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Homepage Archive - July 2024 (page 1)

See Page 1 | 2 | 3 | 4 | of the July 2024 homepage archives.

Friday the 5th

TV Antennas Invite Lightning to Strike

TV Antennas Invite Lightning to Strike, October 1960 Radio-Electronics - RF CafeThe Lightning Protection Institute (LPI)has been around for a long time; in fact, it might have been informally founded by Benjamin Franklin ;-) Last year while working on an installation plan for a friend's solar panel array and equipment room, I found lots of useful info on the LPI website for best practices of lightning protection. I was surprised to learn that there was still disagreement among experts as to whether a raised, grounded surface like the metal roof onto which the photovoltaic (PV) arrays are mounted tended to reduce or increase the likelihood of a lightning strike. There are good theoretical arguments on both sides. I tend to think the raised, broad surface decreases the cloud-to-ground potential and disperses the charge across a larger area, thus reducing chance of a strike. There is also disagreement whether the ground for the PV array should be physically connected to the ground...

Nuclear Radiation & Detection

Nuclear Radiation & Detection, December 1972 Popular Electronics - RF CafeParts 1 and 2 of this series covered the theory of nuclear physics and laboratory investigation devices. This final installation talks about commercially available test instruments for detecting and measuring nuclear radiation levels. My introduction to Geiger counters was in the old The Adventures of Superman television show where they were used by villains to verify that their stash of Kryptonite would be sufficient to disable our superhero. I could not find anywhere whether Kryptonite's emission type is alpha particles (helium nucleus; i.e., 2 protons and 2 neutrons), beta particles (electron), gamma rays (electromagnetic waves), or some other form. Multiple designs of detectors are used based on radiation type and strength to be measured...

Blog: Imagers Identify Thermal Issues

Axiom Test Equipment Blog: Imagers Identify Thermal Issues - RF CafeTranscat | Axiom Test Equipment, an electronic test equipment rental company has published a new blog post that covers how thermal imagers can be used to detect temperature overloads in electrical and mechanical equipment, and what to look for when selecting the one for your project. Electronic performance is affected by temperature, with heat sources inside and outside a device or system. High-power amplifiers exhibit rises in temperature from the heat of semiconductors and must be equipped with cooling for safety and longevity. Other electronic designs can suffer performance degradations when placed too close to heat sources or even when exposed to sunlight. Fortunately, the temperatures of electronic equipment can be measured quickly and accurately without making physical contact, with the aid of IR...

RCA Advertisement on History of Television

RCA Advertisement on History of Television, June 1945 Radio-Craft - RF CafeIt is the opinion of many historians that in order to better understand the present, you need to know the past. Searching for one's roots in this world is big business. Online family tree type websites are used by thousands of people to research their family histories, and some services don't come cheap. You can even pay someone to dig into your past to assimilate all available information and put it in a bound, printed volume. Here on RF Cafe, I research and post a lot of our profession's past. While the individual topics themselves might not bear significantly on the present, having an insight into the people's mindsets and progression of technology is - or should be - motivating. No, most modern televisions do not process analog signals, use a CRT, have vertical and horizontal hold adjustments, but then not too far in the future most televisions won't be much like they are now. Engineers and technicians of today's world have a distinct advantage over prior years' innovators because with enough ingenuity and fortitude...

RF & Electronics Symbols for Visio

RF Electronics Wireless Analog Block Diagrams Symbols Shapes for Visio - RF CafeWith more than 1000 custom-built symbols, this has got to be the most comprehensive set of Visio Symbols available for RF, analog, and digital system and schematic drawings! Every object has been built to fit proportionally on the provided A-, B- and C-size drawing page templates (or can use your own). Symbols are provided for equipment racks and test equipment, system block diagrams, conceptual drawings, and schematics. Unlike previous versions, these are NOT Stencils, but instead are all contained on tabbed pages within a single Visio document. That puts everything in front of you in its full glory. Just copy and paste what you need on your drawing...

Thursday the 4th

What's Your EQ?

What's Your EQ?, March 1964 Radio-Electronics - RF CafeSeeing a reader name of Qutaiba Bassim El-Dhuwaib would not seem unusual in one of today's technical magazines, but having it appear in a 1964 issue of Radio-Electronics was definitely a rarity. Such was the case with this first "Black Box" circuit challenge submitted by the aforementioned subscriber. I took a WAG at the answer and got it right, but without considering the theory behind it. Fortunately, Mr. El-Dhuwaib provides that gory detail for us. It is a pretty clever scheme for effecting a phase shift while not affecting the magnitude. The second mystery circuit requires being familiar with types of meter movements commonly used in DC and AC voltmeters. Having begun in the craft prior to the advent of digital multimeters (that includes me) helps. Such circuits were probably more intuitive to designers in the days of analog...

Tolerance Calculator

Tolerance Calculator, May 1963 Electronics World - RF CafeHere is a type of chart I don't recall seeing before. This Tolerance Calculator Graph makes it very easy to quickly determine the upper and lower extremes of tolerance values for resistors, capacitors, inductors, etc. It was published in a 1963 issue of Electronics World magazine, and can actually be used to find the limits for any number, regardless of units. This is one example of where a physical visual aid can still yield results faster than punching numbers into a calculator, if a number with just a couple significant figures of precision is sufficient...

ARRL Still Fighting Systems Disruption

ARRL Still Fighting Systems Disruption - RF CafeBack in May, the American Radio Relay League (ARRL), the world's largest amateur radio organization, reported a major service disruption. Not a lot of information has been divulged, but it appears to involve member and processing information. Even the phone system was down for a while. Several services, such as Logbook of The World® and the ARRL Learning Center, were affected, as well as mailing of hard-copy magazine editions (which indicates member addresses might have been involved). Per the ARRL: "On or around May 12, 2024, ARRL was the victim of a sophisticated network attack by a malicious international cyber group. ARRL immediately involved the FBI and engaged with third party experts to investigate. This serious incident was extensive and categorized by the FBI as “unique,” compromising network devices, servers, cloud-based systems, and PCs. ARRL management quickly established an incident response team. This has led to an extensive effort to contain and remediate the networks, restore servers, and staff are beginning the testing of applications and interfaces to ensure proper operation."

Denmark Electronics Market

Denmark Electronics Market, December 27, 1965 Electronics Magazine - RF CafeThis is the electronics market prediction for Denmark, circa 1966. It was part of a comprehensive assessment by the editors of Electronics magazine of the state of commercial, military, and consumer electronics at the end of 1965. Unless you can find a news story on the state of the industry, detailed reports must be purchased from research companies like Statista. Their website has a lot of charts on Denmark's current electronics market showing revenue in the consumer electronics segment amounts of US$1,020 million in 2018...

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...

How to Target RFCafe.com for Your Google Ads

Google AdSense - it makes good sense - RF CafeOne aspect of advertising on the RF Cafe website I have not covered is using Google AdSense. The reason is that I never took the time to explore how - or even whether it is possible - to target a specific website for displaying your banner ads. A couple display opportunities have always been provided for Google Ads to display, but the vast majority of advertising on RF Cafe is done via private advertisers. That is, companies deal with me directly and I handle inserting their banner ads into the html page code that randomly selects and displays them. My advertising scheme is what the industry refers to as a "Tenancy Campaign," whereby a flat price per month is paid regardless of number of impressions or clicks. It is the simplest format and has seemed to work well for many companies. With nearly 4 million pageviews per year for RFCafe.com, the average impression rate per banner ad is about 280k per year (in eight locations on each page, with >17k pages)...

Wednesday the 3rd

National Radio Institute Tats

National Radio Institute, March 1964 Radio-Electronics - RF CafeIn 1967, when this National Radio Institute (NRI) advertisement appeared in Radio-Electronics magazine, allowing tattoos to be visible on people representing a company's interest was almost never done. Harley Davidson might have allowed it, or maybe Old Spice after shave lotion, but certainly not typical from an educational establishment pitching electronics instruction. The dude in this ad has a clearly, intentionally visible "tat" on his right arm. It is no accident because the shirt sleeves are rolled up when they don't need to be, and the right sleeve is up twice as far as the left sleeve. The photographers wanted readers to see it. My interpretation of it is "D. S.," and then some illegible character at the end (maybe "jr"?). Any guesses as to what it might be?

Controlling Electronics with Light

Controlling Electronics with Light - RF Cafe"Researchers have successfully manipulated the structural properties of magnetite using light-induced phase transitions. This technique uncovered hidden phases of magnetite, paving the way for new approaches to material manipulation in electronics. 'Some time ago, we showed that it is possible to induce an inverse phase transition in magnetite,' says physicist Fabrizio Carbone at EPFL. 'It's as if you took water and you could turn it into ice by putting energy into it with a laser. This is counterintuitive as normally to freeze water you cool it down, i.e. remove energy from it.' The study discovered that using specific light wavelengths for photoexcitation the system can drive magnetite..."

Ham Radio News

Strays - Lt. Henry B. Harris Killed in Crash, August 1934 QST - RF CafeYou just never know when your number is going to be called. People who engage in a dangerous activity they love often claim that if they are going to die in an accident, it would preferably be while engaging in that activity. It really sucks to die like Army-Air Force Lt. Henry B. Harris who was an accomplished instrument flight research pilot (and noted Ham radio operator). Rather than expiring in an airplane, he met his end as a passenger in a car that was towing some other pilot in a glider. The story is told in the August 1934 issue of the ARRL's QST magazine...

Temwell ½-Price July Filter Sale

Temwell ½-Price July Filter Sale - RF CafeTEMWELL Corporation is a worldwide expert and company in designing & manufacturing RF helical bandpass filters since 1994. For the entire month of July, you will receive a discount of 50% off all filters! We have designed and built up over 5000 completed spec sheets online for displaying all our excellent capability. Furthermore, in order to satisfy more RF engineers and develop projects all over the world, our engineers have designed diplexers and duplexers for 5G, VHF, UHF, TETRA cavity duplexers, helix cavity diplexers, LTE low PIM diplexers, and coaxial duplexers ...

Men Who Have Made Radio: James C. Maxwell

Men Who Have Made Radio: J. C. Maxwell, May 1930 Radio-Craft - RF CafeJames Clerk Maxwell's inception of the theory of electromagnetic radiation is compared in this 1930 Radio-Craft magazine article to if Christopher Columbus had conceptualized the existence of America and mapped its features based solely on observations of how the known oceans and land masses interacted. I have always been amazed at the ability of people who formulate entirely new theories of science, finance, medicine, etc., and manage to detail and support their ideas with hard data and mathematics. Einstein did so with relativity, Dalton did so with atomic structure, Darwin did so with evolution, Pasteur did so with germ theory; the list is long. There are lots of geniuses out there, but a relative few change the world...

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, and more. Page templates are provided with a preset scale (changeable) for a good presentation that can incorporate all provided symbols...

Tuesday the 2nd

Space Stations and Ball Lightning

News Briefs, December 1960 Radio-Electronics - RF CafeWhen I think of the first space station, what comes to mind is the Russian Salyut 1 (c1971), and then America's Skylab (c1973). This "News Briefs" feature in the December 1960 issue of Radio-Electronics magazine claims there was an earlier space station - the Courier. OK, NASA might have called it a space station, but it wasn't a manned space station like the aforementioned were. It launched in early October of that year. Courier 1B (its full designation) was the world's first active repeater satellite, which could receive a message (text, image, voice, or data), store it, then transmit it later. A few details regarding its operation are provided. Also in the news was research into using "ball lightning" as a weapon. That's right, shoot a ball of searing hot plasma toward the enemy to obliterate it - or at least scare the bejeebers...

Storage Chip Has a Near-Infinite Lifespan

Storage Chip Has a Near-Infinite Lifespan - RF Cafe"Chinese scientists say they have developed a groundbreaking material that could give storage chips an almost infinite lifespan. This new type of ferroelectric material could potentially reduce data center costs and have applications in deep-sea exploration or aerospace in the future. Ferroelectric materials are commonly used to make chips for storage and sensing purposes that are critical to artificial intelligence and other hi-tech areas hit by U.S. sanctions, as a tech war plays out between the United States and China..."

Microwave Satellite Communications

Microwave Satellite Communications (The Vault of the Atomic Space Age) - RF CafeTotalTemp Technology's John Booher sent me this item he saw on "The Vault of the Atomic Space Age" Facebook page. Not being a Facebook follower (except for looking for stuff to buy on the Marketplace page), I tried to find the drawing on the website, but there are so many that I never did see it. There are lots of really great vintage photos, advertisements, and artwork in an endlessly scrolling list. Although not mentioned, that antenna looks a lot like Bell Lab's "Sugar Scoop" antenna which was built around 1960 to communicate with early satellites, but also ended up discovering the cosmic microwave background radiation (CMBR) noise form the Big Bang...

Non-Magnetic Coaxial Connectors for DC-40 GHz

Withwave Non-Magnetic Coaxial Connectors for DC to 40 GHz - RF CafeWithwave's Non-Magnetic Coaxial Connectors are widely used in applications that experience strong magnetic field can cause interference or introduce errors such as quantum computing, magnetic resonance imaging(MRI) equipment, the aerospace industry. Constructed of beryllium copper (BeCu) and plating, they features a DC to 40 GHz frequency range and are available in various interface sizes. Applications include quantum computing , military & space, and medical devices (MRI). Withwave is a leading designer and developer of a broad range of RF, microwave, and millimeter-wave test solutions and subsystems with a focus on electromagnetic field...

ECA Model 108 Schematic & Parts List

ECA Model 108 Schematic & Parts List, February 1947 Radio News - RF CafeHere is the ECA (Electronic Corporation of America) Model 108 schematic and parts list as featured in a 1947 edition of Radio-Craft magazine. It had a very unique tabletop chassis design made of formable "plastic-like" Bakelite material. The front panel contains a matrix of slits for the speaker area, and the frequency strip at the top is behind a curved clear window. The speaker driver was a powerful push-pull design. As mentioned many times in the past, I post these online for the benefit of hobbyists looking for information to assist in repairing or restoring vintage communication equipment...

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 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...

Monday the 1st

A Tunnel Diode Oscillator

A Tunnel Diode Oscillator, September 1960 Radio-Electronics - RF CafeBased on three major stories on tunnel diodes in 1960 issues of Radio-Electronics magazine, you might think the relatively new negative resistance device was a big deal. It was. Known also as an Esaki diode, the tunnel diode, named after its inventor, Leo Esaki, in 1957, is a two-terminal semiconductor device which exhibits negative resistance over a certain range of voltage and currents, making it useful as an oscillator and amplifier. Its cost compared to a transistor is much lower, and its operational frequency is much higher than that of a transistor (at least it was so back in 1960 and for a couple decades afterwards). The tunnel diode works on the quantum tunneling principle Big plans were made for using tunnel diodes as local oscillators and even amplifiers in radios and radars. Their relatively low voltage and current handling ability caused them to be preferred less than the high power handling Gunn diode, which emerged just a few years later.

Espresso Engineering Workbook™ v7.1.2024

Espresso Engineering Workbook™ v7.1.2024 - RF CafeThe newest addition to RF Cafe's spreadsheet (Excel) based engineering and science calculator - Espresso Engineering Workbook™ (click to download) is a functional Smith Chart that plots a series of user-defined impedance points. RF Cafe Espresso Engineering Workbook™ is 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 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...

Note on S.W.R. Measurement

Note on S.W.R. Measurement, May 1952 QST - RF CafeHave you ever made a power or noise figure measurement and had to scratch your head over why the reported value made absolutely no sense? How about measuring a positive gain value through a passive device? I have experienced this sort of nonsensical phenomenon on more than one occasion, and to my recollection every time the cause was stray frequencies - often oscillations - mixed in with the intended signal. This app note from a 1952 issue of the ARRL's QST magazine addresses the issue in regard to impedance matching networks that are wideband enough to support RF energy that is outside the band being tuned - or even unexpected inband signals - with a simple method of avoiding such surprises...

Here Is Your Chance to Get Noticed!

25th Anniversary - RF Cafe

News Highlights

News Highlights, April 1972 Popular Electronics - RF CafeTiVO systems are just the latest incarnation of programmable systems for recording television programs for playback at a later time. In 1972, Sears, Roebuck & Company announced "plans to market the first integrated videotape cartridge recording-playback unit for the home." It was part of a package that included a specially designed 25" color TV, a camera, and a recording / playback unit. The projected price of $1,600 is equivalent to $12,006 in 2024 money. As always, it was the early adopter technophiles who financed the engineering and market research that eventually led to the sub-$1,000 monster LED TVs and $200 TiVO units of today. Earned engineering degrees had leveled off in numbers by 1971, with a grand total of 43,167 Bachelor's degrees, primarily electrical engineering...

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, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers" Smith chart design. These would make excellent gifts for husbands, wives, kids, significant others, and for handing out at company events or as rewards for excellent service. My graphic has been ripped off by other people and used on their products, so please be sure to purchase only official RF Cafe gear. I only make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way to help support RF Cafe. Thanks...

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. I also have an extensive list of Recently Added topics.

Homepage Archive Pages

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Rigol DHO1000 Oscilloscope - RF Cafe
withwave microwave devices - RF Cafe

Amplifier Solutions Corporation (ASC) - RF Cafe

ConductRF Phased Matched RF Cables - RF Cafe