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Homepage Archive - March 2024 (page 3)

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

Thursday the 21st

News Briefs

News Briefs, April 1967 Radio-Electronics - RF CafeWhen I hear the name Van de Graaff and think of the Jacob's Ladder gadget a lot of us built in junior high school, it seems like the guy must have been born in the early to middle 19th century, long before Nikola Tesla. In fact, Dr. Robert J. Van de Graaff was born in 1901, and according to this death notice in a 1967 issue of Radio-Electronics magazine, died in January of that year. Also in the news was how aluminum was going to begin replacing copper for building wiring. That didn't last long because by the early 1970s houses were burning down when the soft aluminum cold-flowed at the electrical device screw connections, causing arcing which then started fires. The National Electric Code prohibited its use in new construction for sizes under 10 AWG sometime around 1975. That was when I first starting out as an electrician in training. The industry went to copper clad aluminum for a couple years, then back to solid copper shortly thereafter. Most insurance companies today will not cover houses with aluminum wiring. Read on for other breaking news of the day...

Coax vs. Twinlead

Coax vs Twinlead, July 1965 Electronics World - RF CafeThe debate regarding the superiority of coaxial cable and twin-lead cable, aside from personal preferences, comes down to this: Twin-lead cable has lower loss but is vulnerable to extraneous signal pick-up and is sensitive to nearby objects in the routing path from antenna to receiver; it is also inexpensive. Coaxial cable has higher loss and is more expensive, but is significantly less sensitive to the routing path and external signal interference. In strong signal areas and/or for short runs, higher loss in coax is not an issue, and its higher cost can usually be justified for the near immunity from interference advantage. In areas where the signal at the antenna is weak and the path length to the receiver is long, twin-lead, aside from its lower cost, helps yield a better signal. The same pros and cons apply for the other direction with a signal going from a transmitter to an antenna, but this 1965 Electronics World magazine article is addressing television and radio reception...

Withwave Multicoax Cable Assemblies to 110 GHz

Withwave High Speed & High-Density Multicoax Cable Assemblies - RF CafeWithwave is a leading designer and developer of a broad range of RF, microwave, and millimeter-wave test solutions and subsystems with a focus on electromagnetic field analysis and signal processing. Our newly released High Speed & High-Density Multicoax Cable Assemblies provide a wide range of multiple coax connectors and flexible cable assemblies with a choice of 20,, 40,50, 67, & 110 GHz configurations based on precision array design and superior high frequency cabling solutions. The WMX series is an excellent signal integrity solution for bench-top and automated test equipment to meet increasing demands of the semiconductor and optical test industries, including 5G communications and supercomputing. Vertical mount and edge mount configurations available with 2.54 mm and 4.00 mm connectors...

Voltage-Multiplying Circuits

Voltage-Multiplying Circuits, January 1953 QST - RF CafeVoltage multipliers were found in nearly every form of battery-powered electronics in the days of vacuum tubes, because of the 100-volt or more requirement for plate voltages. Primary batteries in 30, 45, and 67½ volt sizes were produced by Eveready, Burgess, and a few other companies in order to help simplify biasing circuits. They were bulky and heavy, often comprising a significant portion of the assembly's volume. Heavy transformers contributed mightily to the weight and size as well. Exell still manufactures 30, 45, and 67½ V batteries both for the few products that are still designed to use them, and for vintage radio owners. Most circuits that need higher DC voltages these days use DC-DC converters, many of which are ICs that need only a small external inductor (not a transformer). This 1953 article in QST magazine show how high voltages were generated in the days of tubes...

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers" Smith chart design. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. My graphic has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. I only make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way to help support RF Cafe. Thanks...

Wednesday the 20th

Winegard Antenna Systems

Winegard Antenna Systems - RF CafeIt's hard to say what over-the-air (OTA) broadcast television audience size is these days, but there must be enough companies making money from advertising adult diapers, electric scooters, insurance, hearing aids, and supervitamins to pay for the service. I put up an old-fashioned Channel Master long range, multielement VHF / UHF / FM antenna a decade ago while living in Erie, Pennsylvania, in hopes of watching some local programming with news and nearby company promotions. Boy, was I disappointed when most of what appeared was useless programs packed with the aforementioned type of products and services. It was pathetic. When this Winegard Antenna Systems ad appeared in a 1967 issue of Radio-Electronics magazine, it was a different world. Broadcast TV was the dominant entertainment medium, and cable was just beginning to be installed in urban areas - basically where the signal quality was already very good due to proximity to transmission towers. Convincing people to pay for a service they were getting for free, and still having to sit through commercials, was a good bit of marketing savvy. FYI, there are currently 12 VHF (2-13) and 56 UHF (14-69) channels reserved for OTA TV, for a total of 68...

Optical Chopper a la CBS Color TV

Optical Chopper Sanford Research Systems - RF CafeIf you are a frequent visitor of RF Cafe, you have probably seen an article or two on the history of television. Early color TV systems used an electromechanical configuration that "chopped" the electron beam into red, green, and blue sectors at a rate that combined on a projection screen in a manner which presented a broad spectrum. One scheme that was a serious contender over the all-electronic color system was the CBS rotating disk. Believe it or not, the first color TV camera on the moon was similar to the CBS system. An advertisement for a Precision Optical Chopper from Stanford Research Systems recently appeared in MWJ, that made me think of the CBS color mechanism. There are LCD type optical choppers, but they are wavelength dependent and cannot switch at more than a couple hundred Hz...

The Field-Effect Transistor

The Field-Effect Transistor, August 1972 Popular Electronics - RF CafeAlthough the first patent for a field effect transistors (FET) was assigned to Julius Edgar Lilienfeld in 1925, it was not until sometime around 1960 that the first commercial product was available - a MOSFET designed by Dawon Kahng and Martin M. (John) Atalla at Bell Labs. This article from a 1972 issue of Popular Electronics magazine introduces the hobbyist readers to properties and uses for the by-then common junction FET (JFET) and MOSFET. Nowadays, MOSFETs are the backbone of the vast majority of integrated circuits. Note in Fig. 3 where it is shown how the biasing and function of a vacuum tube and n-type JFET are essentially the same. I often recommend to people who are doing one of the Popular Electronics Quizzes that shows a vacuum tube that they mentally substitute a FET for the tube, and proceed to arrive at an answer...

Robot Builds 5-Meter Communications Tower

Robot Builds 5-Meter Communications Tower - RF cafeIs it my imagination, or does this tower have a tilt to it? Since it's meant to demonstrate autonomous erection of communications towers on the moon, I hereby dub it the Leaning Tower of Luna. "In a scenario meant to mimic the lunar surface, four robots cooperatively built a five-meter communications tower, including antenna - and then disassembled it, simulating not only the construction of such a structure but maintenance and sustainable operations for lunar infrastructure development. Robotics company Gitai's Lunar Rover and three of its 'Inchworm' robots achieved the build, which the company called 'groundbreaking' and a first of its kind. Japanese operator KDDI was also a partner on the project, providing specifications and information about their mobile phone base stations that allowed Gitai to develop an antenna suited for robotic construction. Gitai's robotics were selected late last year to be part of the Defense Advanced Research Projects Agency (DARPA)'s 10-Year Lunar Architecture capability study..."

Corrugated-Waveguide Bandpass Filters

Corrugated-Waveguide Bandpass Filters, July 1951 Electronics Magazine - RF CafeMaybe in 1951 when this "Corrugated-Waveguide Band-Pass Filters" article appeared in Electronics magazine, placing a special resonating form inside a section of waveguide was a reasonable option for creating a bandpass filter response, but it sure seems like a hard way of accomplishing the task. As shown in the photo and illustrations, a tapered metallic block with machined fins spaced to resonate at a predetermined frequency created a high frequency cutoff to work in conjunction with the natural low frequency cutoff frequency to create a bandpass combination. A quick search did not turn up any references to such structures being used in modern waveguide bandpass filters, although they might exist. It appears iris coupling of resonating cavities is the method du jour. I admit to not being a waveguide expert, so do your own research on this one. If nothing else, this is a good historical reference...

How to Target RFCafe.com for Your Google Ads

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

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 - and don't miss the blog articles!

Tuesday the 19th

How Come No Two Snowflakes Are Alike?

How Come No Two Snowflakes Are Alike? , 1986 Old Farmer's Almanac - RF CafeWith less than 24 hours left in winter this year (vernal equinox is March 19th at 11:06 pm EDT), I figured I had better get this snowflake article posted now. It appeared in the 1986 edition of The Old Farmer's Almanac (OFA). That's not a publication targeting old farmers, btw. For many decades, I was a faithful purchaser and reader of the OFA, but sometime in the early 2000s, the nature of its contents changed pretty significantly and I lost my interest. I've got enough vintage issues with sunrise and sunset, moonrise and moonset, and high and low tides tables that I don't need newer versions. Besides, all that up-to-the-minute information is available online. But I digress... We've all been told about how no two snowflakes are alike - like fingerprints - and that it has something to so with static electric charges as the flake is formed. Even so, just like DNA controlling how living cells divide and reproduce with and without symmetry, the creation of a snowflake's unique symmetry is and variation is magical...

Laser Scarecrow Deters Murder

Laser Scarecrow Deters Murder - RF CafeThis is a very clever headline from the editors at Photonics magazine. You probably know this, but in case not, a flock or collection of crows is referred to as a "murder of crows." The BirdSpot website offers an explanation for the strange and uncomplimentary moniker, although the etymology is admittedly not for certain. BTW, we also refer to  a charm goldfinches, a siege of herons, a gaggle of geese, and a parliament of owls. Begins the Photonics article: "Using a model laser scarecrow previously developed at the University of Rhode Island, which looks less like a traditional scarecrow and, in fact, much more like a traditional laser module, the researchers presented flocks of European starlings with fresh ears of sweet corn within an enclosure. The team performed two tests. In a 'stick trial,' the researchers stuck corn on a wooden stake to simulate a stalk. In a subsequent 'natural trial,' they placed real corn stalks at various heights. Upon concluding the trials, the team determined that the use of lasers as a scarecrow mechanism reduced crop damage - marginally in stick trials and more substantially in natural trials. The prospect for crop damage, they found, increased as the laser distance increased..."

The Great Electron-Pedantic Project

The Great Electron-Pedantic Project, February 1970 Popular Electronics - RF CafeThere's not a much better way to wrap up a work week than to read through a short technohumor (I just made up that word) novel by Carl Kohler or John T. Frye. Reading a few technocomics (another made-up word) by various illustrators is a great resource, too. This story, which appeared in a 1970 issue of Popular Electronics magazine, is another episode in the life of technotinkerer (a "Maker" in today's lingo) Kohler (who also drew a lot of the technocomics) and his skeptical helpmeet (for good reason) "Friend-Wife," as he unveils his repurposed homebuilt UNIversity computer...

MIT's 2D Integration Breakthrough

MIT's 2D Integration Breakthrough - RF Cafe"MIT's breakthrough in integrating 2D materials into devices paves the way for next-generation devices with unique optical and electronic properties. Two-dimensional materials, which are only a few atoms thick, can exhibit some incredible properties, such as the ability to carry electric charge extremely efficiently, which could boost the performance of next-generation electronic devices. But integrating 2D materials into devices and systems like computer chips is notoriously difficult. These ultrathin structures can be damaged by conventional fabrication techniques, which often rely on the use of chemicals, high temperatures, or destructive processes like etching. A New Integration Technique To overcome this challenge, researchers from MIT and elsewhere have developed a new technique to integrate 2D materials into devices in a single step while keeping the surfaces..."

Solid State Electronics

Solid State Electronics, August 1970 Popular Electronics - RF CafeBeginning in the 1960s, Popular Electronics magazine had a long-running column titled "Solid State" that reported on the newfangled science. Even in 1970, there were still people who distrusted solid state electronic devices in terms of reliability and ruggedness. Their skepticisms were not totally without merit at the time. However, advances were occurring at a very rapid rate. This particular Solid State report describes how charge coupled devices (CCD) might someday serve as photographic imagers because of their efficiency at converting photon impingement to electric charge in potential wells and the subsequent serial shifting of the data to an output port. It also raves at the development by Motorola of RF power transistors (40 W) that exhibited useful gain way up into the 25 MHz realm...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated in all locations on the page! RF Cafe typically receives 8,000-15,000 visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 17,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. Your Banner Ads are displayed on average 280,000 times per year! New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the place to be...

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! 

Monday the 18th

Electronics-Themed Comics

Electronics-Themed Comics, December 1964 Radio-Electronics - RF CafeIt's been a while since I posted a new set of electronics-themed comics from vintage magazines. These three appeared in a 1964 issue of Radio-Electronics. The page 37 comic shows the wife asking a presumably inane question, but in fact there were duo-whatever vacuum tubes that were the inclusion of a pair of single tube types, usually with a 12.6 V heater voltage. A well-known example is the 12AX7, which is essentially a pair of 6AV6 triode tubes. Besides that, there was both a 6SN7 and a 12SN(X)7 tube, the former with a 6.3 V heater and the latter with a 12.6 V heater. Here's a question for you: What is that thing on the floor to the right of the box of vacuum tubes in the page 37 comic?* The page 72 comic is not so far-fetched. I have no doubt that somewhere in the world - multiple places and times, likely - people have heated or cooked something in front of a microwave communications dish...

Russia Avangard Hypersonic Glide Vehicle

Russia Avangard Hypersonic Glide Vehicle - RF CafeA lot has been in the news recently about Russia's new hypersonic glide vehicle capable of delivering nuclear (and conventional) warheads across the globe at over than Mach 20 (14,822 mph) in the atmosphere. That's 4.1 miles per second. From a 150 mile high apogee, that's less than 40 seconds from space to target. Not even a high power laser can stop that. The great circle path from Siberia to San Francisco is 5,900 miles, for a flight time of less than a minute after launch phase. Moscow to D.C., (4,900 miles) takes a little less time. Here is a recent interview with Putin on Russia's state of the union regarding social, economic, and military issues - including hypersonic weapons. Oh, and they're not fixing their low birth rate by importing felons, psycho patients and cannibals from the third World. Interestingly, he addresses the rampant embezzlement schemes that U.S. defense contractors and their management perpetrate. Sure, a lot is propaganda, but so is what comes out of Washington.

Dodging the Weather - With Radar

Dodging the Weather - With Radar, August 1956 Popular Electronics - RF CafeAs with nearly things electronic, innovations in radar systems that were ground-breaking a few decades ago are now available commercially at a small fraction of the cost, a much more compact size, and much greater performance and reliability. Radar operators during World War II noticed that they were able to detect strong rainstorms demonstrating that signals did not necessarily need a metallic object to be reflected strongly enough to be received and processed. Research began soon thereafter to build radars optimized for detecting weather phenomena. Early weather radars were "simple" reflective types that indicated distance, height, and speed (by comparing successive samples). Doppler radar was developed next, adding a much greater capability to characterize particular weather systems according to intensity, direction, rotation (hurricanes , tornadoes), composition (ice, snow, rain, etc.), speed (average and gust), and other parameters...

everything RF's 2024 "RF Filter Digest" eBook

everything RF's 2024 "RF Filter Digest" eBook - RF Cafeeverything RF has published an eBook titled "RF Filter Digest 2024." This eBook is crafted to be a comprehensive resource for anyone looking to learn about the current-generation RF Filters. With the introduction of new wireless technologies, the frequency spectrum is getting very crowded. To maintain seamless operation among these technologies without interference, RF Filters play an integral role. RF Filters are crucial in optimizing signal transmission and reception, selectively allowing desired frequencies to pass through while attenuating unwanted signals. The "RF Filter Digest 2024" eBook discusses the challenges involved with 5G mmWave filtering, high-rejection LTCC filter performance, the role of MMIC filters in developing next-generation systems, and the impact of BAW filters on 5G applications. This eBook also includes an exciting section that discusses filter design in the Cadence AWR design environment...

Opportunity Awareness

Opportunity Awareness, October 1970 Popular Electronics - RF CafeEach month I used to post a list of articles with advice on career enhancement including tips on preparing resumes, conducting yourself properly at interviews, getting along well with co-workers, handling a difficult boss, etc. I also posted links to polls and studies done on career satisfaction, pay rates, education and experience levels, years in the field, etc. Those types of articles have been around since Johannes Gutenberg invented the movable type printing press. In the 1970s, Popular Electronics magazine ran a series of articles titled "Opportunity Awareness" that offered such advice, much of which in principle is still valid today. One of the biggest advantages you can give yourself when job hunting is a willingness to relocate to a new area - even if you need to pay for the move yourself. I moved many times during my career and before getting my BSEE, paid my own moving expenses as a technician...

RF Cascade Workbook

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

Friday the 15th

Fresnel Zone Calculator in Espresso Engineering Workbook

Fresnel Zone Calculator in Espresso Engineering Workbook - RF CafeThere are many online Fresnel Zone calculators. Most do the basic calculation for the maximum radius of the Fresnel Zone for a given frequency and separation between antennas. Some allow you to enter an obstacle's distance from one of the antennas, and its height, then lets you know if the obstacle falls within the Fresnel Zone. Very few plot the shape of the Fresnel Zone, and even less include an obstacle positioned on the plot. Most rare are calculators which take the curvature of the Earth into account. RF Cafe's Espresso Engineering Workbook includes a Fresnel Zone calculator incorporating all those features - and more...

What's Your EQ?

What's Your EQ?, August 1967 Radio-Electronics - RF CafeThis "What's Your EQ?" (EQ = Electronics Quotient) from a 1967 issue of Radio-Electronics magazine offers just two challenges to your circuit analysis prowess. The first, "Voltage Booster," is a classic black box (although I colored it blue) mystery where you are supposed to figure out what is inside that produces the stated output given a stated input. Spoiler: You'll need to be familiar with vacuum tube characteristics in order to solve it. Unlike with many such circuits, a simple mental substitution of a field effect transistor will not do the job. You might as well not even try "Shifted Tuning" unless you have hands-on experience with tuning mechanisms of the era. Just go straight to the answer, and gain an appreciation for advancements in radio technology. Guys like Mac McGregor dealt with this kind of phenomenon on a regular basis...

LadyBug LB5975W 50-75 GHz True RMS Power Sensor

LadyBug LB5975W 50 GHz to 75 GHz True RMS Power Sensor - RF CafeLadyBug Technologies' LB5975W is 50 GHz to 75 GHz a high accuracy, platform independent RF & Microwave Power Sensor for general purpose average power or True RMS and scalar measurements. The sensor features exceptionally fast measurement speed, a broad dynamic range, and the widest set of options for programmatic and embedded applications in the industry. LadyBug's feature rich Power Meter Application is provided with each sensor. Time domain trace visibility is included and aids in setting markers. The sensor is useful in research & development, manufacturing & service applications including radar, satellite and telecommunications. Highlights include coverage from 50 to 75 GHz, accurate power measurements on any modulated signal, dynamic range: -50 to +18 dBm, Just Measure - patented NoZero NoCal before use technology, and a variety of options such as triggering, security & analog outputs...

Mac's Service Shop: Philosophy of a Kit Manufacturer

Mac's Service Shop: Philosophy of a Kit Manufacturer, November 1972 Popular Electronics - RF CafeIf you are a seasoned reader of episodes of "Mac's Service Shop," you might have noticed that the stories almost always begin with either Mac or Barney commenting on the weather, which corresponds to the time of year in which the story was originally published. Note the reference to the "bleak, cold November morning" in this 1972 edition of Popular Electronics magazine. This time around, the boss and trusty employee discuss the value of electronics kits, Heathkits in particular. BTW, Heathkit is now making an impressive comeback into the kit realm with new designs. Manuals for some of the more popular vintage Heathkit projects are available again, which are a welcome thing to collectors. They also are producing some replacement assemblies, like for replacing old Nixie tube displays with LEDs (of course most people would probably rather have replacement Nixie tubes). Back in the 1970s, before everything we bought was assembled in far away lands using pseudo-slave labor, it was often less expensive to buy a kit of parts and put together you own television or radio. It was also an era when electronics service shops still did a brisk business fixing appliances, and building such devices were part of the schooling process for up-and-coming technicians. Every study-at-home electronics course included a color television, AM/FM stereo, and even build-it-yourself...

Huawei Foldable Smartphone's Liquid Armour

Huawei Foldable Smartphone's Liquid Armour - RF Cafe"Researchers with Chinese telecommunications giant Huawei spent three years developing the technology for its foldable phone screens, drawing inspiration from the impact-absorbing qualities of starches under certain conditions. Huawei's technical team told the Post that the resilience of its Mate X3 and X5 phones stemmed from the unique properties of a flexible inner screen beneath the scratch-resistant outer surface. The material - which took more than 100 experiments to develop - is based on a phenomenon that turns starch solution in the right proportions into a non-Newtonian fluid that acts like water but hardens into a solid under sudden impact..."

Solitron Devices Fetrode Advertisement

Solitron Devices Fetrode Advertisement, March 1973 Popular Electronics - RF CafeBy the early 1970s, many types of vacuum tubes had already been replaced by solid state devices. A lot of the resistance by hardline lovers of glowing tubes was beginning to accept the reality of superior electrical characteristics of many types of germanium and silicon diodes and transistors over tube equivalents. During my enlistment in the USAF from 1978-1982, the vacuum tube diode used to trigger the pulse forming network for the airport surveillance radar (ASR) circuit was replaced with a plug-in solid state replacement. It seemed to work just as well. I don't recall ever having to replace the faulty vacuum tube version, so I cannot attest to whether the solid state version was an improvement. Part of the motivation for replacing tubes with solid state devices was obsolescence of the tubes, so maybe that is why it was done. The "fetrode" introduced here by Solitron Devices in this 1973 issue of Popular Electronics magazine was designed to be a plug-in replacement for the 6AK5 vacuum tube, which is a pentode amplifier. Although not specifically stated, I assume the name "fetrode" implies it was a field effect transistor (FET)...

RF Cascade Workbook

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

 

 

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

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- Christmas-themed items

RF Cascade Workbook 2018 - RF Cafe
TotalTemp Technologies (Thermal Platforms) - RF Cafe

Amplifier Solutions Corporation (ASC) - RF Cafe

Innovative Power Products Passive RF Products - RF Cafe