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Homepage Archive - July 2022 (page 2)

See Page 1 | 2 | 3 | 4  of the July 2022 homepage archives.
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Thursday the 14th

Radio-Radar-Sonar in Naval Applications

Radio-Radar-Sonar in Naval Applications, April 1951 Radio & Television News - RF CafeWorld War II was the "necessity" that elicited the "mother of invention" activity responsible for many huge leaps in technology - not the least of which was electronic verbal and non-verbal communications. By 1951, when this Radio & Television News magazine article on the sate of the art of military electronics was published, the United States was already in the midst of another war - this time in Korea - fighting back the frontiers of Communism and despotism. Along with radio and radar, Loran had become a major means of ocean and air navigation. A fair description of the operational details, including timing diagrams, is included in the text. Loran-A, the original system as it came to be known, was fully decommissioned in 1980, thereafter supplanted by Loran-C. With the advent of GPS, Galileo, and Glonass navigation systems and their low equipment and installation costs, Loran-C was eventually no longer needed either, causing it to be decommissioned in the U.S. in 2010. Norway's Loran-C stations, the last operational stations, were scheduled to close in 2016. In case you are wondering...

PCB Technology in Software-Defined Radio

PCB Technology in Software-Defined Radio - RF Cafe"SDR requires a complex web of circuitry on PCBs that not only defines the device's functionality, but also the performance of these microwave and RF systems. Various factors come into play when designing PCBs for SDRs that must maintain signal integrity. Software-defined radio (SDR) requires complex circuitry on printed circuit boards (PCBs) that defines the functionality of the device as well as the performance of these microwave and RF systems. This article discusses the factors that arise when designing PCBs for SDRs that need to maintain signal integrity. What is an SDR? An SDR includes what's commonly termed a radio front-end (RFE) and digital backend. The RFE boards contain the functionality of the radio over a very wide tuning range and incorporate various analog components such as LNAs, mixers, filters, frequency synthesizers, gain/attenuation blocks, and other devices needed for receiving (Rx) and transmitting (Tx) functionality..."

Audiophile Quiz

Audiophile Quiz, November 1957 Radio-Electronics - RF CafeI could be wrong, but I'm guessing the average audiophile in the 1950s and 1960s were probably more technically astute than modern day audiophiles in terms of electrical and physical specifications. That is largely due to how integrated, matched, and compatible system components (receivers, players, amplifiers, speakers, etc.) are nowadays. Newer audio components are also more tolerant of non-optimal configurations. In 1957 when this Audiophile Quiz appeared in Radio-Electronics magazine, the vast majority of electronics equipment used vacuum tubes that used lethally high voltages, so connection and servicing mistakes could be more costly to life, limb, and hardware. Topics like AFC (automatic frequency control), frequency response of recording and playback devices, required technical knowledge for achieving the best performance...

Mac's Radio Service Shop: Barney Takes on Color

Mac's Radio Service Shop: Barney Takes on Color, February 1955 Radio & Television News - RF CafeAlways the consummate story teller, John T. Frye began his writing career long before his "Carl & Jerry" electronics adventure series that ran monthly for many years in Popular Electronics. His style featured creating a dialog between instructor and student, serviceman and customer, husband and wife, father and son, etc., in order to present an educational experience with back-and-forth inquiry and responses. In the end, the reader learns something about both sides of the situation. In this February 1955 story, electronics service shop owner Mac McGregor reassures technician Barney Jameson that given time and patience, he will grasp the circuit concepts of the newfangled color television sets...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features...

Many Thanks to LadyBug Technologies for Their Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Wednesday the 13th

Introducing the Laser

Introducing the Laser, February 1961 Popular Electronics - RF CafeHere is a really good introduction to the way a laser works. In this 1961 Popular Electronics article, author Ken Gilmore discusses a couple Bell Telephone scientists who pioneered long distance laser communications back in 1960. Their experiments began with rather large chemical lasers on the rooftops of buildings separated by 25 miles. Back in the day, most people - including technical types - had never read or heard a description of how a laser works, so this was a brand new concept. Lasers were a science fiction thing used as weapons for battling aliens. We've come a long way since then, with laser communications now taking place within the confines of a semiconductor integrated circuit...

Synchrotron Board Game Encourages Careers in Science

Synchrotron Board Game Encourages Careers in Science - RF Cafe"Synchrotrons and many board games have at least one thing are common - objects are accelerated in a circle but going round and round is not the main point of either. In board games, the object is fun and in 'Diamond: The Game,' [print, cut out, play - free] there is also an educational element. Developed by Mark Basham and Claire Murray at the UK's Diamond Light Source synchrotron and Matthew Dunstan at the University of Cambridge, the game puts players in the role of a researcher at Diamond. By visiting different beamlines while progressing round the board, participants learn about the diversity of science that is done at the facility - including physics, chemistry, cultural heritage, and more..."

Inside the Hi-Fi Tone Arm

Inside the Hi-Fi Tone Arm, February 1960 Popular Electronics - RF CafeEven in the year 2022, there is a huge cadre of turntable aficionados out there whose players can only be taken from them by prying them from their, cold, dead hands. Look at all the buying and selling of turntables that takes place on eBay if you have any doubt (the search I just did turned up more than 800 items). I remember in my U.S. Air Force days, the only time ever lived in mass group quarters (no college dorms for me), guys were in heated competition against each other over who could accumulate the most extensive and expensive hi-fi gear. A large percentage in my barracks were mobile communications types, and they seemed to spend about as much time adjusting their turntables, reel-to-reel tape decks, and receivers for ultimate performance. Entire beer and pizza parties were centered around topics like balancing tone arms. As with most subjects where many "experts" debate, no two could agree on the best method. Here's a little sage advice from a 1960 issue of Popular Electronics magazine in case you're not a seasoned tone arm balancer...

Kadette Jewel 3-Tube Ultra-Midget Receivers

Kadette Jewel Model 40 Chassis 3-Tube Ultra-Midget Receivers Models 41, 43, 44 and 48 Radio Service Data Sheet, July 1936 Radio-Craft - RF CafeFor many years I have been scanning and posting schematics & parts lists like this one from a 1936 issue of Radio-Craft magazine. It features the Kadette Jewel Model 40 Chassis 3-Tube Ultra-Midget Receivers Model 41, 43, 44 and 48 radios in graphical format. It is able to be "miniature" because only three vacuum tubes are used - although a 12A7 diode / tetrode effectively makes it a 4-tube radio. I'm guessing the Kadette Midget might have only worked well in strong signal areas. Often times I run OCR on them to separate the textual content. The radio shown in the thumbnail is currently being offered for sale on eBay†; the price seems a bit steep. The case appears to be in fine physical condition, but the electronics could stand some rework. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. I will keep a running list of all data sheets to facilitate a search. † Usually when I find an item like this on eBay, I have Archive.org's Wayback Machine grab a page snapshot of it and link to it rather than the original eBay page because it will soon disappear...

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 12,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be.

Thanks to TotalTemp Technologies for Continued Support!

TotalTemp Technologies - RF CafeTotalTemp Technologies has more than 40 years of combined experience providing thermal platforms. Thermal Platforms are available to provide temperatures between -100°C and +200°C for cryogenic cooling, recirculating circulating coolers, temperature chambers and temperature controllers, thermal range safety controllers, space simulation chambers, hybrid benchtop chambers, custom systems and platforms. Manual and automated configurations for laboratory and production environments. Please contact TotalTemp Technologies today to learn how they can help your project.

Tuesday the 12th

Rectifying Without Rectifiers

Rectifying Without Rectifiers, July 1952 Radio-Electronics - RF CafeIt took a couple times reading through this "Rectifying Without Rectifiers" article to get the gist of what author H.B. Conant was talking about. He begins by pointing out the negative aspects of using nonlinear metallic rectifiers in a bridge circuit for an electric meter, then goes on to describe an improved "translator" circuit that uses - wait for it - nonlinear metallic rectifiers (or nonlinear resistors made of Thyrite material). If my interpretation is correct, basically the new and improved circuit incorporates a bias voltage that forces the nonlinear element (be it a metallic rectifier or a nonlinear resistance) to operate in a region which passes a higher current level to the meter movement when low values are being measured. One of the drawbacks mentioned of a traditional (at the time) bridge circuit was the need for separate calibration / marking of the meter's scale on the front panel, but then he says the translator meter also does not have uniform scales on all voltage ranges. I are a bit confused...

Transatlantic Communication in the Digital Age

Transatlantic Communication in the Digital Age - RF CafeCabe Atwell has an interesting piece on the EE|Times website entitled, "Transatlantic Communication in the Digital Age," where he does a brief comparison of cable types used at the middle of the 19th century (i.e., 1850+) to those used today. In both eras, inserting amplifiers at intervals was/is necessary in order to maintain an acceptable signal-to-noise ratio. Using optical fiber instead of copper helps matters, but does not eliminate the need for amplifiers. Insulation and protective armor has vastly improved as well since gutta-percha on submarine telegraph cables. Mr. Atwell begins: "Communication between nations and at great distances was not always as available, and certainly not as fast, as it is in many places today. The site of the first transatlantic communication via cable is Valentia Island, Ireland, where over 160 years ago the first telegram was sent between the United States and Great Britain. Sent on Aug. 16, 1858, it read: 'The queen is convinced that the president will join with her in fervently hoping that the electric cable, which now connects Great Britain with the United States, will prove an add..."

Southern California Amateurs Rise to Earthquake Emergency

Southern California Amateurs Rise to Earthquake Emergency, May 1933 QST - RF CafeThis could be a headline for today, tomorrow, or from 89 years ago when this article appeared in QST magazine. It was the latter, following the magnitude 6.4 earthquake that hit the Long Beach, California region. Per Wikipedia, "An estimated $40M worth of property damage resulted, and between 115 and 120 people died. Many of these fatalities occurred as people ran out of buildings and were hit by falling debris." That paled, though, in comparison to the magnitude 7.8 San Francisco earthquake in 1906, where massive destruction occurred and upwards of 3,000 people died. As usual, radio amateurs were some of the first emergency responders on the scene, setting up essential communications centers to assist with search and rescue operations. The Federal Radio Commissions (FRC), precursor to the FCC, issued a note of appreciation...

RCA Cunningham Radiotron Tubes

RCA Cunningham Radiotron Ad, July 1934 Radio News and the Short-Wave - RF CafeBack in the early days of radio - and then later television - companies used big-name media personalities to promote their wares. To a lesser extent some of that happens today as well. Advertisements like this one for RCA's Radiotron vacuum tubes appearing in a 1934 issue of Radio News magazine is typical of what you would have seen in the era. In it, none other than Bing Crosby was joined by a trendily dressed woman who was rejoicing in her decision to buy a new radio that contained those newfangled "Micro-Sensitive" receiver tubes. Radio was considered a mystical entity by most people, and in 1934 there were still many households that did not yet host a radio of any sort. Rural residences often did not have AC service and relied on storage batteries to power machinery and appliances. Farmer Brown had to haul a wagon loaded with heavy lead-acid batteries to town to get them recharged. Some of the more prosperous ruralites had windmill- or water-driven generators to produce the necessary power. In fact, in 1934 a complete power generator setup...

RF Cafe Quiz #16: Antennas

RF Cafe Quiz #16: AntennasAll RF Cafe Quizzes make great fodder for employment interviews for technicians or engineers - particularly those who are fresh out of school or are relatively new to the work world. Come to think of it, they would make equally excellent study material for the same persons who are going to be interviewed for a job. The subject of Quiz #16 is Antennas. You don't need to be an antenna expert to score well, but if you do or plan to work with antennas and cannot answer a question like, "What does dBi, the most often used unit for antenna gain (or directivity), stand for?," then maybe it is time for some review...

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...

Many Thanks to KR Electronics for Long-Time Support!

KR ElectronicsKR Electronics designs and manufactures high quality filters for both the commercial and military markets. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop and individually synthesized filters for special applications - both commercial and military. State of the art computer synthesis, analysis and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Please visit their website today to see how they might be of assistance. Products are designed and manufactured in the USA.

Monday the 11th

Playback Preamp for Stereo Tapes

Playback Preamp for Stereo Tapes, April 1958 Radio-Electronics - RF CafeHmmmm.... at the time I marked this stereo tape playback preamp project for posting I must have had a really good reason for it, but now I can't recall what that really good reason was. Maybe it was simply to mark the point in time when stereophonic electronic equipment was just beginning to be mainstream. Oh well, somebody somewhere will do a Google search on the topic someday and will be elated to find this. Besides, even though the use of vacuum tubes and magnetic tape is way outdated, there is a discussion of hi-fi audio that is still relevant. The article appeared in a 1958 issue of Radio-Electronics magazine. Thanks for your indulgence.

From Transistor to Memristor Switching Technologies

From Transistor to Memristor Switching Technologies - RF Cafe"The invention of the transistor by Bell Laboratory in 1947 ushered in an era of electronic devices that were smaller and ran cooler using far less power than their bulky and fragile vacuum tube counterparts. Transistors function as a binary switch to facilitate electrical current from off to on states. Radios, calculators and telephones were among the first wave of instruments to replace vacuum tubes with the new semiconductor technology. As the technology scaled smaller and smaller, subsequent decades saw the steady integration of silicon transistors into devices, and today's computers, cell phones, watches, pacemakers, and virtually every kind of electronic device relies on them for high-speed processing and memory. Enter the memristor, an electronic device that emulates the binary switch using a two- and also three-dimensional matrix configuration, or cross bar array, to regulate states of conductivity based on current resistance..."

The Pest - Radio Repair

The Pest, July 1952 Radio-Electronics - RF CafeWhile reading through these vintage electronics magazines, I often wish I could have lived in the era and owned an electronics repair shop. Radios, televisions, record players, tape recorders, amplifiers, etc., were very serviceable with plug-in vacuum tube active components and point-to-point wiring with all leaded passive components (capacitors, resistors, inductors, lamps, etc.). I know this from first-hand experience working on a 1960's air traffic control radar system while serving in the U.S. Air Force. As with today, servicemen often get a bad rap undeservedly because of the low morals of some fellow practitioners. While it is unfortunately true that bad eggs exist in the service world, a lot of customers are rotten and try to take advantage of or outright rip off the technician. This story from a 1952 issue of Radio-Electronics magazine is a tongue-in-cheek parody from the viewpoint of a self-righteous customer looking to get his radio repaired...

Centralab Ceramic Capacitors

Centralab Ceramic Capacitors, February 1952 Radio & Television News - RF CafeMaybe it isn't so anymore, but according to Centralab the ceramic raw materials available in abundance in America were electrically superior to those being used in Europe since the early 1900s when German scientists first discovered the dielectric properties of the material. Ceramic capacitors represented a major advance in capacitor technology over liquid and paste dielectric types in most areas of electrical and mechanical specifications such as vibration, aging, vibration and shock, temperature, value stability, voltage and current handling, etc. Centralab ran this advertisement in Radio & Television News magazine spelling out all the virtues of ceramic capacitors that had accumulated due to their research efforts. Philips Electronics' Components division bought Beyschlag and Centralab and merged the two into "BCcomponents," whereupon in 2002 Vishay bought them...

RF Cascade Workbook

RF Cascade Workbook - RF Cafe RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. Chances are you have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system cascade parameter and frequency planner that includes filters and mixers for a mere $45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch and the format is entirely customizable. It is significantly easier and faster than using a multi-thousand dollar simulator when a high level system analysis is all that is needed. An intro video takes you through the main features...

Please Thank Lotus Communication Systems for Their Support!

Lotus Communication Systems Modular RF/Microwave Components - RF CafeLotus Communication Systems began in 2009, setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex Country, Massachusetts. Lotus is committed to highest quality and innovative products. Each RF/microwave module meets exceedingly high standards of quality, performance and excellent value, and are 100% MADE IN USA. Lotus' RF/microwave products cover frequency band up to 67 GHz. Lotus also offers an COTS shield enclosures for RF/microwave prototyping and production. All products are custom designed. We will find a solution and save your time and cost. Lotus has multiple 4 axis CNC machines and LPKF circuit plotters.

Sunday the 10th

Electrical Engineering Theme Crossword for July 10th

Electrical Engineering Theme Crossword Puzzle for July 10th, 2022 - RF CafeWith few exceptions, I, RF Cafe webmaster Kirt Blattenberger, have for more than two decades designed a custom crossword puzzle every week for the benefit of website visitors. This Electrical Engineering Theme Crossword Puzzle was created for July 10th, 2022. All crossword puzzles use a personally built dictionary of thousands of words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword puzzle contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Many Thanks to Anatech Electronics for Long-Time Support!

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

Friday the 8th

CNES RF Propagation Calculations DLL

CNES RF Propagation Calculations DLL - RF Cafe Cool ProductMany thanks to RF Cafe visitor Michael M. for sending me a note about a very handy RF propagation software tool provided free of charge by the French organization Centre National d'Études Spatiales (CNES, National Centre for Space Studies). The PROPAGATION dynamic link library (DLL) contains functions to compute propagation losses according to ITU-R P.† recommendations. Versions are available for both 32- and 64-bit Windows and Linux operating systems, as well as for the C and Visual Basic programming languages. Very conveniently, the DLL functions can be referenced from within an Excel spreadsheet as well*, and a demo (demoprop.xls - see screen shot at right) is provided for reference. To access the DLL contents, add the "Propa" module to your VBA (Visual Basic for Applications) code and call away. A full list of the functions is given below, including ones for gaseous, cloud and rain attenuation that factors in temperature, precipitation intensity, and atmospheric noise, as well as for inputting geographic location (latitude, longitude, and elevation) and antenna parameters...

Science & Engineering News Website Pop-Ups

Science & Engineering News Website Pop-Ups - RF CafeAs part of the immense amount of work that goes into publishing RFCafe.com, I regularly visit science and engineering websites to gather relevant headlines and stories. Most - far more than half - present pop-up advertisements and/or cookie acceptance screens, all of which must be responded to before being able to use the website. Don't get me wrong, I appreciate the services provided by them, but do find the imposition very inconvenient. Some are so bad that I have stopped including them in my lists of headlines and stories. You will please note that RF Cafe never has and never will subject you to sure an intrusion to your browsing endeavors. I also make far less income than they do because of refusing sponsors who want to use that form of advertising. Click on the above thumbnail to see some of the offender website screen shots.

Novel Radio Items

Novel Radio Items, August September 1940 National Radio News - RF CafeMy father used to refer to the "sweet-voiced lady predicting the weather over and over again" as my girlfriend because I would call the "WEather 6-1212" phone number (936-1212) so often. It really wasn't because I was infatuated with her voice, it's that I was obsessed with weather forecasting. Most of my free time as a kid and teenager was spent building and flying model airplanes and rockets, and at eighteen years of age I began taking full-size aeroplane flying lessons, so my world revolved around a zone extending from terra firma up to about 5,000 feet AGL. This collection of communications news items in a 1940 edition of National Radio News includes the creation of that very recorded weather forecasting service (we lived about 30 miles east of Washington, D.C.). Now, I admit to having a bit more of a problem explaining my frequent calling of the local time annunciator lady at "TIme 4-1212" (844-1212)...

NASA Releases JWST "Teaser" Photo

NASA Releases James Webb Space Telescope "Teaser" Photo - RF CafeThis is incredible, and the best is yet to come. "We're less than one week away from the July 12, 2022, release of the first science-quality images from NASA's James Webb Space Telescope, but how does the observatory find and lock onto its targets? Webb's Fine Guidance Sensor (FGS), developed by the Canadian Space Agency, was designed with this particular question in mind. Recently it captured a view of stars and galaxies that provides a tantalizing glimpse at what the telescope's science instruments will reveal in the coming weeks, months, and years. FGS has always been capable of capturing imagery, but its primary purpose is to enable accurate science measurements and imaging with precision pointing. When it does capture imagery, it is typically not kept: given the limited communications bandwidth between L2 and Earth, Webb only sends data from up to two science instruments at a time. But during the week-long stability test in May, it occurred to the team that they could keep the imagery that was being captured because there was available data transfer bandwidth. The engineering test image - produced during a thermal stability test in mid-May..."

One Problem in Choosing Test Leads

One Problem in Choosing Test Leads, July 1953 QST - RF CafeIn this 1953 QST magazine article, Authors Cohen and Hessinger warn about the need to consider the capacitive loading effects of shielded and closely-space test leads when measuring other than direct current or very low audio or line frequencies. Lead capacitance is especially likely to affect measured values when the frequency is high and/or the source and load impedances are high. As was common in the day, capacitance units of μμfd (micro-micro farads = 10-6 x 10-6 = 10-12 F) are cited, which is equivalent to units of pF (10-12 F)...

Electronics for Tomorrow

Electronics for Tomorrow, April 1955 Popular Electronics - RF CafeCooling devices based on the Peltier effect were first demonstrated by French physicist Jean Charles Athanase Peltier when he noted the presence of heating or cooling at an electrified junction of two different conductors types (opposite of a thermocouple). Widespread commercial use depended on finding efficient materials that could be produced inexpensively. Music synthesizers, to be practical, needed to await the availability of miniaturized electronics like transistors and memory elements. Light amplification similarly depended on affordable sources to be anything more than a laboratory curiosity. Fortunately, by the mid 1950s such entities were becoming reality. This 1955 Popular Electronics magazine article reports on a few of those items...

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 12,000 pages in the Google search index, RF Cafe returns in favorable positions on many types of key searches, both for text and images. New content is added on a daily basis, which keeps the major search engines interested enough to spider it multiple times each day. Items added on the homepage often can be found in a Google search within a few hours of being posted. I also re-broadcast homepage items on LinkedIn. If you need your company news to be seen, RF Cafe is the place to be.

Many Thanks to ISOTEC for Continued Support!

ISOTEC Corporation - RF CafeSince 1996, ISOTEC has designed, developed and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components and filters for wireless service providers including non-magnetic connectors for quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM RF connectors components such as power dividers and directional couplers. Off-the-shelf and customized products up to 40 GHz and our low-PIM products can meet -160 dBc with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and high-performance. Designs that are cost effective practical and repeatable.

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