Homepage Archive - August 2019 (page 2)

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

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Friday 16

Comic with an Electronics Theme, May 1955 Popular Electronics

Comic with an Electronics Theme, May 1955 Popular Electronics - RF CafeIf you are familiar with Carl Kohler's illustrations from his numerous humorous (a rhyme!) electronics-themed stories in Popular Electronics magazine, then this comic from the May 1955 issue will be recognized as having come from his hand. The 1950s through maybe the early 1980s was a big time for do-it-yourself hobbyists of all sorts, including those who dabbled in electronics as Hams, household handymen, kit builders, etc. In many cases high quality products could be purchased more cheaply as kits, as evidenced by the popularity of Heathkit and similar companies. By the mid to late 1990s, super-cheap labor - verging on slavery - in the Far East was doing the majority of component production and product assembly, so eventually an inversion ...

The Rise and Fall of IoT in the 2.4-GHz Band

The Rise and Fall of IoT in the 2.4-GHz Band - RF CafeJoel Brand has an interesting short article posted on the Electronic Design website entitled, "The Rise and Fall of IoT in the 2.4-GHz Band." "Self-interference cancellation could very well be the linchpin to a resurgence of the 2.4-GHz band. Way back when the 5-GHz band was opened for unlicensed Wi-Fi usage, many predicted the death of 2.4 GHz. The 5-GHz band enabled much faster speeds thanks to the increased amount of bandwidth available at the higher frequency. Channels as wide as 160 MHz were introduced (and the industry is mulling the introduction of 320-MHz channels), whereas the entire 2.4-GHz band is only about 80 MHz wide. As the FCC and other regulators are looking to open the 6-GHz band for Wi-Fi usage, there's no doubt that consumer appetite for higher bandwidth and faster speed will be served at the higher frequencies ..."

Many Thanks to MECA Electronics for Their Long-Time Support!

MECA ElectronicsSince 1961, MECA Electronics has designed and manufactured an extensive line of RF & microwave components for in-building, satellite, radar, radio, telemetry, mobile radio, aviation & ATC. Attenuators, directional & hybrid couplers, isolators & circulators, power dividers & combiners, loads, DC blocks, bias-Ts and adapters & cables. MECA has long been the 'backbone' of high performance wired and air-interfaced networks such as in-building applications, satellite communications, radar, radio communications, telemetry applications, mobile radio, aviation & air traffic communications. 

RF Cafe Quiz: Archaic Scientific Words & Definitions

Quiz #18: Archaic Scientific Words & Definitions - RF CafeThis particular quiz tests your knowledge of archaic scientific words & definitions. Choose the best answer for the spirit of the quiz; i.e., the one that represents the newer term or the abandoned definition. All RF Cafe quizzes would make perfect fodder in 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.

Quantum Microphone Detects Presence of Phonons

Quantum Microphone Detects Presence of Phonons - RF Cafe"A superconducting qubit can be used to reliably detect the presence of multiple phonons at the same time, US physicists have demonstrated. Patricio Arrangoiz-Arriola and colleagues at Stanford University built their 'quantum microphone' using materials that minimized phonon losses, while narrowing the spectra of their qubit's emissions to reduce uncertainties. The technology could allow for new capabilities in quantum computing, including modems that link together many quantum computers at different locations. While the quantum properties of photons have been explored and exploited extensively ..."

QuinStar Technology: mm-Wave Active & Passive Components

QuinStar Technology mm-Wave Products - RF CafeQuinStar Technology designs and manufactures mm-wave products for communication, scientific, and test applications along with providing microelectronic assembly, rapid prototyping, and mass customization. Amplifiers, Oscillators, Switches, Attenuators, Circulators, Isolators, Filters, Waveguide, Antennas, Phase Shifters, Transceivers, Mixers, Detectors. QuinStar specializes in cryogenic amplifiers, circulators, and isolators. Please visit QuinStar today to see how they can help your project.

Thursday 15

Planning to Be an Electronic Engineer?

Planning to Be an Electronic Engineer?, June 1955 Popular Electronics - RF CafeThis article from a 1955 issue of Popular Electronics magazine describes my evolution from electrician to electronics technician to electronics engineer. For that matter, it describes the paths many people I have worked with over the years have taken. My mentor at my first job as an RF engineer after graduating with a BSEE from the University of Vermont began as a technician in the Army, and then he went to school part-time while working a full-time job to earn his BSEE. In my next job as an RF engineer there were at least two guys I knew who had also taken that path. Although not by any means absolute criteria for judging an engineer's enthusiasm, I will say that at least as a distinct segment of RF engineering, those who are amateur radio operators and/or those who began life as a technician ...

Using the Varicap

Using the Varicap, May 1958 Radio-Electronics - RF CafeYou and I know them as 'varactor diodes,' but originally the semiconductor junctions whose reverse bias determines its capacitance was called the 'Varicap.' The new and wondrous semiconductor craze was in full swing by 1958. Scientists, engineers, and hobbyists were burning the midnight oil (to use a popular phrase of the day) performing experiments and designing circuits to replace vacuum tubes and manual controls with transistors and other electrically variable semiconductors. The Varicap had the ability to tune receiver and transmitter oscillators and filters without the need for high tube bias voltages and large mechanically variable multi-plate capacitors. This article from Radio-Electronics says early Varicaps cost $4.50 apiece ...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 Is Available Now! - RF CafeRF Cascade Workbook 2018 is the next phase in the evolution of RF Cafe's long-running series, RF Cascade Workbook. 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 ... 

Saelig Intros Rigol MSO8000 2 GHz, 4-Channel DSO Series

Saelig Introduces Rigol MSO8000 2 GHz 4-Channel Digital Oscilloscope Series - RF CafeSaelig Company has introduced the new Rigol Technologies MSO8000 Series of digital oscilloscopes, which combine best in class sampling (10 GSa/sec) and memory depth (500 Mpts) with a modern, flexible user interface enabled by Rigol's new UltraVision II architecture and innovative Phoenix chipset. Three models are available with input bandwidths from 600 MHz to 2GHz, each with 4 analog channels. The series is MSO ready: an optional 16-channel logic analyzer interface is provided to provide digital debug capabilities with the addition of 16 channel probes and software. The advanced MSO8000 Series features a 10.1" 1024 x 600 capacitive multi-touch color LCD screen with 256-level intensity grading and a waveform refresh rate ...

Russia ID'ed as Radioactive Ruthenium Leak Source

Russia ID'ed as Radioactive Ruthenium Leak Source - RF Cafe"The botched production of a powerful neutrino source is the most likely cause of a radioactive cloud that enveloped much of Europe in the autumn of 2017. That is the conclusion of a group of radiation experts from across the continent who have used isotope monitoring and chemical analysis to try and understand where the leak came from. The researchers think that the isotope involved - ruthenium-106 - was probably released during an accident, possibly an explosion, involving spent fuel at the Mayak reprocessing plant in southern Russia. Aerosols containing ruthenium-106 were detected ..."

KR Electronics: RF & Microwave Filters

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.

Wednesday 14

How to "Arrest" Lightning

How to "Arrest" Lightning, May 1955 Popular Electronics - RF CafeBefore the advent of electrical distribution systems and electronics, the hazard of lightning was primarily from fire ignition and, to a lesser extent, bodily injury (to humans and animals). In fact, it was Benjamin Franklin's discovery that lightning was a form of electricity that led to his subsequent invention of the lightning rod system that, after being installed on Philadelphia's tallest wooden structures, significantly reduced the incident of lightning-related devastating fires which had been ravaging the city for years. Once cities began installing electric power lines, they were to lightning what trailer homes* are to tornadoes - strong attractors. Line protection systems were soon developed to help stop strikes which sometimes caused electrocution to people inside homes who happened to be touching a light switch or plumbing fixture ...

USAF Deploys Ground-Based Directed Energy Laser Weapon

USAF Deploys Ground-Based Directed Energy Laser Weapon - RF Cafe"The U.S. Air Force announced Friday it will soon deploy two ground-based laser weapons to an undisclosed location to test how they can be used against small drones, the service's first 'operational field test' of an experimental 'directed energy" weapon. On Friday afternoon the Air Force announced a $23M sole-source contract for two of Raytheon's High Energy Laser Weapons Systems, through which the systems are to be tested for 12 months in an undisclosed 'contested environment' outside the continental United States. 'What we really want to do is figure out how we can deploy these systems in an environment where our warfighters work and train every day ..."

The Secret Keepers

The Secret Keepers, August 1962 Popular Electronics - RF CafeRACEP (Random Access and Correlation for Extended Performance), was an early form of frequency hopping spread spectrum (HFSS) devised by the Martin Company (now Lockheed-Martin). It was used for secure voice communications and worked by sampling speech in small 'slices' and then transmitting each slice modulated onto a carrier whose frequency was determined by a predetermined sequence of center frequencies. A receiver with a matching sequence key would then decode the speech and, with appropriate filtering, reassemble it into its original content. President John F. Kennedy had such systems at his disposal whether on the road or in the Oval Office. General Electric (GE) had a different idea it dubbed 'Phantom' that spread the signal over a very wide bandwidth. Today, we refer to it as Direct Sequence Spread Spectrum (DSSS) ...

Signal Hound Announces Test Equipment Rental Program

Signal Hound Announces New Test Equipment Rental Program - RF CafeSignal Hound, a developer of optimized solutions for RF signal test and measurement, announces a new rental program for all Signal Hound spectrum analyzers, vector signal generators, and tracking generators. Signal Hound's equipment rental rate is only 6% of the cost of a device per month for as long as the renter wants to keep the device, with a one-month minimum rental period. If the renter wants to purchase the device after the rental period, 30% of the total amount spent on the rented product can be applied to a new version of the same device type. "Our rental program is designed to remove the hesitation that an organization might have in allocating budget towards a new type of test equipment ...

Innovative Power Products: RF & Microwave Passive Components

Innovative Power ProductsInnovative Power Products (IPP) has over 30 years of experience designing & manufacturing RF & microwave passive components. Their high power, broadband couplers, combiners, resistors, baluns, terminations and attenuators are fabricated using the latest materials and design tools available, resulting in unrivaled product performance. Applications in military, medical, industrial and commercial markets. Take a couple minutes to visit their website and see how IPP can help you today.

Tuesday 13

Mac's Radio Service Shop: New Uses

Mac's Radio Service Shop: New Uses, June 1958 Radio & TV News - RF CafeIf there was another episode of Mac's Radio Service Shop where Barney was the primary teacher and Mac was the student, I don't remember what it was. In fact, this is about as total of a role reversal as there can be. First, Mac admits to having chased a presumed oscilloscope issue down the proverbial rabbit hole only to realize the cause of the problem was totally unrelated. Then, Barney produces a nifty device meant for recording telephone conversations and demonstrates to Mac a couple ingenious applications he discovered that were handy for troubleshooting television sets. When reading Mac's description of using a magnet to alter the electron beam in a CRT, it reminded me of how cool it was on the CRT displays to run a magnet ...

VITA67.3 Nano Miniature RF Cables for VPX Systems

VITA67.3 Nano Miniature RF Cables for VPX Modular Systems - RF CafeConductRF's close partnership with TE in its development of its new Nano-miniature RF Solutions for VITA67.3 has put us in a great position to support your VPX RF cable assembly needs. Modular solution supports 8 to 18 positions, flexible 0.047" diameter cable, supports frequency up to 70 GHz, use with standard solutions (SMA, SMPM, etc.), 2x density of Vita67.1. ConductRF's PFT33 Series of Micro Flexible Cable Assemblies has been designed directly with TE Connectivity involvement and in partnership to maximize the capabilities of TE's new Vita67.3 NanoRF VPX modular connector system. ConductRF offers its soft FEP jacketed ø0.047" cable to facilitate maximum flexibility and provides solutions for jumper cables ...

Generators, Electricity - Basic Navy Training Courses

NAVPERS 10622, Chapter 14 - Generators, Electricity - Basic Navy Training Courses - RF CafeIn keeping with a very common practice of using water flowing through a garden hose as a teaching aid analogy for newcomers, the title of this chapter of the NAVPER 10622 Basic Navy Training Courses, "Generators - Electrical Pumps," is likening electrical generators to water pumps. It is an apt analogy, but whereas a water pump can cause water pressure and flow of a physical substance already on-hand, electrical "pumps," aka generators, literally creates its "flow" from thin air (even a vacuum with no air). An electrical generator exploits the phenomenon discovered by (or at least credited to) Michael Faraday whereby a conductor moving through a magnetic field - or a magnetic field moving past a conductor ...

Thanks to Transient Specialists for Continued Support!

Transient Specialists - RF CafeTransient Specialists specializes in EMC test equipment rentals and carries a complete line of ESD guns, surge immunity test equipment, and EFT generators. Rentals available for military (Mil-Std 461), automotive (ISO 7637), and commercial (IEC 61000-4) EMC testing. Flexible terms, accredited calibrations and technical support on EMC testing equipment offered. Equipment consists of top EMC Test System manufacturers, including Teseq, Thermo Keytek, EM Test and EMC Partner.

An Analytical Model of Quad Cable to 1 GHz

An Analytical Model of Quad Cable to 1 GHz - RF CafeThis is part 2 of the High Frequency Electronics article entitled, "An Analytical Model of Quad Cable to 1 GHz," by Kenneth Schneider. It's not for the feint of heart. "Studies performed in developing the model indicate that this is principally caused by the aperiodic twists and to a much lesser extent by the increase in the imaginary component of the dielectric constant. Notice at the extreme right-hand side of each of the figures- close to 1 GHz. This behavior seems 'to burst out again.' Computations indicate that this is 'roughly' repetitive in with increasing frequency. The presence of this behavior with |ELFEXT| repeatedly going through 0 dB may well affect the cancellation of FEXT through vectoring ..."

Bittele Electronics: PCB Fabrication & Assembly

Bittele Electronics PCB Fabrication - RF CafeSince 2003, Bittele Electronics has consistently provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly services. It specializes in board level turnkey PCB assembly for design engineers needing low volume or prototype multi-layer printed circuit boards. Free Passive Components: Bittele Electronics is taking one further step in its commitment of offering the best service to clients of its PCB assembly business. Bittele is now offering common passive components to its clients FREE of Charge.

Monday 12

Geniac Problem Solving Computer

Geniac Problem Solving Computer, June 1955 Popular Electronics - RF CafeI remember seeing advertisements for the "Geniac Electric Brain" in technical magazines like Popular Electronics, Mechanix Illustrated, Popular Science, etc., back in the 1960s and 70s. Even then it seemed like a hokey attempt to pitch a mechanical gizmo as an honest-to-goodness computer. Personal computers were still a decade or more away and only multi-million-dollar mainframe computers were available, so the opportunity for Joe Sixpack to own a "problem solving" computer was a real temptation. No, I never bought one; my first computer was a second-hand Timex Sinclair 1000 with a membrane keyboard and a cassette tape deck as a program storage device. Anyway, when I found this article in a 1966 issue of Popular Electronics, I figured maybe other people of my vintage would enjoy reading about its inner workings ...

UCMMT 2019, August 20-22

12th UK/Europe-China Workshop on Millimetre-Waves and Terahertz Technologies (UCMMT) 2019 - RF CafeThe 12th UK/Europe-China Workshop on Millimetre-Waves and Terahertz Technologies (UCMMT) 2019 will be held at the Graduate Centre, Queen Mary University of London from August 20th to 22nd. The UCMMT was created in 2008 to stimulate and strengthen scientific collaboration and knowledge and cultural exchange. The workshop is held annually, alternating between Europe and China. This conference is now well established and has become a special premier international forum for the exchange of ideas on state-of-the-art research in mmWave and THz science and technologies. Keynote speakers include Sir Colin Humphreys, Dr. Hanyang Wang, Professor Wei Hong, Prof. Yong Fan, and Mr. David R. Vizard.

Promote Your Company on RF Cafe for as Little as $45/Month

Sponsor RF Cafe for as Little as $35 per Month - RF CafeRF Cafe typically receives 8,000-15,000 website visits each weekday and about half that on weekends. RF Cafe is a favorite of engineers, technicians, hobbyists, and students all over the world. With more than 7,000 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, Facebook, and Twitter. If you need your company news to be seen, RF Cafe is the place to be. Banner advertising begins at $175/month ...

Understanding Cable Flammability Ratings

 - RF CafeL-Com has a good PDF document summarizing the flammability ratings of various types of cable. They also have some short videos showing how the cables react to a flame. These materials appeared in an article in NASA's Motion Design magazine, which also included a good definitions summary table of MICE (mechanical, ingress, climatic, and electromagnetic ) parameters in IE (Industrial Internet) standards. Many RF engineers must design systems with user and control interface in these environments and need to be familiar with the technology ...

Who Killed the Signal?

Who Killed the Signal?, February 1943 QST - RF CafeIf you're a newcomer to the game, it may seem that radio theory already has enough mystery without adding more. True, the technical journals - even QST, sometimes - do make it a mysterious subject with their textbook language and complex notations. Radio isn't really any more mysterious or complex than many a detective story - at least not after you've read the last page and know "who­dunit." The difference lies in the method of presentation. There may be some utility, then, in the idea of presenting radio fundamentals in the manner of detective fiction. That's what this is - a series of radio lessons in the guise of a detective-mystery yarn. Instead of human characters we'll use another kind - but we'll try to make the characterizations true and the background and incident realistic. Our purpose is to divert ...

Windfreak Technologies: USB-Powered RF Synthesizers, Mixers

Windfreak TechnologiesWindfreak Technologies designs, manufactures, tests and sells high value USB powered and controlled radio frequency products such as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters. Since the conception of WFT, we have introduced products that have been purchased by a wide range of customers, from hobbyists to education facilities to government agencies. Worldwide customers include Europe, Australia, and Asia. Please contact Windfreak today to learn how they might help you with your current project.

Sunday 11

Technical Headlines Crossword Puzzle for August 11, 2019

Engineering & Science Crossword Puzzle August 11, 2019 - RF CafeThis RF Cafe Engineering & Science Crossword Puzzle contains at least 10 words from headlines posted on the homepage during the week of August 5 through August 9, 2019 (marked with an asterisk*). These custom-made engineering and science-themed crossword puzzles are done weekly for the brain-exercising benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. Every word and clue - without exception - in these RF Cafe puzzles has been personally entered into a very large database that encompasses engineering, science, physical, astronomy, mathematics, chemistry, etc. Let me know if you would like a custom crossword puzzle built for your company, school, club, etc. (no charge).