Homepage Archive - July 2020 (page 1)

Tuesday 7

Robot Makes Radios

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

FCC Ground Conductivity Map

The U.S. Federal Communications Commission published a Ground Conductivity Map for the continental United States in 1975, and it is still the most current version. No doubt more modern ground conductivity equipment and methods could produce a more detailed and accurate map, but for general purposes, this suffices. When more precise local soil conductivity measurements are required by electric utilities, communications installations, etc., teams of technicians and/or engineers are dispatched to obtain measurements. Many moons ago (early 1990s) while doing a short stint at the Potomac Edison Electric Company in Hagerstown, Maryland, our electric substation guys had some pretty impressive measurement gear that used probes pounded into the ground in multiple locations to gets resistance (conductivity) readings between them. Where the soil conductivity is not sufficient to meet specifications with simple ground rods and/or meshes, chemical agents would be spread around the area...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 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. 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...

What Is It?

If subjects pertaining to electronics - particularly vacuum tubes - are like music to your ears, then this poem titled "What Is It?," from the February 1943 edition of QST, should suit you just fine. The rhyming words are supplied by author Frank Judd; you just need to supply the harmony. You might recognize paraphrasing of other familiar works such as Longfellow's "Paul Revere's Ride." Poems like this one were actually quite common back in the day. In fact if you look through the list of articles that I have posted from vintage QSTs, you will find about a dozen...

Many Thanks to Nova Microwave for Continuing Support!

Nova Microwave is a leader in technically differentiated electronic and radio frequency Ferrite Circulators and Isolators that connect, protect and control critical commercial and military wireless telecommunications systems. Our staff is dedicated to research and development of standard and custom design quality Ferrite Circulators and Isolators from 380 MHz to 26.5 GHz. Available in single or multi-junction topographies, the Nova Microwave product line of is specifically designed for use in varied environmental and temperature extremes. 

Alexander Graham Bell's Audio Recordings Heard 130 Years Later

If you had to guess, what would you say the image to the left represents? Part of a printed spiral inductor? How about a printed antenna for near field communications (NFC)? Need a hint? OK, the object is part of a project that Alexander Graham Bell, his cousin Chichester Bell, and Charles Sumner Tainter worked on in their Volta Laboratory Associates labs. No, it's not a neatly wound coil of telephone cable. It is a section of an audio recording etched on a glass platter in November of 1884. After being stored at the Smithsonian Museum for 130 years, this and a few other recording media was lent to the scientists at Lawrence Berkeley National Laboratory with hopes that they could apply newly invented noninvasive, non-contact techniques to scan the disc and use software algorithms to recover the data. Thomas Edison had introduced his phonograph to the world in 1877...

Bittele Electronics: PCB Fabrication & Assembly

Since 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 6

Burgess Battery Company

Before there were electric generators onboard airplanes to power communications equipment, aviators relied on storage batteries to operate their radios. Before that, there were no radios at all aboard airplanes. Although Wilbur and Orville Wright first piloted their Wright Flyer in 1903, by the end of the decade airplanes were becoming a common sight across the country and across the civilized world. By the middle of the second decade experiments were being done with airborne radio. They were heavy vacuum tube units with heavy lead-acid batteries. Antennas sometimes hundreds of feet long needed to be reeled out and in once at altitude. The earliest transmitter (for 2-way communications) were spark gap types, meaning of course Morse code was the medium. That's right, the pilot - often alone without an assistant - sent messages by tapping out dits...

Please Welcome NorthEast RF as an RF Cafe Supporter!

NorthEast RF provides quick-turnaround antenna testing services for IOT and M2M devices. Either passive antenna measurements, or OTA cellular device pre-compliance. We supply 2D | 3D antenna patterns along and antenna efficiency measurements in a report along with a data file for use with a pattern viewer. The near-field antenna test system is ideal for either free space or verification of body worn devices using our selection of human head and hand phantoms. NorthEast RF's comprehensive antenna testing services include linear | circular polarized antenna measurements and OTA cellular device pre-compliance. Antennas can be rapidly evaluated and optimized using our fast near field spherical system. Test results supplied in data file with pattern viewer software. Turnaround time is usually 3-days. Please take a few minutes to see how they can help your project.

Single-Spin Electron Paramagnetic Resonance Spectrum

"A high-resolution paramagnetic resonance detection method based on the diamond nitrogen-vacancy (NV) color center quantum sensor was proposed and experimentally implemented in a study led by academician DU Jiangfeng from CAS Key Laboratory of Microscale Magnetic Resonance of University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS). The researchers obtained the single-spin paramagnetic resonance spectrum with kilohertz (kHz) spectral resolution. The study was published in Science Advances. A major development trend of electron paramagnetic resonance spectroscopy is to get as accurate information as possible from as few samples as possible, which requires enhancing..."

San Francisco Circuits Announces NIST 800-171 Compliance

"San-Francisco-Circuits-NIST-800-171-Compliance-7-6-2020.htm" target="_top"> San Francisco Circuits (SFC), a provider of "San-Francisco-Circuits-NIST-800-171-Compliance-7-6-2020.htm" target="_top"> PCB fabrication and assembly, announces they are fully compliant with the National Institute of Standards and Technology (NIST) Special Publication 800-171 requiring companies to adhere to specific guidelines to protect data and information pertaining to federal or state agencies. Being in compliance ensures proper data handling is in place for maintaining the trust of partners, vendors, contractors, and customers–especially when federal or state agencies are involved. The federal government requires companies to be compliant with 800-171 to protect Controlled Unclassified Information (CUI). CUI is sensitive information relevant to the interests of the United States government...

MEMS Switches to Be Replaced by NEMS Relays?

Bill Schweber's article on the Electronic Design website entitled, "Watch Out, MEMS Switches - Much-Smaller NEMS Relays Are Coming After You!" shows once again that every new paradigm-changing miracle product and method is eventually trumped and rendered obsolete. "Using phase-change materials, researchers have devised a nanoscale metal-contact on/off switch that doesn't use a flexure element and is far smaller than its MEMS-based counterparts. There's no doubt that devices based on MEMS (microelectromechanical systems) processes and technologies have radically changed the world of sensors and solid-state functions. Since they became commercially viable in the 1980s beginning with analog airbag impact-acceleration sensors...

Windfreak Technologies: USB-Powered RF Synthesizers, Mixers

Windfreak 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 5

Independence Day 2020 Radio Crossword Puzzle

This week's custom RF Cafe crossword puzzle celebrates the 244th anniversary of the signing of the Declaration of Independence, and uses as a background the John Trumbull painting. Clues marked with an asterisk (*) are part of the theme. Each week for two decades, for the sake of all avid cruciverbalists amongst us, I have created a new technology-themed crossword puzzle using only words from my custom-created lexicon related to engineering, science, mathematics, chemistry, physics, astronomy, etc. You will never find among the words names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort. You might, however, find someone or something in the otherwise excluded list directly related to this puzzle's technology theme...

Friday 3

Printed Radio Components

As I have written often, Hugo Gernsback was one of the electronics industry's most prolific authors, inventors, and innovators. In this 1947 article in his Radio-Craft magazine, he proposes using printed components in place of leaded resistors. In fact, he sold printed resistive cards through his Radio Specialty Company (Rasco) that could be cut into whatever size was needed to achieve the required amount resistance based on a certain ohms/square value. He also mentions creating printed inductors on Bakelite and even fashioning variable-coupling transformers with a pair of inductor plates sliding relative to each other, similar to capacitive "variometers" used for tuning RF circuits. Not to neglect the possibility of capacitors, Gernsback suggests possibly spraying a thin conductive coating on paper and then rolling multiple layers into a tubular form, achieving a smaller form factor per unit capacitance that what was currently being achieved. Single- and double-sided printed circuit boards were already being used for some high volume, compact portions of assemblies, and he proposes improving methods to eventually...

CMT Release Compact VNAs with Improved Performance

"Copper-Mountain-Technologies-Compact-VNAs-Improved-Performance-7-2-2020.htm" target="_top"> Copper Mountain Technologies has released the new Compact S5045 and M5045 VNAs with a frequency range from 9 kHz to 4.5 GHz. Featuring a dynamic range of 130 dB typ. and measurement speed of 70 µs, these new "Copper-Mountain-Technologies-Compact-VNAs-Improved-Performance-7-2-2020.htm" target="_top"> Compact VNA offerings will effectively replace the functionality of the recently discontinued S5048, while delivering improved performance. The S5045 will come with the advanced software features engineers expect from CMT's S Series Compact VNAs. The M5045 will join the M Series line of Compact VNAs and include standard VNA software features in an economical package that excludes a number of advanced software features...

Northrop Grumman, Boeing Build C-Band Satellites to Clear 5G Spectrum

"SES, leader in global content connectivity solutions, announced its selection of two U.S. satellite manufacturers, Northrop Grumman and the Boeing Company, to deliver four new satellites as part of the company's accelerated C-band clearing plan to meet the Federal Communication Commission's objectives to roll-out 5G services. Northrop Grumman will deliver two flight-proven GeoStar-3 satellites, each equipped with a high-quality C-band payload to deliver the superior customer experience that end users are accustomed to. The two satellites - SES-18 and SES-19 - will be designed, assembled and tested in Dulles, Virginia. The Boeing Company will deliver a pair of highly efficient all-electric 702SP satellites. The two satellites - SES-20 and SES-21 - will be manufactured and assembled in Los Angeles, California..."

Today, July 3, Marks the Beginning of The Dog Days of Summer

The Dog Days of Summer, contrary to what many people believe, is named not to describe the hottest, most humid, most oppressive period of the year, but marks the astronomical point in time following the heliacal rising of the star system Sirius, aka the Dog Star in the constellation Canis Major. 40 days later, on August 11th, the Dog Days end. That also happens to be middle of summer (not midsummer), which is on or about August 6th. Never having been a proponent of summer, the end of the Dog Days has always meant we're closer to the end of summer than to the beginning, and autumn is on the way.

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

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 (of course a gratuity will be graciously accepted). 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...

Google Technology & Science Doodles

Do you remember seeing a cool Doodle on the Google search page and would like to find it again? Would you like to see not only the Doodle that piqued your interest, but ALL of the Doodles that Google has ever published? You can do that, but what might be more useful would a page full of all the technology- and science-related Doodles (click large image below) or some other specific topic. Fortunately, there is an easy way to find what you want by going to the Google website and typing "google doodles" into the search box, or just go to www.google.com/doodles. Once you get there, enter the specific event that interests you. Since some events have Doodles in more than one year, add a year to your search to narrow down returns...

San Francisco Circuits: PCB Fabrications & Assembly Service

SF 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."

Thursday 2

Transatlantic News

"Transatlantic News" was a regular column in the 1940 issues of Radio-Craft magazine, written by their European correspondent Major Ralph Hallows. As the title suggests, it reported on happenings from across the pond. A couple items caught my attention in this edition. One is about one of the first instances of the prediction of existence of a D-Layer in the ionosphere based on radio signal propagation characteristics noted by operators. The article estimates a height of about 30 miles, while the modern definition of the D-Layer places it at between 60 km (37 mi) to 90 km (56 mi). It also has a piece describing a simple method for silver plating without the need for supplying an electrical current. It involves making a paste of silver chloride and cream of tartar (potassium bitartrate) and rubbing it on the target metal. Supposedly the bond is as durable as electroplating...

It's All About the Antennas for 5G

Lou Frenzel has an article on the Microwave & RF website entitled, "It's All About the Antennas for 5G." He begins: "For 5G technology to function as expected in apps from factory automation to self-driving vehicles, multiple antennas must be properly implemented. When studying 5G NR operation, it's not immediately obvious that 5G meets all of the objectives of the 3GPP standard by using advanced antenna technology. Antennas are often overlooked and treated with indifference. After all, antennas are just that nuisance metal thing that you have to put on a radio to make it work. In the case of 5G, antennas play a major role in achieving the expected features and performance. The primary objectives of 5G NR are..."

Please Welcome ISOTEC as an RF Cafe Supporter!

Since 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...

Radio Terms Illustrated

The "Radio Terms Illustrated" comics was a pretty clever feature in Radio-Craft magazine in the 1940s. Readers submitted ideas about how words and phrases commonly used in electronics and communications could be rendered in comical picture form. Illustrator Frank Beaven, who did work for many magazines of the day, then put pen to paper to render the kinds of comics shown here. You will note that the first of the drawings, "Amplitude," is one which probably would not pass editorial review these days, but was de rigueur back in the days when men made up the vast majority of readers. By today's standards many advertisers would face a threat of boycott and a front-page apology would be demanded... and then the magazine would be forced out of business anyway. There is no satisfying "the mob." Utter destruction of the past is their goal. To show how extreme...

RF Cascade Workbook 2018

RF Cascade Workbook 2018 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. 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...

Alliance Test Equipment: Used & Refurbished, Purchase & Rental

Alliance 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. Please visit Allied Test Equipment today to see how they can help your project.

Wednesday 1

Radio Inventions of Lee de Forest

As is the case with most genius inventors who change the world, Lee de Forest's contribution to the world of electronics neither began with nor ended with his invention of the Audion amplifying vacuum tube. As detailed in many of the other articles published in the January 1947 edition of Radio-Craft magazine that commemorated the 40-year anniversary (see ToC), de Forest's path from a simple open flame type of demodulator to the ultimate design of the evacuated glass-encased Audion tube with plate, control grid cathode, and heater element required many years of trial and error. The stories were so captivating that I actually read every article in this edition. Eventually, I will have all of them posted. This particular piece by Fred Shunaman reports on some of the many other innovative, patented inventions of de Forest such as antenna transmission lines (twin lead and coaxial), radio signal detector...

2nd Edition of Artech House Radar Best Seller Available

"Artech-House-Cognitive-Radar-Knowledge-Aided-Adaptive-6-30-2020.htm" target="_top"> Artech House today announced the release of "Cognitive Radar: The Knowledge-Aided Fully Adaptive Approach," Second Edition by Joseph R. Guerci. Hurry to get the discounted new-release price. This highly anticipated second edition of the bestselling Cognitive Radar: The Knowledge-Aided Fully Adaptive Approach, the first book on the subject, provides up-to-the-minute advances in the field of cognitive radar (CR). Adaptive waveform methods are discussed in detail, along with optimum resource allocation and radar scheduling. Chronicling the field of cognitive radar (CR), this cutting-edge resource provides an accessible introduction to the theory and applications of CR and presents a comprehensive overview of the latest developments in this emerging area...

Many Thanks to ConductRF for Continued Support!

ConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 

Electronics-Themed Comics from a 1958 Radio-Electronics

Good, clean humor has always been a welcome addition to my day whether it comes in the form of a printed comic strip, a TV show, or someone's mouth. My father's side of the family was populated with many jokesters who could be counted on to deliver an ad hoc pun or zinger at the appropriate moment. The environment instilled a great appreciation for such entertainment, so these electronics-themed comics that appeared in editions of Radio-Electronics, Popular Electronics, et al, are a refreshing distraction from the workaday world. An old saying claims "laughter is the best medicine," and while it cannot cure cancer, a good dose of humor often helps ease the pain...

Fractal Cloaking Antennas

Fractals have been a mathematical curiosity since first being popularized by Benoit Mandelbrot (who coined the term) in the 1960s. Perhaps, and in retrospect no coincidence, was the popularity of the cloaking concept featured in the 1960s phenomenon called Star Trek. I say coincidence because who would have guessed that some of the leading research in invisibility cloaking would involve barriers derived from fractal forms? Have aliens been guiding the technology? If so, maybe they're working at Fractal Antenna Systems, because in mid December the company issued a press release detailing work being done on a cloaking system that works in the microwave band (as opposed to visible light) - chosen for convenience...

RF Superstore: Supplier of RF & Microwave Components

RF Superstore launchedin 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!

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. Some quoted items have been shortened to save space. About RF Cafe.

Homepage Archive Pages

2026:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2025:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

2024:  Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

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)

- Christmas-themed items