please visit Centric RF today.

Wednesday the 15th

Electronics-Themed Comics, April 1952 Radio-Electronics

Electronics-Themed Comics, April 1952 Radio-Electronics - RF CafeThese four electronics-themed comics appeared in the April 1952 issue of Radio-Electronics magazine. For those of you not around during the analog over-the-air broadcast era that existed prior to the industry-wide switchover to all digital transmissions, "snow" is the noise on the video portion of the composite signal. In areas of weak signals, the snow could make the channel unusable. It was a big problem for a lot of people, especially those with a poor TV receiver, an underrated antenna, an antenna without a rotator for pointing in the direction of the strongest signal (not necessarily directly toward the broadcast tower), poor lead-in cable, or in a location too far away from the TV station or in an area blocked by obstacles. The equivalent of snow in the digital signal world is the broken up, pixelated display when your signal is low. I think the comic on page 64 is really clever, although it might trigger a snowflake (whilst on the subject of snow in two of the other comics) out there who happens to see it...

Many Thanks to KR Electronics for Long-Time Support!

KR ElectronicsKR Electronics designs and manufactures high quality filters for both the commercial and military markets. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop 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.

Satellites to 3D Print Their Own Antennas in Space

Satellites Will 3D Print Their Own Antennas in Space - RF CafeThis is a great idea! "A crucial part of any satellite launched into orbit is its antenna. The challenge, however, is that its (typically) dish-shaped antenna is big, heavy, and difficult to fit comfortably into any reasonably-sized rocket fairing. So researchers at Mitsubishi Electric Research Laboratories (MERL) in Cambridge, Mass., wondered, What if satellites simply skip over the whole problem? That is, don't bring an entire, oversize antenna assembly up into space with the satellite but instead 3D print it once the satellite reaches orbit. MERL has in fact developed an on-orbit, antenna 3D-printing technology that uses photosensitive resin, hardened by solar ultraviolet light. The new technique, the researchers say, potentially allows the dish to achieve high gain and wide bandwidth (which requires a large antenna), while still keeping the satellite that's launched from Earth lightweight and small..."

Are Your Electrolytics Leaky?

Are Your Electrolytics Leaky?, March 1957 Radio & Television News - RF CafeAnyone who has dealt with older electronics equipment knows that one of the first kinds of components to go bad is the electrolytic capacitor. Materials used at the time degraded fairly rapidly, especially compared to modern materials, which facilitated leakage of stored charge between the rolled up layers of conductive plates and interstitial insulating paper (or other material) layers. As outlined in this 1957 article from Radio & Television News magazine, symptoms of electrolytic capacitor malfunction in radio and television are most often some form of audible noise, light or dark lines within the picture scan, or outright power supply failure. Since electrolytics are typically large valued capacitors, they are used in power supply circuits for filtering the line 50 or 60 Hz (depending on your country) AC frequency (and their harmonics) and for interstage AC coupling. This article presents a simple method for testing leakage levels in electrolytic capacitors to determine whether they should be replaced. Many restorers of old electronic equipment routinely replace all the original electrolytic capacitors because it is almost certain that leakage will either...

Crosley Model 56FC Tabletop Radio

Crosley Model 56FC Tabletop Radio, September 1947 Radio News - RF CafeFor many years, I have been scanning and posting schematics & parts lists like this one for the Crosley Model 56FC tabletop radio, which appeared in a 1947 issue of Radio News magazine. Often, a description of the radio's operation and detailed tuning instructions are provided - sort of like a Reader's Digest condensed version of the Sams Photofact data pack. In this instance, only the schematic and parts list are provided. When the textual content is also available, I usually OCR it and post it along with the graphical stuff. 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. I keep a running list of all data sheets to facilitate a search...

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 ConductRF for Continued Support!

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

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.

Homepage Archive Pages

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- Christmas-themed items

Exodus Advanced Communications Best in Class RF Amplifier SSPAs - RF Cafe
Windfreak Technologies Frequency Synthesizers - RF Cafe

Werbel Microwave (power dividers, couplers)

Axiom Test Equipment - RF Cafe