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Circulators & Isolators Quiz

Quiz #76: Circulators & Isolators Quiz - RF CafeWelcome to the RFCafe Isolators & Circulators Quiz, a technical overview focused on non-reciprocal microwave components. These specialized devices are the primary tools used to protect sensitive signal sources from reflected power and to route signal flow in multi-stage RF systems. Whether you are isolating a high-power transmitter from a high-VSWR antenna, developing duplexers, or optimizing the signal isolation between cascaded amplifiers in a precision measurement setup, a solid grasp of circulator and isolator physics is essential. This assessment addresses the fundamental properties of ferrite-based non-reciprocal hardware, including insertion loss, port-to-port isolation, power...

What Does Your Daily Commute Cost You?

What Does Your Daily Commute Cost You? - RF Cafe SmorgasbordHow far do you commute each day for the privilege of doing your part to push back the frontiers of technical ignorance and to boldly go where no engineer - or technician - has gone before. Do you know what the cost equates for you each year? This handy-dandy infographic lays out some gruesome numbers. Those with a weak stomach probably should pass on viewing this one. Here's a hint at what you will see: See that big $795 in the thumbnail image? That's the average cost per year for commuting -- per mile! Yessiree, if you live just 10 miles from work, you're losing nearly $8,000 per year, depending on you automobile type, on gas, tires, maintenance, devaluation, and loss of your personal time (which is valuable, after all). Back in the early 1990s I drove about 45 miles each way...

Measuring Semiconductor Device Input Parameters with Vector Analysis

Measuring Semiconductor Device Input Parameters with Vector Analysis - RF Cafe WebsiteJoe Cahak, owner of Sunshine Design Engineering Services in Ramona, California, has written a white paper entitled, "Measuring Semiconductor Device Input Parameters with Vector Analysis." This article covers a recent test experience that utilized some thinking about the test fixture, the bias requirements and the device mounting and special calibration offsets needed to de-embed the test fixture response from the device response within the test fixture. The device also had to have bias on several ports simultaneously. We had to establish a "reference plane" within the fixture, from which we can use the Vector Network Analyzer's Port Extension or Phase Offset to dial out the distance from our 1 port calibration reference plane to the point of short reference within the fixture. With this phase offset compensation we can then measure...

Low-Pressure Modulation Facts

Low-Pressure Modulation Facts, July 1953 QST - RF Cafe WebsiteAuthor Howard Wright takes the opportunity here to distill the concept of modulation down to its basic operation while dispensing with the garbled mix of "graphs, formulas, charts, vectors, diagrams, and Greek letters which often enter into various discussions of modulation". Wright describes how to the uninitiated radio dial spinner, the culmination of events occurring behind the scenes in an AM reception is akin to knowing "that, to be reproduced, the picture [in a magazine] was broken down into its primary colors, if all we had to go by was the original print and the magazine?" That is a very apt comparison...

Many Thanks for Alliance Test Equipment's Support!

Allied Test Equipment Products - RF Cafe WebsiteAlliance Test Equipment sells used / refurbished test equipment and offers short- and long-term rentals. They also offer repair, maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP, Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization with ability to source hard to find equipment through our network of suppliers. Alliance Test will purchase your excess test equipment in large or small lots. Blog posts offer advice on application and use of a wide range of test equipment. Please visit Allied Test Equipment today to see how they can help your project.

Mac's Radio Service Shop: A Little Lightning

Mac's Radio Service Shop: A Little Lightning, July 1948 Radio News - RF Cafe WebsiteBenjamin Franklin is famous for his kite-flying experiment whereby he "discovered" not electricity (as many people believe), but that lightning is a form of electricity (most people thought it was a jet of gas). A lesser known fact about Mr. Franklin is that he invented the lightning rod after realizing the electrical nature of lightning. His understanding of electric fields facilitated an implementation whereby hefty iron cabling interconnected a tall, pointed rod installed at the tallest point on a building and a spike driven into the ground. Lightning typically strikes the object that is the shortest distance (in terms of electrical field strength) from it because the discharge can begin at the lowest voltage. The presence of the grounded lightning rod above the highest point on a structure effectively brings that point all the way down to ground level...

Radio Terms Illustrated

Radio Terms Illustrated, August 1947 Radio-Craft - RF Cafe WebsiteThese "Radio Term Illustrated" comics from vintage Radio-Craft magazines are some of my favorite tech-themed comics. Most were drawn by Frank Beaven in response to suggestions / requests by magazine readers. The one here from page 80 entitled "Crystal Gazing" was done by Franklin Folger. If you didn't know that it appeared in a 1947 edition, you might assume it depicts a Steam Punk themed LCD computer monitor mounted atop a Morse code straight key, but of course it is not. At the time, cathode ray tubes (CRTs) were the only form of video display, and while small like the one in the drawing (and round, unlike the drawing), they were far from flat. Little did the artist suspect that his "Crystal Gazing" idea meant to imply a type of mystic's medium for seeing...

Negative Feedback Transistor Amplifiers

Negative Feedback Transistor Amplifiers, May 1957 Radio & TV News - RF Cafe WebsiteThe big graphic with Figures 1 through 17 reminds me of the kinds of study sheets I used to make when cramming for exams in my college circuits courses. Did I ever tell you about the wise guy instructor I had for my first Circuits class at the University of Vermont? Anyway, this article provides an introductory level treatment of using negative feedback in amplifier circuits. Lots of illustration and formulas are included. Frequencies are at baseband, so you won't learn any secrets for high frequency amplifier stabilization, but then even RF and microwave circuits eventually need to convert down to baseband at some point for sampling or for use as audio or video...

QST Strays: Powder Puff Derby

Powder Puff Derby Peanuts July 6, 1975 - RF Cafe WebsitePrior to seeing this new tidbit in a 1976 issue of QST magazine, I had no idea that the wife of Peanuts comic strip creator Charles Schulz was an airplane pilot - and that is with having been a huge Peanuts fan for decades. Other than one of Snoopy's alter egos being that of a World War I flying ace, there is no other theme of airplanes in the strip, although according to this article, there was a 1975 Sunday comic strip with Peppermint Patty and Marcie flying atop Snoopy's doghouse, from California to Michigan. The Straits Area Radio Club (W8GQN) provided communications for the Powder Puff Derby, aka the Women's Air Derby, race in which Mrs. Jean Clyde Schulz took part in 1970, 1971, and 1975. It was a very long course - more than 2,000 miles as the crow flies...

SPURS Software - RF Design Magazine Software Contest

SPURS Software - RF Design Magazine Software Contest Winner (November 1992) - RF Cafe WebsiteWay...... back in 1992, RF Design magazine ran a software contest. Those were the days when most engineers and hobbyists wrote software in either Basic or Fortran. I happened to use Turbo Pascal, by Borland. At the time, I was working as an RF engineer for Comsat, in Germantown, MD. Having done a lot of frequency conversion designs in my previous work at General Electric, and even more there at Comsat, I had already written a crude program to calculate mixer spurious products, so this challenge gave me the excuse I needed to refine the user interface and add some creature comfort features like...

Time for Another Breakthrough

"It Seems to Us..." Time for Another Breakthrough, August 1976 QST - RF Cafe WebsiteAmateur radio operators - and all electromagnetic spectrum users for that matter - have always lamented crowded bands and interference (QRM and QRN). That goes for licensed and unlicensed bands. In 1976 when this editorial was printed in the ARRL's QST magazine, spectrum occupation within allocated bands was defined by commonplace analog AM and FM methods. Co-existence was generally not possible for operation within a common frequency range. Spread spectrum modulation / demodulation changed all that beginning in the 1990s, but prior to then such schemes were largely the exclusive domain of military communications, as were many other spectrum-saving methods which are commonplace today. A big part of the reason is the significant advances in digital processing hardware and software, along with declassification of some of the algorithms that eventually found their way into cellphone, WiFi, and other commercial applications. Given that many of the professional engineers...

They're Taking the Guesswork out of Scatter Communications

They're Taking the Guesswork out of Scatter Communications, September 1969 Electronics Illustrated - RF Cafe WebsiteAs with many areas of electronics communications, much of both the initial and continued research in atmospheric scattering of electromagnetic signals was/is done by amateur radio operators. The phenomenon is routinely used for accomplishing long distance communications (DX, in Ham terms) by exploiting the reflection property of ionized layers when radio signals impinge at a certain angle. The portion of the signal that returns to the transmitter location, when monitored, can provide information to the sender about the height, distance, and frequency range of the reflecting atmospheric layer. Some of the first indications of backscattering were noticed by radar operators who would receive echo returns from "phantom" targets that were really atmospheric reflections...

Admiral "Aeroscope" Midget Sets Radio Service Data Sheet

Admiral "Aeroscope" Models 161-5L, 162-5L and 163-5L Midget Sets Radio Service Data Sheet, August 1939 Radio-Craft - RF Cafe WebsiteFor many years I have been scanning and posting Radio Service Data Sheets like this one featuring the Admiral "Aeroscope" 161-5L, 162-5L, and 163-5L Midget Set models which appeared in a 1939 issue of Radio-Craft magazine. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. Some websites offer to sell this information, but often what is shown here is enough to get an old radio working again since most times both schematics and alignment steps are included. I keep a running list of all data sheets to facilitate a search... 

War Advertising Council

War Advertising Council, February 1944 Popular Science - RF Cafe WebsiteI'm probably one of the few people remaining who fairly regularly recite the World War II (WWII) era slogan of "Use it up. Wear it out. Make it do, or Do without." One of the primary killers of economies has been inflation, whatever the cause - usually deficit spending by government and/or printing of fiat money. Wartime typically produces high inflation levels due to the need to produce the equipment necessary to wage a battle. Supply and demand are another cause of inflation. If the demand is greater than the supply, prices go up because owners want to maximize profits. If the need for skilled labor is greater than what is available, workers demand higher pay, and the price goes up. During WWII, as the chart to the upper left shows, inflation rates were sky high, and the government propagandists called on the citizens to "do their part" to keep prices under control by not creating a higher demand then the supply chain could accommodate...

Many Thanks to San Francisco Circuits for Continued Support!

San Francisco CircuitsSF Circuits' specialty is in the complex, advanced technology of PCB fabrication and assembly, producing high quality multi-layered PCBs from elaborate layouts. With them, you receive unparalleled technical expertise at competitive prices as well as the most progressive solutions available. Their customers request PCB production that is outside the capabilities of normal circuit board providers. Please take a moment to visit San Francisco Circuits today. "Printed Circuit Fabrication & Assembly with No Limit on Technology or Quantity."

Antenna Theory Quiz

Quiz #77: Antenna Theory Quiz - RF Cafe WebsiteWelcome to the RF Cafe Antenna Theory Quiz, a specialized assessment designed to test your knowledge of the radiating structures that define the success of any RF communications system. From fundamental dipole operation and feedpoint impedance to the critical nuances of gain, polarization, and pattern formation, a deep understanding of antenna physics is essential for any serious radio enthusiast or professional engineer. This quiz challenges you on key concepts, including the characteristics of Yagi-Uda arrays, the significance of front-to-back ratios, the dynamics of ground planes, and the practical challenges of matching networks. By evaluating your grasp of these essential antenna principles...

Mathematical Puzzles, 1981 Old Farmer's Almanac

Mathematical Puzzles, 1981 Old Farmer's Almanac - RF Cafe WebsiteEach autumn I used to anxiously await the appearance of the newest edition of The Old Farmer's Almanac on the store shelf, and such was the case with this 1981 issue. It is not that I was/am an avid farmer, just that I enjoy reading the anecdotes, tales, and interesting historical tidbits included amongst the pages along with tables of high and low tides, moon and sun rising and setting times, astronomical events, and weather patterns expected for the year that lay ahead. Most of all, I liked working the puzzles and riddles. Over the years the difficulty levels gradually got lower and lower (aka dumbed down), to the point where for the last decade or so I have not even bothered buying the OFA. Now it is full of numbnut stuff...

Electronics-Themed Comic, Popular Electronics

Electronics-Themed Comic, February 1972 Popular Electronics - RF Cafe WebsiteThis is a great electronics-themed comic from a February 1972 issue of Popular Electronics. It encompasses the essence of the stereotypical salesman ruse, especially in that era when people were sure that electronics repair services were out to rip them off by selling unneeded services and replacement parts. Aspiring TV technicians who couldn't grasp the technology moved on to working as mechanics in a garage, poking tiny holes in brake lines to scare owners into paying for complete braking system rebuilds. I usually like to post multiple comics on each page, but at the moment only this one is available...

Frequency-to-Meter Conversion Chart for Hams

Frequency-to-Meter Conversion Chart for Hams & SWL's, June 1966 Popular Electronics - RF Cafe WebsiteAs with your school and college days where once there was no longer any reason to memorize physical constants, conversion formulas, and names of people, places, and things, much of the noggin's gray matter was repurposed to remember topics of more immediate need. You can always look up what you have forgotten. While studying for your Ham radio or FCC license, being able to be able to quickly convert between wavelength and frequency is essential. Recalling on demand frequency-wavelength pairs is a real time saver on a timed exam. Even being able to perform the conversion on a calculator during the test takes up valuable time that could be better used on other tasks. This handy-dandy chart for converting...

IMS 2026 Coverage by everything RF!

everything RF IMS 2026 Event Coverage - RF Cafe WebsiteIMS 2026 (IEEE MTT-S International Microwave Symposium) is the world's premier RF and microwave conference, bringing together thousands of industry professionals from around the globe to explore the latest technologies, tools, and technical developments. IMS2026 will feature the RFIC Symposium, the new RFSA and RFTT Symposia, and conclude with the ARFTG Microwave Measurement Conference. everything RF website's medai team is providing full coverage of the event. Stop by Booth 24048 to meet the crew.

The Man Who Pinned Wings on the Navy

The Man Who Pinned Wings on the Navy, July 1961 Popular Science - Airplanes and RocketsIn 1961, the United States Navy commemorated the fiftieth anniversary of the A-1 Triad, the service's first aircraft. This milestone honored Glenn Hammond Curtiss, the father of naval aviation, who designed the versatile machine capable of operating on land, water, and air. Born in Hammondsport, New York, in 1878, Curtiss possessed an innate obsession with speed and mechanical ingenuity. Before revolutionizing aviation, he dominated motorcycle racing, famously earning the title of the fastest man on Earth. His transition to flight led to landmark achievements, including winning the Gordon Bennett trophy in France and executing the first successful U.S. intercity flight...

Today in Science History - RF Cafe Website
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Homepage Archives - RF Cafe

The RF Cafe Homepage Archive is a comprehensive collection of every item appearing daily on this website since 2008 - and many from earlier years. Many thousands of pages of unique content have been added since then.

 

The Propagation of Short Waves

The Propagation of Short Waves, February March 1932 Short Wave Craft - RF Cafe WebsiteThis is the second of a two-part series discussing the propagation of shortwaves, the first part having appeared in the December 1931 / January 1932 edition of Short Wave Craft. Keep in mind that at the time of the writing, no instrumented sounding rockets had been sent into the upper atmosphere for empirical measurements, so the author's conjectures being inaccurate are forgivable. Mr. Meyer's supposition that there are "cosmically-located network of conductive lines" that influence seasonal propagation as the earth moves through them during its revolution around the sun is actually not an unreasonable theory for its era. It certainly is no more outlandish than a modern-day celebrated astrophysical genius proposing a series of vibrating 'strings' in an 11-dimensional universe...

Howard W. Sams & Co. Ad

Howard W. Sams & Co. Ad, March 1958 Radio News - RF Cafe WebsiteI'm guessing most RF Cafe visitors who are more than 50 years old are familiar with, and even have seen, the Sams Photofacts packages of documentation for consumer electronics appliances that include televisions, radios, phonographs, clock-radios, tape recorders/player, amplifiers, etc. Most electronics service shops couldn't have existed with them since many manufacturers did not distribute technical and service data to anyone who was not a certified, sanctioned dealer. Howard Sams, the company's founder, did the equivalent for electronics of what Chilton did for cars and trucks. They basically reverse engineered models bought off a showroom floor. This advertisement from a 1958 issue of Radio & TV News magazine features the man himself, Howard Sams, so now you'll recognize him if you pass him on the street...

Engineering & Science Crossword Puzzle for January 19

Engineering & Science Crossword Puzzle January 19, 2020 - RF Cafe WebsiteAs with my hundreds of previous engineering and science-themed crossword puzzles, this one for January 19, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you.

Buy & Sell Ham Radio Operator Homes

Amateur Ham Radio Operator Homes - Buy & Sell, Kirt's Cogitations #318 - RF Cafe WebsiteA couple years ago a house two streets away had an estate sale after the elderly gentleman who owned it passed on. There was a lot of old amateur radio gear for sale, and most of it had been bought early in the morning, right after the beginning of the sale according to the man's daughter who was on-hand. The newspaper notice mentioned the Ham equipment. In the back yard was a nice 40-foot crank-up tower that was a bit weather-worn, but otherwise appeared to be in good condition. She said that was the first item sold. I didn't ask how much she got for it. The house was to be sold, and they were glad to have the tower gone before listing it on the market. I have wondered in the past when seeing a "For Sale" sign in the lawn of a house with one or more radio towers in the yard how much they would impact the sale price. Some Hams would plan to take...

The Enormous Electron

The Enormous Electron, April 1944 Radio-Craft - RF Cafe WebsiteAnyone who pays attention in a present-day high school physics class would read this article from 1944 and immediately appreciate the advances that have been made in atomic theory during the ensuing 75 years. With modern knowledge, it is hard to believe that even in 1944 someone would seriously suggest that theorized sub-electronic particles (building blocks of electrons) might be responsible for supporting the propagation of electromagnetic energy. We still consider the electron to be an elementary particle (although now not so the proton and neutron), but at this point we are aware of many elementary particles other than the electron (some of which make up protons and neutrons). There are six types of quarks, the gluon, the photon, three types of bosons, and five other types of leptons other than the electron - for a total of 17. The author's characterizing of the electron as having a "flitting and jerking" "enormous" positional presence...

Amplifier Quiz - 1964 Popular Electronics

Amplifier Quiz (A) February 1964 Popular Electronics - RF Cafe WebsiteHere be another brain teaser from quizmaster Robert P. Balin. The "Amplifier Quiz" is one of sixty or so I have posted thus far from vintage issues of Popular Electronics magazine. Having been created in 1964, the circuit schematics use vacuum tubes, but don't let that inhibit you from taking the test. Enhancement mode field effect transistors (FETs) are an apt analogy to tubes for determining function, so I added symbols for FETs next to the vacuum tube symbols to help you visualize the equivalence. I usually do a respectable job on these quizzes, but have to admit to only getting 4 out of 6 this time (67%), and one of those was just a lucky, semi-educated guess. Shameful.

Report on the Soviet Earth Satellite

Report on the Soviet Earth Satellite, February 1958 Radio & TV News - RF Cafe WebsiteInterestingly, the February 1958 article in Radio & TV News magazine entitled "Report on the Soviet Earth Satellite" never mentions the craft's name - "Sputnik 1," or "Простейший Спутник-1," which in English is "Elementary Satellite 1." Sputnik 1 was, in case your history is a bit fuzzy, the world's first successful artificial communications satellite. Launched by the Union of Soviet Socialist Republics (USSR) on October 4, 1957, Sputnik 1 remained operational for about three weeks in low Earth orbit (284 miles average), during which time radio receiving stations across the globe anxious tuned in hoping to hear the 20.005 MHz and 40.002 MHz pulses that alternately repeated continuously in an alternating manner - the first FSK (frequency-shift keying) from space. Ruskie engineers made the signal frequencies and periods as stable as possible in order to enable careful frequency and timing...

Minnesota Mining & Manufacturing (3M) Company Ad

Minnesota Mining & Manufacturing (3M) Company Ad, March 1958 Radio News - RF Cafe WebsiteAdvertisements for this Scotch 200 magnetic tape product appeared many time in electronics magazines during the big stereo era that ran from the 1950s through to the 1980s. High Fidelity (Hi-Fi) was a big deal as major improvements in receivers, tape decks, phonographs, amplifiers, and speakers were being made. I decided to highlight this one in particular for a couple reasons. First is that when I was in the USAF stationed at Robins AFB, GA (1979-1982), one of the roommates I had in the barracks had a father whom, at least per his claim, invented reflective tape for 3M. The guy was a true Lennon fanatic, and even wore faux Lennon glasses when off duty. He didn't look the part. When Mark David Chapman shot and killed Lennon on December 8, 1980, his entire raison d'être came to an end. I'm surprised he didn't go for psychiatric counseling. Second, did you know (or care) that "3M" stands for...

Airborne Digital Computer

Airborne Digital Computer, February 1958 Radio & TV News - RF Cafe WebsiteEach month Radio & TV News magazine contained a section entitled, "What's New in Radio," which reported on some of the latest happenings in the fields of commercial, military, space, transportation, broadcast, and all other forms of wireless communications. This 1958 issue show the world's first volume production airborne digital computer, designed by Hughes Aircraft Company, installed in the nose of a U.S. Air Force F-102A Delta Dagger fighter jet (built by Convair). The 456th Fighter Interceptor Squadron website has a lot of information about the Hughes MA-1 Digitair computer and its integration with airborne radar to create a flight control system that could guide aircraft to a target for ordinance (bombs, missiles) deployment. Other topics included a wideband oscilloscope from Electronic Industries (EIC) that handled a whopping 5 MHz...

Bell Telephone Laboratories Ad - Coaxial Electron Tube

Bell Telephone Laboratories Ad, Coaxial Electron Tube June 1954 Radio & Television News - RF Cafe WebsiteFor a given semiconductor compound, the maximum operational speed of a transistor is governed pretty much by its gate thickness. Capacitance and impurities along with lithography precision and accuracy are the culprits. Shrinking gate sizes and growing crystals with greater purity has driven operational speeds upward significantly over the years. An equivalent set of issues plagued vacuum tube development a century ago. The physical spacing of grid elements wrt each other as well as to the cathode and plate placed an upper limit on amplification bandwidth. As always, judicious study of the underlying causes led to the development of new designs that, along with improved manufacturing techniques, overcame existing barriers and, also as always, exposed yet a new set of limiting criteria for conquering...

Bell Telephone Laboratories: New Twist in Memory Devices

Bell Telephone Laboratories: New Twist in Memory Devices, February 1958 Radio & TV News - RF Cafe WebsiteUpon seeing this advertisement by Bell Laboratories for their "Twistor" form of magnetic memory data storage in a 1958 issue of Radio News magazine, my thought was that it was just another flash in the pan, so to speak, in the history of breakthrough, paradigm-changing inventions. It was a variation of the non-volatile magnetic core memory that used sections of ferromagnetic wire twisted around copper wire in such a way that electrical currents directed to particular intersections in an x-y grid would cause a magnetic orientation to be set (store a bit) and a set or read and sense wires permitted detection of the stored magnetic field to be determined (read a bit). The Twistor was hailed as a much more manufacturable form of the magnetic core memory, which required production workers with small hands and finger to manually thread...

$5.00 for Best "YL" Photos

$5.00 for Best "YL" Photos, May 1935 Short Wave Craft - RF Cafe WebsiteNews headlines are filled with stories about how certain segments of the society are routinely excluded from participation in activities which have been historically 'dominated' by adult white males. Not only have 'outsiders' been prevented from engagement, but, you would likely conclude based on the invective words that drip from the pens and/or mouths of those reporting, tireless campaigns have been mounted to see to it that exclusiveness continues. I will agree that there have been instances of preferential treatment by some groups and people, but I also know many attempts have been made over the decades to attract other than white males into all kinds of activities normally associated with white males. In fact, it is not a stretch to say many specialty groups go out of their way to make a big deal out of non-typical persons interested in joining. Here is one of many examples that appeared in a 1935 (yes, 1935) edition of Short Wave Craft where the editor, Hugo Gernsback, encouraged women and girls to get involved in amateur radio...

Engineering & Science Crossword Puzzle January 26th

Engineering & Science Crossword Puzzle January 26, 2020 - RF Cafe WebsiteAs with my hundreds of previous engineering and science-themed crossword puzzles, this one for January 26, 2020, contains only clues and terms associated with engineering, science, physical, astronomy, mathematics, chemistry, etc., which I have built up over nearly two decades. Many new words and company names have been added that had not even been created when I started in the year 2002. You will never find a word taxing your knowledge of a numbnut soap opera star or the name of some obscure village in the Andes mountains. You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical location like Tunguska, Russia, for reasons which, if you don't already know, might surprise you...

Robot Makes Radios

Robot Makes Radios, September 1947 Radio-Craft - RF Cafe WebsiteBritish engineer John Sargrove was to the production of radios what Henry Ford was to automobiles. At the time this "Robot Makes Radios" article appeared in a 1947 issue of Radio-Craft magazine, Sargrove had recently put his Electronic Circuit Making Equipment (ECME) fully automated assembly line into operation. Applying knowledge from two decades of developing methods of crating inductors, capacitors, resistors, and interconnecting conductors using controlled deposition of various materials on flat substrates, he was able to build 2-tube AC/DC radios at a rate of up to three per minute, with only two ECME operators - one at the input and one at the output. The only manual assembly required was the installation of a potentiometer-switch, a transformer, speaker...

Hazel TV Episode "Stop Rockin' Our Reception"

Hazel TV Episode "Stop Rockin' Our Reception" - RF Cafe Video for EngineersQST reader George P. Orphan, KG4DXJ, wrote in the February 2020 issue's "Letters from Our Members" column about an episode of the old "Hazel" television show entitled, "Stop Rockin' Our Reception," where interference on the Baxters' TV set was blamed on the "shortwave set" operated by a teenager, Bruce, who had recently moved in down the street. George Baxter, the household's impulsive lawyer father, was convinced enough that Bruce, a friend of his son, Harold, was responsible that he paid a visit to the boy's house and spoke to his father about it. Bruce politely informs Mr. B that unless his television was was manufactured before 1950, it was unlikely that his operations on the 10-meter band would be causing the interference, but it fell on deaf ears. Shortly thereafter, a power company investigator was seen walking around the front yard with a box bearing a loop antenna on the top of it. At the request of Bruce's father...

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