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 LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives Magazine Sponsor RF Cafe Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Alliance Test Equipment Centric RF Empower RF ISOTEC Reactel RF Connector Technology San Francisco Circuits Anritsu Amplifier Solutions Anatech Electronics Axiom Test Equipment Conduct RF Copper Mountain Technologies Exodus Advanced Communications Innovative Power Products KR Filters LadyBug Technologies Rigol TotalTemp Technologies Werbel Microwave Windfreak Technologies Wireless Telecom Group Withwave RF Cafe Software Resources Vintage Magazines RF Cafe Software WhoIs entry for RF Cafe.com Thank you for visiting RF Cafe!
Werbel Microwave (power dividers, couplers)



TotalTemp Technologies (Thermal Platforms) - RF Cafe

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

RF Cascade Workbook for Excel

RF & Electronics Symbols for Visio

RF & Electronics Symbols for Office

RF & Electronics Stencils for Visio

RF Workbench

T-Shirts, Mugs, Cups, Ball Caps, Mouse Pads

These Are Available for Free

Espresso Engineering Workbook™

Smith Chart™ for Excel

Windfreak Technologies SynthHD PRO - RF Cafe

Homepage Archive - July 2023 (page 1)

See Page 1 | 2 | 3 | 4 | of the July 2023 homepage archives.

Friday the 7th

What's Your EQ?

What's Your EQ?, May 1964 Radio-Electronics - RF CafeAll three questions in the May 1964 Radio−Electronics magazine "What's Your EQ?" challenge should not be too difficult for most RF Cafe visitors. EQ, by the way, stands for "Electronics Quotient." For the first one, you might want to make use of the Delta-Wye converter in the newly released (and free) Espresso Engineering Workbook™. With the Voltage Divider, don't bother trying to write multiple equations in multiple unknowns. By inspection you can deduce what the voltage drop across the 2.5 kΩ resistor are, then knowing that the current through all resistors is the same, figure out the required values of R1 and R3. Finally, sum all the resistances and multiply by the current. Done. I have to admit to not getting the Doodle answer. If I had time, I'd do the oscilloscope thing to verify the author's solution...

Spectrum Analyzers Help Find Harmful Interference

Axiom Blog: Spectrum Analyzers Help Find Harmful Interference - RF CafeAxiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post entitled "Spectrum Analyzers Help Find Harmful Interference," that helps users find a spectrum analyzer with the functionality needed to simplify interference hunting in a desired frequency range. The growing number of wireless applications and signals creates increased opportunities for interference when signals are not properly monitored. When interference does take place, it degrades system performance and inevitably must be detected and eliminated. This requires spectrum monitoring and interference hunting with the right tools and the best equipment for that job is the spectrum analyzer. With a spectrum or signal analyzer teamed with a suitable antenna, it is usually possible to detect and measure a source of RF interference. By measuring as many as the signals within a frequency range of interest, such as around 2.4 GHz for Bluetooth and wireless local area network (WLAN) signals and any additional, unwanted signals, potential interference can be detected and displayed with a spectrum analyzer...

Line Impedance Stabilization at 70

Line Impedance Stabilization at 70 - RF Cafe"Seventy years ago in May, the 5 microhenry line impedance stabilization network (LISN) made its debut in MIL‑I‑6181B.2. Aside from the EMI receiver itself, the LISN is one of the oldest and most successful pieces of EMI test equipment in existence. And while EMI receivers have changed a great deal since 1953, the 5 μH LISN is not only still with us, but almost unchanged and used in commercial aviation and the automotive industry, as well as military applications worldwide. Other LISNs have come and gone, and others are with us still. The way we use LISNs has changed over time, not always for the better. But the LISN is here to stay in the world of EMI testing. In the beginning, radio receivers used on WWII Army aircraft were quite susceptible to very low levels of noise on their primary (28 Vdc) power input. Further, unshielded antenna lead-ins were very susceptible to capacitive crosstalk from noisy 28 Vdc electrical power feeds. The first EMI standards tried to control both these radio frequency interference (RFI) coupling paths. Prior to 1953, JAN-I-2255 used a pair of 4 μF bypass capacitors in shunt (8 μF total capacity between power feeder and ground plane) and a 10' length of power wire suspended not more than ¼" from the ground plane..."

Ethernet at 50: Past, Present, & Future

Ethernet at 50: Past, Present, and Future - RF CafeI still use wired Ethernet to my computer. "Ethernet is the backbone of our connected world and 2023 marks the 50th anniversary of this pervasive technology. The efficiency and resiliency of Ethernet makes it applicable to a broad set of applications, increasing the importance of interoperability. One overarching tenet of the Ethernet Alliance's mission is the proliferation of interoperability for the wide range of devices, interconnect solutions, and data rates within the Ethernet ecosystem. The basic network components haven't really changed; with each advancement of speed, we're still testing switches, systems, and network interface cards (NICs) connected with cables and optical modules. However - and under the covers, so to speak - there's been an explosion of applications centered on, and anchored by, Ethernet's communications frameworks..."

Truetone Model D2616 Tabletop Radio

Truetone Model D2616 Tabletop Radio, November 1946 Radio News - RF CafeThis schematic diagram and parts list for the Truetone model D2616 radio was published in the November 1946 issue of Radio News magazine. It is a very modern (at the time) tabletop design sporting a smooth, shiny white phenolic chassis, equipped with Truetone Stratoscope technology. Both RCA and Hazeltine patents are noted. Truetone was the branded name used by Western Auto. The photos here are from a recent eBay auction where the winner paid a mere $79.99 (I have Archive.org save the page for the sake of posterity). It is in incredibly good condition for an 80 year old radio that does not appear to have been reconditioned. 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. I will keep a running list of all data sheets to facilitate a search...

RF & Electronics Symbols for Office™

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

Many Thanks to Withwave for Long−Time Support!

Withwave RF & Microwave Components - RF CafeWithwave manufactures an extensive line of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch, board edge, panel mount), calibration kits (SOLT), a fully automated 4-port vector network analyzer (VNA) calibrator, between- and in-series connector adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes & probe positioner. Special test fixtures for calibration and multicoax cable assemblies. Frequency ranges from DC through 110 GHz. Please contact Withwave today to see how they can help your project succeed.

Thursday the 6th

Principles of Modern Radar, Part I

Principles of Modern Radar Part I, June 1960 Radio-Electronics - RF CafeRadar, as with a lot of (probably most of) technology that once was the purview of military, government, university, and corporate entities due to size, complexity, and cost, now is integrated into many consumer products. Boaters and even private aviation pilots have benefitted from radar for decades, at ever increasing levels of capability and often decreasing cost. Your car is one of the biggest beneficiaries of modern radar if it has back-up sensors, lane keeper-inner, low visibility assistance, collision avoidance, and other functions. A mix of short-range, medium-range, and long-range radar, in conjunction with lidar and sonar, is utilized to implement the big scheme dubbed Advanced Driver Assistance Systems (ADAS). Self-driving cars are utterly dependent on all these technologies. This "Principle of Modern Radar" article form a 1960 issue of Radio-Electronics magazine is a good summary on where the transition to commercialization began...

NFC Forum Technology's 2028 Roadmap

NFC Forum Technology's 2028 Roadmap - RF Caf"The NFC Forum, the leading standards body for Near Field Communication (NFC) technology, announced today that it has unveiled its Technology Roadmap outlining key plans and research efforts through 2028. This comprehensive roadmap includes five key initiatives and offers a unique glimpse into the future of NFC, highlighting the technology's direction and anticipated product development, market, and business opportunities for the next two to five years. The Technology Roadmap will be presented by a panel of Forum senior leaders during a public webinar on June 27, 2023, at 9:00 a.m. Eastern. The technology roadmap was collaboratively developed by leading Forum members, including Board representatives from Apple, Google, Huawei, Identiv, Infineon, NXP, Qualcomm, Sony, and STMicroelectronics as well as the Forum's 400-member company community..."

Decimeter Waves - The Future of Radio

Decimeter Waves - The Future of Radio, November 1935 Short Wave Craft - RF CafeMillimeter waves (mm-waves) are the subject of a great many articles today describing advances being made in the part of the spectrum above 30 GHz (Ka and EHF bands, mm-wave); however, when this piece was published in 1935, it was decimeter waves - what is now referred to as UHF -  that were the big to-do. Crowded frequency bands have been a problem since the beginning of radio because technology is constantly not only filling available bandwidth, but also pushing the frontiers higher. The advantage of going higher in frequency is that required bandwidths for existing modulation schemes represent a smaller percentage of the center frequency. For example, an 802.11b WiFi signal's 22 MHz bandwidth represents roughly 1% of its 2.4 MHz center frequency. 802.11a does 20 MHz at 5 GHz for 0.4%. Extend that center frequency up to 50 GHz and the channel occupancy is a mere 0.04%. That means for the same total band occupancy of 1% as with 802.11b, you can fit in 25 equivalent slots. The problem with going higher in frequency is that components are typically more costly and trickier to implement, and the power falls off faster with distance according to the familiar Friis equation...

RF Cafe Espresso Engineering Workbook™ for Excel

RF Cafe Espresso Engineering Workbook™ for Excel - RF CafeThe first major new release of RF Cafe's spreadsheet (Excel) based engineering and science calculator is now available - Espresso Engineering Workbook™. 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. Now that a more expandable basis has been created, I plan to add new calculators on a regular basis...

Werbel Intros 0.5 to 2 GHz Directional Coupler

Werbel Microwave Intros 0.5 to 2 GHz Directional Coupler - RF CafeWerbel Microwave presents an impressive array of features in our latest offering. With a wide frequency range spanning from 0.5 to 2 GHz, the C-1002-20 directional coupler stands out for its exceptional performance across the 0.5 to 2 GHz frequency range. This coupler boasts excellent coupling flatness, good directivity, and high power handling capabilities. It is the perfect choice for a wide range of applications, including lab testing and power monitoring over broad frequency bands. The key features of the C-1002-20 coupler offer significant advantages. Its wide bandwidth eliminates the need for component switching in lab testing, as it covers the desired frequency range. With a high directivity of 30 dB (typ.) up to 2 GHz, the coupler allows accurate sampling of input powers while minimizing the impact of output mismatches. Additionally, its excellent return loss of 30 dB (typ.) up to 2 GHz ensures minimal undesired reflections and amplitude ripple...

Wartime Solder

Wartime Solder, September 1942, Radio-Craft - RF CafePrior to the big push for leadless solder in the 1990s, probably 99% or more of the solder used by industry, tradesmen, and hobbyists contained lead. The 60/40 Sn-Pb (and 63/47) alloy, both with and without a rosin core, was used for electrical work, electronics, plumbing, copper guttering, radiators, and many mechanical assemblies made of steel, brass, copper, tin, etc. Between World War I, "The War to [Not] End All Wars," and World War II, the electronics industry exploded in growth. All realms of society and government became utterly dependent on products assembled using solder. Both tin and lead were abundantly available, making it inexpensive. Properties of Sn-Pb solder were well known, and methods for is use were simple. At the breakout of WWII, America's main source for tin was a group of countries under the control of Japanese forces. As with a lot of other resources during wartime, tin was regulated and meted out by the government...

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...

Thanks to PCB Directory for Continued Support!

PCB  Directory - RF CafeThe leading website for the PCB industry. PCB Directory is the largest directory of Printed Circuit Board (PCB) Manufacturers, Assembly houses, and Design Services on the Internet. We have listed the leading printed circuit board manufacturers around the world and made them searchable by their capabilities - Number of laminates used, Board thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing, fabrication, assembly, prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.

Wednesday the 5th

Around the World in 80 Seconds with SAC

Around the World in 80 Seconds, July 1960 Radio-Electronics - RF CafeWhen this "Around the World in 80 Seconds" editorial was published by Radio-Electronics magazine editor Hugo Gernsback in 1960, the Cold War was reaching a crescendo level. Iron Curtain countries were saber rattling about imminent nuclear strikes against Capitalist Pig entities like the United States and Western Europe. Movies, books, and newspaper and magazine articles by the scores were produced to warn the public about the potential for mutual assured destruction between nuclear armed countries. At the time, that included the U.S., Russia, the UK, and France had at least performed nuclear detonations, then China in 1964. 1962 was the year of the Cuban Missile Crisis. This article extols the capabilities of the Strategic Air Command's worldwide communication capabilities as witnessed personally by Mr. Gernsback during a publicity demonstration. Of the three branches involved, land-based (telephone) comms was declared to be 99% reliable, narrowband radio rated 95% reliability...

China Restricts Exports of High-Tech Metals

China Restricts Exports of High-Tech Metals"China has imposed export curbs on two metals used in computer chips and solar cells, expanding a squabble with Washington over high-tech trade ahead of Treasury Secretary Janet Yellen's visit to Beijing this week. The controls on gallium and germanium are intended to 'safeguard national security,' the Commerce Ministry said late Monday. Chinese leader Xi Jinping's government is frustrated by U.S. curbs on access to advanced processor chips and other technology on security grounds. But Beijing has been slow to retaliate, possibly to avoid disrupting China's fledgling developers of chips, artificial intelligence and other technology. China is the biggest global source of gallium and germanium. The U.S. gets about half its supply of both metals directly from China. Yellen is due to arrive as part of efforts by the Biden administration to revive relations that have plunged to their lowest level in decades..."

Antenna Placement Does Make a Difference

Antenna Placement Does Make a Difference!, November 1966 Popular Electronics - RF CafeThis article in a 1966 issue of Popular Electronics magazine presents a surprising and maybe even counterintuitive (to those uninitiated in antenna physics) result when measuring the radiation pattern of a CB-type antenna mounted at various points on a car. If you were asked to make a rough sketch of the radiation pattern when the antenna is mounted in the center of the roof, center of the trunk, and on each of the front and rear and left and right fenders, would yours look like those in the article (assuming an all-metal car)? Today, there are many electromagnetic radiation pattern simulators available to help predict antenna performance in just about any scenario imaginable. Design verification is then usually performed either in actual operational conditions, in anechoic chambers, in TEM cells, or on outdoor test sites. Being able to accomplish the initial simulation using highly refined software algorithms can save huge amounts of money and time, just as with circuit simulation and PCB / enclosure layout...

PCB Insertion Loss Guide

San Francisco Circuits: PCB Insertion Loss Guide - RF CafeSan Francisco Circuits, a popular provider of PCB fabrication and assembly, has published a PCB Insertion Loss Guide. The term "Insertion loss" typically refers to the loss of signal strength as it passes through system-level cabling / components and PCB-level traces within high-speed (3 GHz+) systems / optical fibers and PCB stack-ups. When designing new PCBs, it's important to mitigate loss, typically expressed in decibels (dB), as it can lead to critical system failures if left unchecked. San Francisco Circuits has created a new resource to assist PCB designers with the best practices surrounding PCB Insertion loss. The causes and contributors to insertion loss include overall transmission length, connectors & cables, high-loss materials, and higher frequency systems. How each affects a system overall along with tips on how to combat insertion loss are detailed...

Television I.Q. Quiz

Television I.Q. Quiz, October 1948 Radio & Television News - RF CafeTechnology advancement has always been about research and development in all fields related to the concept, be it any combination of mechanical, electrical, programming, implementation, usage, or training. Television went fundamentally unchanged from the time of its commercial implementation in the early part of the last century until the advent of plasma screens (i.e., no more raster-scanned CRTs) in the latter part of the last century. Color tubes added complexity to the signal, but it was still an analog signal. Then came digital broadcasting in the early part of this century. The same sort of evolution occurred with telephones and to some extent with radio. This Television I.Q. Quiz from a 1948 edition of Radio & Television News magazine will give you some insight into how TVs used to work...

Promote Your Company on RF Cafe

Sponsor RF Cafe for as Little as $40 per Month - RF CafeBanner Ads are rotated 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. Your 728x90-px and 160x600-px Banner Ads are displayed on average 225,000 times per year! 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. If you need your company news to be seen, RF Cafe is the place to be...

Please Visit Empower RF's Website in Appreciation of Their Support

Empower RF Systems - RF CafeEmpower RF Systems is the technological leader in RF & microwave power amplifier solutions for EW, Radar, Satcom, Threat Simulation, Communications, and Product Testing. Our air and liquid cooled amplifiers incorporate the latest semiconductor and power combining technologies and with a patented architecture we build the most sophisticated and flexible COTS system amplifiers in the world. Solutions range from tens of watts to hundreds of kilowatts and includes basic PA modules to scalable rack systems.

Tuesday the 4th

Radio-Electronics Puzzler

R-E Puzzler, October 1967 Radio-Electronics - RF CafeThere's no hiinggthe truth about how well I did - or didn't do - on this "the truth about how well I did - or didn't do - on this "R−E Puzzler" from the October 1967 issue of Radio−Electronics magazine, because contrary to the publisher's promise, a solution was never published in a later issue (I looked for it in the six subsequent issues and could not find it). Therefore, the R−E Puzzler Solution posted at the bottom of this page shows the answers I was able to figure out which, embarrassingly, results in a score of only 17/25 = 68%. I'm pretty confident of being able to get all of them if I spent more time, but that's it for about 30 minutes worth of cogitating. If you know more of the words, please send me an e-mail and I'll add them to the solution. Thanks...

Atmospheric Attenuation to 1000 GHz

Atmospheric Absorption (Specific Attenuation) Chart to 1000 GHz - RF CafeMicrowave Journal ran a piece in the June issue entitled, "InP HBT Technology: Advantages, Applications and Future Challenges." To be honest, the article itself didn't interest me all that much, but there is a nice graph within that plots signal atmospheric attenuation levels up through 400 GHz, which is relevant because G-Band, which is the currently targeted new realm of spectrum use, covers 110 to 300 GHz*. Operations need to exploit the areas with minimal attenuation, which are at 140 and 220 GHz. In the secure satellite communications realm, the opposite is desirable; frequencies at maximum atmospheric attenuation are used to minimize reception by Earth-based listeners. 60 GHz has long been the home of spy satellites, and now that InP and GaN enable operation into G-band, other frequencies can be exploited. *Today, I spent a couple hours extracting data points and plotting the newest (2022) "Specific Attenuation Due to Atmospheric Gases, Calculated at 1 GHz Intervals," which goes all the way to 1000 GHz (1 THz). I also posted the numeric values of the frequency and attenuation values used to generate the maximums and minimums of both the "Standard" and the "Dry" plots...

Rover Radio Boys on the Moon

I Will Not Bite His Ear, Or the Rover Radio Boys on the Moon, April 1933 QST - RF CafeIf you think the title of this piece, "I Will Not Bite His Ear, or the Rover Radio Boys on the Moon," has anything to do with the story, you would be in error ... at least as far as I can reckon there's no connection. Keep in mind that this mini-novel appeared in the "April Fool" section of the April 1933 QST magazine issue. I have posted a couple of the "Fools" pieces which accompanied it (see TOC beginning on page 25). Read with caution. The image of Queen Elizabeth cradling a vacuum valve (not tube!) under her arm like a rugby football (to continue the Eurocentric theme) in the comic certainly grabs one's attention, as do the "250-watter lights" on the the royal bathroom wall. You need to switch into a early twentieth century mindset while perusing the story in order to appreciate the humor...

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 Anatech Electronics for Long-Time Support!

Anatech Electronics logo - RF CafeAnatech Electronics (AEI) manufactures and supplies RF and microwave filters for military and commercial communication systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters, and RF products. Standard RF filter and cable assembly products are published in our website database for ease of procurement. Custom RF filters designs are used when a standard cannot be found, or the requirements dictate a custom approach for your military and commercial communications needs. Sam Benzacar's monthly newsletters address contemporary wireless subjects. Please visit Anatech today to see how they can help your project succeed. 

The Declaration of Independence

The unanimous Declaration of the thirteen united States of America

In CONGRESS, July 4, 1776. The unanimous Declaration of the thirteen united States of America, When in the Course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation. We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. -- That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, -- That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security. -- Such has been the patient sufferance of these Colonies; and such is now the necessity which constrains them to alter their former Systems of Government. The history of the present King of Great Britain is a history of repeated injuries and usurpations, all having in direct object the establishment of an absolute Tyranny over these States. To prove this, let Facts be submitted to a candid world...

Monday the 3rd

Hugo Gernsback, 1884-1967

Hugo Gernsback, 1884-1967, October 1967 Radio-Electronics - RF CafeNobody is irreplaceable. That is a common argument offered in response to an assertion that a particular person is the only one capable of fulfilling a certain role in business, sports, community, and other areas. While it is mostly true (except in the case of some personal relationships), securing the service of that person is capable of filling the figurative shoes of the contested soul is often difficult or impossible. A more accurate argument might be that out of the field of people qualified to replace someone in a particular role, the likelihood of doing so is essentially zero. To my knowledge, nobody ever uttered any form of that statement regarding me; however, many certainly said it about Hugo Gernsback. Except for here on RF Cafe, Mr. Gernsback is not often mentioned these days, but throughout the first half of the last century, his name was well known by those with an interest in science, electronics, and science fiction. This pseudo-eulogy / mini-biography appeared in the October 1967 issue of Radio-Electronics magazine, which was the last of many publications he founded...

Philco Model 38-116 Code 125 Radio

Philco Model 38-116 Code 125 Radio, February 1938 Radio-Craft - RF CafeA fair number of these Philco Model 38-116 Code 125 floor-sitting console style radios are still in existence and have been restored by collectors. They appear on eBay and vintage radio blogs. I have been scanning and posting Radio Service Data Sheets like this one for many years now. Having two full pages devoted to a single radio like this from a 1938 issue of Radio−Craft magazine is rare. 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...

Baseball-Sized Hail Destroys 5.2 MW PV Array

Baseball-Sized Hail Wreaks Havoc on 5.2 Megawatt Solar Array - RF Cafe"Baseball-sized hail took out a solar farm in Scottsbluff, Nebraska. The hail shattered most of the panels on the 5.2-megawatt solar project, sparing an odd panel like missing teeth in a white smile. Wyoming has only one commercial-scale solar farm, but a second project is under construction south of Cheyenne. The Federal Emergency Management Agency ranks this area in its the highest category for hail risk on the national index. Don Day, Cowboy State Daily meteorologist, said the hail would have reached terminal velocity during its descent, which is the maximum speed an object will reach when falling. The hail would have likely struck the panels going 100 to 150 mph..."

Relative Traffic Standings

Relative Traffic Standings, April 1932 QST - RF CafeWe take wireless communications for granted. Just as people my age thought pocket-size transistor radios that ran on 9V batteries were always available, today's kids give no thought to whether there was a time when everyone did not carry a cellphone around. FM radio, if listened to at all nowadays, is likely either via an Internet connection or via an embedded FM radio IC in his/her phone, with ear bud wires acting as an antenna. It is obviously no big deal, since it always was so. In the early part of the last century most people did not own any sort of radio - not even a commercial AM broadcast receiver. Having something as mysterious as a shortwave "rig" was an indication of technical prowess since many operators built their own equipment from kits or schematics. Participation in amateur radio worldwide was huge at the time, which is amazing given the amount of work required to set up even a relatively simple CW (Morse code) setup. The American Amateur Radio League (ARRL) published extensive lists of reported contacts (QSLs in Ham-ese) every couple months. Purely for illustrative purposes, I have posted all 15 pages of very tiny print as submitted by operators for the April 1932 edition of QST magazine. The effort required to assimilate and type in all the names, locations, call signs, etc., was enormous, especially since the info...

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...

 Thanks to Amplifier Solutions Corporation (ASC) for Continuing Support!

Amplifier Solutions Corporation (ASC) - RF CafeAmplifier Solutions Corporation (ASC) is a manufacturer of amplifiers for commercial & military markets. ASC designs and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers for low, medium and high power applications using Gallium Nitride (GaN), Gallium Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility in the town of Telford, PA. We offer excellent customer support and take pride in the ability to quickly react to evolving system design requirements.

Sunday the 2nd

Electronics Theme Crossword for July 2nd

Electronics Theme Crossword Puzzle for July 2nd, 2023 - RF CafeThis custom RF Cafe electronics-themed crossword puzzle for July 2nd 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. Being that "B" is the 2nd letter of the alphabet, it is used as the first and/or last letter of many words in today's crossword puzzle - as well as in-between. Those clues are marked with an asterisk (*). 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.

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...

Please Thank Axiom Test Equipment for Continued Support!

Axiom Test Equipment - RF CafeAxiom Test Equipment allows you to rent or buy test equipment, repair test equipment, or sell or trade test equipment. They are committed to providing superior customer service and high quality electronic test equipment. Axiom offers customers several practical, efficient, and cost effective solutions for their projects' TE needs and is committed to providing superior customer service and high quality electronic test equipment. For anyone seeking a way to offload surplus or obsolete equipment, they offer a trade-in program or they will buy the equipment from you. Some vintage items are available fully calibrated. Please check out Axiom Test Equipment today - and don't miss the blog articles!

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

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)

Windfreak Technologies SynthHD PRO - RF Cafe
Innovative Power Products Passive RF Products - RF Cafe

Noisecom

ConductRF Phased Matched RF Cables - RF Cafe