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Tech Industry Headlines - RF Cafe - Archive -

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Great Deal on Coaxial
and Twisted Pair Cable

Coaxial and Twisted Pair Cable for Sale - RF Cafe

Spools of various types of communications cables - RG-59 coax and a few kinds of twisted pair cables. Some reels / boxes are full or nearly full, and I guestimate at least 100 feet on others. Photos are shown below. Since I do not have the time or the will to unspool, measure the length of, and re-spool any of it...

Industry News Briefs

Industry News Briefs, April 1968 Radio-Electronics - RF Cafe"A battle is developing over spectrum space." That is the opening line in the News Briefs feature of Radio-Electronics magazine in 1968. Spectrum crowding then is peanuts compared today's airwaves. The Federal Communications Commission (FCC) began auctioning off spectrum in 1994 ("Auction 1"), selling space in the Narrowband Personal Communication Service (PCS) band. Since then, billions of dollars have been sucked out of the commercial sector (ultimately paid by private users). Governments have an insatiable appetite for Other People's Money (OPM, pronounced "opium"), and rule with the heavy-handed power authority of all federal enforcement agencies - including the military. The sunspot maximum for Solar Cycle 20 occurred around May 1969, with a monthly occurrence of 169. The NOAA chart shows Solar Cycle 20 is one of the longest on record but far from one of the most intense. The previous cycle peaked at 359 sunspots. We are currently on the upward side of Solar Cycle 25, with a peak thus far of 112 sunspots. It looks a lot like Cycle 24...

New Letter Contest for Servicemen

New Letter Contest for Servicemen, August 1944, Radio-Craft - RF CafeHallicrafters gave servicemen an opportunity to earn some cash by writing about their font line experiences using radio equipment built by Hallicrafters. The $100 top prize in 1944 is the equivalent of $1,705 in 2023 money (per the BLS Inflation Calculator) - not chump change in any year. Hallicrafters was a premier manufacturer of radios for commercial, hobby, and military use before World War II broke out. Once the United States was drawn in by the Imperial Japanese Navy's December 7, 1941 surprise attack on Pearl Harbor, no time was wasted converting the majority of production for electronics, transportation, and other realms into almost exclusively war production. Hallicrafters was, of course, onboard. Life took a sudden turn for many Americans as fathers, husbands, cousins, uncles, and brothers went off to fight battles in foreign lands. Communications to and from loved ones back home were difficult as priority was assigned to military channels, but that didn't discourage thousands of servicemen from writing letters during moments of discouragement or following victories. Many were penned from inside fox holes and bunkers...

FCC Updates National Broadband Map

FCC Updates National Broadband Map - RF CafeNote "equity" vs. "equality" - a significant difference meaning a legally mandated result vs. an unbiased opportunity to achieve a result. Marxism vs. capitalism. The Federal Communications Commission has released an updated version of its National Broadband Map, one that FCC Chairwoman Jessica Rosenworcel said reflected a 'big' step in a new, iterative process that is meant to provide a more accurate and up-to-date picture of broadband access across the United States. This version of the map, as well as continued challenge-based refinements, will be used as the basis for state allocations from the massive Broadband Equity, Access, and Deployment (BEAD) funding program aimed at closing the digital divide, according to the National Telecommunications and Information Administration. The executive-branch agency added that it 'is confident that with this data as a baseline, we will be able to effectively allocate [BEAD] funds by the end of June. We will continue to monitor the FCC's updates to availability data to ensure that we make a well-informed allocation of these vital funds.' The FCC released what it called its 'pre-production' maps..."

Leeds "The Home of Radio" - NYC Radio Row

Leeds "The Home of RADIO" Advertisement, December 1931 QST - RF CafeLeeds, which dubbed itself "The Home of Radio," has been in New York since at least 1923. This advertisement appeared in the December 1931 edition of QST magazine. Leeds is still in operation today in Brooklyn under the name of Leeds Radio. They were one of the original "Radio Row" companies. Looking at the ad is a step back ninety years into the past, but the nostalgic waxing does not have to end there. If you want a trip back to the beginning days of the World Wide Web, go to the current Leeds Radio website. It's format-less text presentation with basic hyperlinks is circa 1992 when bulletin boards ruled the day and the Mosaic browser was just giving web surfers their first taste of a GUI. The only images I found on the Leeds website were a few scans of old advertisements...

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 or so 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. Check them out!

Many Thanks to Reactel for Their Long-Time Support!

Reactel Filters - RF Cafe

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

Loral Distributor Products Hernia Relief

Loral Distributor Products, April 1968 Radio-Electronics - RF Cafe"Getting a hernia and not getting paid for it?" That's the lead question in this Loral Distributor Products ad in a 1968 issue of Radio−Electronics magazine. My response is to ask the obvious question: Are there actually people who do get paid for getting a hernia? Hernia repair† surgeons probably saw a lot of business from TV repair guys who did in-home service and had to lug sets from the truck to and from the house and shop. Even with using a hand truck the large console type TVs were a bear to move around. If you have seen some of the electronics themed comics from magazines of the era (I've posted hundreds of them), the often stressful life of mobile repair guys is a common topic. Loral doesn't offer a solution to boat-anchor-heavy TV sets, but they do claim using their capacitors will reduce the number of repeat service calls needed...

IPP's Online Interactive S-Parameter Viewer

IPP Announces Unique Online Interactive S-Parameter Viewer - RF CafeInnovative Power Products (IPP), with more than 30 years of experience designing & manufacturing RF & microwave passive components, is proud to announce its unique online Interactive S−Parameter Viewer! This one-of-a-kind online viewer allows you to scroll, zoom, point and select a sub-band. The viewer, still in beta, adds the flexibility of showing out-of-band data as well as the value at each data point just by hovering the cursor over the data point. Use the checkboxes to view individual S−Parameters, or choose to view by groups: All Transmission, All Reflection, All Isolation or All Parameters. You can view data in Log−Magnitude view, as a Smith Chart, or as Unwrapped Phase...

Atomic Radiation: Types & Relationships

Atomic Radiation: Types & Relationships, May 1969 Electronics World - RF CafeNuclear energy was a big topic in the 1960s and 1970s as it was believed to be the future of electrical power generation for the world (at least up until the 3 Mile Island, Chernobyl, and Fukushima incidents occurred). Ships and submarines were being powered by reactors that allowed them to run for months at a time without refueling, atmospheric emissions were practically zero, and the fuel source was abundant (albeit not simple to obtain). Medical and space applications were increasingly dependent on a greater knowledge of radiation and its effects on humans, plants, animals, and electronics. Many people by that time were working with and around radiation sources, so having knowledge of which is and is not safe was paramount to responsible activities. Proper operation of many types of equipment depend on adequate shielding from the effects of radiation. Probably the two major discriminators...

Gravitational Lensing Yields New Value for Hubble Constant

Gravitational Lensing of Supernova Yields New Value for Hubble Constant - RF CafeWho says that supergenius astrophysicists don't have a sense of humor? Certainly not me, and here's proof. A news story entitled "Gravitational Lensing of Supernova Yields New Value for Hubble Constant," tells an amazing account of how a group of researchers exploited the phenomenon of gravitational lensing (a relatively new discovery) by a recently discovered supernova to calculate a more accurate value for the Hubble constant (H0). Here's the hilarious part: One of the three primary research groups in the quest for ever-improved Hubble constant values calls itself H0LiCOW (H0 Lenses in COSMOGRAIL's Wellspring). "A study of how light from a distant supernova was gravitationally lensed as it travelled to Earth has been used to calculate a new value for the Hubble constant - an important parameter that describes the expansion of the universe ... The lumpy distribution of mass in the cluster created a complex gravitational field that sent the supernova's light along several different paths towards Earth. When the supernova was first observed in 2014, it appeared as four points of light. As the four points faded, a fifth appeared 376 days later. This light was delayed by the longer path it had taken through the cluster. During those 376 days the universe had expanded, which means that the wavelength of the late arriving light was redshifted..." Holy cow, another nonconstant constant!

Editorial - The Origin of "Ham"

Editorial - The Origin of "Ham", December 1931 QST - RF CafeHere it is the year 2023, a full 92 years after this editorial was published in ARRL's QST magazine, and nobody is any more certain of the origin of the term "Ham" being applied to amateur radio operators than they were in 1931. Being closer to the date of origin, though, might have given editor Kenneth Warner a bit more insight. In fact, the term Ham is usually uttered in a mildly pejorative manner; e.g., "he is such a ham." Per the QST's editor's research, Ham might be a shortening of Hamlet, referring to Shakespeare's play and the 2-bit actors who endlessly recited the lines in an attempt to impress others. Analogously, a Ham radio operator would be a professional broadcaster wannabe. However, Mr. Warner offers an even more plausible explanation that has the term descending more directly from the craft of amateur radio operation. Read on to find out...

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 or so 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. Check them out!

Please Thank Werbel Microwave for Continued Support!

Werbel MicrowaveWerbel Microwave is a manufacturer of RF directional and bidirectional couplers (6 dB to 30 dB) and RF power dividers / combiners (2− to 16−way) with select models operating up to 26.5 GHz and 100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are designed and manufactured in our Whippany, NJ, location. Custom products and private label service available. Please take a couple minutes to visit their website and see how Werbel Microwave can help you today.

Electronics-Themed Comics

Electronics-Themed Comics (p69), April 1961 Radio-Electronics - RF CafeHere be a new trio of tech-themed comics, this time from the April 1961 issue of Radio-Electronics magazine. The one on page 69 is my favorite. In the page 85 comic, there is a squarish "U" shaped line between the one guy's finger and the other guy's elbow, and I can't figure out what it is supposed to be. What am I missing? The page 96 comic is kinda dumb. Did people refer to that form of antenna as an "antler" back in the day? A firm called MCM Manufacturing Company, in Fort Worth, Texas, made a line of mobile antennas and support products (mounts, cables, etc.) called Antler CB Antennas, but from what I can find they didn't come into being until the 1970s. The advertisement shown here appeared in a 1977 issue of Popular Electronics magazine. Maybe I missed something...

Cold Cathode Tube Demonstrated

Cold Cathode Tube Demonstrated!, January 1935 Short Wave Craft - RF CafeCold cathode tubes are distinguished from hot cathode tubes in that they do not use a separate heated element in order to generate free electrons (thermionic heating). Rather, a "starter" type process is used to initiate the electron generation and then a cascade multiplication keeps the process running. Although this 1935 Short Wave Craft magazine article reports on a cold cathode oscillator vacuum tube - designed by none other than television pioneer Philo Farnsworth - some more familiar examples are neon and fluorescent bulbs and even the veritable Nixie tube...

Forksheet: Imec's In-Between Transistor

Forksheet: Imec's In-Between Transistor - RF Cafe"The architecture shrinks circuits in a valuable step toward the ultimate CMOS device. The most advanced manufacturers of computer processors are in the middle of the first big change in device architecture in a decade - the shift from finFETs to nanosheets. Another 10 years should bring about another fundamental change, where nanosheet devices are stacked atop each other to form complementary FETs (CFETs), capable of cutting the size of some circuits in half. But the latter move is likely to be a heavy lift, say experts. An in-between transistor called the forksheet might keep circuits shrinking without quite as much work. The idea for the forksheet came from exploring the limits of the nanosheet architecture, says Julien Ryckaert, the vice president for logic technologies at Imec. The nanosheet's main feature is its horizontal stacks of silicon ribbons surrounded by its current-controlling gate. Although nanosheets only recently entered production..."

Find the Brightest Bulb Quiz

Find the Brightest Bulb Quiz, April 1960 Popular ElectronicsHere is a nifty little exercise that appeared in the April 1960 edition of Popular Electronics magazine. The "Find the Brightest Bulb Quiz" has ten different light bulb circuits and challenges you to figure out which bulb would burn the brightest. All are intuitively obvious to most of us who have been in the field for decades, but do you remember how to do a circuit mesh analysis to prove your "gut?" One way to help figure out what is going on is to re-draw the circuit to eliminate crossing lines, if possible, as in circuit numbers 2, 4, 6, and 10. Also try drawing electrically common nodes as a single connection point, as in circuit #2 where the two nodes in the upper left and right corners are actually the same point. Finally, try to re-arrange the circuit branches into obvious parallel and series paths to make clear any interdependencies and independencies...

RF & Electronics Stencils for Visio

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

Thanks Again to Aegis Power Systems for Continued Support!

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

Antenna Rotators

Antenna Rotators, April 1968 Radio-Electronics - RF CafeThe purpose of directional antennas is not just to increase gain along a particular radial in order to enhance weak signals, but also to reduce gain in all other directions so as to minimize interference. Interference can be both signals from unrelated emitters and from multipath signals that originated from the same emitter. Hence, a directional antenna can be advantageous in an environment where a relatively strong signal from the intended emitter is surrounded by other strong signals. Even if the interfering signals are not on the same frequency, the effect of raising the overall noise floor and/or generating intermodulation products can degrade the intended signal significantly enough to bugger audio and/or video. The solution is to mount the receiving antenna on a rotator so that it can be pointed in a direction which results in the best signal. Here is my Alliance U-100 Tenna−Rotor write−up with photos...

Electron Mobility Faster in GeSn Than Si or Ge

Electron Mobility Faster in GeSn Than in Si or Ge - RF Cafe"Electrons and other charge carriers can move faster in germanium tin than in silicon or germanium, enabling lower operation voltages and smaller footprints in vertical than in planar devices, say CEA-Leti researchers. This proof-of-concept breakthrough means vertical transistors made of germanium tin are promising candidates for future low-power, high-performance chips and possibly quantum computers. GeSn is otherwise compatible with the existing CMOS process for chip fabrication. Because germanium and tin come from the same periodic table group as silicon, these transistors could be integrated directly into conventional silicon chips with existing production lines. 'In addition to their unprecedented electro-optical properties, a major advantage of GeSn binaries is also that they can be grown..."

Ionospheric-Propagation Predictions

Ionospheric-Propagation Predictions, April 1969 Electronics World - RF CafeMuch has been learned and published about the various layers of the ionosphere since its first being measured with sounding rockets in the 1950s. Both professional and amateur communications operators are very interested in its properties. Long term (seasonal) and short term (daily) patterns have been discerned that help make some of the ionosphere's effect on the propagation of electromagnetic (radio) signals somewhat predictable, but there are still many unpredictable events that hamper - and often enhance - communications. Sun spots and coronal mass ejections, volcanic eruptions, hurricanes, and other natural events cause sporadic changes in the ionosphere. Real-time atmospheric propagation conditions are monitored and reported on many websites worldwide...

Antenova Pharaoh: Big Step in 4G/LTE Antennas

Antenova Pharaoh: A Big Step Forward in 4G/LTE Antennas - RF CafeAntenova Ltd, the UK-based manufacturer of antennas and RF antenna modules for M2M and the IoT, is delighted to introduce you to Pharaoh (SR4L073): the perfect antenna for your next 4G or 5G project. Pharaoh is a switch-free, surface-mount (SMD) antenna which is designed to unlock the full potential of LTE performance on limited ground planes. Pharaoh represents a significant breakthrough in 4G/LTE antenna technology that promises to hugely improve what is possible for devices with limited PCB real estate. This is why: Maximising Performance Rather than being a tiny antenna requiring a large ground plane, Pharaoh enables you to shrink the overall footprint on your design while enabling strong performance across every 4G/LTE band including the very lowest. Gaining Certification Faster Achieving certification for the smallest 4G/LTE devices can be an expensive and time-consuming process. Pharaoh has been proven by an independent PTCR...

Derivation of Phase Angle Error Due to VSWR Mismatch

Derivation of Phase Angle Error Due to VSWR Mismatch - RF CafeTry finding the equation for phase angle error due to VSWR mismatch, and you will likely fail. Extensive keyword searches for related terms will turn up websites that present the formula for amplitude error due to VSWR mismatch, but not for phase angle error due to VSWR mismatch. If you are fortunate enough to find the equation, you almost certainly will not be given the derivation. The actual equation, εθmax = |Γ1 | • |Γ2|, is so simple that it seems unbelievable, but here its validity is demonstrated. Well, the search is over thanks to Haris Tabakovic, who was kind enough to provide this excellent derivation for the benefit of RF Cafe visitors...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeNew Scheme rotates all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000 website visits each weekday. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 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. 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 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.

Power Dissipation in Resistors or Transistors

Power Dissipation in Resistors or Transistors, August 1963 Radio-Electronics - RF CafeCharts and nomographs are not nearly as useful or necessary today for the design and troubleshooting of electronics due to the ready availability of calculators in the form of computers, tablets, and smartphones. Determining parallel and series resistance, capacitance, and inductance, reactance, power dissipation, resonant frequency, voltage dividers, etc., can easily be done with the push of a few buttons (or virtual touch-sensitive screen buttons). Not only is it not necessary to know the equations behind the calculations, but you don't even need the know how to enter mathematical operations into a calculator. A lot of old-schoolers say the availability of newfangled electronic gizmos contributes to the dumbing down of technicians and engineers. If you can't use a slide rule, then you don't truly understand the science. I wonder if their attitudes were the same when special-purpose cardboard slide calculators and even design charts like this one and nomographs were published?

Ceramic Filters

Ceramic Filters, April 1969 Electronics World - RF CafeThe introduction of low cost, small-footprint ceramic filters were unquestionably a boon to efforts at reduction in end-product package size and manufacturing cost. Very good Q and selectivity, no tuning required, and good temperature stability made them perfect for use as IF filters in broadcast radio receivers, at 10.7 MHz (FM) and 455 kHz (AM). They became available for commercial use around 1960. This publically available paper published in 2000 from the IEEE provides some historical perspective to ceramic filters: The History of Ceramic Filters, by Satoru Fujishima. The Clevite Corporation, for which this Electronics World author, Reg Zimmerman worked, is mentioned in the IEEE paper, as is Murata, for being pioneers in the ceramic filter field...

Nanostructure Flat Lens for Tiny Cameras

Nanostructure Flat Lens for Tiny Cameras - RF Cafe"Inside today's computers, phones, and other mobile devices, more and more sensors, processors, and other electronics are fighting for space. Taking up a big part of this valuable real estate are the cameras - just about every gadget needs a camera, or two, three, or more. And the most space-consuming part of the camera is the lens. The lenses in our mobile devices typically collect and direct incoming light by refraction, using a curve in a transparent material, usually plastic, to bend the rays. So these lenses can't shrink much more than they already have: To make a camera small, the lens must have a short focal length; but the shorter the focal length, the greater the curvature and therefore the thickness at the center. These highly curved lenses also suffer from all sorts of aberrations, so camera-module manufacturers use multiple lenses to compensate, adding to the camera's bulk. With today's lenses, the size of the camera and image quality are pulling in different directions. The only way to make lenses smaller and better is to replace refractive lenses with a different technology..."

Practical Applications of Simple Math

Practical Applications of Simple Math - Part II, June 1944 QST - RF CafeRecognizing that many people were reluctant to approach the theoretical aspect of electronics as it applied to circuit design and analysis, QST (the American Radio Relay League's monthly publication) included equations and explanations in many of their project building articles. Occasionally, an article would be published that dealt specifically with how to use simple mathematics. In this case, the June 1944 edition, we have the second installation of at least a four-part tutorial that covers resistance and reactance, amplifier biasing (tubes since the Shockley-Bardeen-Brattain trio hadn't invented the transistor yet) oscillators, feedback circuits, etc. I do not have Part I from the May 1944 edition or Part IV from the August 1944 edition, but if you want to send me those editions, I'll be glad to scan and post them...

Electronics Theme Crossword Puzzle for June 4

Electronics Theme Crossword Puzzle for June 4, 2023 - RF CafeThis week's crossword puzzle for June 4th sports an electronics theme. This being the fourth day of the month, many of the words begin and/or end with the letter "D." Besides that, we're only two days away from "D-Day." All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny, Hedy Lamarr, or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Fuses Are Not for Confusion

Fuses Are Not for Confusion, October 1960 Electronics World - RF CafeBack in the early 1990s I had my first need as a product design engineer to select a fuse type; it was for protecting a downconverter chassis. Having already worked in the electronics and electrical equipment installation and maintenance field for twenty years, I have had to replace many fuses of many different types in many types of assemblies ranging from AC motor controls to microprocessor boards. Slo−Blo, Fast−Blo, Standard−Blo, high voltage and low voltage, high current and low current, glass bodied, plastic bodied, and even metal explosion-proof bodied fuses were in the realm my experience. However, some other engineer had already decided what the appropriate fuse was for the application. I assume each instance had been determined from a selection process based on knowledge of both the device to be protected and the characteristics of the fuses. Not just any fuse will do the job. Sometimes you get lucky and the one used will work so long as the current and voltage ratings are within the normal operational range of the product being protected, but if that was generally the case, there wouldn't be such a large variety of fuse types, n'est−ce pas? This "Fuses Are Not for Confusion" article from a 1960 issue of Popular Electronics magazine is a great primer on the art of fuse selection...

Alternative Energy: Savior to an Alternate Universe

Alternative Energy: Savior to an Alternate Universe - RF Cafe SmorgasbordA few years ago, my local newspaper, Erie Times-News, printed this letter that I submitted: "As an electrical engineer, I have always embraced the technology behind wind, hydro, solar and other forms of 'alternative' energy production. It is undoubtedly cool. What I despise is an agenda by special interest groups to mislead the public regarding the maturity and efficiency of those systems in an effort to destroy the nuclear and fossil fuel industries that drive our economy. The recent failure of the 5-year-old wind turbine at Tom Ridge Environmental Center is a good example. Numbers were not provided for that turbine, but were for the one on Barracks Beach, also offline (Erie Times-News, March 31). The turbine and tower cost about $36,000 in 2004 dollars, when installed. The stated best-case energy generation for it is 15,000 kwh/ year. Electricity rates around here are about 13 cents/kwh...

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Copyright: 1996 - 2024

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    Kirt Blattenberger,

    BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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