Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising Magazine Sponsor RF Cafe RF Electronics Symbols for Visio RF Electronics Symbols for Office Word RF Electronics Stencils for Visio Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Anritsu Alliance Test Equipment Amplifier Solutions Anatech Electronics Axiom Test Equipment Berkeley Nucleonics Centric RF Conduct RF Copper Mountain Technologies Empower RF everything RF Exodus Advanced Communications Innovative Power Products ISOTEC KR Filters Lotus Systems PCB Directory Rigol San Francisco Circuits Reactel RFCT TotalTemp Technologies Triad RF Systems Windfreak Technologies Withwave LadyBug Technologies Wireless Telecom Group Sponsorship Rates RF Cafe Software Resources Vintage Magazines Thank you for visiting RF Cafe!
DC-70 GHz RF Cables - RF Cafe

Homepage Archive - January 2022 (page 4)

See Page 1 | 2 | 3 | 4 of the January 2022 homepage archives.

Monday the 31st

Telemetry Engineer Needed at National Radar Test Facility

Telemetry Engineer Needed at National Radar Test Facility - RF CafeReliance Test & Technology (RT&T), a high-technology firm specializing in information systems, science and engineering, and technical and administrative services, is seeking a Telemetry Engineer for work at the National Radar Test Facility at White Sands Missile Range. The Telemetry Engineer is responsible for the architectural design, integration, testing and operation of telemetry systems for the Dynamic Range Measurement System (DRMS). Experience with flight test instrumentation and telemetry (TM) systems, telemetry ground stations such as the Advanced Range Data System (ARDS) and Data Acquisition, Recording and Telemetry (DART) systems. Strong technical background with technical problem-solving skills. Must be hands-on and capable of working with limited to no supervision. Expert knowledge of systems engineering practices & best practices...

Century-Old Electrochemistry Law Updated

Century-Old Electrochemistry Law Updated - RF Cafe"The Gouy-Chapman theory describes what happens near an electrode when it is in contact with a salt solution, but this description does not match reality. Researcher Kasinath Ojha, assistant professor Katharina Doblhoff-Dier and professor Marc Koper present a new version. 'The next generation of textbooks on electrochemistry is going to look different.' When you look inside a fuel cell, one of the things you will see is an electrode, often made of platinum. This piece of metal is in contact with a salt solution, which contains positively and negatively charged particles called ions. If you were to zoom in on the interface between the electrode and the salt solution, you would perceive all kinds of interactions. At the surface of the electrode, a shortage or abundance of electrons exists..."

Philco Model 200-X Radio Service Data Sheet

Philco Model 200-X Radio Service Data Sheet, December 1934 Radio-Craft - RF CafeIn order to facilitate searches for information on vintage radios, I have been scanning and running OCR (optical character recognition) on many of the Radio Service Data Sheets like this one featuring the Philco Model 200-X, 10-tube high-fidelity superheterodyne model in graphical format, rather than run OCR on them to separate the textual content. It appeared in the December 1934 issue of Radio−Craft magazine. A fine restored example of the Philco Model 200−X appears on the Radio Museum website. 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. A running list of all data sheets can be found at the bottom of the page to facilitate a search...

Signal Hound Intros Free LTE Analysis Mode in Spike™

Signal Hound Introduces Free LTE Analysis Mode in Spike™ - RF CafeSignal Hound recently updated its flagship Spike software to include LTE Analysis Mode. Users and fans of the company's free and heavily capable spectrum analyzer software will now find a highly useful LTE measurement function in the package. The addition of an LTE utility to the core spectrum analysis software package, Spike, aligns with Signal Hound's commitment to its customers and users - to provide unrivaled value in the test equipment industry. Spike contains an ever-growing list of analysis tools for measuring the world's most popular communication signals, making Signal Hound and Spike the most cost-effective solution for many communications and network engineers. Spike's new LTE measurements allow for the monitoring and scanning of LTE downlink signals. Customers can monitor a single frequency or define...

Zeppelin Radio Equipment

Zeppelin Radio Equipment, July 1936 Radio-Craft - RF CafeMay 6, 1937, is the date of the Hindenburg disaster at the Naval Air Station in Lakehurst, New Jersey, and is the RF Cafe logo theme for that Day in History (see upper left page corner). Ironically, last night while looking through the July 1936 edition of Radio-Craft magazine, I saw this news article reporting on preparations being made in the onboard radio and direction finding equipment for Hindenburg's maiden voyage from its home base in Frankfurt, Germany to North America. No one at the time of this article suspected such a terrible fate was looming less than a year later. Theories abound regarding the cause of the fatal fire, but there is no doubt that a combination of highly flammable hydrogen gas and an also highly flammable graphite dope (used to make it conductive and lightning impervious) impregnated cloth envelope was responsible for the incredibly rapid consumption...

Promote Your Company on RF Cafe for as Little as $40/Month

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 Bittele Electronics for Continued Support!

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.

Sunday the 30th

Antenna Theme Crossword Puzzle for January 30th

Antenna Theme Crossword Puzzle for January 30th, 2022 - RF CafeThis custom made Antenna theme crossword puzzle for January 30th is provided compliments of RF Cafe. 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 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!

Thanks to Windfreak Technologies for Continued Support!

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.

Friday the 28th

More About Attenuators

More About Attenuators, January 1954 Radio-Electronics - RF CafeI didn't know that another name for a nomogram (or nomograph) is an "abac," but thanks to Mr. Crowhust in this 1954 Radio-Electronics magazine article I now do. At first I thought maybe it was a shortened version of abacus, but I couldn't find anything suggesting that. Anyway, this article presents a couple abacs you do not often (if ever) see - the attenuation and reflection levels for resistive attenuators when the impedance(s) are incorrect for the designed values. Keep in mind, particularly when using off-the-shelf components like attenuators, filters, power couplers and splitters, PIN switches, etc., that if your source and load impedances are not exactly the same as the component input and output impedance (usually 50 Ω or 75 Ω), the response will not be as advertised. Achieving the proper performance will require inserting an impedance matching section...

How Electrons Respond to X-rays

How Electrons Respond to X-rays - RF Cafe"A study of electron dynamics timed to millionths of a billionth of a second reveals the damage radiation can do on a molecular level. The first-of-its kind study used ultrafast X-ray laser pulses to disrupt the electrons in a molecule of nitrous oxide and measure the resultant changes with unprecedented accuracy. The work, published today in Science, was performed at the Linac Coherent Light Source (LCLS) at the Stanford Linear Accelerator Centre (SLAC), Stanford, U.S. and was supported by a team of five scientists from Imperial College London. Conventional X-rays used in imaging and radiotherapy can cause damage to cells, but exactly how on a molecular level is not known. Additionally, new high-intensity and short-pulse-duration X-ray lasers are being proposed to image smaller molecules with greater precision, leading to questions about potential damage this could cause to living tissue. For the first time..."

ConductRF Ruggedized Replacement VNA Cables

ConductRF Ruggedized Replacement VNA Cables 2022 - RF CafePrecision Ruggedized VNA Cables from ConductRF offer RF Engineers great alternatives to costly OEM cables that are now past their best days. We have standards for applications at 18 GHz, 27 GHz, 40 GHz, 50 GHz & 70 GHz. Our torque resistant connector heads and phase stable constructions ensure great performance for many tests to come. ConductRF VNA series provides customers with reliable ruggedized solutions for Lab and Production Vector Network Analyzer testing. With options for 18 GHz, 26.5 GHz, & 40 GHz, these cables offer cost leading alternatives to original OEM VNA cable solutions. VNA Series cables are enhanced with a stainless steel spiral armor, providing protection from excess bending and crushing forces. A black non-conductive outer cover completes the product. These cables are phase stable during flexing and have an operating life cycle...

An Interesting Experiment in Weighing the Electron

An Interesting Experiment in Weighing the Electron and What It May Mean, September 1932 Radio News - RF Cafe"We might say almost, that all modern scientific investigation in the basic sciences, and a good deal of all practical developments, are connected in some way or other with the electron." So writes Dr. Irving J. Sax in this 1932 issue of Radio News magazine regarding the incentive for determining as precisely as possible the mass and electrical charge of an electron. The Bohr atomic model had just been introduced two decades earlier, so the entire concept of particle physics was still in its infancy. As with most areas of physics, experiments are conducted with particular biases and expectations such that often the results are manipulated as needed to conform to preconceptions. Look no further than the complex retrograde motion planetary models devised and perfected by early astronomers who believed the universe revolved around the Earth. It wasn't until a heliocentric model was accepted (following the exile and execution of many "heretics") that orbital systems became simplified and readily explainable. The same, to some extent, has been true of subatomic particle physics, except digging deeper into the true nature of the beast has continually revealed greater and greater complexity. Each time a new "fundamental" particle is discovered through empirical testing, an new, more basic element is theorized...

CONATEL Relies on Efficient Microwave Link Measurement from R&S

CONATEL Relies on Efficient Microwave Link Measurement from Rohde & Schwarz - RF CafeCONATEL, the regulatory authority of Paraguay, has chosen the R&S AMS aerial monitoring system from Rohde & Schwarz to efficiently verify the technical parameters of the ever-increasing number of microwave links in the country. R&S AMS is a small, lightweight monitoring payload carried by a commercial drone. This solution allows easy, economic and effective measurements by flying inside the main lobe of microwave links that usually run horizontally tens of meters above the ground and are otherwise very hard to access. The R&S AMS payload comprises a spectrum analyzer, antenna, control computer, Wi-Fi unit and battery pack. Having its own battery and data link make the payload independent from the drone's infrastructure. Weighing less than 4.5 kg...

Acid-Flux Solder

Acid-Flux Solder, April 1951 Radio & Television News - RF CafeIf you do repair or restoration work on electronics assemblies with leaded components (i.e., not surface mount), large metal mounting tabs, or other relatively high mass surfaces to be soldered and the surfaces are contaminated and/or not easily tinned, then the advice offered in this 1951 Radio & Television News magazine article is well worth considering. Acid flux is normally taboo around electronics, but, as author Herbert Brier points out, there are instances where, with careful work, it can be used to create surfaces which can then be soldered using standard rosin flux. The key is to use the acid flux sparingly and being sure to thoroughly clean off the acid flux residue before moving on to rosin flux. I have done this with both electronics and mechanical parts (such as music wire for model airplane landing gear). I do NOT recommend ever using acid flux on insulated wire if the flux can wick up under the insulation, and NOT on stranded wire since the flux will get between the individual strands and can eat away at it over time. An exception might be if the aforementioned wires are just being tinned and can be placed in an ultrasonic cleaner...

Promote Your Company on RF Cafe for as Little as $40/Month

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.

Please Thank RF Superstore for Their Continued Support

RF Superstore coaxial cable, connectors, adapters - RF CafeRF Superstore launched in 2017, marking the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and microwave Industry. Pasternack fundamentally changed the way RF components were sold. Partner Jason Wright manages day-to-day operations, while working closely with Mr. Pasternack to develop RF Superstore into a world class RF and microwave component supplier. RF coaxial connectors & adapters, coaxial cable & cable assemblies, surge protectors, attenuators. Items added daily. Free shipping on orders over $25. We're leading the way again!

Thursday the 27th

Standing Wave Ratio

Standing Wave Ratio, December 1974 Popular Electronics - RF CafeThere is no such thing as too many articles on the subject of standing wave ratio. Standing waves were known and studied long before their behavior in transmission lines was of concern. Although the Wikipedia entry for standing waves credits Michael Faraday for first noticing them, undoubtedly centuries prior to that scientists like Archimedes, Isaac Newton, and Descartes observed and studied standing waves in ropes, vines, water, and other media. Author Carl Drumeller went into a fair amount of detail with his description of the phenomenon and the mathematical treatment of it, although he avoided the application of complex numbers lest he scare away those unfamiliar with them (a wise decision). This is one of the rare articles where voltage, current, and power standing wave descriptions are provided...

Impossible Material Possible in Graphene Sandwich

Impossible Material Possible in Graphene Sandwich - RF Cafe"Atoms bind together by sharing electrons. The way this happens depends on the atom types but also on conditions such as temperature and pressure. In two-dimensional (2D) materials, such as graphene, atoms join along a plane to form structures just one atom thick, which leads to fascinating properties determined by quantum mechanics. Researchers at the University of Vienna in collaboration with the Universities of Tübingen, Antwerp and CY Cergy Paris, together with Danubia NanoTech, have produced a new 2D material made of copper and iodine atoms sandwiched between two graphene sheets. The design of new materials allows for either improved efficiency of known applications or totally new applications that were out of reach with the previously existing materials..."

Transistor Roundup

Transistor Roundup, December 1961 Radio-Electronics - RF CafeWhen this "Transistor Roundup" article appeared in a 1961 issue of Popular Electronics magazine, the world was just getting serious about the transition from vacuum tubes to semiconductors. The slow take-up with solid state diodes and transistors was not simply a matter of not wanting or trusting the newfangled technology; it was also a practical matter of components being available which could be used in place of existing technology from both a performance and price perspective. In looking through the transistor parameter pages, the highest cutoff frequency I find is 800 mc (MHz), which was pretty good for the day, but most topped out in the tens of MHz. Power dissipation was a mere 75 mW, so that limited applications to low power oscillators, switches, and amplifiers. As we now know, within a decade semiconductors would completely replace tubes in new equipment except for high power and high voltage circuits...

Velocity Modulation of Electron Beams

Velocity Modulation of Electron Beams, May 1939 QST - RF CafeVarian is a company familiar to most people involved in early development of radar and other higher power microwave systems. While the name sounds like a moniker construed from a combination of technical terms, it is actually the surname of engineer brothers Russell H. and Sigurd F. Varian. They are credited with building the first practical reflex klystron tube, and its variant the rhumbatron, while at Stanford University. Velocity modulation, the subject of this 1939 QST magazine article, changes the speed of a stream of electrons flowing at a constant current rate, rather than modulating the current. It was a big deal that eventually found application in CRT displays for adding another dimension to information on monochrome presentations...

Modelithics COMPLETE Library v21.9 for Sonnet Suites

Modelithics Releases the Latest COMPLETE Library v21.9 for Sonnet Suites - RF CafeModelithics® is pleased to announce the release of version 21.9 of the Modelithics COMPLETE Library for Sonnet Suites. Modelithics models represent discrete components that are typically very difficult to represent with EM analysis, thus combining Modelithics circuit models with Sonnet Suites software represents a "best of both worlds" simulation experience. This new release includes the addition of 23 new models as well as compatibility with the latest version of Sonnet (v18). The Modelithics COMPLETE Library for Sonnet Suites includes over 360 Microwave Global Models™ for capacitor, inductor, and resistor part series. Version 21.9 adds new models to the library for components from vendors such as AMOTECH, Coilcraft, KEMET, Kyocera-AVX, Passive Plus, TDK, and Vishay, among others. Specifically, new Microwave Global Models are included for the AMOTECH A60Z and A60L capacitor series. Both models are validated to 50 GHz. Version 21.9 also includes new models for the TDK CGA1A2C0G, CGA1A2X7R, and CGB1T3X5R0J104M capacitor series...

FCC Cancellation Notice for Amateur Radio Station During WWII

FCC Cancellation Notice for Amateur Radio Station During WWII - RF Cafe SmorgasbordYou probably read a while back of the San Francisco's Bay Area Rapid Transit (BART - good acronym, as in Simpson) shutting down cellphone service in order to thwart a rumored attempt to organize a flash mob attack. 1st Amendment groups have sued BART over the action. Also in the news has been the government's plan for being able to shut down the Internet in the event of a national emergency (defined as whatever they need it to mean). We already know that Big Brother has the capability to universally control both wired and wireless phone service. OnStar-equipped vehicles have been shut down remotely by law enforcement. It all seems very Orwellian, but it began before the publication of "1984" (in 1949). Did George just dream up the book's theme of total government control and a lemming populace, or did it come from astute observations of past behavior that was projected into the future? On December 8, 1941, the day after the Japanese attack on Pearl Harbor, the FCC issued a "Notice to All Amateur Licensees" that began thusly: "All amateur licensees are hereby notified that the Commission has ordered the immediate suspension of all amateur radio operation in the continental United States...

Post Your Engineer & Technician Job Openings on RF Cafe for Free

Engineering Job Board - RF Cafe RF Cafe's raison d'être is and always has been to provide useful, quality content for engineers, technicians, engineering managers, students, and hobbyists. Part of that mission is offering to post applicable job openings. HR department employees and/or managers of hiring companies are welcome to submit opportunities for posting at no charge. 3rd party recruiters and temp agencies are not included so as to assure a high quality of listings. Please read through the easy procedure to benefit from RF Cafe's high quality visitors...

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.

Wednesday the 26th

Tesla's Trickery

Tesla's Trickery, May 1960 Popular Electronics - RF CafeIf a kid built a Jacob's Ladder type of high voltage spark machine today and took it to school, he would probably be accused of bringing a lethal weapon onto the grounds. An FBI SWAT team would subsequently storm his house at 5:00 in the morning and drag him and his family members out onto the front lawn in their pajamas and conduct a thorough search of the premises for other such weapons of mass destruction. The mainstream media would all be there, having been tipped off by the Feds. In the 1970s when I was in junior high school in Annapolis, Maryland, a couple times a year one of us electrical tinkerers would show up with one to amaze and, to be honest, scare fellow students. Mine was housed in a shoebox and was barely powerful enough to generate a respectable climbing arc on a dry winter day...

Electrically Adaptive Liquid Camera Lens

Electrically Adaptive Liquid Camera Lens - RF Cafe"Researchers in China have developed an adaptive liquid lens based on dibutyl adipate (DBA), a new electrically responsive fluid that changes focal length when a voltage is applied. According to the team, the lens is suitable for mobile phone cameras, endoscopes, eyeglasses and machine vision applications because it is lightweight, compact and simple to fabricate. 'The human eye can arbitrarily focus on objects at different distances at incredibly fast speeds,' said research team leader Miao Xu from Hefei University of Technology. 'Inspired by this functionality, we developed an eye-like adaptive liquid lens that can be used to diverge or converge light by changing the shape of the DBA liquid.' In Optics Letters, the researchers describe their new DBA-based adaptive liquid lens..."

PMI January 2022 Product Announcement

Planar Monolithic Industries' (PMI) January 2022 Product Announcement - RF CafePlanar Monolithic Industries (PMI) recently introduced six new products in their extensive line of RF and microwave components. Included are a DC to 40 GHz absorptive, SPST PIN diode switch; a 110 to 210 MHz frequency discriminator; a 0.5 to 18.0 GHz non-reflective, 10 bit, 60 dB PIN diode attenuator; a 160 MHz frequency discriminator; a 0.1 to 50.0 GHz SP8T absorptive switch; and a 26.5 to 40.0 GHz, passive amplitude equalizer with a negative slope. Contact PMI today for more information...

Hogarth in Echophone Radio Company Ad

Hogarth in Echophone Radio Company Ad, June 1945 Radio-Craft - RF CafeHogarth is a comic character invented by the Echophone Radio Company. Their bespectacled Army grunt was one of the first technology nerd types who always managed to appear with pretty girls. His caricature evolved quickly over the two or three year run of the advertisements in electronics magazine. Most Echophone Radio ads I have seen either feature Hogarth and his woman/women or Hogarth and a demanding sergeant. This full-page advertisement appeared in the June 1945 edition of Radio−Craft magazine. Echophone radios can still be found on eBay for fairly low prices - often less than the shipping cost...

R&S Equips German Navy's NH90 MRFH w/Secure Comms

Rohde & Schwarz Equips German Navy's NH90 MRFH with Secure Communications - RF CafeRohde & Schwarz will equip the German Navy's NH90 Multi-Role Frigate Helicopter (MRFH), with SOVERON family airborne radios that include embedded COMSEC. Each aircraft is fitted with three VHF/UHF transceivers plus spares. The navy will receive 31 helicopters - a naval version of the NH90 - that offer close-range protection, anti-surface-warfare (ASuW) und anti-submarine-warfare (ASW), transport, and search and rescue capabilities. The SOVERON family airborne transceiver uses state-of-the-art communications algorithms that were standardized throughout NATO, and particularly for naval applications. The transceiver's interfaces...

Youngest YL Amateur Radio Licensee

Strays - Youngest YL Amateur Radio Licensee, October 1953 QST - RF Cafe7-year-old Sharon Pakinas was celebrated as the youngest licensed female - aka "YL" (young lady) - Ham radio operator in 1953. That was quite an accomplishment considering that she had to not only pass the written test which included FCC regulations, operational guidelines, electrical theory, but also pass a 5 word-per-minute Morse code test! From what I can find in a Google search, the current youngest licensed girl is 5½-year-old Rosalie White, from Long Beach, California, who earned her ticket in 1991 while a 5 WPM code test was still required. In 1991, the Morse code test for the Technician level license was removed, allowing easier access to Ham radio. The FCC dropped the Morse code requirement for all license levels in 2007...

Resistance Measurements

Resistance Measurements, January 1946 Radio News - RF CafeThe advent of FET-input multimeters greatly reduced reading accuracy errors due to not taking into account the impedance of devices being measured. A certain amount of familiarity with how to interpret the indication on a meter movement on analog meters is still required based on the multiplier switch position and scale selected, but for most users simply reading the number beneath the pointer - or interpolating its position between two numbers - is good enough. Mirrored scales take the some of guesswork out of that by reducing parallax issues. Finally, digital multimeters (DMMs) hit the scene and made slackers out of just about all of us when it comes to making voltage, current, and resistance measurements. With few exceptions, only production test, research, and metrology environments require pulling out the meter specifications to determine precision and accuracy numbers...

RF & Electronics Symbols for Office™

RF & Electronics Schematic & Block Diagram Symbols for Office™ r2 - RF Cafe It 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!

Thanks to Anritsu for Their Support!

Anritsu (electronics test equipment)Anritsu has been a global provider of innovative communications test and measurement solutions for more than 120 years. Anritsu manufactures a full line of innovative components and accessories for RF and Microwave Test and Measurement Equipment including attenuators & terminations; coaxial cables, connectors & adapters; o-scopes; power meters & sensors; signal generators; antenna, signal, spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth & WLAN testers; PIM testers; amplifiers; power dividers; antennas.

Tuesday the 25th

Carl and Jerry: The Black Beast

Carl and Jerry: The Black Beast, May 1960 Popular Electronics - RF CafeBefore a plethora of readily available and affordable electronic and mechanical components of all sorts was at your fingertips (on a keyboard), often times project builders and repairmen either did without, substituted "close enough" parts, waited a long time for mail order, drove long distances to a supply house, or did like Carl and Jerry did in this May 1960 Popular Electronics magazine adventure - they modified on-hand equipment to suit the need. Replacing the center conductor of a length of RG-58 coaxial cable in order to change its capacitance (and impedance) might seem like an extreme measure to take, but half a century go it was de rigueur with hobbyist of all sorts. Magazines of the era nearly always had monthly hints, kinks, tip, and suggestions features, enthusiastically provided by readers who had already reaffirmed the old adage of necessity being the mother of invention. As is author John Frye's normal practice...

Thales & Airbus Perlan Glider Test Extreme Altitude Communications

Thales & Airbus Perlan Glider Test Extreme Altitude Communications - RF Cafe"Thales has partnered with the climate and aerospace research project Airbus Perlan Mission II, with plans to create the 'highest ever Wi-Fi hotspot.' Airbus Perlan Mission II Through the partnership, Thales will aim to fly its latest mobile satellite communications system, FlytLink, in a zero-emission glider to more than twice the altitude of a commercial airline flight. Based in Nevada, the Airbus Perlan Mission II team is planning for a possible return to flight this year in the US and El Calafate, Argentina. The group has already set aviation world altitude records in the Perlan 2 glider, which was designed, built and deployed to fly to 90,000ft. Launched in 2015, the Perlan 2 achieved its highest record-setting flight of above 76,000 in 2018. The organisation's mission is to conduct climate, atmospheric and aeronautical research at extreme high altitudes. Applications of its research include informing more accurate climate change models, innovating zero-emission aviation and demonstrating feasibility of using energy-efficient winged aircraft on Mars..."

Radio History and Growth

Radio History and Growth, September 1942 Radio Retailing Today - RF CafeDuring my daily technical headlines search, one of the websites I regularly visit is Radio Ink. As a lifelong fan of over-the-air broadcast radio (and TV), it is interesting to see what trends are playing themselves out. OTA (over the air) broadcasting is struggling to survive in this modern world of Podcasts and Internet streaming broadcasts; indeed, I do a lot of my radio listening via the Internet because the local stations don't provide what I want. The Big Media types are involved in a major lobbying effort to mandate FM radio receivers in all cellphones, which of course is a prime example of corporate chieftains using their financial might to pay off politicians for something that the rest of us will ultimately have to foot the bill for. Radio's early days faced no such dilemma. People the world over were excited about the advent of radio and eagerly awaited their favorite broadcasts each day...

RF Superstore Is Your Source for Bulk Coaxial Cable

RF Superstore Your Source for Bulk Coaxial Cable - RF CafeRF Superstore offers a wide selection of popular coaxial cable in bulk lengths at exceptional prices - order by the foot for any custom length needed for your project. RF coaxial connectors are available for terminations. RF Superstore also offers power couplers, attenuators, terminations, DC blocks, surge protectors, waveguide, and more. The launch of RF Superstore in 2017 marked the return of Murray Pasternack to the RF and Microwave Industry. As founder and CEO of Pasternack Enterprises from 1972 to 1992, Mr. Pasternack fundamentally changed the way RF components were sold throughout the industry. His signature catalog greatly simplified the ordering process and became the industry standard for RF component sales. We're leading the way again...

Test Tube for Sound: Bell Telephone Labs

Test Tube for Sound: Bell Telephone Labs, December 1947 Radio News - RF CafeSome people like to demean engineers and scientists for their propensity to want to conduct experiments and obtain measured, empirical data rather than "winging it" and being satisfied with intuitive knowledge or the contemporarily popular term "gut." If mankind had not adopted scientific methods and ventured beyond the so−called cradle of civilization on the African continent, we would all still be living in grass huts, hurling rocks at prey, and foraging for berries. Quantifying and categorizing all things in nature helps inventors create new and improved implements that help make life better. Early on it was mostly individuals like Archimedes, Euler, Newton, and Edison who built the pool of knowledge that fed and evolved into corporations, governments, and universities doing the vast majority of the work. Bell Laboratories is probably one of the most recognizable names for a group of people that collectively produced an immense amount of data and products...

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 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."

Monday the 24th

R/C Triplex: 3 Controls on 1 Channel

R/C Triplex: Three Controls on One Channel, November 1956 Popular Electronics - RF CafeThis "R/C Triplex: Three Channels on One Channel" article that appeared in a 1956 issue of Popular Electronics magazine was written by a fellow who was well known in the aeromodeling world at the time - Claude McCullough. Claude won many titles in precision scale for both control line (C/L) and radio control (R/C). As was the case with many R/C modelers of the era, he did a lot of experimentation with transmitters, receivers, and electromechanical devices used to move control surfaces. Rubber-band-powered escapements dominated the field, but some servomechanisms were being developed to provide a means for proportional control and/or a more powerful means of multiposition control. As can be seen in the video I produced showing how a typical escapement worked, the output drove the airplane's rudder to either neutral, full left, or full right deflections, with no position in-between. To actuate the control, the R/C pilot pushed a button on the transmitter the number of times required to affect the desired control movement. That made for somewhat jerky flights, but it was a very popular setup...

Superpower Molecule Could Revolutionize Science

Superpower Molecule Could Revolutionize Science - RF Cafe"When scientists discovered DNA and learned how to control it, not only science but society was revolutionized. Today researchers and the medical industry routinely create artificial DNA structures for many purposes, including diagnosis and treatment of diseases. Now an international research team reports to have created a powerful supermolecule with the potential to further revolutionize science. The work is published in Nature Communications. The researchers describe their supermolecule as a marriage between DNA and peptides. DNA is one of the most important biomolecules, and so are peptides; peptide structures are used, among other things, to create artificial proteins and various nanostructures. 'If you combine these two, as we have, you get a very powerful molecular tool..."

Windfreak App Note: Testing RF Generators for Reliability

Windfreak App Note: Testing RF Generators for Reliability - RF CafeDavid Goins, founder of and chief engineer for Windfreak Technologies, has written a number of application notes pertaining to the specification and testing of RF and microwave frequency signal generators. Most of the articles include features and applications for Windfreak Technologies products, but the concepts are universally applicable. His latest, "Testing RF Generators for Reliability" is featured here. It begins: "We pride ourselves in designing, building, and selling high value radio frequency products that are thoroughly evaluated and tested. All of our products go through rigorous testing before releasing to our customers. Our devices have proven to be very reliable. In rare cases, we have had a product come back for repair caused by output amplifier failures. In this post, we explain the testing process we go through to ensure our high-quality products and the two reasons for output amplifier failures..."

The Semiconductor Diode

The Semiconductor Diode, May 1961 Popular Electronics - RF Cafe"What are these devices?" "How do they work?" "What are their characteristics?" "How are they used?" Those are the kinds of questions about semiconductor diodes posed - and answered - in this article in a 1961 issue of Popular Electronics. Author Jim Kyle runs through a short history of he diode and then delves with more detail into physical construction, I-V curves, power handling, junctions capacitance, resistance, etc. An interesting point mentioned is that while a semiconductor diode will conduct some finite amount of current when biased in the reverse direction (sometimes a desired characteristic), a vacuum tube diode will not conduct at all when reverse biased - thereby making the tube a more perfect rectifier...

Westinghouse "Columnaire" Radio Service Data Sheet

Westinghouse "Columnaire" Models WR-8 and WR-8-R (Remote Control) Radio Service Data Sheet, June 1931 Radio-Craft - RF CafeWestinghouse's motive for dubbing the Model WR−8 the "Columnaire" is apparent when you see a photograph of it. This model also had a −R version with remote control. The remote, though, has a cable attached to it; it's not wireless like today's remote controls. There are some very nice photos of a fully restored WR−8−R version on the AntiqueRadios.com website forum. Look about half-way down the page. Near the bottom of the page is a copy of an advertisement for the Westinghouse WR-8 with a price of $193 (~$3,563 in 2022 money per the BLS Inflation Calculator). The fundamental circuit of these receivers is the WRV5 receiver chassis and power pack shown in Data Sheet No. 29. The model WR-6 is a highboy; its circuit is the same as used in the WR−6, except as modified for tone control. The Model WR−7 is similar to the model WR−6, except as modified for an electric phonograph...

Radio Electromagnetic Spectrum Frequency Bands

Radio Electromagnetic Spectrum Frequency Bands - RF CafeIn response to my solicitation for information on the origin of band letter designations, a website visitor offered this: "I just looked at your web page that gives the names of the various RF bands, and, in one place asked for any information on origins of the names. I have some history on the band names that apply to UHF and above. In the early days of radar (during WWII), the British and the U.S. researchers at MIT chose, arbitrarily I believe, letter designations for radar frequencies. The frequencies that were then possible to use for radio communication were just called by their 'meter range' names: HF, VHF and UHF. The new frequencies that were then only used for deployable radar sets, and for new technology looking for even shorter wavelength radars, were given letter designations. So, in the 1940s and 1950s, radar sets were identified as being UHF, L-Band, S-Band, C-Band, X-Band and K-Band. Later they added Ku-Band - presumably for 'K Upper,' but I do not know..."

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 for Alliance Test Equipment's Support!

Allied Test Equipment Products - RF CafeAlliance 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.

Sunday the 23rd

Amateur Radio Theme Crossword Puzzle for January 23rd

Amateur Radio Theme Crossword Puzzle for January 23rd, 2022 - RF CafeThis January 23rd custom made crossword puzzle has an Amateur Radio theme, compliments of RF Cafe. 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 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!

Google's White Spaces Spectrum Database

Google's White Spaces Spectrum Database - RF Cafe SmorgasbordThere are not many technical realms where Google engineers have not either entered or created. Wireless connectivity is key to their continued dominance in the information domain, so they understandably have a vested interest in the "white space" spectrum debate. White space comprises portions of the electromagnetic spectrum where bands are either unlicensed or where licensed bands are or will be up for grabs. An example of the former is the 2.4 GHz Wi-Fi band, and an example of the latter is some parts of the broadcast television band that is being vacated in areas. Although this information is a few years old, it shows how Google was working early−on with the Federal Communications Commission (FCC) to build a real-time database of what they term "dynamic spectrum" in order to provide useful information about available white space (now directs here) to both users and providers. A separate database is available for fixed and mobile spectrum. Enter your location of interest and the map zooms into that region. For instance, in my town (at the time) of Erie, Pennsylvania (see marker on map below), as of January 2013 when this was first posted there were 21 channels available...

Get Your Custom-Designed RF Cafe Gear!

Custom-Designed RF-Themed Cups, T-Shirts, Mouse Pads, Clocks (Cafe Press) - RF CafeThis assortment of custom-designed themes by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins, Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's" design has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per item - Cafe Press gets the rest of your purchase price. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. It's a great way to help support RF Cafe. Thanks...

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.


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.

Homepage Archive Pages

2023:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2022:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2021:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2020:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2019:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2018:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2017:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2016:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2015:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2014:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2013:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2012:  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 (no archives before 2012)

Innovative Power Products Couplers
Windfreak Technologies Frequency Synthesizers - RF Cafe
Innovative Power Products Passive RF Products - RF Cafe
Anatech Electronics RF Microwave Filters - RF Cafe

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free


About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024


    Kirt Blattenberger,


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...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website: