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"Lightning has no sympathy for the feeble electrical schemes of civilized man." - David Heiserman

New Radiation Standards Set

Governments are historically fond of creating laws, standards, regulations, codes, ordinances, directives, notices, prohibitions, restrictions, bylaws, ordinances, and all other manner of ways to control our lives - all for our own good, don't you know. Sometimes those impositions are useful, and other times - maybe most times - they are just forms of control to keep the figurative boot on the equally figurative throats of the proletariat. According to this 1969 issue of Radio-Electronics magazine, the U.S. Department of Health, Education, and Welfare has recently been ordered to create standards for maximum radio frequency radiation exposure levels for various commercial electronic products. The move was largely driven by concerns over radiation from color televisions x-ray emission from super high voltage cathode ray tube (CRT) biases, and from microwave ovens, both of which were relatively new household appliances...

Time Reflection Measured in Microwaves

"Physicists in the U.S. have observed an effect known as time reflection in an electromagnetic wave for the first time. They detected the phenomenon - the temporal counterpart of familiar spatial reflection - by rapidly switching a series of capacitors in a novel type of metamaterial. They say the result could improve wireless communication and ultimately help bring about long-sought-after optical computing. Everyday reflection involves the transformation of a wave packet when it meets an interface in a distinct region of space. The process preserves temporal ordering, so that the leading part of the incident wave remains ahead after reflection. This means that objects further from a mirror look more distant in the reflection, while sounds in an echo arrive back in the same order they were emitted. Time reflection instead involves a wave packet being transformed as a result of an abrupt change in time that applies equally throughout the medium it is traversing. In other words, the material in question experiences a sudden shift in its properties..."

Mac's Radio Service Shop: Advertising for Dessert

Return on investment for advertising is always a prime consideration for companies, regardless of how wide the perspective audience or the size of the competition. Luck plays some part in whether a certain advertising campaign is successful, but as Mac points out in the July 1949 edition of Radio & Television News magazine, there is great advantage to measuring the effectiveness of each advertising strategy. Advertising has never been cheap, especially in venues with a large contingent of followers. In the Internet age, one of the more popular schemes is 3rd-party pay-per-click ads that are served by a central distributor (like Google and Bing) based on intelligent algorithms designed by teams of business and marketing experts. Based on my conversations with some RF Cafe advertisers who have tried Google's AdWords program, most are not happy with the results because they experience a low ratio of clicks-to-sales. Those who report success are people who have expended a lot of effort learning how the system works and how to exploit it - often after learning the hard way what the wrong way is. Unlike his fellow radio service and sales shops operators in the story, it is doubtful many businesses would be willing to share their hard-earned secrets with competitors...

You Don't See This Every Day!

Whilst on the way to a doctor appointment this morning (3/30/2023), we saw this guy driving his car with the hood smashed into the windshield. It appears the wind stream must have blown it back while driving down the road since the windshield was smashed as well. We followed him for about 5 miles on West Wendover Road, in Greensboro, NC, before he turned off onto a side road. How he managed to see well enough to guide the car is a mystery. There must have been a slim line of sight between the dashboard and under the edge of the hood based on how he was leaning over in the seat. Other drivers kept well away from him, but I had to take a risk and get up next to him to get this video. It was extremely dangerous of him to do so, but awfully funny as well.

Teledyne Relays 50⁺ GHz Mini Matrix Boxes

Teledyne Relays, a leading provider of high-performance coaxial switches, is pleased to announce the addition of 50⁺ GHz coaxial switches to its Mini Matrix Box product line. The new switches are available in SPDT, Transfer, and Multi-throw configurations each with their own GUI. They can be ordered with or without terminations, offering flexibility for various applications in RF and automated test equipment. Teledyne Relays Mini Matrix Boxes are a compact, plug-and-play solution, offering USB or Ethernet control for efficient and reliable switching in laboratory and production environments. With the addition of the 50⁺ GHz switches, Teledyne Relays can meet the growing demand for testing higher frequency applications in the industry. "The introduction of the 50⁺ GHz coaxial switches is an exciting milestone for Teledyne Relays. We are committed to delivering high-quality, reliable, and innovative solutions that help our customers stay ahead of the curve," said Michael Palakian, Teledyne Relays Vice President of Global Sales & Marketing...

Color Television?

The 1954 Tournament of Roses (aka Rose Bowl Parade) was famously the world's first national commercial color television broadcast, provided by the National Broadcasting Company (NBC). Prior to the NTSC (National Television Systems Committee) finally settling on an all-electronic scheme for TV sets, many electro-mechanical and electro-optical types were developed. The integrated RGB (red, green, blue) color gun within a cathode ray tube (CRT) was a relatively new concept in 1949. This Radio & Television News magazine article presents some of the propositions by the two major research and development players at the time: RCA and CBS. They might seem ridiculous in the light of knowledge available now, but a round wheel wasn't immediately obvious to Oog sitting in his cave, trying to figure out an easier way to transport that mastodon carcass...

RF Cascade Workbook

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

Many Thanks to Aegis Power Systems for Their Continued Support!

Aegis Power Systems is a leading supplier of AC-DC and DC-DC power supplies for custom and special applications. Aegis has been designing and building highly reliable custom power supplies since 1995. They offer a complete line of switch mode power supplies and power converters for a variety of markets including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft, EV, telecom, and embedded computing applications. Design and manufacture of custom power supply solutions to meet each customer's exacting specifications. Please visit Aegis Power Systems today. Manufactured in the USA.

News Briefs: e-Vehicles & More

Hugo Gernsback was the Ulrich L. Rhode of the early 20th century; he was very accomplished in many areas of electronics, was a prolific publisher of technical content, knew everyone of any import in the technology realm, had successful business ventures, and seemed to always be getting presented with awards from one group or another. With guys like Gernsback and Rhode, organizations considered themselves honored to have their offers accepted in order to be worthy of the recipient's attention. This collection of industry New Briefs in the January 1967 issue of Radio−Electronics magazine included the Antique Wireless Association (still in existence) giving an award to Gernsback. It also reported on General Motors using silver-zinc battery packs, SCR's and specially designed ac motors in its experimental Electrovair II - a conversion of its gas-powered Corvair. The government-controlled BBC's domination over "free" radio broadcasting was getting a challenge from the Popular Music Authority...

Microsatellites Reduce Space Junk

"Satellite powered by 48 AA batteries and a $20 microprocessor shows a low-cost way to reduce space junk. Common sense suggests that space missions can only happen with multimillion-dollar budgets, materials built to withstand the unforgiving conditions beyond Earth's atmosphere, and as a result of work done by highly trained specialists. But a team of engineering students from Brown University has turned that assumption on its head. They built a satellite on a shoestring budget and using off-the-shelf supplies available at most hardware stores. They even sent the satellite - which is powered by 48 Energizer AA batteries and a $20 microprocessor popular with robot hobbyists - into space about 10 months ago, hitching a ride on Elon Musk's SpaceX rocket..."

Bell Telephone Labs Coaxial Cable

When you read today where someone writes about, "back in the eighties...," you naturally think of 1980-something. This 1949 Radio & Television News magazine advertisement from by Bell Telephone Laboratories mention of "back in the eighties" was referencing the 1880s, not the 1980s. What was six decades ago at the time is now thirteen decades ago - yikes! The picture juxtaposes a telephone pole massively populated with horizontal cross timbers, insulators, and wires, with an engineer holding up a section of coaxial cable that was in the process of replacing the poles and wires. Thanks to Bell Labs' relentless R&D efforts, those early single-channel, short distance twisted pairs were obsoleted by 1,800-channel coax. Fiber optic cables today typically support more than 30,000 voice channels...

Measuring with Humor

A relatively new feature has been appearing on the Microwaves & RF website entitled "Measuring with Humor," compliments of Fluke Calibration. I just saw it and don't know how long it has been running, but there are four of them thus far. The comic depicts situations commonly experienced by people in the test equipment realm. Fluke, of course, is one of America's most well-known and oldest test equipment manufacturers. I have used Fluke (founded in 1948) gear since first entering the electronic and electrical field in the 1970s. It always seemed strange to me that a high end electronic test equipment company would assume the name "Fluke," even though it is the name of company founder John Fluke. Even though a fluke can be defined as an unexpected stroke of good luck, it often has a negative connotation describing an outlier event not typical of the norm. The Fluke company's good reputation is due to smart employees who design and manufacture good products - definitely not a fluke.

Understanding the JFET

Adolph Mangieri, who authored articles in other electronic magazines in the 1970s and 1980s, provides a good introduction to junction field effect transistors (JFETs) in this 1973 piece in Popular Electronics magazine. As mentioned, JFETs were a relative newcomer at the time to the commercial electronics world because of high fabrication costs. Obtaining consistent pinch−off voltages and gains was largely responsible for the relatively high production costs due to substrate purity and doping issues. Semiconductor processing and some circuit application examples are included. One of the first big commercial applications of the JFET was probably transistorized multimeters, which enabled a very high input impedance. Doing so helped minimize the loading effect on the meter on the circuit under test...

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. 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...

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

It's Monday again. Here is another batch of electronics-themed comics to help cheer you up. They appeared in the April 1963 issue of Radio−Electronics magazine. Usually the meaning of the comics is immediately apparent, or maybe after a little critical investigation, but I'm going to need some help with the page 20 comic. I must be missing something obvious. There is nothing else on the page it came from that it is supposed to go with. Maybe it is simply implying the lonely life of a TV repairman on a service call. The page 49 comic plays on the era's popular notion of a husband-wife battle involving his quest for bigger and better (and more expensive) electronics gear. If you don't "get" the humor, note the stacking of the equipment - which is stereo. Page 88's topic is as apt today as it was 60 years ago. Page 105 is yet another instance of man's obsession with stereos back in the day...

IDTechEx Report on 6G Market 2023-2043

"IDTechEx, an independent market research and business intelligence provider claims that 6G will arrive in 2028 at the earliest in its recently published market research report, "6G Market 2023-2043: Technology, Trends, Forecasts, Players". 6G, compared to its predecessor, is expected to offer significantly better communication capabilities, such as Tbps-level peak data rates, microsecond-level latency, and 99.99999% network dependability. Although 6G promises a lot, it is unlikely that 6G will be in daily life soon, despite the fact that several important companies and nations have already begun 6G research, as shown in the figure below, the telecom industry needs to address several issues before seeing the success of 6G. The difficulties are not only in THz technology but also in identifying applications that will fuel 6G adoption. IDTechEx has been researching 5G and 6G for years. This article will discuss some of the hardware-related hurdles to 6G connectivity..."

Barry Goldwater, K7UGA, Ham Radio Operator

A lot of famous people have been or are currently amateur radio operators, including many present-day astronauts who broadcast from the International Space Station (ISS). Some media people, like Tim Allen, star of the Home Improvement and Last Man Standing fame, became a Ham after playing a character who is one on his show. A 1958 edition of Popular Electronics magazine published a story titled "VIP's Are Hams Too!," which included Arthur Godfrey (9K4LIB), Herbert Hoover, Jr. (W6ZH), and Arthur Collins (W0CXX). I wrote an article on radio host Jean Shepherd (K2ORS), of "A Christmas Story" fame. Senator Barry Goldwater (K7UGA), of Arizona, was also an active Ham, as evidenced here in this May 1967 edition of the ARRL's QST magazine. Senator Goldwater also appeared in the June 1967 issue of QST...

EMI in Connected Vehicles

"Automakers need to rein in electromagnetic interference before it pumps the brakes on in-vehicle connectivity innovations. In early 1979, Ralph Liuzzi installed a mobile transmitter in his customer's Cadillac Seville. However, Mr. Liuzzi found that whenever he attempted to transmit, the car's engine would stall, resulting in a serious safety hazard for both driver and pedestrians. At the time, the National Highway Traffic Safety Administration (NHTSA) cited a 'lack of documentation on the effects of Electromagnetic Interference (EMI) on automobile electronic engine control systems,' but reviewed the case and eventually found that indeed EMI played a key role in the system malfunction. 'The problem of EMI is a relatively new one in automotive technology since electronics have only recently been introduced into usage in automobiles,' the NHTSA said in its report. Now, more than 40 years later, the problem of EMI has only grown..."

Hetro Air-Ace Series M, 4−Band Superhet

This is another Radio Service Data Sheet which appeared in the May 1936 edition of Radio-Craft magazine. I post this schematic and functional description of the Hetro Air-Ace Series M, 9-Tube 4-Band Superhet manufacturers' publications for the benefit of hobbyists and archivists who might be searching for such information either in a effort to restore a radio to working condition, or to collect archival information. A thorough search on the Internet turned up no examples of a surviving instance of the Hetro Air-Ace Series M radio. BTW, the "Air Ace" part of the name refers to the radio air, as in "on the air" or "over the air," not a fighter pilot ace with a certain number of kills painted on the side of his airplane...

Promote Your Company on RF Cafe

New 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 17,000 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 Berkeley Nucleonics for Continued Support!

Berkeley Nucleonics Corporation (BNC) is a leading manufacturer of precision electronic instrumentation for test, measurement, and nuclear research. Founded in 1963, BNC initially developed custom pulse generators. We became known for meeting the most stringent requirements for high precision and stability, and for producing instruments of unsurpassed reliability and performance. We continue to maintain a leadership position as a developer of custom pulse, signal, light, and function generators. Our designs incorporate the latest innovations in software and hardware engineering, surface mount production, and automated testing procedures.

Electronics Mathematics Quiz

Don't let the title scare you away from this "Electronic Mathematic Quiz." It appeared in the June 1969 issue of Popular Electronics magazine, and was created by quizmaster Robert Balin. There are no scary equations to complete and no mental calculations to bend your brain. Instead, the "mathematics" required is to recognize physical and electrical signal shapes which are described by common mathematics terms. For instance, a cardioid approximates the electromagnetic radiation pattern of many directional antennas, which may include a parabolic dish. Differentiator and integrator circuits generate distinct waveforms. Phase angles and critical angles are familiar to circuit designers and radio operators. Shape letter "E" will likely be familiar according to its name, although you might not know what it is in the world of electronics...

Ultrathin Metasurface Display Rivals LCD

"Currently, LCD screens are the most dominant and popular display technology for televisions and monitors, but they are unlikely to get significantly better in the future. Now a new study finds the kind of physics that make microscopic 'invisibility cloaks' possible may lead to next-generation 'metasurface' displays roughly 1/100 the thickness of the average human hair that could offer 10 times the resolution and consume half as much energy as LCD screens. LCD technology depends on liquid crystal cells that are constantly lit by a backlight. Polarizers in front and behind the pixels filter light waves based on their polarity, or the direction in which they vibrate, and the liquid crystal cells can rotate the way these filters are oriented to switch light transmissions on and off. LCD screens do continue to see advances by improving the liquid crystals, the display technology or the backlight. 'However, improvement on LCD technologies are now mostly just..."

Howard Explorer Model W All-Wave Superhet

Here are the schematics, chassis layout, and service info for the Howard Explorer Model W Deluxe 19 Tube All-Wave Superheterodyne console style (sits on the floor) radio. The wooden cabinet format is somewhat unusual in that the top is a flat surface rather than the having more typical curvaceous lines that radios of the era sported. It looks a lot like the models with built-in phonographs, where the top would tilt upward. The Radio Service Data Sheets that were published in Radio-Craft usually seem to have more information included than those published in other magazines, at least in the same era (1940-ish). It might have to do with how much material is provided by the manufacturer rather than a decision by the magazine editors. This one appeared in the September 1934 issue. Believe it or not, there are still people searching for such data. I could not find an example of a real surviving Howard Explorer Model W radio...

Morse Code Rhythm Patterns from A to Z

Given that this "Morse Code Rhythm Patterns from A to Z" article (p58) appeared in the April issue of QST magazine, I was careful to ascertain that it was not written for fools. It seems authentic, but for the life of me I don't know how many people would find the proposed Morse Code learning system to be a natural method. Author Bill Cody (K3CDY) is a musician who is accustomed to reading music, so for him and other talented musical types, maybe such a system facilitates the learning of code. To people like me, it's like suggesting a method for more easily learning how to apply a bandage by adapting brain surgery principles. Unfortunately, you'll need to be an ARRL member for access to the online article, or maybe you can borrow a copy of the magazine from a friend (but you'll still need to sign in for the music/code sheets). I'm still trying to figure out which article is the April Fools bait. BTW, I remember using one of those Isolate Pad Circuit-Board Construction tools when making proto boards (p91).

Micro-Waves Span the English Channel

We "Baby Boomers" remember a time when cell towers did not present a ubiquitous (and, frankly, ugly) presence across the landscape. Microwave relay towers for television and telephone links could be spotted sitting atop hilltops and mountain ridges in some areas, and giant television and radio station towers sat behind broadcast stations, and multi-element antennas dotted house rooftops everywhere. Our grandparents (Millennials' great grandparents) remember when even microwave relay towers were missing. This 1936 article reports on the first microwave links spanning the English Channel to replace expensive and trouble-prone submerged cable. Part of the impetus, not mentioned within, was the building inevitability of war with Germany and the vulnerability of those communications links to being compromised by Nazi submarines and divers...

Electronics Theme Crossword for March 26th

This custom RF Cafe electronics-themed crossword puzzle for March 26th contains words and clues which pertain exclusively to the subjects of electronics, science, physics, mechanics, engineering, power distribution, astronomy, chemistry, etc. If you do see names of people or places, they are intimately related to the aforementioned areas of study. As always, you will find no references to numbnut movie stars or fashion designers. Need more crossword RF Cafe puzzles? A list at the bottom of the page links to hundreds of them dating back to the year 2000. Enjoy.

Please see the RF Cafe Homepage Archives for previous items of interest...