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Homepage Archive - June 2025 (page 2)

See Page 1 | 2 | of the June 2025 homepage archives.

Friday the 20th

Comics with an Electronics Theme

Comics with an Electronics Theme, March 1965 Popular Electronics - RF CafeTGIF, and that means tech-themed comics from vintage electronics magazines if I happen to have any. You'll really appreciate the comic on page 96 of the 1965 issue of Popular Electronics magazine. In a way, the drawing's concept was very prescient regarding the future of flexible, bendable circuits. A big part of the electronics world at the time centered around servicing all the newfangled circuits and test equipment for troubleshooting and aligning them. As is still true today, technology changed quickly and there was always a newer model television, radio, tape recorder, stereo system, video recorder, etc. Customer interactions and repair shop experiences provided plenty of amusing fodder for magazine articles and comics. I took the liberty of coloring them...

Facts About Lightning Protection

Facts About Lightning Protection, July 1959 Electronics World - RF CafeLightning season is upon us once again. The National Weather Service says June, July, and August, are the most active lightning months in the U.S., which is probably true in all of the northern hemisphere, and then December, January, and February in the southern hemisphere. According to the National Safety Council, the average American has a 1:114,195 chance of being killed by lightning in a lifetime (which ends abruptly upon being killed). That's much less than your chance of dying due to cancer (1:7) or being killed in a car accident (1:102), but is sucks if you're that one in 114,195. Not all lightning strikes are fatal, but many cause personal and property damage. Mitigating the chance of being harmed requires taking some simple actions to not expose...

Engineering & Tech Headlines <Archives>

• FCC Accuses EU Regulators of Harbouring Anti-American Biases

• GlobalFoundries Pledges $16B U.S. Investment

• Wireless Providers Dominating Broadband

• Q1 Mobile Core Market up 32% YoY

• Supply Chain Must Confront Divergence

Thursday the 19th

Amateur 2-Meter FM Repeaters

Amateur 2-Meter FM Repeaters, May 1973 Popular Electronics - RF CafePrior to the advent of earth-orbiting satellites, very long range communications like between continents was dependent on the state of the various ionosphere levels. There is never a completely predictable "open" channel from point A to point B. A satellite repeater, however, while not always in a position to be within view of both points, at least is predictable based on a published ephemeris of times and positions. The first OSCAR (Orbiting Satellite Carrying Amateur Radio), now governed by AMSAT, was launched in December of 1961. This 1973 article in Popular Electronics mentions OSCAR 6, which was launched in October 1972...

Anritsu to Demonstrates Key Non-Terrestrial Network

Anritsu Collaborates with Industry Leaders to Demonstrate Key Non-Terrestrial Network Use Cases - RF Cafe"Anritsu Corporation announces its participation as a Test and Measurement partner in two pioneering demonstrations of 3GPP Rel-17 compliant Non-Terrestrial Network (NTN) technology at the 2025 5GAA meetings in Paris. The demonstrations provided the first of their kind measurements showcasing the readiness of the technology and ecosystem to revolutionize automotive safety. In one of the collaborations with industry leaders BMW Group, Deutsche Telekom, Viasat and Skylo, Anritsu contributed to successful measurements of end-to-end NTN Key Performance Indicators (KPIs)..."

Electronics Metals Quiz

Electronics Metals Quiz, October 1964 Popular Electronics - RF CafeThis Electronics Metals Quiz appeared in the October 1964 edition of Popular Electronics. Given the era and obsolescence of some technologies, a couple of the drawings might not be recognizable to you. Accordingly, I feel obligated to clue you in on those. "B" is a television iconoscope, which was used in early TV video cameras. "D" is a phonograph stylus. For "F," keep in mind the prevailing semiconductor material at the time. "I" is a type of heater element that could be screwed into a light bulb socket (I used to have a couple). "J" is supposed to be a needle for a meter movement. Now that you know, have at it. The process of elimination should result in a good score. I got 10:10, but then I'm older than the quiz...

A Bonus for CATV Subscribers: Cable FM

A Bonus for CATV Subscribers: Cable FM, January 1971 Popular Electronics - RF CafeAccording to a plethora of news reports in the last few years, the "cord cutting" phenomenon is having a significant impact on cable media providers. Consumers long ago grew tired of the monopolistic practices of corporations forcing mostly unwanted programming onto everyone and then trying to convince them that they were getting a good deal if the cost per channel was considered. No one bought that argument, but it didn't matter because there was no competition for service. Public Utility Commission (PUC) efforts to force prime line owners to rent out "space" in an attempt to provide competitive products has never worked, but that doesn't keep PUCs from trying (job security). The advent of wideband wireless service has opened up a new realm of media delivery that is leaving wired service in the dust. Not only is cellphone...

Trump Mobile Launches w/Golden Phone

Trump Mobile Launches w/Golden Phone - RF Cafe"Trump Mobile launches as a new mobile service and will also sell its own mobile device, the T1, offering an 'all-American service for our nation's hardest-working people.' 'Alongside the team from Trump Mobile, Donald Trump Jr. and Eric Trump unveil T1 Mobile, a transformational, new cellular service designed to deliver top-tier connectivity, unbeatable value and all-American service for our nation's hardest-working people,' opens a post on the Trump Organisation website. Trump Mobile claims to be a next-generation wireless provider.' It offers 5G service through all three major cellular carriers, presumably meaning T-Mobile, AT&T and Verizon, and it is holding up The 47 Plan as a flagship package which goes for $47.45 per month..."

Anxiety Amid Affluence: Why Color-TV Makers Worry

Anxiety Amid Affluence: Why Color-TV Makers Worry, December 27, 1965 Electronics Magazine - RF CafeDecisions, decisions, decisions. As the title states, color television manufacturers were, in 1965, finding themselves between a rock and a hard place, as the saying goes, regarding a change from vacuum tubes to transistors. The buying public (aka consumers) had mixed emotions about the newfangled semiconductors based at least partly on bad information about transistors. Transistors had been designed in various circuits for a decade and a half and were gaining rapidly in performance and reliability. The price was coming down, but as reported here, still cost $5 to $10 apiece compared to a $1 vacuum tube. Company management needed to decide whether to delay implementing the new engineering and production methods required to deal with transistors for a couple more years until the market had more time to make up its mind whether to begin. A couple firms enthusiastically...

Wednesday the 18th

Hams in Combat: A Lady of Mercy

Hams in Combat: A Lady of Mercy, July 1944 QST - RF CafeThis is another installment of the "Hams in Combat" series that the ARRL's QST magazine ran during WWII. I enjoy vicariously waxing nostalgic of a time before I was born, at time when there was still honor, courage, selflessness, and pride of country. During World War II, it was an ingrained part of most citizens, whether or not they happened to be serving in the military. Our modern day troops still have it, but sadly fewer and fewer people see their own country as any place special in the world. Many don't believe it ever was. Sure, as General William Tecumseh Sherman famously said, "War is hell," but then again so is witnessing the tearing apart of your country from forces within...

Trump Admin Overturns BEAD Rules for Satellites

Trump Admin Overturns BEAD Rules for Satellites - RF Cafe"The Trump administration has changed the rules on broadband funding in the US in a widely-anticipated move that could open the way for satellite companies to cash in. The president has made a number of alterations to the Broadband Equity, Access, and Deployment (BEAD) programme, pitching them as an exercise in cutting red tape. The changes cover a range of T&Cs, including environmental and inclusion issues, but the one capturing column inches is around technology; where once BEAD was heavily skewed towards fibre deployment, those applying for funding will now be able to use whatever technology they wish, including satellite or wireless. Such a change has been on the cards for the past few months..."

Light-Sensitive Photodiodes

Light-Sensitive Photodiodes, July 1969 Electronics World - RF CafePhotodiodes and phototransistors were relatively new on the electronics scene in 1969 when this article appeared in Electronics World magazine. Prior to semiconductor light detectors, vacuum phototubes did the job in cameras, motion sensors, light level detectors, medical imaging equipment, etc. High voltages and the large volume for containing components supporting vacuum tubes created hazards (especially with medical equipment), inconvenience, and high cost. What we take for granted nowadays in terms of price, performance, reliability, and size was all yet to be worked out with the new technology...

Werbel 10 dB Directional Coupler for 0.3 to 8 GHz

Werbel Microwave WMC-0.3-8-10dB-S Directional Coupler for 0.3 to 8 GHz - RF CafeWerbel Microwave's Model WMC-0.3-8-10dB-S is a directional coupler that covers 300 MHz to 8 GHz with broadband flat coupling response, high directivity, and excellent return loss performance. Frequency sensitivity is ±0.6 dB typical. High directivity of 25 dB typical. Mainline insertion loss of 1.3 dB typical includes loss due to coupling factor. Return loss 23 dB typical. Aluminum enclosure measures 6.00 x 0.73 x 0.50 inches with threaded mounting holes. SMA Female connectors. The device is RoHS compliant but may be special ordered with Lead solder to support military applications...

Tuesday the 17th

Room Acoustics for Stereo and Entertainment Systems

Room Acoustics for Stereo and Entertainment Systems, February 1960 Electronics World - RF CafeHome entertainment is as big of a deal (or bigger) today as it was in the 1960's and 1970's when high fidelity personal sound gear was coming into the mainstream. Capability and features were going up while the price was coming down on really nice equipment. In order to achieve theater quality sound from your stereo and/or large screen television, thought and planning is essential or you will end up with a confusing mess of directed and reflected sounds. This article contains very valuable information on room configuration and sound absorbing materials and strategies. A fairly extensive table of common floor, wall, and ceiling sound absorption coefficients is provided, as are charts of reverberation times of various venues and volumes...

DSTL Leads Effort to De-Orbit Satellites

DSTL Leads Effort to De-Orbit Satellites - RF Cafe"Efforts to tackle space debris are underway with an experiment to de-orbit CanX-7, a Canadian satellite that began a controlled descent using space sails in May, 2017. CanX-7 is part of the Daedalus experiment, an effort led by scientists at the Defence Science and Technology Laboratory (DSTL) to tackle space junk. According to NASA, over 500,000 items are tracked as they orbit Earth, yet fewer than 5,000 are operational satellites. Travelling at speeds of up to 17,500mph, relatively small pieces of orbital debris can damage a satellite or a spacecraft. DSTL says the most congested area sits in low Earth orbit (LEO) where collisions..."

The Venerable Simpson 260 Multimeter

Simpson 260 Multimeter - RF CafeThe Simpson 260 multimeter (now up to model P) has been around a long time - about eight decades. It is on version 8 now. My first encounter with a Simpson 260 was in my high school electrical vocational classes. We had them in the USAF radar shop as well, then in every company lab in which I worked. Sadly, I do not personally own one, and at $850 (doh! get it...Simpson?), never will. John Ellis has a nice historical account of the Simpson 260 multimeter in the July 2018 issue of QST magazine. Unfortunately the ARRL does not make the article available online to non-members, but surely there is a Ham nearby who can lend you his/her copy for reading. An advertisement for the Simpson 260 VOM, which I do have in full, appearend the  July 1944 edition of QST.

Giant Billboard Antennas for Space-Age Radars

Giant Billboard Antennas for Space-Age Radars, December 1971 Popular Electronics - RF CafeSteerable phased array antenna systems used to be the exclusive domain of military and aerospace radar and electronics warfare systems. The expense involved in both the hardware and the electronics required for controlling the beam was expensive and complicated. Larger phased array antennas for lower frequency bands are still relatively expensive. However, small cell wireless phone and WiFi applications in the 2.4 GHz and higher bands are seeing the development and deployment of phased arrays that will search for and track individual users in order to allocate antenna gain and signal power where it is needed, rather than using an omnidirectional radiation pattern. Physically steered directional antennas are not capable of the speeds needed to do the job. In the last couple years, MMIC phased antenna arrays have begun appearing in the news for millimeter-wave systems...

Withwave Board-Mount 45° Connectors (to 67 GHz)

Withwave Board-Mount 45° Board-Mount Connectors (DC to 67 GHz) - RF CafeWithwave 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 analysis and signal processing. Withwave's 45 degree connectors are specifically designed for easy installation in tight spaces, providing a reliable 45° connection with a solderless contact to the PCB surface on test and measurement boards. These connectors deliver outstanding electrical transition performance up to 67 GHz while also significantly reducing installation time...

Monday the 16th

Mac's Service Shop: Radio Interference

Mac's Service Shop: Radio Interference, January 1972 Popular Electronics - RF CafeAlthough published in a 1972 issue of Popular Electronics magazine, the topic of dealing with radio interference is timeless. Some of the sources of radio interference change over the years, but there is always a need to discover and resolve such problems, and more importantly, use the lessons learned to attempt to prevent it in the first place. The January setting in the Great Lake Midwest region of the U.S. is right on time for when this is being posted. It's snowing here in Erie, Pennsylvania, as I write this, the temperature is about 24°F, and the wind is howling at 15-20 miles per hour as is has been all night. "Someone must have sprayed circuit-cooler around out there," Barney (Mac's able young assistant) complained. "Man, it's cold!" That about sums up today's weather. Unfortunately for Barney, he would be called upon to leave the warmth of the shop to make a service call to figure out why CB radio transmissions...

The Peril of AI-Generated Misinformation

The Peril of AI-Generated Misinformation: A Self-Flagellating Treatise on the Erosion of Truth, Kirt's Cogitation #371 - RF CafeAs mentioned often before, I have been using various AI engines a lot in the last year. Topics include writing VBA code for Excel and JavaScript code for HTML pages, generating historical data on technology pioneers, companies, components, and events; doing research on medical diagnosis and treatment, computer issues, car care, food nutrition, and child development; and content for my RFCafe.com and AirplanesAndRockets.com websites. Most replies are good, but for objective data nearly always require multiple solicitations to arrive at an acceptable and useful result. Sometimes, AI responses are outrageously in error. Here are the exact instructions posed to AI engines (Arya, ChatGPT, Gemini, Grok) regarding the probable disasterous result of unchecked propagation of erraneous information...

Shielding to Prevent Radiation

Shielding to Prevent Radiation - RF Cafe"This is the first of seven articles devoted to the topic of shielding to prevent electromagnetic wave radiation. The shielding theory is based on the accepted theory originally presented in and embraced by many EMC experts. The results presented here are valid under the assumption of a uniform plane wave with normal (perpendicular) incidence on a boundary between two media. Fundamental Framework Shielding theory is based on three fundamental concepts: Reflection and transmission of electromagnetic waves at the boundaries of two media, Radiated fields of the electric and magnetic dipole antennas wave, and Impedance of an electromagnetic wave. The first concept leads to the analytical formulas for the far-field shielding..."

Attack Planes Hug Hostile Terrain with New Radar

Attack Planes Hug Hostile Terrain with New Radar, February 21, 1964 Electronics Magazine - RF CafeAccording to this 1964 article in Electronics magazine, the U.S. Air Force's decision to build radar systems that would enable low altitude, terrain-following flight paths for strategic and tactical aircraft was in response to the shooting down of Gary Powers' U-2 spy craft in 1960. The event made clear that simply flying high over enemy territory and dropping bombs would not be a reliable strategy since surface-to-air missiles could reach and destroy aircraft before they got to their targets. Terrain-following capability on the part of bombers and fighters would add a major element of surprise since approach paths could be masked until it was too late to take offensive action. That approach was not without its risks and faults, as made apparent by the Dr. Strangelove movie satire that poked fun at the very concept...

IPP-7181 80-1000 MHz,250 W, Hybrid Coupler

Innovative Power Products IPP-7181 80-1000 MHz,250 W, SMD 90° Hybrid Coupler - RF CafeIPP's new broadband 90° hybrid coupler, the IPP-7181, covers 80 - 1000 MHz with an impressive power handling of 250 W CW in a surface mount package. Measuring 1.00" x 1.75" x 0.260", the IPP-7181 provides excellent performance in a compact package; its insertion loss is less than 0.90 dB, VSWR is less than 1.40:1, isolation is greater than 15 dB, and phase balance is ±6 degrees. From 125 - 1000 MHz, its amplitude balance is ±1.0 dB, and ±2.0 dB at 80 MHz. The IPP-7181 can be used in a variety of applications ranging from VHF to UHF including radio communications, broadcasting, radar...

Self-Assessment of "The Peril of AI-Generated Misinformation"

  Self-Assessment of "The Peril of AI-Generated Misinformation"  

Anritsu to Demonstrates Key Non-Terrestrial Network

Anritsu Collaborates with Industry Leaders to Demonstrate Key Non-Terrestrial Network Use Cases - RF Cafe"Anritsu Corporation announces its participation as a Test and Measurement partner in two pioneering demonstrations of 3GPP Rel-17 compliant Non-Terrestrial Network (NTN) technology at the 2025 5GAA meetings in Paris. The demonstrations provided the first of their kind measurements showcasing the readiness of the technology and ecosystem to revolutionize automotive safety. In one of the collaborations with industry leaders BMW Group, Deutsche Telekom, Viasat and Skylo, Anritsu contributed to successful measurements of end-to-end NTN Key Performance Indicators (KPIs). The joint effort focused on measuring NTN KPIs to demonstrate the feasibility and effectiveness of use cases, such as local hazard warning and emergency messaging. A separate collaboration with industry leaders LG Electronics, Cubic3, Viasat, and Skylo focused on measuring NTN KPIs to demonstrate the capability to support use cases such as Voice over NTN and switching between terrestrial and non-terrestrial networks. "

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GoFundMe Campaign for RF Cafe

GoFundMe Capmpaign for RF CafeFor over a quarter of a century, RF Cafe has stood as a beacon of free, high-quality engineering knowledge - serving professionals, students, and hobbyists without paywalls, data harvesting, or corporate influence. Founded and single-handedly maintained by Kirt Blattenberger, this one-man passion project has grown into an indispensable repository of RF/microwave engineering resources, vintage technical literature, and practical tools. Now, RF Cafe needs your help to ensure its survival in an era of rising costs, intrusive ads, and corporate-controlled information. Donations via gofundme are tax-free per IRS rules, so the full amount is received. Thank you for your support!

Smartphone Market Downgrade

Smartphone Market Downgrade Not Just About Tariffs - RF Cafe"Another analyst firm has downgraded its growth forecast for the global smartphone market, but while US tariffs are a key reason for the shift, there are other issues at play, including weakness in China. Counterpoint Research on Wednesday revealed that it has revised down its predictions for this year. Having previously expected 4.2% year-on-year growth in smartphone shipments in 2025, it is now looking at a 1.9% increase. That's quite a change, and the headline reason behind it is of course the tariff issue. The analyst firm is not the first to change its projections due to the tariffs, IDC having done just that a fortnight ago. But in addition to reinforcing the hypothesis..."

New Semiconductor Supercharges 6G

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

 

 

 

 

 

 

 

 

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.

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KR Electronics (RF Filters) - RF Cafe