Search RFCafe.com                           
      More Than 18,000 Unique Pages
Please support me by ADVERTISING!
Serving a Pleasant Blend of Yesterday, Today, and Tomorrow™ Please Support My Advertisers!
   Formulas & Data
Electronics | RF
Mathematics
Mechanics | Physics
     AI-Generated
     Technical Data
Pioneers | Society
Companies | Parts
Principles | Assns


 About | Sitemap
Homepage Archive
        Resources
Articles, Forums Calculators, Radar
Magazines, Museum
Radio Service Data
Software, Videos
     Entertainment
Crosswords, Humor Cogitations, Podcast
Quotes, Quizzes
   Parts & Services
1000s of Listings
 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

Software: RF Cascade Workbook
RF Stencils for Visio | RF Symbols for Visio
RF Symbols for Office | Cafe Press
Espresso Engineering Workbook

Aegis Power  |  Alliance Test
Centric RF  |  Empower RF
ISOTEC  |  Reactel  |  RFCT
San Fran Circuits

ConductRF Phased Matched RF Cables - RF Cafe

Windfreak Technologies Frequency Synthesizers - RF Cafe

Innovative Power Products (IPP) Directional Couplers

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

LadyBug LB5954L Power Sensor with LAN Option - RF Cafe
Today in Science History

The Bridged-T

"The Bridged-T Filter, February 1964 Radio-Electronics - RF CafeThe bridged-T filter is a quick-and-dirty construct used to notch out a specific frequency that is interfering with a desirable frequency or band of frequencies. It is a resonant LC (inductor-capacitor) circuit consisting of a single inductor "bridging" a pair of series capacitors having a resistor to ground between them, or, if preferred, a capacitor bridging one or two inductors. A convenient nomogram (aka nomograph) is provided by the author in this 1964 Radio-Electronics magazine article for quickly selecting values, which was a very popular design aid in the pre-calculator era. A slide rule could be used to calculate a range of values when only a single variable was in play, but juggling more than one variable (component value) was greatly aided by a multivariable nomograph. Truth is nomographs can still...

Carl & Jerry: TV Picture

Carl & Jerry: TV Picture, June 1955 Popular Electronics - RF CafeTelevision, in 1955, was still a relatively new phenomenon to many - maybe even most - people. According to multiple sources, the portion of American households with a TV set went from under 20% in 1950 to nearly 90% ten years later in 1960. That was a meteoric rise, particularly considering the expense of even a minimal TV. The technology was not even available commercially when most people were born, so the rush to join in on the craze was akin to the mass adoption of cellphones in the 1990s. "Carl & Jerry" creator John Frye used his pair of electronics-savvy teenagers to help make the "magic" behind recreating a moving picture on a CRT miles away from where it was created. Water flowing through a garden hose has often been employed as an analogy for current flowing through a wire to explain electricity to laymen and beginning students of the craft. Here, it is not water flowing through the hose but water leaving the hose and flowing through the air that serves to represent an electron stream travelling from the electron gun to the phosphor-coated glass front of a CRT. Frame rates, scan lines, deflection coils, and other relevant terms are i

RF Front-End Tech Drives Automotive Innovation

RF Front-End Tech Drives Automotive Innovation - RF Cafe"The RF front-end (RFFE) industry, valued at $21 billion, is expanding beyond its traditional focus on mobile and infrastructure to drive innovation in the automotive sector. Each segment within the industry presents unique dynamics and growth opportunities. After a difficult 2022, the smartphone market is showing signs of recovery, with expected year-over-year growth of 4%, projected to reach 1.2 billion units by 2024. The mobile RFFE market is predicted to hit US$18 billion by the end of 2024, though it may face stagnation due to market saturation and pricing pressures. This market is expected to expand, with the 2027 launch of RedCap..."

Magnetoresistance: Better Than Hall-Effect Multipliers

Magnetoresistance: Better than Hall-Effect Multipliers, April 6, 1964 Electronics Magazine - RF CafeI'm having a hard time writing this with my eyes rolled back in my head. The last time I experienced this level of overwhelmedness was probably the third or fourth week of my feedback and control class at UVM. Even though electricity and magnetism shares many complimentary and parallel concepts, for some reason thinking in terms of magnetics when describing amplifiers, mixers, modulators, etc., has always caused brain freeze. Maybe it has to do with an ingrained bias due to my earliest dealings with circuits being from a technician background before earning an engineering degree. The equations of electric fields and magnetic fields are very similar so that helps lower...

Thanks to Temwell for Their Support!

Temwell (filters) - RF CafeTemwell is a manufacturer of 5G wireless communications filters for aerospace, satellite communication, AIoT, 5G networking, IoV, drone, mining transmission, IoT, medical, military, laboratory, transportation, energy, broadcasting (CATV), and etc. An RF helical bandpass specialist since 1994, we have posted >5,000 completed spec sheets online for all kinds of RF filters including helical, cavity, LC, and SMD. Standard highpass, lowpass, bandpass, and bandstop, as well as duplexer/diplexer, multiplexer. Also RF combiners, splitters, power dividers, attenuators, circulators, couplers, PA, LNA, and obsolete coil & inductor solutions.

What's Your EQ?

What's Your EQ?, February 1962 Radio-Electronics - RF Cafe Here we are with another set of three "What's Your EQ?" circuit challenges, these from the February 1962 issue of Radio-Electronics magazine. As usual, those challenges provided by Jack Darr are the purview of television servicemen of the era. The photo shown of the problematic CRT display looks like a chest x-ray or maybe hieroglyphics in the dark corner of a cave, but evidently the artifacts are readily identifiable to an initiated few. The Forbidden Current Path circuit answer is not what I thought it would be. I maintain that whether my answer or the designer's answer is correct depends on the physical...

New Wireless Data Rate Record Set

New Wireless Data Rate Record Set - RF Cafe"A new world record in wireless transmission, promising faster and more reliable wireless communications, has been set by researchers from UCL. The team successfully sent data over the air at a speed of 938 Gb/s over a record frequency range of 5–150 GHz. This speed is up to 9,380 times faster than the best average 5G download speed in the UK, which is currently 100 Mb/s or over. The total bandwidth of 145 GHz is more than five times higher than the previous wireless transmission world record. Typically, wireless networks transmit information using radio waves over a narrow range of frequencies..."

Sputnik: A Brief History

Sputnik: A Brief History - RF CafeSputnik refers to the first series of satellites launched by the Soviet Union. The word "Sputnik" means "satellite" in Russian. The launch of Sputnik 1 on October 4, 1957, marked a monumental moment in human history, heralding the dawn of the Space Age and sparking a fierce technological competition known as the Space Race between the United States and the Soviet Union. This satellite, the world's first artificial one, orbited Earth at an altitude of roughly 215 to 939 kilometers and broadcast a radio signal that astonished the world, particularly in the United States, where it spurred rapid advancements in aerospace and scientific research. The successful launch of Sputnik was an achievement that was years in the making, involving a combination of visionary planning, political motives, and intensive engineering by some of the Soviet Union's top scientists.

Blog: Air Quality Measurements with Particle Counters

Axiom Test Equipment Blog: Provide Essential Air Quality Measurements with These Particle Counters - RF CafeTranscat | Axiom Test Equipment, an electronic test equipment rental and sales company has published a new blog post entitled "Provide Essential Air Quality Measurements with These Particle Counters" that covers how particle counters can provide essential measurement capabilities that can help avoid contamination and support high manufacturing yields. These measurement tools can detect and measure microscopic particles suspended in air that can contaminate the most carefully planned manufacturing lines. Air particle counters can be designed for various...

Receiving U.S. Satellite Signals

Receiving U.S. Satellite Signals, March 1958 Radio News - RF CafeIn 1958, most people were not accustomed to seeing the now-familiar maps plotting sinusoidal courses of satellites across the face of the earth. It had only been in October of the previous year that any object other than the moon was in orbit around our home planet - that was U.S.S.R.'s Sputnik. Just as people of all ages and all backgrounds enthusiastically joined in the newfangled phenomenon of aeroplanes after the Wright Brothers flew their fragile craft at Kitty Hawk, electronics communications and scientists worldwide hopped aboard the satellite train. This article from a 1958 issue of Radio & TV News magazine provided insight into the construction and flight characteristics...

Thanks Again to LadyBug Technologies for Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Radio and Television News - Predictions

Radio and Television News, January 1969 Electronics World - RF CafeWhat were some of the top issues of the radio and television industry half a century ago? In a lot of respects, the same things that concern it today. A ready supply of service technicians was a concern that was taken seriously by the Electronics Industry Association (EIA). While there are not many local repair shops for electronics products nowadays, there is still a huge demand to techs who are willing and able to do the hard work of keeping the world's communication infrastructure operational - climbing towers, repairing cell equipment. Now, as then, good pay, job security, benefits, and respect for the job being done were at the top of...

RIGOL Introduces Oscilloscope & Generator Lines

Impressive Performance at an Impressive Price: RIGOL Introduces Oscilloscope & Generator Lines - RF CafeIn a parallel to the traditional test setup of signal generation and signal acquisition, RIGOL Technologies announced today the latest additions to its portfolio of performance measurement equipment with the introduction of the DG5000 Pro Series Generators and DHO/MHO5000 Series Oscilloscopes. The DHO/MHO5000 Series bring next-level performance to RIGOL's respected line of high-resolution oscilloscopes, while the DG5000 Pro generators do the same for the company's capable Pro Series arbitrary waveform generators...

Basic Electronic Counting

Basic Electronic Counting, March 1958 Radio News - RF CafeWhen selecting articles for posting here on RF Cafe, I like to include ones that are directed toward newcomers to the field of electronics as well as for seasoned veterans. This piece from a 1958 issue of Radio & TV News magazine entitled "Basic Electronic Counting," is a prime example in that it introduces the concept of binary numbers. We've all been there at some point in our careers. A big difference between now and when this article appeared is that in 1958, almost nobody was familiar to binary numbers, and fuggetabout [sic] octal and hexadecimal. Only those relatively few people designing and working with multimillion dollar, vacuum tube-based digital computers installed in universities, megacorporations, and government research facilities had ever dealt with digital numbers. The earliest example of powers of two I remember was back in junior high school. It had to do with a

Art of Invention Constantly Reinvented

Art of Invention Constantly Reinvented - RF cafe"Every invention begins with a problem - and the creative act of seeing a problem where others might just see unchangeable reality. For one 5-year-old, the problem was simple: She liked to have her tummy rubbed as she fell asleep. But her mom, exhausted from working two jobs, often fell asleep herself while putting her daughter to bed. 'So [the girl] invented a teddy bear that would rub her belly for her,' explains Stephanie Couch, executive director of the Lemelson MIT Program. Its mission is to nurture the next generation of inventors and entrepreneurs. Anyone can learn to be an inventor, Couch says, given the right resources and encouragement. 'Invention doesn't come from some innate genius, it's not something that only really..."

Mechanical Filters

Mechanical Filters, April 1969 Electronics World - RF CafeMechanical filters of the type described in this 1969 Electronics World magazine article are yet another example of the genius of some people. They are actually a form of electromechanical device in that the applied electrical signals are first converted into mechanical signals, followed by resonant mechanical elements that discriminate according to frequency, and finally a conversion back to an electrical signal is made. It is fundamentally the same principal as a crystal, SAW, or BAW filter, albeit each with distinctly different methods and topologies. Mr. Donovan Southworth, of Collins Radio, presents the basics of mechanical filters in this brief write-up...

Thanks Again to LadyBug Technologies for Continued Support!

LadyBug Technologies RF Power Sensors - RF CafeLadyBug Technologies was founded in 2004 by two microwave engineers with a passion for quality microwave test instrumentation. Our employees offer many years experience in the design and manufacture of the worlds best vector network analyzers, spectrum analyzers, power meters and associated components. The management team has additional experience in optical power testing, military radar and a variety of programming environments including LabVIEW, VEE and other languages often used in programmatic systems. Extensive experience in a broad spectrum of demanding measurement applications. You can be assured that our Power Sensors are designed, built, tested and calibrated without compromise.

Electronic Test Paper

Electronic Test Paper, July 1963 Radio-Electronics - RF CafeAttempts at making an electronically printed facsimile (fax) of an original document at a location distant from the source have been around for quite a while. As mentioned by Radio-Electronics magazine editor Hugo Gernsback in this article, Samuel Morse had a crude working device for printing messages on paper even before his eponymously named code of dots and dashes became famous in 1837. A couple decades earlier, a fellow named John Redman Coxe, of Philadelphia, Pennsylvania, devised a method of electronically printing images and text on paper using a conductive solution and a direct current pile (aka battery). Dr. Coxe, a physician, is not a well-known figure in the electronics world, but in his day...

"Edge of Chaos" High-Performance Microchips

"Edge of Chaos" High-Performance Microchips - RF Cafe"Researchers have discovered how the 'edge of chaos' can help electronic chips overcome signal losses, making chips simpler and more efficient. By using a metallic wire on a semi-stable material, this method allows for long metal lines to act like superconductors and amplify signals, potentially transforming chip design by eliminating the need for transistor amplifiers and reducing power usage. A stubbed toe immediately sends pain signals to the brain through several meters of axons, which are composed of highly resistive fleshy material. These axons operate using a principle known as the 'edge of chaos,' or semi-stability, enabling the swift and precise transmission of information..."

Japanese Trade-Name Directory

Japanese Trade-Name Directory, August 1969 Electronics World - RF CafeThe January 1969 issue of Electronics World magazine published an extensive list of Japanese company trade names and their addresses. Many of them went out of business or were bought by other corporations long ago, as occurs in all countries. "Aiwa" is listed twice, but that might have been a legitimate duplication due to separate locations (BTW, I owned an Aiwa stereo at one time). My first "real" cassette tape deck was made by TEAC (founded in 1953 as the Tokyo Electro Acoustic Company) and my first "real" stereo receiver was made by Sansui. I remember the line in "Back to the Future 3" where Doc Brown, having time-travelled from 1955, makes a disparaging remark about a circuit in the DeLorean failing because of it being labeled "Made in Japan." Marty counters...

Engineering & Tech Headlines <Archives>

• ARRL Defends 902-928 MHz Amateur Radio Band

• FCC's Auto Safety Spectrum Rules

• $5M in U.S. Chips Act Money to Metrology Projects

• U.S. State Department Approves Surveillance Radar System Sale to Romania

5G Americas ITU IMT-2030 Vision for 6G White Paper

John Redman Coxe: A Short Biography

John Redman Coxe: A Short Biography - RF Cafe - RF CafeJohn Redman Coxe was a prominent American physician, scientist, and innovator born on September 20, 1773, in Philadelphia. Coxe's intellect and curiosity drove him toward an illustrious career in both medicine and early scientific exploration, which included experimentation in electrochemistry. He graduated with a degree in medicine in 1794, setting the course for his lifelong journey into medicine and early scientific innovation. Coxe broadened his approach to medicine and science, inspiring him to explore the convergence of scientific methods and practical applications. John Redman Coxe is most remembered not only for his contributions to medicine but also for his interest in experimental physics, particularly in the field of electrochemistry...

Thanks to TotalTemp Technologies for Continued Support!

TotalTemp Technologies - RF CafeTotalTemp Technologies has more than 40 years of combined experience providing thermal platforms. Thermal Platforms are available to provide temperatures between -100°C and +200°C for cryogenic cooling, recirculating & circulating coolers, temperature chambers and temperature controllers, thermal range safety controllers, space simulation chambers, hybrid benchtop chambers, custom systems and platforms. Manual and automated configurations for laboratory and production environments. Please contact TotalTemp Technologies today to learn how they can help your project.

Vibration and Shock - Nature's Wrecking Crew

Vibration and Shock - Nature's Wrecking Crew, August 1966 Radio-Electronics - RF CafeWhen I saw this 1966 Radio-Electronics magazine article entitled, "Vibration and Shock - Nature's Wrecking Crew," for some reason the first thing I thought of was "The Wrecking Crew," that anonymously played the music for a huge number of popular singers - mostly those without prominent bands of their own during the 1960s and 1970s rock-and-roll era. ...but I digress. My introduction to the potential deleterious effects of vibration on electronics was in the 1970s, with airborne receivers and servos in my radio controlled model airplanes. Even though they were transistorized, vibration from glow fuel engines could wreak havoc with potentiometers in servos and solder joints everywhere, including battery packs. I remember seeing the control surfaces jitter...

Raytheon Needs Tube Design Engineers

Raytheon Manufacturing Company Needs Vacuum Tube Engineers, July 1944 QST - RF CafeYou don't see jobs advertisements like this anymore. Here is an ad that appeared in the the July 1944 edition of QST (the American Radio Relay League's, ARRL's, monthly magazine), placed by Raytheon Manufacturing Company (now just Raytheon Company), looking for vacuum tube design, test, and processing engineers. Licensed amateur radio operators were in high demand during the war years because of their knowledge and enthusiasm for electronics and wireless communications. I hope you didn't come to this page hoping to really find a tube designer job available. Of course, there are still vacuum tubes being designed for TWTs and magnetrons, but those are few and far between...

The Carborundum Signal Detector

The Carborundum Signal Detector - RF CafeThe "carborundum" signal detector, an innovative device developed by engineer General H. H. C. Dunwoody in the early 20th century, represents a significant advancement in radio technology, particularly in the context of crystal detectors used for receiving radio signals. This device utilized the unique properties of silicon carbide, also known as carborundum, which was synthesized in the late 19th century by Edward Goodrich Acheson. The connection between Dunwoody and the material lies in the application of carborundum as a semiconductor in radio signal detection. The operational theory of the carborundum signal detector is rooted in its ability to rectify alternating current (AC) signals. When radio waves, which are essentially electromagnetic waves...

Lossless Electronics with Innovative Quantum Sandwich

Lossless Electronics with Innovative Quantum Sandwich - RF Cafe"Researchers have created a cutting-edge structure by placing a very thin layer of a special insulating material between two magnetic layers. This new combination acts as a quantum anomalous Hall insulator, significantly broadening its potential use in developing ultra-efficient electronics and innovative solar technology. A Monash University-led research team has found that a structure featuring an ultra-thin topological insulator, sandwiched between two 2D ferromagnetic insulators, transforms into a large-bandgap quantum anomalous Hall insulator. This heterostructure opens the door to ultra-low energy electronics and even topological photovoltaics..."

Radio Theme Crossword Puzzle for June 6th

Radio Theme Crossword Puzzle for June 6th, 2021 - RF CafeFor twenty years now, I have been creating weekly crossword puzzles for the education and enjoyment of the technically minded visitor like you. This Radio Theme Crossword Puzzle for June 6th has many words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

VSWR | Return Loss | Reflection Coefficient Calculator

VSWR to Return Loss to Reflection Coefficient Conversion Calculator - RF CafeThis online calculator converts between return loss (RL), voltage standing wave ration (VSWR), and reflection coefficient (Γ). It also calculates the amplitude and phase error created by imperfect impedances. Two VSWR values are taken as input. Finally, VSWR improvement due to attenuation is calculated. Numerical inputs are not error trapped. Absolute values of inputs are used for calculation.

Balsa Weight for Various Densities

Balsa Weight for Various Densities - RF CafeBalsa is one of the lightest woods available, and in many respects has the highest strength-to-weight ratio of any wood - even oak. The chart at the right gives a comparison of a few familiar wood types. Hobby grade balsa is harvested in the jungles of Ecuador, kiln dried, cut into large blocks, and shipped to the U.S. for final cutting and sanding. Most balsa from hobby shops is in the 8-10 lbs/ft3 realm. The rock-hard stock that nobody wants is sent to the airplane kit manufacturers ;-) The vast majority of the balsa wood I use for building model airplanes comes from Sig, Midwest, and Balsa USA. Other suppliers have materialized in the past few years. Since the rise of mammoth wind turbines for electricity generation, balsa's use as a core material for blades has caused a severe shortage in the modeling realm. Balsa prices have skyrocketed in the past decade..

Walter Ashe Radio Company

Walter Ashe Radio Company, March 1954 Radio & Television News - RF CafeTrigger Alert: Don't look at this advertisement from a 1954 issue of Radio & Television News magazine if you are easily offended by what used to be an effective marketing technique, but is now considered too exploitative for use. The "Cancel Culture" mindset of today's easily offended (often agenda-driven) citizenry would likely work to have Walter Ashe driven out of business for such an ad. If you dare to peek at the advertisement - and I'm not recommending that you should if it might jeopardize your place in society, be sure to note the fire hydrant...

R.F. - Is It Dangerous?

R.F. - Is It Dangerous?, April 1960 Electronics World - RF CafeThe ubiquitous presence and usage since the 1970s of microwave ovens has made most people aware of the ability of radio frequency (RF) energy to heat substances containing water. Both animate and inanimate objects are included. In 1960, when this article was written, the effort had really just begun to inform the general public about the potential hazards of RF energy depending on its combination of wavelength (frequency) and power. The good news about RF radiation versus beta radiation due to radioactive decay is that the former is not potentially cancer-causing. The latter is termed "ionizing radiation" because it has the ability to knock electrons off their attending atoms, and can cause cancer. Extremely short electromagnetic (EM) wavelengths above the ultraviolet can also ionize atoms, but that is well above the EM spectrum region considered to be RF...

Electronics and the IGY - Part I

Electronics and the IGY - Part I, February 1958 Radio Electronics - RF CafeThe International Geophysical Year (IGY) began on July 1 of 1957 and ran through December 31 of 1958. It was the dawn of space / high altitude flight and there was a great need to learn as much as possible about the physics of the upper atmosphere and the void of space. The USSR successfully flew their first three Sputnik satellites and the U.S. was scrambling to get Echo into orbit (finally on August 12, 1960, after the end of IGY). The Cold War was at its peak (Bay of Pigs incident was just a few years away), and the science world was looking for a way to provide a unifying tie between the planet's countries. "During this time, more than 5,000 scientists and engineers of more than 60 nations ...

Radar "Sidelight"

Radar "Sidelight", December 1955 Popular Electronics - RF CafeWhen I saw this photo of a man holding a fluorescent light bulb in the beam of a radar antenna, it reminded me of how we used to do the same thing on our AN/MPN-14 radar system in the USAF. The unit in the photo is a General Electric's FPS-6 height-finding radar, which operates in the S-band 2,700-2,900 MHz region. The AN/MPN-14 is a mobile ground control approach (GCA) with both an S-band airport surveillance radar (ASR) and an X-band precision approach radar (PAR). Our S-band radar had a 600 kW peak power whereas the FPS-6 put out a couple megawatts, but 600 kW was enough to light the bulb. Of course these days you would never see a company-sponsored photo of a man standing in front of a high power radar antenna with a fluorescent light bulb in his hand ...

Solid State - Early Mention of GaAs

Solid State - Early Mention of GaAs, April 1966 Popular Electronics - RF CafeWhen is the last time you heard someone refer to electronics as "solid state?" It was a necessary differentiator during the era of transition from vacuum tubes to semiconductors. Mere utterance caused fear in some, and futuristic hope in others. "Solid State" was a big buzz phrase in marketing to household consumers and industry planners. Why, I ask, was "solid state" chosen as the term to counter vacuum tube electronics? Did we ever refer to tubes as "gaseous state" or "plasma state" devices? Maybe the "solid" part of "solid state" evoked a sympathetic emotion with the coincident hippie / beatnik era population's usage...

Implausible Remarks (Sequel 1)

Implausible Remarks (Sequel 1), September 1966 Popular Electronics - RF CafeThe July 1966 issue of Popular Electronics began a series of anecdotal instances of stupid and/or funny remarks made by people about electronics. Some are supposedly by those who are in the trade and should know better. I have to take issue with and question the veracity of one instance in this first sequel, which claims a technician coming out of military service are apt to make statements such as fuses being bad because they are "shorted." It must have been submitted by an anti-military hippie of the era, because there's no way anything other than a vanishingly small minority of techs who have spent two to four years or more years servicing real electronic equipment would say ...

Sunspots Aid Radio Signals

Sunspots Aid Radio Signals, July 1957 Radio & TV News - RF CafeSunspot cycles repeat approximately every 11 years, so there had only been six solar maximums from the beginning of long distance radio communications (Marconi in 1901) up until this article was published in 1957. That year ('57) had the sun experiencing an extremely high number of sunspots (see chart below), as had the previous few years, which caused communications to be profoundly affected during the period. Under ideal conditions, high energy electrons typically ejected from the sun (coronal mass ejection, CME) cause the Earth's ionosphere to become an excellent reflector of RF energy at certain wavelengths, resulting in phenomenal long distance contacts. Under the worst conditions, extreme levels of "noise" are injected into radio signals, thereby severely degrading or even eliminating communications. This story reports on a comprehensive study on the effect of such activity on long distance communications...

RF Engineering Theme Crossword for January 31st

RF Engineering Theme Crossword Puzzle for January 31st, 2021 - RF CafeThis RF Engineering Theme crossword puzzle for January 31st contains only words and clues related to engineering, mathematics, chemistry, physics, and other technical words. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate the effort. You will need to print out a hard copy. Enjoy!

Understand the System

Understand the System: JK-RS Flip-Flop, September 1971 Popular Electronics - RF CafeThe extreme level of complexity and consolidation of circuit functions in today's functional integrated circuit (IC) blocks makes it so that people with almost no instruction or experience in circuit and system design can assemble and make work some pretty impressive creations. The days of vacuum tubes and early discrete semiconductors required a designer to know how to properly bias and interface various sections of circuits and systems. Nowadays, with the ready availability of impedance-matched amplifiers, filters, mixers, couplers, detectors, and other pre-packaged components, even RF and microwave frequency systems are within the reach of relative amateurs. Likewise, people interested in digital and microprocessor circuits...

TV Trouble Quiz

TV Trouble Quiz, July 1966 Popular Electronics - RF CafeVery few people these days would have any clue as to the causes of the CRT-type TV picture problems shown here - I certainly don't, even after looking at the answers (except for #4, which is pretty obvious given the choices offered). What I can claim is to have likely seen each one of those types of issues with all the cheap TV sets I've owned (especially #9). My current 26" LCD television (I only own one TV), which is ten years old this year, is still working fine and never displays any of those funny patterns. In the days of the Macs TV Service Shop stories, survival in the business...

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...

Radar Scores SAC Bombing Test

Radar Scores SAC Bombing Test, December 1956 Popular Electronics - RF CafeMost people have heard of the incredibly accurate Norden bombsight (see video of the Norden bombsight) that was credited for revolutionizing accuracy of heavy bombers like B-17s, B-24s, and B-29s. It was an electromechanical device that took bombardier inputs of altitude, airspeed, heading, and wind speed and direction, then calculated the impact point of the bomb. An accuracy of 75 feet was claimed under ideal conditions - provided by a mechanical computing device. By 1956 when this article was published (eleven years after WWII and three years after Korea), the Norden had been replaced by radar-integrated bombing systems. Additionally, ground-based radar measurement systems were in use to train aircrews without the need to drop physical bombs. Instead, virtual bombs were launched and computers in a Radar Bomb Scoring (RBS) unit...

RCA Radio - Cost Reduction

RCA Radio - Cost Reduction, March 1946, Radio-Craft - RF CafeIf you have seen many of the articles I post from vintage electronics magazines, you know I often compare prices from the magazine's era to today's prices. The online Inflation Calculator from the Bureau of Labor Statistics (BLS) is as good as any, so it is used. This RCA advertisement in a 1946 issue of Radio-Craft magazine boasts of how drastically the cost of vacuum tubes has come down since 1923. It claims a $9 tube in 1923 costs a mere 80¢ in 1946; that is about 1/11th of the original price. Prior to around 1965, inflation was very low, so the inflation-adjusted price for the $9.00 tube would be $9.80 in 1946 - a full 23 years later (a 9% increase, per the BLS). Therefore, the 80¢ price is an even better deal. Let us compare that to what a $9 item 23 years ago (1998) from today (2021) would cost now. Per the BLS Inflation Calculator, it would take $15.06 in 2021...

All-Way FM Antenna

All-Way FM Antenna, March 1948 Radio-Craft - RF CafeHave you heard of an Alford Loop antenna? I hadn't until reading this article. It is a four-sided structure consisting of identical folded ½-wave dipoles on each side, with a common feed. Opposing sides have their elements 180° out of phase with respect to each other. The intention is to provide nearly omnidirectional FM radio reception across the entire 88-108 MHz band. A little research on the Alford Loop reveals that Mr. Andrew Alford developed this configuration to enable simultaneous, co-located transmissions of FM radio stations. In that case the four antennas are individually fed by transmitters on different frequencies. Alford is credited with inventing antenna systems for the VFH Omnidirectional Range (VOR) and Instrument Landing System (ILS) navigational aids...

Microwaves for the "Ham"

Microwaves for the "Ham", August 1952 Radio & Television News - RF CafeWhile this article is directed at amateur radio operators who want to explore working in the microwave bands, it is good fodder for anyone who wants a fundamental introduction to waveguides, resonant cavities, distributed elements, and atmospheric propagation. If that describes you, and particularly if you have formulaphobia, then start reading. Even though the article appeared in a 1952 issue of Radio & Television News, the list of frequency band allocations are not much different than today so the information is useful. Unknown to many is that in the early part of the last century Amateurs pioneered the use of microwave bands when the Federal Communications Commission (FCC) allocated the spectrum to them since many "experts" considered it unusable ...

Aircraft Detection Prior to the Invention of Radar (Acoustic Defense)

Aircraft Detection Prior to the Invention of Radar (Acoustic Defense) - RF CafeBeginning in the middle of the 1930s, engineering labs in the U.S. and Europe were experimenting with radar systems. Early radars did not have the slick plan position indicator (PPI) displays that modern systems use for plotting target movement for indication of azimuth (direction) and range (distance). Instead, oscilloscopes showed radar returns as amplitude blips along a time base that represented range. Azimuth was determined by where the operator pointed the antenna (rotating versions came later). Since radar cross section stealth technology had not been invented yet, the amplitude of the signal was useful a measure of the size of the target. Prior to the invention of radar (RAdio Detection And Ranging), other means were needed to detect...

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...

LadyBug LB5954L Power Sensor with LAN Option - RF Cafe
Windfreak Technologies Frequency Synthesizers - RF Cafe

Anritsu Test Equipment - RF Cafe

Noisecom