Search RFC: |                                     
Please support my efforts by advertising!
About | Sitemap | Homepage Archive
Serving a Pleasant Blend of Yesterday, Today, and Tomorrow™
Vintage Magazines
Electronics World
Popular Electronics
Radio & TV News
QST | Pop Science
Popular Mechanics
Radio-Craft
Radio-Electronics
Short Wave Craft
Electronics | OFA
Saturday Eve Post
Please Support My Advertisers!

Aegis Power | Centric RF | RFCT
Alliance Test | Empower RF
Isotec | Reactel | SF Circuits

Formulas & Data

Electronics | RF
Mathematics
Mechanics | Physics


Calvin & Phineas

Resources

Articles, Forums, Radar
Magazines, Museum
Radio Service Data
Software, Videos


Artificial Intelligence

Entertainment

Crosswords, Humor Cogitations, Podcast
Quotes, Quizzes

Parts & Services

1000s of Listings

        Software:

Please DONATE

RF Cascade Workbook | RF Symbols for Office
RF Symbols for Visio | RF Stencils for Visio
Espresso Engineering WorkbookCafe Press
Exodus Advanced Communications Best in Class RF Amplifier SSPAs - RF Cafe

Electronics-Themed Comic, February 1972 Popular Electronics

Electronics-Themed Comic, February 1972 Popular Electronics - RF CafeThis is a great electronics-themed comic from a February 1972 issue of Popular Electronics. It encompasses the essence of the stereotypical salesman ruse, especially in that era when people were sure that electronics repair services were out to rip them off by selling unneeded services and replacement parts. Aspiring TV technicians who couldn't grasp the technology moved on to working as mechanics in a garage, poking tiny holes in brake lines to scare owners into paying for complete braking system rebuilds. I usually like to post multiple comics on each page, but at the moment only this one is available...

Betavoltaic Cell Needs No Charging

Hybrid Betavoltaic Cell Needs No Charging - RF Cafe"Scientists have achieved a major breakthrough by creating the world's first next-generation betavoltaic cell. This advanced power source was made by directly connecting a radioactive isotope electrode to a perovskite absorber layer, a cutting-edge material known for its efficiency. Betavoltaic cells generate electricity by capturing beta particles emitted during the natural radioactive decay. In theory, they can operate for decades without maintenance. Beta particles also present excellent biological safety advantages, as they cannot penetrate human skin. The newly developed technology offers a stable, long-term power supply without the need for recharging, making it a promising next-generation..."

B&K Manufacturing Co. Advertisement

B & K Manufacturing Co. Advertisement, April 1960 Electronics World - RF CafeUntil solid state electronics had supplanted the majority of vacuum tube type televisions and radios, portable tube testers were essential equipment to successful, efficient troubleshooting and repair in businesses and people's homes. Yep, believe it or not the stories told about doctors and electronics repairmen visiting homes are not just fables. I remember as recently as the 1960s having our family doctor make house calls when I or one of my fours sisters got sick. Both doctors and TV servicemen ceased the practice at about the same time - probably the result of a Brotherhood of Electronics Technicians and General Practitioners collective bargaining agreement ;-) Many column inches of editorials, articles, comics, and letters to the editor were devoted to the trials and tribulations of in-home servicemen and the experiences...

How a Capacitor Works

How a Capacitor Works Block DC Pass AC - RF CafeFinally, a concise, 1,000-word essay (a picture's worth a thousand words, right?) that illustrates how a capacitor can block direct current (DC), but pass alternating current (AC), has been published! Even the uninitiated layman can now understand a principle that has stumped even electrical engineering students for two centuries. What used to require a familiarity with Faraday's and Ampere's laws, electric field and charge theory, and a mastery of calculus to fully comprehend, is now within the grasp of the common man. It is no longer necessary to use the water system equivalent (e.g., pressure=voltage, flow=current, diameter=resistance) of a rubber diaphragm inside a pipe to get through to fledgling electric circuit students. This ingenious drawing appeared on an online news site (no attribution).

Frequency-to-Meter Conversion Chart for Hams & SWL's

Frequency-to-Meter Conversion Chart for Hams & SWL's, June 1966 Popular Electronics - RF CafeAs with your school and college days where once there was no longer any reason to memorize physical constants, conversion formulas, and names of people, places, and things, much of the noggin's gray matter was repurposed to remember topics of more immediate need. You can always look up what you have forgotten. While studying for your Ham radio or FCC license, being able to be able to quickly convert between wavelength and frequency is essential. Recalling on demand frequency-wavelength pairs is a real time saver on a timed exam. Even being able to perform the conversion on a calculator during the test takes up valuable time that could be better used on other tasks. This handy-dandy chart for converting...

Quadrature FM Detectors: Function and Failure

Quadrature FM Detectors: Function and Failure, December 1959 Electronics World - RF CafeQuadrature modulation and demodulation is as commonplace and unremarkable today as were Space Shuttle launches before NASA cancelled the program in 2011 (eliminating America's ability to send astronauts into space). However, before integrated circuit implementation was available, it was a relatively rarely employed scheme. Yes, there were many applications using analog quadrature systems, but use with digital communications requires closely matched (amplitude and phase) pairs of mixers and power splitters / combiners, along with close tracking over time and temperature. The "magic" of quadrature systems is...

Phosphors and Their Uses

Phosphors and Their Uses, December 1959 Electronics World - RF CafePhosphorous: From Latin phosphorus "light-bringing," from Greek Phosphoros "morning star," literally "torchbearer," from phos "light," contraction of phaos "light, daylight" + phoros "bearer," from pherein "to carry." Long before mankind had developed methods of bombarding phosphorous compounds with electron beams to make them glow, 17th-century scientist Hennig Brand observed the characteristic light emitting property of phosphorous when exposed to oxygen. No doubt the Ancients noticed the naturally occurring glow of bioluminescent plants and animals, and maybe even luminescent glow caused by the breaking open of phosphorous-containing rocks. Radioactive decay in the vicinity of phosphorescent materials can also cause a...

Engineering & Tech Headlines <Archives>

• 5 Trends Set to Redefine Global Telecoms

• RAN Sales Grow in U.S., Decline Globally

• U.S. Restricts EDA Software Sales to China

• FCC To Close Robocaller Network Loophole

• NI Highlights Role of AI in SDR Solutions for SIGINT

She Wore a Red Germanium

She Wore a Red Germanium, January 1965 Popular Electronics - RF CafeAllegory is not an often seen style of prose in the electronics writing world, and typically is not meant to be humorous; however, there have been a few instances of it in the vintage electronics magazines I read. One of the most famous examples of allegory is a story by Paul Bunyan titled "Pilgrim's Progress." "She Wore a Red Germanium," by Leta Foster Ide, is a more contemporary form of allegory that RF Cafe visitors will appreciate. Mike R. Fonic (microphonic) is the lead character in the story who complains to his doctor, "I'm off my feed. Got no capacity. Fact is, I'm in a breakdown." Mike's wife's Aunt Enna (antenna) is no help, evidently. Come to think of it, the author's name, Leta Foster Ide...

Hi-Fi Crossover Networks

Hi-Fi Crossover Networks (part 2), May 1959 Electronics World - RF CafeSince I am currently planning a loudspeaker configuration to replace the original speaker in my 1941 Crosley 03CB floor model AM / shortwave radio set, this article made for a good refresh on audio frequency crossover networks. A very nice set of design charts is provided. Of course today there is no need to design and build your own since commercial units are very good and cost less than what I could build myself. Many moons ago while serving in the USAF at Robins AFB, Georgia, I did actually build my own crossover circuit for use in custom speaker cabinets I built in the base woodshop. The speaker that came in the Crosley has a 12" cone, which is still in good condition, but it uses an electromagnetic voice coil rather than a permanent magnet like modern speakers use...

Solder Gun Thermal Wire Stripper

Solder Gun Thermal Wire Stripper, May 1959 Electronics World - RF CafeHidden away on page 134 of a 1959 issue of Electronics World, at the end of a Mac's Service Shop-like electronics shop docudrama (Another Day in the Shop) is this handy tip on how to fabricate a make-shift thermal wire stripper from a soldering gun or a soldering iron. The beauty of thermal strippers over mechanical strippers is that they do not nick the underlying metal wire. Heated elements melt the insulation and then a blunt edge is used to slide the insulation off the end of the wire. Another advantage is that you can strip a wide range of wire gauges and insulation types without needing to adjust the jaws or change to a different hole location - although a proper temperature setting is required to avoid a gloppy, stringy mess...

Anatech Electronics Intros 3 New Filter Models for July

Anatech Electronics Intros 3 New Filter Models for July 2025 - RF CafeAnatech Electronics offers the industry's largest portfolio of high-performance standard and customized RF and microwave filters and filter-related products for military, commercial, aerospace and defense, and industrial applications up to 40 GHz. Three new filter models have been added to the product line in July, including a 1200-3000 MHz highpass filter, a 118-137 MHz user-tunable VHF filter, and a 1215.6-1239.6 MHz / 1563.42-1587.42 MHz GPS L1/L2 cavity duplexer filter. Custom RF power filter and directional couplers designs can be designed and produced with required connector...

At the 1929 Radio World's Fair

At The 1929 Radio World's Fair, November 1929, Radio-Craft - RF CafeYou've heard of the World's Fairs, the most familiar probably being the 1933 Chicago World's Fair where the theme was "A Century of Progress." World's Fairs have been held in various cities worldwide since the late 1790s. In 1929, the World's Fair was held in the United Kingdom, but the "Radio World's Fair," which began its annual run in 1924 (click on stamps thumbnail), was held in New York City. Surprisingly little exists on the Internet about the events. It was more of a trade show to introduce new products than it was a fair, as can be seen from the photos. Radios with decorative wooden cabinets were becoming popular as the number of commercial broadcast stations was growing rapidly. Remote control in the day meant a handheld unit with a cable attached to the main system. Crosley introduced its first gendered radio model - the Monotrad...

R. F. Interference Filters

R. F. Interference Filters, April 1969 Electronics World - RF CafeSprague Electric engineer Benedict Rosen, discusses how the characteristics of a circuit in need of protection against RF interference needs to be considered when selecting filter components. He points out that attempting to hang a shunt feedthrough capacitor on the input and/or output of a low impedance (e.g., 50 Ω) RF circuit could make the situation worse, depending on whether the circuit is strongly capacitive or inductive in its out-of-band region. Sprague was a major manufacturer of all sorts of capacitors qualified for use in military and aerospace systems, so they put a lot of effort into characterizing device parameters over a wide range of voltage, current, power, temperature, mechanical, and frequency environments...

UJT Monostable / Monocycle Multivibrator

UJT Monostable / Monocycle Multivibrator, April 1969 Electronics World - RF CafeMonostable multivibrator, one-shot multivibrator, monocycle multivibrator - it's a matter of semantics, although the circuit designer doesn't necessarily think so. The distinction, evidently, is that this monocycle multivibrator uses a positive-going pulse as a trigger and the output in its rest (stable) state is a digital "0" (low). A mere 2 mA of current flows since all the unijunction transistors (UJTs) are turned off. A UJT, to refresh your memory, is not used as a linear amplifier because of its regenerative, negative resistance operating region that causes it to effectively lock into a fully on or fully off conduction state until an external stimulus causes...

Notable Quote by Dilbert

Dilbert Notable Quote - RF Cafe"Forecasts are mostly just guessing plus math" - Dilbert, 12/1/2017. It was part of a dialog with the Pointy-Haired Boss who compelled Dilbert to prepare a financial report for him...

Thanks Again for Windfreak Technologies' 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.

Of Zerts, Plenches and Spunfits

Of Zerts, Plenches and Spunfits - RF CafeThe manned space program has unarguably provided mankind with many new and innovative tools, medicines, electronics, materials, physics, materials, appliances, and mathematics. Known officially as "spinoffs," products include items like the portable heart defibrillator unit, the portable vacuum cleaner, freeze-drying food processors, powdered lubricants, memory foam, quartz clocks and battery-powered tools. Many NASA inventions have not found an application in your basement or garage, however, because their purpose is too specialized. Take, for instance, the ZeRT, or Zero Reaction Tool. It is basically a torque wrench that is operated by one hand by squeezing. As the name implies, the ZeRT removes the consequence of Newton's third law motion...

Low-Noise Receiver Performance Measurements

Low-Noise Receiver Performance Measurements, March 1969 Electronics World - RF CafeI was first introduced to the concept of receiver noise figure at the start of my engineering career in 1989 at General Electric AESD in Utica, NY. During my four years in the U.S. Air Force working on airport surveillance and precision approach radars, I do not recall having ever heard the term noise figure or noise temperature. We did signal to noise and signal sensitivity measurements as part of the normal maintenance, but the terms never arose. Ditto for my courses at the UVM. We never did cascade parameter calculations for noise figure, intercept points, compression points, etc. That is primarily the realm of practicing...

New Semiconductor Supercharges 6G

New Semiconductor Supercharges 6G Delivery - RF CafeA team at the University of Bristol developed SLCFETs, a breakthrough transistor structure that leverages a latch effect in GaN materials to enhance speed and power, advancing the future of 6G. Self-driving cars that eliminate traffic jams, receiving a healthcare diagnosis instantly without leaving your home, or feeling the touch of loved ones across the continent may sound like science fiction. However, new research led by the University of Bristol and published in the journal Nature Electronics could bring these possibilities closer to reality, thanks to a groundbreaking breakthrough in semiconductor technology...

Bell Telephone Labs' Sugar-Scoop Antenna

Bell Telephone Labs' Sugar-Scoop Antenna, November 1960 Electronics World - RF CafeBeing the birthday of Dr. Robert W. Wilson, there is no better occasion to post this article about the "sugar-scoop" antenna used by the two Bell Telephone Labs engineers (the other being Dr. Arno A. Penzias) who serendipitously discovered the cosmic microwave background radiation (CMBR) believed to be a signature of "The Big Bang." The pair were investigating an unexplained hiss in the background of the very low noise receiver attached to the antenna. That microwave energy was constant and came from all areas of the sky, regardless of where the antenna was pointed. They eventually deduced that the signature was consistent with...

Many Thanks to ConductRF for Continued Support!

ConductRF coaxial cables & connectors - RF CafeConductRF 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! 

Radio Industry Unfair?

Radio Industry Unfair?, May 1946, Radio-Craft - RF CafeTo some extent, I agree with the readers of Radio-Craft magazine who wrote to editor Hugo Gernsback complaining about the lack of opportunity available to radio servicemen returning from the battlefield at the end of World War II. As noted in this editorial entitled, "Radio Industry Unfair?," many are people who sold or took leave from their established electronics service and/or stores in answer to their country's call to go abroad to fight for the free world. However, Radio-Craft was, throughout 1945, filled with advertisements by electronics manufacturers promising jobs and opportunities and anticipated demand for representation by service shops and sales outlets. Evidently, it did not turn out to be so, at least to the degree predicted. Gernsback does have a good point, though, that if the letters submitted to him are an indication of the quality...

Today in Science History

Today in Science History - RF Cafe

Espresso Engineering Workbook™ for Excel

RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeThe newest release of RF Cafe's spreadsheet (Excel) based engineering and science calculator is now available - Espresso Engineering Workbook™. Among other additions, it now has a Butterworth Bandpass Calculator, and a Highpass Filter Calculator that does not just gain, but also phase and group delay! Since 2002, the original Calculator Workbook has been available as a free download. Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is also provided at no cost, compliments of my generous sponsors. The original calculators are included, but with a vastly expanded and improved user interface. Error-trapped user input cells help prevent entry of invalid values. An extensive use of Visual Basic for Applications (VBA) functions now do most of the heavy lifting with calculations, and facilitates a wide user-selectable choice of units for voltage, frequency, speed, temperature, power, wavelength, weight, etc. In fact, a full page of units conversion calculators is included. A particularly handy feature is the ability to specify the the number of significant digits to display. Drop-down menus are provided for convenience...

Recent Developments in Electronics

Recent Developments in Electronics, September 1965 Electronics World - RF CafeThe items reported in the September 1967 issue of Electronics World magazine represent the beginning stages of many technologies that are still in used today. The monolithic ferrite memory was a major producibility improvement in what was formally hand-wired toroidal matrices of cores. They were the first step in integrated memory (although we don't use magnets anymore in ICs (just on hard drives). The Electronically Controlled Robot looks like something from a modern Japanese university - without the skin, hair, and eyeballs. Note that as today, supplying power is one of the biggest hurdles in making a human-looking robot (umbilical required). The Solid State Camera "Tube" is one of the very first solid state camera imaging chips. It had a whopping 2,500 pixels. The Computer-Directed Drawing Machine converted a 2-dimensional drawing into a 3-dimensional perspective. Shipboard Satellite Communications was at the time one of the first uses of satellites for global communications, it being a big deal because...

78th Anniversary of Operation Overlord

Hallicrafters Advertisement Operation Overlord D-Day, July 1944 QST - RF CafeWith today being the 78th anniversary (June 6, 1944) of the D-Day invasion of Normandy (aka Operation Overlord) and other beachheads on the coast of France, I thought posting this advertisement from the July 1944 edition of QST magazine would be apropos. This issue of the magazine probably arrived in ARRL member's mailboxes within a couple weeks of the miraculously successful invasion of Omaha Beach, Utah Beach, Gold Beach, Juno Beach, and Sword Beach. When you consider that in those days - and also not so long ago for that matter - the lead time for going to the printing presses was measured in months, the fact that this ad made the final cut for the next month's issue (July) is noteworthy. Accordingly, I duly make note. Back in the 1980s, there was a big push for commercial-off-the-shelf (COTS) equipment to be used in military equipment in order to save money. It was the era of $600 hammers and $7000 coffee makers manufactured by defense contractors. The Project On Government Oversight (POGO) was created to address concerns. Anyway, donations of equipment and components from private citizens...

The World Administrative Radio Conference (WARC)

A Report on the World Administrative Radio Conference, December 1971 Popular Electronics - RF CafeThe World Administrative Radio Conference (WARC) is associated with the International Telecommunications Union (ITU). It is hard to pin down exactly when the organization's name official became the WARC since it is no longer a separate entity, and good luck locating a definitive history on the WARC proper. The closest I could come to determining a time when it was first referred to as the World Administrative Radio Conference was from this list of all radio conferences on the ITU website. The Geneva 1967 WARC is it. Previous events did not include the word "World" in them, from what I could find. Please let me know if you have another authoritative source...

Bliley Electric Company Advertisement

Bliley Electric Company Advertisement, April 1945 Radio News - RF CafeBliley Electric Company is one of the relatively few companies that advertised regularly in electronics magazines during the World War II era that is still in business today - at least under the same name (Bliley Technologies now, but still the same base name). While the company is no longer located in the Union Station Building anymore, it does still live in Erie, Pennsylvania, only a mile or so from where I Melanie and I last lived there (2021). They still make crystals today, albeit with different materials and different methods. In fact, there is a short Bliley company history video on their website, and also this video from a local TV station showing of the internal workings at Bliley...

Tech-Related Comics from The Saturday Evening Post

Tech-Related Comics from The Saturday Evening Post - RF CafeA few years back, I bought the issues of The Saturday Evening Post which contained the very first published comics from Peanuts creator Charles Schulz. As with just about everything else, they were available on eBay for a few bucks apiece (although prices have really gone up since the beginning of the year). Most of the issues also had articles and advertisements - and even comics - that make appropriate fodder for both RF Cafe and my hobby website, Airplanes and Rockets. Here are a few of the tech-related comics I found. The first one might seem to be a bit distasteful to the survivors of the RMS Titanic disaster and/or their relatives, given that only 36 years had passed. The next one is about architectural engineer - ahem, and the Hazel comic applies for obvious reasons...

Liquid Crystals for Electronics

Liquid Crystals for Electronics, January 1973 Popular Electronics - RF CafeLiquid crystals have been with us for so long now that it is hard to imagine a time when they were considered a scientific laboratory entity. Before being controlled by electric fields for use in alpha-numeric displays, the thermal properties of liquid crystals of the cholesteric type found applications in temperature and power measurements. Since the colors scattered by cholesteric liquid crystals under incandescent light are unique to a given temperature, measurement of temperature is possible to an accuracy of better than 0.1 °C. Bendix manufactured a liquid crystal microwave power density meter. Nematic liquid crystals are the type found in displays (twisted nematic LCD's) and are controlled by an electric field which causes light to be transmitted or blocked at varying levels. In 1973 when this article appeared in Popular Electronics magazine, Seiko...

Fractal Cloaking Antennas

Fractal Cloaking Antennas - RF CafeFractals 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...

TV X-Rays Are Back

TV X-Rays Are Back, June 1969 Radio-Electronics - RF CafeColor television was a big hit with homeowners and was adopted fairly rapidly in the 1960s even considering the relatively high cost and low number of network color broadcasts in the beginning years. The enthusiasm underwent a severe reduction when word got out that large doses of x-rays were streaming out of the front of the CRT for sets that did not take precautions to prevent it (which was the majority of sets initially). The major cause was extremely high voltages applied between the electron gun and phosphorescent raster grid - in the neighborhood of 35 kV or more - when the high voltage regulator circuit malfunctioned. Note that even when everything was working properly, a small amount of x-ray radiation was emitted. The x-ray problem...

Nomograph Construction

Nomograph Construction, June 1946, Radio-Craft - RF CafeEven in this current age of ubiquitous computers and cellphones (also computers), there is still ample reason to consider using nomographs for presenting data and providing a hand calculation or conversion resource. In days prior, nomographs were an indispensible tool for both design and troubleshooting circuits. A huge number of nomographs can be found here on RF Cafe as they appeared in vintage magazine articles. This 1946 issue of Radio-Craft presents the first of a two-part tutorial on creating nomographs for any purpose, and uses current, voltage, and resistance as an example. Their utility is not limited to electrical and electronic topics, as many have been created for plumbing, hydraulics, mechanics, chemistry, finance, aerodynamics, pneumatics, lighting, acoustics, and I've even seen one...

Bell Telephone Laboratories Advertisement

Bell Telephone Laboratories Advertisement, October 1949 Radio & Television News - RF CafeBell Telephone Laboratories used to run some pretty interesting advertisements in magazines back in the 1940s through 1960s that touted the many communications innovations coming from their scientists and engineers. They built what was indisputably the worlds best, most reliable telephone network. It, along with the Interstate Highway System, is credited for a large part of what fueled America's growth so significantly after World War II. This ad from a 1949 issue of Radio & Television News magazine tells how repairmen used a specially designed sensor to trace out faulty phone lines by listening for a test signal sent out by the central office. What caught my attention about this ad was the uncanny resemblance the man in the photo has to Melanie's father - especially with the ball cap and glasses...

The Amana Radarange

The Amana Radarange, March 1955 Popular Electronics - RF CafeAs legend goes, the use of microwaves for preparing food was pursued after a serendipitous discovery by Raytheon engineer Percy Spencer whereby he noticed the chocolate bar in his pocket had melted while he was working near a radar transmitter magnetron. Being a newly discovered phenomenon in 1945, Mr. Spencer was probably not aware that his own body parts were being likewise cooked, but he did recognize the commercial potential of an oven that used microwaves to cook food. It only took Raytheon (Amana) to have the first Radarange available for sale to professional kitchens. This article was printed a full decade after the discovery and even then the size and power consumption was too great for grandma's countertop ...

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...

TV Station List Test Patterns & Logos

TV Station List Test Patterns & Logos, January 1951 Radio-Electronics - RF CafeAnyone out there old enough to remember when you were a kid and managed to be able to stay up late enough, maybe on a Saturday night, to be able to watch the television station sign off the air at night? Here in the U.S., the custom was to announce the end of the programming day, play the National Anthem, and then put up the station logo while broadcasting a single tone. The tone and test patterns were actually used by TV technicians for calibrating instruments for use in servicing sets. In 1951 when this TV Station List appeared in Radio-Electronics magazine, black and white (B&W) was still the standard, so these images are what you would have seen then. I'm not quite that old (born in 1958), but I do recognize the stations we could receive at my parent's home in Mayo, Maryland. Being located between Washington, D.C., and Baltimore, a pretty good selection of both VHF and UHF...

Basic Digital Logic Course - Number Systems

Basic Digital Logic Course, December 1974 Popular Electronics - RF CafeThis first of a three-part series on digital electronics run by Popular Electronics magazine begins with introducing binary (base 2), octal (base 8), and decimal (base 10) number systems, along with conversions between the types. Sure, this is probably old-hat to most RF Cafe visitors, but there is always a new cadre of electronics enthusiasts entering the field who appreciate the instruction. No matter how advanced digital electronics gets, a fundamental understanding and fluency in binary arithmetic is essential to success whether as a hobbyists or as a professional. If you cannot move effortlessly between the various number formats (which also include hexadecimal and Gray code), then continuing to Boolean algebra...

Exodus Advanced Communications Best in Class RF Amplifier SSPAs - RF Cafe