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Homepage Archive - April 2024 (page 1)

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

Friday the 5th

Fairchild Engine and Airplane Corporation - Electronic Energy

Fairchild Engine and Airplane Corporation - Electronic Energy, February 1944 Popular Science - RF CafeAt the same time that radio frequency waves were being applied to wireless communications, they were also being used for applications in medicine, food preparation and sterilization, manufacturing, and in other realms. The usefulness of x-rays was known to most people, even if they didn't understand them. At much lower frequencies, particularly microwaves, RF signal interaction with water and other types of liquid molecules provides an effective and efficient means of heating to accelerate cooking of meat and curing of adhesives. The latter is what this Fairchild infomercial appearing in a 1944 issue of Popular Science magazine touted as an example of how they are inventing and applying cutting edge technology to help win World War II. The use of microwave heating for curing plywood has been used since high power vacuum tubes capable of those frequencies were invented...

3D Smith Chart Software

3D Smith Chart Software - RF CafeDr. Andrei Muller, progenitor of the world's first 3D Smith Chart software program, has teamed with a handful of able colleagues to release a commercial version of this paradigm-changing design and analysis tool. 3D Smith Chart enables you to visualize S-parameter data in ways not possible from the Flatland dweller's perspective that is the traditional 2D Smith chart. Flatland existed in a plane, and from an observer's perspective a 3-dimensional object entering the plane from along the Z-axis seemed to appear out of nowhere; only its distance and width changed as it passed through. Flatland dwellers rejected the existence or even the possibility of a third dimension, dismissing offhand a rational requirement for one, even punishing the citizen who dared to propose such a concept. After all, two dimensions had served the world just fine. A similar restraint on perspective is imposed upon the classic 2D Smith chart. 3D Smith Chart does for the Smith chart what Einstein's concept of Relativity did for physics by adding the fourth dimension of time. Just as with most new concepts, the true value of the relatively new 3D Smith Chart (debuted in 2013) has not been grasped yet by the engineering world. Heck, getting your head around even the classic Smith chart is daunting enough for the neophyte RF guy (or gal), so a bit of apprehension is understandable. As with the classic Smith chart...

Kynar Pennsalt Vinylidene Fluoride Resin

Kynar Pennsalt Vinylidene Fluoride Resin, April 6, 1964 Electronics Magazine - RF CafeDid you know that at least originally the term "Wire-Wrap" was - and maybe still a - registered trademark of Gardner-Denver Company? Kynar insulation, whose full name is Kynar polyvinylidene fluoride (PVDF) resin, is most likely a familiar type of insulation due to its widespread use on wire-wrap wire. It had very recently been introduced to the electronics world when this advertisement appeared in a 1964 issue of Electronics magazine. The contemporary name used by its manufacturer, Arkema, is Kynar500®, and the coating's use has expanded well beyond the electronics industry into architectural and mechanical coatings. I did a LOT of manual wire-wrapping on Mil-Spec equipment while working as a technician at Westinghouse Oceanic Division in the early and mid 1980s. The massive wire-wrapped board shown in the ad was done by an automated machine. There were times that the guys in my work area (code-named "HK") had to do rework based on an engineering circuit change. Most often it was a nightmare because the manner in which the machines wrapped wires on posts (sometimes three-high) required unwrapping and then re-wrapping dozens of wires because the ones we really needed to access were below a wrap that was at the top of the post. Workmanship standards prohibited (for good reason) unwrapping and then re-wrapping the same wire because the sharp edges of the square posts (which created the gas-tight connections) weakened the wire during straightening...

Withwave Vertical Launch 0.8 mm Connector for DC-145 GHz

Withwave Vertical Launch 0.8 mm Connector for DC to 145 GHz - 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 Vertical Launch 0.8 mm Connectors are specially designed for solderless vertical PCB launch on test & measurement board. These connectors have excellent electrical transition performance from DC to 145 GHz respectively as well as reduce installation time by eliminating soldering. Withwave also has a line of 0.8 mm Connector Adaptors and 0.8 mm Cable Assemblies, all for DC to 145 GHz...

$15 Federal License Fee for Telephone Users?

$15 Federal License Fee for Telephone Users?, December 1958 Telephone News - RF CafeIf you have read as many vintage electronics magazines as I have, one thing that is obvious is how many of the same issues that plagued the field since the middle of the last century are still with us today - only in a much worse way by now. Government meddling, regulation and taxation are amongst the top offenders. Both the electric power industry and the communications industry have been hit hard, and huge costs to consumers is the result. Itemized bills from the utility companies do not give the full picture of what a large percentage of your monthly premiums go to feed the government beast. You might see some line items for taxes, surcharges, contributions and user fees, but those being paid for you by the providers (i.e., absorbed in the base charge) are hidden. One of the more recent, highly publicized example was the "Gore Tax" (Universal Services Fund) that added $1 to everyone's landline bill to provide subsidized Internet (most people had dial-up at the time) and other services to schools, libraries, and "the underprivileged." Once most people had dumped landlines, the FCC started adding fees to cellphone bills to pay for high speed Internet service (E-Rate) to the aforementioned users. As always, those of us who pay our own way without burdening others are forced to provide freebies for a largely undeserving (IMO) host of citizens and non-citizens...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF CafeIt was a lot of work, but I finally finished a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog, antenna, and other commonly used symbols for system block diagrams and schematics created for Visio™. Each of the 1,000+ symbols was exported individually from Visio in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or down without becoming pixelated, so all the shapes can be resized in a document and still look good. The imported symbols can also be UnGrouped into their original constituent parts for editing...

Thursday the 4th

Radio Builds Railroads in the Sky

Radio Builds Railroads in the Sky, March 1948 Popular Science - RF CafeFor about a year before the end of World War II, with the surrender of Germany in May 1945 and Japan in September 1945, companies that had either voluntarily or forcibly converted their efforts and facilities to the design and production of weapons and support equipment, were running advertisements in magazines promising grand new products and services for the civil sector based on knowledge gained from "mother," that is the entity metaphorically credited for spurning invention. In many ways the promise was kept through advances in radio, medicine, automation, materials science, recovering and refining of raw materials, mass production, physics and chemistry, firearms, mathematics, land, water, and air-based transportation, etc. Lots of war surplus hardware was made available at huge discounts as a means of thanking the public for sacrifices made during the war. This "Radio Builds Railroads in the Sky" article from a 1948 issue of Popular Science magazine reports on a system of aerial navigation using a triangulation system, which derives from wartime methods...

3D Printing Millions of Microscale Marvels

3D Printing Millions of Microscale Marvels - RF Cafe"A new process for microscale 3D printing creates particles of nearly any shape for applications in medicine, manufacturing, research, and more - at the pace of up to 1 million particles a day. 3D-printed microscopic particles, so small that to the naked eye they look like dust, have applications in drug and vaccine delivery, microelectronics, microfluidics, and abrasives for intricate manufacturing. However, the need for precise coordination between light delivery, stage movement, and resin properties makes scalable fabrication of such custom microscale particles challenging. Now, researchers at Stanford University have introduced a more efficient processing technique that can print up to 1 million highly detailed and customizable microscale particles a day. 'We can now create much more complex shapes down to the microscopic scale, at speeds that have not been shown for particle fabrication previously, and out of a wide range of materials,' said Jason Kronenfeld, PhD candidate..."

Peacetime Uses for V2 Rocket, by Arthur C. Clarke

Peacetime Uses for V2 Rocket, by Arthur C. Clarke - RF CafeThis article by science fiction writer Arthur C. Clarke, of 2001: A Space Odyssey fame, suggested the use of surplus German V-2 (Vergeltungswaffe 2; i.e., Retribution Weapon 2) rockets for launching scientific payloads into space rather than for launching terrorizing attacks on European cities. The October 1945 publishing date was after Germany had surrendered in the spring of that year and Allied forces were rounding up war criminals and confiscating documents and equipment. Clarke describes how an "artificial satellite" could be caused to circle the earth "perpetually" and was published in the October 1945 edition of Wireless World magazine. The pilot-less V-2, along with the V-1 "Buzz Bomb," were launched from within Germany and caused massive structural damage and human death and suffering. For war progenitor and aggressor, Germany, to call it a retribution weapon was a gross misnomer, especially considering it was the second time (WWI and WWII) in three decades that the country had attempted to bring Europe under its dominance with brutal assaults...

Werbel Directional Coupler for 6 to 18 GHz

Werbel Microwave Directional Coupler for 6 to 18 GHz - RF CafeModel WMC-6-18-30dB-S from Werbel Microwave is a directional coupler that covers 6 to 18 GHz with broadband flat coupling response, high directivity, and excellent return loss performance. The high coupling value and short mainline minimizes lost power during the monitoring. Covers the upper half of C band, X band and Ku band in a single package measuring only 1.00 x 0.6 x 0.5 inches. Our unique design approach to couplers provides a maximally flat coupling response across the passband with minimal ripple, typically ±0.5 dB or less. Directivity 14 dB typical. Return loss 21 dB typical. Insertion loss 0.4 dB typical. Assembled and tested in USA using RoHS compliant materials, although lead solder may be used on special order to support military applications...

Microtubes, aka Peanut Tubes

Microtubes, aka Peanut Tubes, November 1947 Radio-Craft - RF CafeA month before Bell Laboratories' announcement of the transistor invention by Mssrs. Bardeen, Shockley and Brattain, Radio-Craft magazine editor Hugo Gernsback published a piece extolling the virtues of a newly developed microtube, aka a "rice-grain" tube. As connected as Gernsback was in the electronics industry, it is doubtful he knew of the impending game-changing invention. Commercialization of the transistor took a few years to get to the point where the devices could be manufactured cheaply and reliably enough to begin being integrated (pun intended) into products, so vacuum tubes still reigned for another decade or more. While the microtubes were designed into such products as portable radios, hearing aids, and other things in desperate need of size reduction, standard tubes continued to be used in the majority of things. Even the military and aerospace industries elected largely to pass on microtubes and instead wait for semiconductors. Still, there was no guarantee in 1947 that solid state would ever displace vacuum tubes for anything other than specialty products; it was still a very much unknown realm. Gernsback quickly embraced transistors after the announcement was made...

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 3rd

Plastics Industries Technical Institute

Plastics Industries Technical Institute, February 1944 Popular Science - RF CafeVarious forms of plastics began appearing in laboratories in the early 1800s. Polystyrene was invented by Eduard Simon around 1839, polyvinyl chloride (PVC) was created by Eugen Baumann in 1872, Jacques Brandenberger came up with cellophane in 1908, acrylic appeared in 1936, and polyurethane in 1937. Whinfield and Dickson invented polyethylene terephthalate (Pet) in 1941, 1951 saw polypropylene (PP) invented by Paul Hogan and Robert Banks, and Dow Chemical came out with Styrofoam in 1954, and polyimides appeared in 1964. When this full-page advertisement by the Plastics Industries Technical Institute appeared in Popular Science magazine in 1944, plastic had gained a lot of favor in the public realm thanks to its application in fighting against Axis powers in World War II. Rugged, lightweight, highly formable canopies and windshields for aircraft, trucks, and boats were significant advantages over glass. Use for lightweight and durable field equipment and clothing, as well as components in artillery equipment was also extremely helpful in our ultimate victory. "There is a tremendous demand for men and women trained in this exciting new giant industry. The future is so vast that some predictions seem exaggerated - almost fantastic..."

Even More on Resistor Solid Regular Polygons

Not being satisfied with merely providing the solution for the resistor cube, Mr. John Carpenter followed up with an application of the "Equivalent Resistors of Polyhedral Resistive Structures" method. He states: The paper by F. J. van Steenwijk is beautiful. Having a current of I / (H - 1) leaving the remaining terminals is a wonderful insight. Before you post anything, I should tell the other part of the story. This puzzle has been around for over a century. For instance it appeared in Brooks, E.E. and A. W. Poyser, Electricity and Magnetism: A Manual for Advanced Classes, Longmans, Green, 1914. I found this reference [for a Resistor Tesseract]. It was also in the 1912 edition of the same book. I hav[n't] seen any earlier references to it. And yet there seem to be very few efforts to draw the circuit as a planar network which shows the three planar axes of symmetry through the cube. I set out to do this, and considered what the cube would look like if it were drawn on a great circle map with the input node at the centre and the output on the other side of the sphere. That got me to Fig. 2 on the cube page in the attached file. I then straightened some of the lines which got me to Fig 3. The three planes of symmetry in the cube are now very apparent, which makes the points of equal voltage apparent. This makes the parallel resistor solution very straightforward. Fig. 3 also makes it very straightforward to seen the current distribution, and derive a solution by summing voltages. I suggest to you that Fig. 3 makes the problem very much easier, if not trivial...

De Forest the Inventor

De Forest the Inventor, January 1947 Radio-Craft - RF CafeWhen most people are asked to name prolific inventors, people like Thomas Edison and George Westinghouse, with 1084 and 361 each, respectively, come to mind - at least for the United States. As of this writing, Kangguo Cheng of IBM holds the record with 2039 U.S. patents assigned. Nikola Tesla had about 300 patents. Lee de Forest, the subject of this 1937 Radio-Craft article, had a little over 180 patents. That still qualifies as prolific by my estimation. However, there is more to ranking a person's inventive worth than the number of patents awarded - like how profoundly his or her invention(s) impacted the world. For instance, Alexander Graham Bell had a mere 18 patents awarded in only his name, with 12 more shared patents. If you look through Wikipedia's "List of Prolific Inventors," you will see a lot of names with a lot of patents assigned, but most of those names are probably unfamiliar. Notice how many of the old patent art looks like something from a Dr. Seuss kids' book; e.g., Figure 5, "A pneumatic telephone for communication on trains." See the January 1947 Radio-Craft table of contents for more articles on Lee de Forest...

World's 1st N-Channel Diamond MOSFET

World's 1st N-Channel Diamond MOSFET - RF Cafe"A National Institute for Materials Science (NIMS) research team has developed the world's first n-channel diamond MOSFET (metal-oxide-semiconductor field-effect transistor). The developed n-channel diamond MOSFET provides a key step toward CMOS integrated circuits for harsh environment applications, as well as the development of diamond power electronics. The research is published in Advanced Science. Semiconductor diamond has outstanding physical properties such as ultra wide-bandgap energy of 5.5 eV, high carriers mobilities, and high thermal conductivity, which is promising for the applications under extreme environmental conditions with high performance and high reliability, such as the environments with high temperatures and high levels of radiation (e.g., in proximity to nuclear reactor cores). By using diamond electronics, not only can the thermal management demand for conventional semiconductors be alleviated but these devices are also more energy efficient and can endure much higher breakdown voltages and harsh environments..."

Stack TV Antennas to Increase Signal Strength and to Reduce Ghosts

How to Stack TV Antennas to Increase Signal Strength and to Reduce Ghosts, November 1965 Popular Electronics - RF CafeYou probably won't find too many people stacking television antennas these days, but many Hams still do it. Vertical stacking is used primarily to increase overall gain without appreciably altering the azimuth beam, while horizontal stacking forms a tighter azimuth beam without appreciably affecting the overall gain. When it comes to optimizing antenna designs installations for operations below about a gigahertz, Amateur Radio practitioners have pretty much written the book on the subject - actually, they have written hundreds of books on the subject. Antenna stacking is often used in areas where space and/or neighborhood covenants restrict the size and placement of external structures, but as pointed out in this article, it also may be the only solution for getting consistent performance in the presence of widely varying signal path conditions. Note that the TV channel / frequency table does not include the UHF band. That is likely because UHF at the time (1965) was not where the major broadcast stations transmitted, so not as many people would have been concerned with them. It wasn't until the mid to late 1950's in the U.S. that UHF started becoming widely used...

RF & Electronics Symbols for Visio

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

Tuesday the 2nd

R-E Puzzler

R-E Puzzler, April 1967 Radio-Electronics - RF CafeHere is another "R-E Puzzler," by Mr. Edmund Braun, this one in the April 1967 issue of Radio-Electronics magazine. Unlike traditional crossword puzzles, this one has no linking Down words, only Across words. Maybe he should have dubbed it an "acrossword puzzle." The format does make figuring out some of the words more difficult than the other way, but at least one letter - never more than two - is provided for each word. I managed to get all except number 7, "Phenolic compound having good electrical resistance." After looking at the answer, I feel like an idiot - definitely should have gotten it after mentioning it in my write-ups so often. Hopefully, you will do better. If you like this R-E Puzzler, there are others...

Axiom Blog: Analyze AC/DC Power for the Highest Quality

Axiom Test Equipment Blog: Analyze AC/DC Power for the Highest Quality - RF CafeAxiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post that covers Power Analyzers vs. Power Quality Analyzers, and how to select the correct one for your application. Power and its quality from various supplies, such as charging stations, must be established, and maintained through appropriate measurement cycles, and power analyzers and power quality analyzers are among the best equipment for regularly checking on power supplies and how well they are performing. The basic difference between the types of units is that power analyzers measure power while power quality analyzers measure the quality of power over time. Finding an AC/DC electric power measurement solution can take time, due to the large assortment of performance parameters associated with power and power quality. Fortunately, by understanding the needs of an application for electric power, selection of the optimum measurement tools for power analysis can be simplified and how well a power supply meets the requirements of a particular electric load can be determined. Power analysis involves measurements of key electrical parameters...

Edison Gets Buff with Rugged Incandescents

Edison Gets Buff with Rugged Incandescents - RF Cafe Cool ProductThomas Edison would be proud at the inventiveness of entrepreneur Larry Birnbaum. So am I. By now we all know about the ludicrous worldwide ban on the sale of incandescent light bulbs over a certain wattage. Here in the U.S., the ban was slated to begin in January of 2012 with prohibition against 100 watt bulbs, and over a couple years would eventually ban the sale of anything larger than 40 watts. Instead, we are to buy mercury-filled, electronic waste-filled CFL bulbs or >$60 apiece LED bulbs. Within that 40-to-100 W range, several classes of specialty lights are exempt from the regulation including appliance lamps, rough service bulbs, 3-way bulbs, colored lamps, stage lighting, and plant lights. The rough-service class is where Mr. Birnbaum and his Newcandescent™ company (now defunct) comes in. Unlike the standard incandescent bulb that is typically rated for a 750-to-1,000-hour lifetime, Newcandescent bulbs are rated for a 10,000 hour lifetime (10x-to-13x as long). They are advertised at 7 years. Anyone who has used CFL bulbs has probably already experienced a failure - long before their expected longevity of 5-7 years. Standard frosted incandescent bulbs from Newcandescent cost $2.88 each...

Quantum Films for High-Speed Terahertz Electronics

Quantum Films for High-Speed Terahertz Electronics - RF Cafe"A research team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the University of Salerno in Italy has discovered that thin films of elemental bismuth exhibit the so-called non-linear Hall effect, which could be applied in technologies for the controlled use of terahertz high-frequency signals on electronic chips. Bismuth combines several advantageous properties not found in other systems to date, as the team reports in Nature Electronics. Particularly: the quantum effect is observed at room temperature. The thin-layer films can be applied even on plastic substrates and could therefore be suitable for modern high-frequency technology applications. 'When we apply a current to certain materials, they can generate a voltage perpendicular to it. We physicists call this phenomenon the Hall effect, which is actually a unifying term for effects with the same impact, but which differ in the underlying mechanisms at the electron level. Typically, the Hall voltage registered is linearly dependent on the applied current,' says Dr. Denys Makarov..."

Where Do the Scientists Belong?

Where Do the Scientists Belong?, February 19, 1949, The Saturday Evening Post - RF CafeHere is a good quiz that tests your knowledge of classifications of science fields. It appeared in a 1949 edition of The Saturday Evening Post magazine. Even if you do not particularly know the relationships, you should be able to get most if not all twelve correct with a combination of surety, recognition of word roots, and a process of elimination. I managed to guess 10 out of the 12. Good luck. BTW, I bestowed the clown colors on the distinguished professors' duds...

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, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Monday the 1st

30-Day LP Record

30-Day LP Record, April 1961 Radio-Electronics - RF CafeI don't know where the name Mohammed Ulysses Fips came from, but it is the pseudonym chosen by editor Hugo Gernsback. The first and middle names are easy enough to ascertain an origin. According to the iGENEA website: "The last name Fips is most commonly found in the Netherlands, as well as in other parts of Europe. The surname originated in the Netherlands, likely from personal names or nicknames related to the word 'vips' ('expensive' or 'luxurious'). The earliest recorded Fips dates back to 1490 in the Netherlands." Hugo Gernsback was born in 1884 in Luxembourg City (Luxembourg), separated only by Belguim from the Netherlands, so maybe that is where he came up with it. For some reason, the articles written by Mohammed Ulysses Fips, purportedly a member of the Islamic Radio Engineers (I.R.E), always appeared in April issues of Radio-Craft and Radio-Electronics magazine. Here is his "30-Day LP Record" entry...

Elemental Carbon and Sodium Sue to Redeem Their Reputations

Elemental Carbon and Sodium Sue to Redeem Their Reputations - RF CafeFrom Bill Schweber at the Microwaves & RF website: "Two essential elements resent being maligned for the implications of their higher-level molecules. Representatives of the recently formed Society for Elemental Justice (SEJ) announced that they're suing major media and related institutions for misuse of the basic terms 'carbon' and 'sodium' in place of the full molecule designations 'carbon dioxide' (CO2) and 'sodium chloride' (NaCl). Speaking on behalf of these vital elements, SEJ says these elements are constantly being libeled and slandered when they're cited as sources of climate or health issues. The spokesperson noted that 'carbon' (atomic number 6, symbol C) is a vital building block for life as well as many industrial processes and products, whether it's seen as graphite, diamonds, or many other allotropic forms. Further, carbon is harmless in its elemental state. Sodium (atomic number 11, symbol Na) is also being maligned...

Orbital Express Refuels Satellites

U.S. Space Force Orbital Express Refuels Satellites - RF Cafe"In April 2007, the Defense Advanced Research Projects Agency demonstrated the ability to refuel a satellite in orbit - equipping a spacecraft with a robotic arm, docking it to another spacecraft and transferring nearly 32 pounds of hydrazine into its fuel tank. The mission, known as Orbital Express, was full of technology firsts, according to Fred Kennedy, who led the project for DARPA. Along with demonstrating the first-ever in-space refueling operation, the U.S. mission showcased the ability to use tracking and imaging sensors to attach to a receiving satellite and perform maintenance, such as swapping out a battery or replacing a flight computer. 'The big deal was autonomy,' Kennedy told C4ISRNET in a Feb. 27 interview. 'We were able to show sort of a push-button approach to getting up close and personal to a spacecraft and delivering a variety of servicing capabilities.' But four months after it took flight, the Air Force and NASA - DARPA's mission partners for the effort - pulled the plug on the program. The project, conceived to support a space-based radar program that was canceled before Orbital Express even got off the ground, lacked a clear mission application, according to the Air Force and NASA. Orbital Express undergoes testing in space. (U.S. Defense Advanced Research Projects Agency) The outcome wasn't particularly surprising for DARPA, whose projects often explore technologies that are ahead of their time..."

Hog-Wash from Our Readers

Hog-Wash from Our Readers, April 1933 QST - RF CafeThe editors of the American Radio Relay League's (ARRL's) QST magazine went all out for April Fool's Day in 1933. Maybe it was a way to help ease the pain of the country's ongoing Great Depression. Amongst the proof of my statement are items like "The American Radiator Delay League," "Quiescent Autonomous Magnification Superintendence," "At Last - Some Different Toobs!," and "I Will Not Bite His Ear, or the Rover Radio Boys on the Moon."There are others that I haven't gotten around to publishing yet. Humor was a bit different nearly a century ago, so expect some head scratching to figure out what the con is. This "Hog-Wash from Our Readers" column is a variation of the regular reader-submitted comments. Pay careful attention to the spellings of words - a common mechanism used back in the day...

Anatech Intros 3 New Filter Models for April

Anatech Electronics Intros 3 New Filter Models for April 2024 - RF CafeAnatech Electronics offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Three new filters have been announced for April 2024 - a 2000 MHz cavity bandpass filter with a 1 dB bandwidth, a 5250 MHz cavity bandpass filter with a 33 MHz 3 dB bandwidth, and a 5000 MHz cavity bandpass filter with a 200 MHz bandwidth. Custom RF power filter and directional couplers designs can be designed and produced with required connector types when a standard cannot be found, or the requirements are such that a custom approach is necessary...

How to Use Your Radio

How to Use Your Radio, April 1934 Tower Radio Magazine - RF CafeThis 1934 edition of Tower Radio magazine was thrown in with a batch of vintage radio magazines I bought on eBay. Most of the content pertains to entertainers of the day rather than with technical issues. Reportedly, it was only sold at Woolworth's stores. Ironically, the number of households with over-the-air (OTA) radio listeners today, at least as a percentage of the population if not in absolute numbers, is probably about the same as in 1934 when commercial radio broadcasting was just getting a foothold. These days, many - if not most - people listen to radio and podcasts via cellphone and/or Internet streaming media than from over-the-air broadcasts, even while in their cars. Organizations like the National Association of Broadcasters (NAB) are trying to change that, but it's an uphill battle. I tune in to OTA when possible, but with my radio sitting close to the computer with all the EMI it spews, it is nearly to impossible to get a clean AM signal...

RF Cascade Workbook 2081.6 Update!

RF Cascade Workbook - RF Cafe

Whilst working on a new version of RF Cascade Workbook (which is a ways off), I found two rows of redundant calculations in the Filter & LO area. If you own any previous version of RFCW2018, I will be glad to send you a the new file if you send me an e-mail.

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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