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2 | of the October 2025 homepage
archives. Friday the 31st
 Not everyone whose name sounds like "Goebbels"
was a bad guy. Heinrich Göbel was a German-born American mechanic and inventor,
also known by his Anglicized name, Henry Goebel - as used here in this 1964
Popular Electronics magazine article that disputes whether or not Thomas Edison
was the true
inventor of the incandescent bulb. As with the debate over whether Gustave
Whitehead beat the Wright brothers with the first man-carrying airplane to
take off and fly under its own power, and whether Elisha Gray beat Alexander Bell,
there were supposedly credible witnesses to prove claims. Courts have decided otherwise,
but that does not rule out the possibility of error. Mr. Goebel reportedly
had supporters who saw his home-brew incandescent bulbs burning...
 Anritsu Company has launched the
MN4765B-0140 O/E Reference Calibration Module,, the world's fastest and first
traceable solution to support the testing demands of next-generation data centers
and the explosive growth of Artificial Intelligence (AI) and Machine Learning. As
data centers transition from 224 Gbps to 448 Gbps per lane to achieve
total data rates like 1.6T, the required bandwidth for electrical-optical (E/O)
modulators and optical-to-electrical (O/E) photodetectors now exceeds 130 GHz.
The new MN4765B-0140 is engineered to meet this critical need, pushing the measurement
frontier to 145 GHz...
 After many years of reading
Mac's Service Shop sagas, a persistent theme seems to be Barney's
refusing to refer to equipment schematics while troubleshooting, thereby often wasting
valuable time. According to business owner and electronics sage Mac McGregor, assuming
that what is typical for most sets will apply to all sets can and does create a
fertile environment for frustration - and profit loss. Mac's advice to check "simple
things first," has always been my troubleshooting philosophy - maybe because identifying
the "hard things" has nearly been my undoing many times when the trouble is not
simple. One of first things I do is check switches, connectors, and user-accessible
potentiometers for proper operation (when potentially responsible for the problem,
of course). I've written many times about how often a dirty connector is the culprit...
 Many
thanks to P.S. for generously making what I believe is the 5th (or maybe 6th?) donation
I have received since beginning RF Cafe in 1999! Actually, while very gratefully
welcoming donations, I always encourage someone to instead buy my
excellent software,
or maybe even advertise his/her
company's offerings on the RF Cafe website. In doing so, you get something
out of the deal - in addition to the warm, fuzzy feeling you have from doing a good
deed. I have a feeling at least one of my current advertisers is operating under
that model. Regardless of your motivation, the extreme increase in cost of living
in the past half decade has taken a severe toll on the bank account, so thanks immensely
to all who have ever supported RF Cafe in any way!
 This "Recent Developments in Electronics"
from a 1960 issue of Electronics World had a lot of
antenna news that included a retarded surface wave antenna with
high gain and low silhouette for use in airborne early warning radar as well as
ground based and shipboard radar, a pair of 60-foot tropospheric scatter antennas
that are specially mounted at opposite ends of a 180-mile long section of the Gulf
of Mexico, and a 104-foot-long rotating 50-ton radar antenna used for the SAGE early
warning system. Also reported was Westinghouse Electric's airborne Stratovision
for broadcasting educational television programming to rural areas out of reach
of existing towers...
 Innovative Power Products has been designing
and manufacturing RF and Microwave passive components since 2005. We use the latest
design tools available to build our baluns, 90-degree couplers, directional couplers,
combiners/dividers, single-ended transformers, resistors, terminations, and custom
products. Applications in military, medical, industrial, and commercial markets
are serviced around the world. Products listed on the website link to detailed mechanical
drawings, electrical specifications, and performance data. If you cannot find a
product that meets your requirements on our website, contact us to speak with one
of our experienced design engineers about your project.
Thursday the 30th
 Mr. Ronald Wilensky provided the "Electronic
Sticklers" circuits for the February 1959 issue of Popular Electronics magazine.
The first one I got right away. With number two, I'd determined he was just lucky
it worked - for the exact reason given by the answer. Stickler #3 simply requires
you to rearrange the schematic a bit to uncross wires (or look closely at the connections),
then the answer jumps right out at you. The last one is the toughest challenge.
It is an oldie but goodie. I worked out the resistor cube a long time ago and posted
it here on RF Cafe. I make no claim to be an electronic circuit maven, so if I can
do them, then so, probably, can you. Bon chance!
 A few months ago, one of America's big-city
mayors made the proclamation, "We're not going to make America great again. It was
never that great." There has been a big push in the last decade to not only erase
the
significant accomplishments and sacrifices of America's and Western
Europe's past, but to vilify those people and institutions that make up that past.
Purging the records and rewriting history is a tried and true method of assuring
few have easy access to archival material documenting the accomplishments of the
nation's past. Along with desiring to provide useful and interesting material to
people seeking technical and historical information, my motivation...
 "The convergence of interactions among optics,
acoustics, and electronics leads to some fascinating research advances. A good example
of this interplay is seen in recent work at Stanford University, where a team devised
a novel way to use acoustic waves to manipulate light that has been confined to
gaps only a few nanometers across. It resulted in
detailed control over the color and intensity of light via mechanical means.
In brief, the team placed gold nanoparticles in a particle-on-mirror configuration
with a few-nanometers-thick, compressible polymer spacer. Surface acoustic waves
(SAWs) driven by an interdigital transducer (IDT)..."
 Since 2000, I have been creating custom
engineering- and science-themed crossword puzzles for the brain-exercising
benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury
is out on whether or not this type of mental challenge helps keep your gray matter
from atrophying in old age, but it certainly helps maintain your vocabulary and
cognitive skills at all ages. A database of thousands of words has been built up
over the years and contains only clues and terms associated with engineering, science,
physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing
your knowledge of a numbnut soap opera star or the name of some obscure village
in the Andes mountains. You might, however, encounter the name of a movie star like
Hedy Lamarr or a geographical...
 Exploiting the electronic nature of living
organisms through contrived application and manipulation of electric currents has
been a goal of researchers (and quacks) ever since Luigi Galvani first discovered
that connecting a battery lead to a frog's leg would cause it to kick.
Psychogavanic reflex (PGR) is the technical term for the science.
Once it was determined that all forms of fauna would respond to electrical stimulation,
it wasn't long before the same sort of treatment was applied to all forms of flora.
Many people (not me, for the record*) believe that talking to plants can influence
their health and growth, so why not - so goes the reasoning - try electric currents
as well. We all know from spy, war, sci-fi, and horror movies that under the right
conditions...
 Temwell 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.
Wednesday the 29th
 The
Wheatstone bridge is a fundamental electronic circuit invented by Charles Wheatstone
in 1843, renowned for its exceptional precision in measuring unknown electrical
resistances. Its basic configuration consists of four resistors arranged in a diamond
pattern with a voltage source and a zero-center galvanometer. When the bridge is
"balanced" and the galvanometer reads zero, the ratio of the resistances is equal,
allowing the value of an unknown resistor (Rx) to be calculated using the formula
Rx = R2 × (R3/R4). This Popular Electronics magazine article explains how
to construct a simple, accurate bridge using a slide wire for R3 and R4, where their
ratio is determined by the lengths of the wire. By selecting a known resistor for
R2 and adjusting the slide until balance is achieved, one can precisely calculate
Rx. Beyond resistance, the principle is widely adapted for measuring capacitance,
inductance, and in various control and testing applications, making it one of electronics’
most versatile circuits.
 Here are a few
tech-themed comics from the April 1967 edition of Popular
Electronics magazine depicting the perception of techies during the era. As
mentioned before, stereo equipment was a big deal in the era, back before most people
listened to music through ear buds attached to smartphones. When in the USAF in
the early 1980s, a sure sign of hipness was to have 19" equipment rack in your barracks
room, stuffed full with a reel-to-reel tape deck, a high end AM/FM receiver ("tuner,"
to the audiophile), power amplifier that could deliver at least 200 W per channel,
a dual cassette deck, turntable (referring to it as a "phonograph" revealed your
squareness). Of course no self-respecting stereo aficionado would be caught dead
with an 8-track tape deck in the rack...
 No more forcing a square chip onto
round wafer. "The advanced-packaging needs of AI chips are driving a move by the
semiconductor tool and material industry to supply
rectangular
panels aimed at taking market share from the round silicon wafers we are all
so familiar with. Toolmakers Lam Research and Nikon are among companies selling
advanced packaging equipment for panel production, with an industry takeoff starting
as early as 2027, according to Lam. Top foundry TSMC, which has dominated advanced
packaging of AI chips for customers like Nvidia and AMD, is likely to yield its
hegemony of heterogeneous..."
 An alternate title for this article that
appeared in a 1969 issue of Radio-Electronics magazine could have been,
"How to Build a J-K Flip-Flop." Author Leonard Geisler takes the
reader through a step-by-step assembly of a functional J-K flip-flop using a collection
of 1- 2- and 3-input NAND gates. The 1-input NAND, in case you are wondering, is
used as an inverter. The piece reads like an in-depth first-semester electrical
engineering technician course textbook. In the process of building the J-K, an R-S
(reset/set) flip-flop is described. Nowhere does Geisler offer an explanation of
from where the "J" and the "K" input labels come. According to electrical engineer
Sourav Bhattacharya blog, it was Dr. Eldred Nelson of Hughes Aircraft who first
coined the term J-K flip-flop...
 "everything RF has launched
RF AI Expert, a first-of-its-kind AI-powered tool built specifically to answer
technical questions on RF and Microwave topics . Unlike generic AI platforms, RF
AI Expert delivers precise, industry-focused answers drawn exclusively from trusted,
verified sources. When users ask a question, the RF AI Expert scans over 5,000 white
papers, articles and documents to give a helpful and accurate answer. The tool has
been trained on an extensive knowledge base that includes: 2,500+ white papers from
leading manufacturers, research institutions, and standards bodies. 1,500+ original
technical articles from the everything RF editorial team..."
 When the electronics product world consisted
of vacuum tube based circuits, the physical sizes of standard fixed-value passive resistors, inductors, and capacitors were not of much concern
in terms of how much volume they consumed. R's, L's, and C's, had wire leads protruding
from their molded bodies, or in the case of larger power supply filtering capacitors
had solderable tabs. Point-to-point wiring consisted of components and hookup wire
suspended in the air between solder terminal strips and tube base tabs. Even with
miniature (peanut) tubes, all but the largest passives had no significant impact
on overall unit size. Once semiconductors came onto the scene, everything changed.
Suddenly, even the standard 1/4 W carbon resistor and tantalum capacitor became
a significant factor when attempting to reduce size...
Tuesday the 28th
 Here is a fairly simple
quiz on AC circuit analysis. If you are not already comfortable
with adding series and parallel circuits containing resistors, capacitors, and inductors,
you will appreciate the simple formula presented that will keep the sweat level
down ;-) . An even simpler form that solves explicitly for the four variables
are as follows: VTotal = √ [(VL - VC)2
+ VR2]
VR = √ [(VT)2 - (VL - VC)2]
VL = VC + √ [VT2 - VR2]...
 This
Carl and Jerry adventure serves as a warning to be certain of your information
source before launching into a potentially dangerous endeavor. The tech-savvy teens
are typically more cautious with their experiments, gags, and projects, but this
time they took the word of a neighbor regarding research performed by scientists
at the U.S. Department of Agriculture's Bee Culture Laboratory in Madison, Wisconsin,
without verification. The old saying about a little bit of knowledge being a dangerous
thing certainly played out here. I won't give away the ending, but it wasn't hard
to figure events would take...
 "Cornell engineers have created the world's
first 'microwave
brain' - a revolutionary microchip that computes with microwaves instead of
traditional digital circuits. This tiny, low-power processor performs real-time
tasks like signal decoding, radar tracking, and data analysis while consuming less
than 200 milliwatts. Cornell's Microwave Brain Breakthrough Cornell University scientists
have created a new kind of low-power microchip called a 'microwave brain,' capable
of processing both ultrafast data and wireless communication signals by using the
unique properties..."
 "Rediscovery of FM Broadcasting" could be a contemporary headline.
The decline of broadcast radio has been a major concern of station owners for well
over a decade since Internet and satellite radio has dominated the venue through
which listeners access radio stations. Local broadcasters have long aired syndicated
programs that include national advertising, but the money to pay for those segments
came from revenue supplied largely by local companies. FM broadcasting began commercially
around 1945 in the familiar 88-108 MHz band yielded by the military following
World War II, and grew in number of stations very rapidly in the first few
years. Then, it began a decline for a few more years until finally leveling off
after about a decade. Even though FM had a clear advantage (literally) over AM because
of electrical noise immunity...
 This photo of
Ray Dolby holding one of his prototype noise reduction circuits
is probably the most widely published of him and therefore the most iconic of the
Dolby noise reduction system. Audiophiles of the era (and today for that matter)
immediately recognize the man who took the hisses and pops out of their beloved
music. I always like to keep in mind when reading article like this one in a 1971
issue of Radio-Electronics magazine is that when it was originally published,
Dolby had not yet become a household word and news of his accomplishment was just
getting out. Many articles, books, and research papers have been written on how
the Dolby system works. At least five of them from the groundbreaking era have been
posted here on RF Cafe, so you can get some insight into the excitement. The technical
term "companding" (compressing and expanding) was being seen in print for the first
time...
 Amplifier 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.
Monday the 27th
 This "Bio-Electric
Quiz" by Robert Balin appeared in a 1964 issue of Popular Electronics
magazine. Your job, if you decide to accept it, is to match up the electronic /
electrical devices in the pictures with the parts of the human body associated with
all or part of the device. It is pretty self-explanatory (and simple), but for the
newbie (or someone not old enough to guess some of them, the mechanics equivalent
would be if there was a drawing of a foundation for a house and on option for "foot"
(a la footer, or footing) would be chosen. Now that I look at the ten items, there
are probably only three that are...
 One of the monthly columns in R/C Modeler
magazine, written by Chuck Cunningham, entitled "Cunningham on R/C," that reported
on the current state of radio control, which had only fairly recently evolved into
fully solid state, proportional control systems. Anyone involved in electronics
is painfully familiar with the weird kinds of issues that crop up in complex circuits
that operate in hostile environments. The March 1970 issue contained part of an
article authored by D. L. Klipstein, Director of Engineering, Measurement Control
Devices, entitled, "Murphy's Law: The Contributions of Edsel Murphy to the Understanding
of the Behaviour of Inanimate Objects.*" Only a few of the items were printed
in Cunningham's column, but I managed to locate a copy of the full article...
 "Iridium Communications and Qualcomm Technologies
have integrated Iridium data services into the
Snapdragon Mission Tactical Radio, aiming to deliver resilient, secure L band
satellite links for U.S. government and approved allied users. The effort targets
handheld and mounted radios, autonomous systems, and other platforms that operate
where terrestrial networks are congested, compromised, or absent. The Snapdragon
platform aggregates multiple Iridium services on a single chipset to match mission
needs. Short Burst Data supports low-latency messaging and telemetry, while Iridium
Burst enables simultaneous broadcasts to unlimited enabled devices. Pairing the
Iridium waveform..."
 The term "ovonic" - a fairly unfamiliar word
these days - appeared in the May edition of Radio-Electronics, in an article
entitled, "All About Ovonics," just a few months after this news item ran in the
January issue (which I posted last month). Ovonics is a portmanteau of "Ovshinsky"
(from Stanford R. Ovshinsky, the inventor) and "electronics." Read the "All About
Ovonics" article for a deeper dive into the subject. The big deal, which turned
out to be not a big enough deal, was the use of
amorphous "glassy" compounds as semiconductors rather than the
standard crystalline silicon structures. Maybe someday an enterprising genius inventor
type will give a rebirth to the concept...
 The problem of and concern about our country's
youngsters seemingly not being overly interested in
pursuing technical career paths is a theme often heard in the
tech news media and workplaces. As our world grows increasingly automated and everything
from light bulbs to telephones and automobiles are so packed with "no user serviceable
parts inside," there seems to be little motivation for an otherwise potential budding
tinkerer to take stuff apart to discover what makes it work. In the "old days" like,
say, 1955, products were much more accessible to kids' curious nature and explains
why fostering the next crop of engineers, scientists, and technicians took care
of itself. You might think so, but alas, the dilemma evidently persists with each
succeeding generation...
Friday the 24th
 This 1964 Popular Electronics magazine
article describes building "Big TC," a
Tesla coil inspired by Nikola Tesla, capable of producing nearly 250,000 volts.
It creates spectacular foot-long corona discharges and excites neon or fluorescent
lamps up to five feet away. Costing about $30 (in 1964), it's ideal for demonstrations
or science fairs. The circuit features a 12,000-volt neon sign transformer charging
a glass-plate capacitor, which discharges through a spark gap into primary coil
L1 (20 turns of heavy wire). This generates radiofrequency harmonics, stepped up
by secondary coil L2 (2,000 turns of No. 26 wire). Assembled on a 22" x 22" plywood
base, components use high-voltage wire, insulators, and standoffs. The spark gap
employs...
 Here is another electronics challenge for
you to try - the "Resistor
Function Quiz." It covers basic functions of resistors in various circuits.
The quiz appeared in the January 1962 edition of Popular Electronics magazine,
compliments of Robert P. Balin. I got 100%, just for the record - PhD not required,
by the way. Having worked with tubes in the days of yore helps with figure B since
it does not really have a direct transistor equivalent, but by process of elimination
you can get it...
 "The holy
grail of personal computing has always been a single, seamless experience that follows
you from your pocket to your desk. For decades, this dream has been a graveyard
of ambitious failures. Now, in the fall of 2025, the whispers are growing louder:
In partnership with Qualcomm, Google is making a serious play to bring Android-based
PCs to the mainstream. Google's effort isn't just another Chromebook; it's a full-fledged
effort to scale the worlds dominant mobile operating system into the laptop form
factor.
Googles Android PC initiative represents a direct assault on the traditional..."
 Since 2000, I have been creating custom
technology-themed crossword puzzles for the brain-exercising benefit
and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out
on whether or not this type of mental challenge helps keep your gray matter from
atrophying in old age, but it certainly helps maintain your vocabulary and cognitive
skills at all ages. A database of thousands of words has been built up over the
years and contains only clues and terms associated with engineering, science, physical,
astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge
of a numbnut soap opera star or the name of some obscure village in the Andes mountains...
 All college curricula seem to have a number
of particular "weeding out" courses that cull the herd - so to speak - from the
eventual graduating class. The unfortunate victims are then faced with either dropping
out of college (not always such a dooming fate) or choosing a different major. For
mechanical engineers (MEs) it was often statics; for electrical engineers (EEs)
it was
AC circuits - the topic of this article. DC is relatively simple because voltage
and current is always in phase, thus no "hard" vector math is involved, but throw
in reactance with its attendant non-zero phase angles and suddenly the student is
faced with trigonometry - the kiss of death to mathphobes. My experience in engineering
school showed that for MEs who lived through statics, dynamics provided the next
level of weeding out (it nearly got me). For EEs it was Fourier and Laplace transforms.
Level three for MEs was thermodynamics (thermogodda**its was a popular alternate
title)...
 Please take a few moments to visit the
everythingRF website to see how they can assist you with your
project. everythingRF is a product discovery platform for RF and microwave products
and services. They currently have 354,801 products from more than 2478 companies
across 485 categories in their database and enable engineers to search for them
using their customized parametric search tool. Amplifiers, test equipment, power
couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Thursday the 23rd
 In this Carl & Jerry, our familiar two
young electronics enthusiasts are experimenting with a peculiar atmospheric phenomenon
during a spring thunderstorm. As usual, the story takes place at the time of year
in which it appeared in Popular Electronics magazine - Spring. Jerry has
constructed a sensitive audio setup in his basement laboratory specifically designed
to detect "whistlers" - eerie, descending-toned sounds created by very-low-frequency
radio waves from lightning strikes that travel along Earth's magnetic field lines
to the southern hemisphere and back. Using a homemade loop antenna wound with speaker
wire and a multi-stage amplification system, they successfully capture a faint whistler
after a lightning flash. However, while adjusting the antenna's orientation, they
begin picking up strange, unexplained signals...
 This is the first of a two-part "Radar Principles" article by British engineer and researcher Dr.
R.L. Smith-Rose. Dr. Smith-Rose explains the basics of radio detection and ranging
using simple illustrations and calculation examples. When these articles were written,
radar had recently been credited with playing a major role in helping the Allies
successfully wage war against aggressive Axis powers that were ravaging London and
other European cities with air attacks comprised of both manned and unmanned vehicles.
While the principles of radar were somewhat familiar to people because of its analogy
to using hearing to estimate distance and location, the actual science behind the
operation of radar was and still is considered a form of black magic nearly everyone...
 "Researchers have introduced a new way to
create
multicolored lenses that could pave the way for a generation of compact, low-cost,
and high-performance optics for portable technologies like drones and smartphones.
According to Mr. Joshua Jordaan, lead author of the study from the Research School
of Physics at the Australian National University and the ARC Centre of Excellence
for Transformative Meta-Optical Systems (TMOS), the design employs stacked layers
of metamaterials. These layers make it possible to focus multiple wavelengths from
an unpolarized light source across a wide diameter, addressing one of the main drawbacks
of traditional metalenses..."
 A nice article by Donald Lancaster appeared
in an issue of Radio-Electronics magazine that introduces and puts into
layman's terms the relatively new (at the time) world of
digital logic circuits. Rapidly falling prices and equally rapidly
rising performance fuelled the craze. By 1969, most of the barriers preventing former
never-tubers from adopting the fledgling semiconductor paradigm and there was by
then a new generation of electronics hobbyists, technicians, and engineers who had
"grown up" on transistors and integrated circuits. I like the author's analogies
for AND gates and OR gates that involve the familiar objects that include a garden
hose with the house tap and nozzle, and the kitchen sink faucet with the hot and
cold handles. It's interesting how often water, a substance generally to be avoided
around electricity...
 Today's electronics and RF magazines tend
to cater to engineers and managers, as opposed to technicians and hobbyists. That's
not to say that techs do not benefit from the material presented, but that information
is typically concerned with new product and system design with little attention
paid to troubleshooting and maintenance. The predecessors to modern magazines much
more often included articles on the latter. Publications like Popular Electronics,
being intended for hobbyists, featured useful quizzes, "how to" articles, and troubleshooting
tips along with product reports and an occasional design methodology piece.
Electronics World, the predecessor to Popular Electronics, was more
of an equal split between professional and hobby themes. This particular article
tests the reader's
knowledge of capacitors by proposing circuit failure examples...
 The 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 22nd
 Carl Kohler's dry techno-humor hits a new
high with "Mettle
Detector," in a 1957 issue of Popular Electronics magazine. Our familiar
hubby, who is the quintessential do-it-yourself hobbyist and adopter of somewhat
overzealous projects (in the opinion of "friend-wife"), is once again forced to
justify his latest obsession. In this case, it is a metal detector. Keep in mind
that in 1957, you could not walk into a store or place an online order to buy such
a device. Magazines of the day, including this one, ran articles for building metal
detectors, and they were big, heavy, and not even as sensitive as a $50 cheapie
today. You'll get a kick out the plot. It reminds me of my own experience with a
metal detector, where I blindly tossed a quarter into the sand at a beach...
 "While
developing LiDAR technology, scientists unexpectedly discovered how to generate
multiple laser colors from a single chip. Their innovation could transform data
centers and communications by delivering faster, cleaner, and more efficient light
sources. Accidental Discovery in the Lab A few years ago, researchers in Michal
Lipson's lab came across something unexpected. Their work at the time focused on
improving LiDAR, a technology that measures distance using lightwaves. The team
was designing powerful chips capable of generating brighter, more intense beams
of light..."
 Since 2000, I have been creating custom
science and technology-themed crossword puzzles for the brain-exercising
benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury
is out on whether or not this type of mental challenge helps keep your gray matter
from atrophying in old age, but it certainly helps maintain your vocabulary and
cognitive skills at all ages. A database of thousands of words has been built up
over the years and contains only clues and terms associated with engineering, science,
physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing
your knowledge of a numbnut soap opera star or the name of some obscure village
in the Andes mountains. You might, however, encounter the name of a movie star like
Hedy Lamarr...
 Collins Radio Company (later on Rockwell
Collins and now Collins Aerospace) has been around since 1933. Like the vast majority
of U.S. companies during the World War II era, they - management and employees -
took great pride in doing their part for the war effort. Unlike today, when a relatively
few people actually know someone on active duty in the armed forces, workers were
very likely to have a brother, son, father, or husband in the service. Here is an
advertisement that I scanned out of my copy of the April 1945 QST magazine.
It mentions that many of the employees are amateur radio operators. During the war,
a call went out for surplus equipment from all sources, including amateurs, so some
sacrificed their personal equipment for the good...
Tuesday the 21st
 This 1957 Popular Electronics article
describes the
Edison Radio Amateur Award, established by General Electric in 1951. The prestigious
honor, judged by a committee of national figures, recognized the ham radio operator
who performed the most exceptional public service each year, awarding him or her
a trophy and $500. The piece chronicles the winners from 1952-1956, including Don
Mullican for tornado relief and Stan Surber for Arctic communications. The 1956
winner was Mae Burke, W3CUL, who handled an immense volume of messages for servicemen
and their families. The committee also issued special citations to others, like
a teenager who relayed traffic from Antarctica and operators who provided lifesaving
communications during emergencies and natural disasters. The article underscores
that nominees came from all backgrounds, with some even being bedridden, proving
the profound morale-building and altruistic power of amateur radio.
 In March of 1958 when this article appeared
in Popular Electronics, learning of semiconductor devices other than
transistors was usually new to experienced professionals as well
as to hobbyists. Vacuum tubes still dominated electronic products in the day. Companies
like General Electric, Sylvania, and RCA were the pioneers for development of Zener
diodes, photodiodes, SCRs, thyristors, etc. Relatively simple compounds like selenium,
germanium, silicon, and lead and cadmium sulphides were used. The exotic witch's
brew of elements in modern semiconductors - particularly those used to photovoltaics
- were likely not even envisioned in 1958. This article discusses some of "new"
devices using simple compounds...
 "A new process makes it easier to recycle
the chemical elements used to make the strongest permanent magnets. These
rare earth
magnets are used in hard drives and EV motors. Beyond their use in magnets,
rare earth elements are used in lasers, glass, electronics, and a host of other
applications important to modern daily life. They are expensive to mine and separate,
and have long been a geopolitical football in trade wars, including the current
one between the United States and China. Compared with existing methods to recover
rare earth elements, a process based on rapidly heating waste magnet..."
 Even though this article was written more
than half a century ago, the fundamentals of
protecting relays against interference from either internally
generated or externally generated noise haven't changed. Sometimes a datasheet will
recommend protection and noise suppression techniques, and when that is that case,
the manufacturer's advice should be followed (unless you have a really good reason
to deviate, possibly voiding a warranty). When you find yourself on your own with
the design, whether a new creation or modifying an existing circuit, use this article
and the very comprehensive table of application examples. This reminds me of the
early 2000's when the RFIC company I worked for was in a frenzy developing ways
to protect the inputs and outputs of their devices...
 Werbel Microwave began as a consulting firm,
specializing in RF components design, with the ability to rapidly spin low volume
prototypes, and has quickly grown into a major designer and manufacturer with volume
production capacities. Werbel is proud to announce its model
WMDDC-2-18-10dB-S, a true dual directional coupler that covers the 2 to 18 GHz
band with excellent return loss, coupling flatness and high directivity. Its advantage
is a smaller and more lightweight housing than two independent couplers, thereby
eliminating reflections caused by additional cabling. Improved performance over
separate couplers due to the lack of interconnections and cable between. Werbel
Microwave products are designed, assembled, and tested in USA. ISO 9001:2015 certified.
"No Worries with Werbel!"
 At the end of the last century (the 20th),
aside from the impending total collapse of the world's electrical infrastructure
due to Y2K computer date issues, technovisionaries (a word I just made up) predicted
the near-term demise of local over-the-air (OTA) broadcasting of both commercial
radio and television. Cable and satellite was going to supplant it all. For a short
while things seemed to be going that way, particularly as both forms of media (radio
and TV) began being available via smartphones. The FCC (Federal Communications Commission)
was so sure OTA television was dead that it wanted to reallocate unused spectrum
(white space) for other uses. It also mandated a conversion of all TV broadcasting
to be done in digital form. The plan forced either trashing of existing television
sets and purchase of new models or the purchase of analog-to-digital conversion
boxes. The compliant public folded like a cheap suit...
Monday the 20th
 Not a lot of information is available on
the history of General Electric Company's annual
Edison Radio Amateur Award; in fact, I could not find an actual photo of one.
There is an "Edison Award" being given today, but it is an annual Dutch music prize
awarded for outstanding achievements in the music industry, comparable to the American
"Grammy Award." This 1953 QST magazine promotion encouraged nominations
for the Edison Radio Amateur Award, sponsored by GE's Tube Department. First being
given in 1951, the award honored Thomas Edison's legacy by recognizing licensed
radio amateurs in the continental U.S. who performed significant public service
through their hobby. The winner would receive the Edison trophy...
 Last Fall I posted part 2 of this
Radio-Electronics article first because I did not yet have the May issue
that contained part 1. So, if you read "JFET's - Put Last Month's Theory to
Work" and have been waiting with bated breath for part 1, you may breathe easily
again; here it is. Author Thomas Haskett enthusiastically introduces readers to
the
junction field effect transistors (JFET) as a more natural replacement
than the bipolar junction transistor BJT) for vacuum tubes because of JFET (and
other varieties of the FET) operational parameters being much more those of tubes
than a BJT. Regarding his conversion, Haskett refers to himself as a "die-hard 'fire-bottle'"
man - a term with which I am not familiar. My assumption is that "fire-bottle" is
a slang name for vacuum tubes because of how hot they get, and they glow orange
like a fire in a glass bottle...
 In his usual manner, John T. Frye uses
tech-savvy teenage experimenters Carl Anderson and Jerry Bishop to teach a lesson
while writing a compelling saga. In this case Jerry gets "bitten" by house current while fiddling with a receiver chassis.
Before certain safety measures were required by law, many electrical devices - radios,
televisions, vacuum cleaners, shop tools, kitchen appliances, etc. - were sold with
with either existing shock hazards or the potential for (no pun intended) a shock
hazard in certain usage or failure modes. Before the advent of polarized two-pronged
plugs and grounded 3-prong plugs, some devices presented hazardous voltage levels
to the user by virtue of a direct connection to exposed conductive (metal) surfaces.
In this instance, under normal operational conditions with the chassis installed
in its wooden case and plastic or phenolic control...
 everything RF has released a new eBook titled
Introduction to Spectrum Recording and Playback, sponsored by ERISYS RF Solutions.
This in-depth technical guide is designed for engineers and professionals seeking
to understand how modern RF recorders capture, store, and replay complex signals
for analysis, testing, and mission-critical applications. As today's spectrum environments
become more dynamic and congested, record-and-playback systems have become essential
tools for signal intelligence, interference hunting, and wideband system validation.
The eBook takes readers from the fundamentals through advanced architectures - covering
topics such as high-fidelity recording, A/D...
 In the beginning, man created monophonic
(mono) radios and phonographs that had sound with no
spatial separation (left and right) in the source(s) and featured
a single speaker. As such, except for being sure to not locate your radio or phono
behind the sofa, sound perception at any point the room was fairly consistent -
except maybe for volume level. Still, there was ample opportunity for the time of
arrival due to multipath effects to distort the sound. Up until the 1950s or so,
most homes had hardwood floors (with a few rugs) and rock-hard plaster walls to
reflect sound waves, and rooms were relatively sparsely populated with furniture
and wall hangings (look at photos in vintage magazines for proof), all of which
provided means for distorted sound at a distance. And man said, "Let there be stereophonic
(stereo) sound," which...
 "AWS
outage hits major apps and services, resurfacing old questions about cloud redundancy.
Amazon Web Services is showing 'significant signs of recovery' after a major outage
early Monday that impacted sites and services including Facebook, Snapchat, Coinbase
and Amazon itself - reviving concerns about the internet's heavy reliance on the
cloud giant. The problems began shortly after midnight Pacific in Amazon's Northern
Virginia (US-EAST-1) region. In an update shortly after 2 a.m., AWS blamed a DNS
resolution issue with DynamoDB, meaning the internet's phone book failed to find
the correct address for a database service used by thousands of apps to store and
find data. OpenAI's ChatGPT..."
Friday the 17th
 Citizens Band (CB) radio was a big deal
in 1962 when this article was published in Popular Electronics magazine.
It addressed a common misconception among CB radio users that the FCC was inactive
in policing the airwaves. Contrary to this belief, the FCC was regularly issuing
"show cause" notices, a serious step beyond simple warnings ("pink tickets") that
required licensees to justify why their licenses should not be revoked. Specific
examples are cited of violations that prompted these notices, including transmitting
obscene language, engaging in non-essential "ham-type" gossip, and failing to adhere
to the mandatory two-minute silent periods after five minutes of transmission...
 If you happen to be Estonian, you might
think of something entirely different than most of us do when we hear the word "getter." In fact, you probably capitalize the word since it is
the name of a pop singer from your country, Getter Jaani. If you are a child living
in Japan, you would probably think of Getter Robo, an anime from a popular cartoon
series. I, and I dare say just about everyone else that visits RF Cafe, knows getter
as that silvery deposit (typically barium) that resides inside vacuum tubes for
the purpose of helping to maintain the vacuum and to absorb pesky random molecules
that might otherwise cause electrical noise in the circuit. This article from a
1958 edition of Radio-Electronics discusses the purpose of getter. BTW,
I had never heard of either of the other two Getters due to OGS (old guy syndrome)...
 Sun and
wind are not going to power AI and cryptocurrency data mining. "What happens when
you say 'Hello' to ChatGPT? Such a simple query might seem trivial, but making it
possible across billions of sessions requires immense scale. While OpenAI reveals
little information about its operations, we've used the scraps we do have to estimate
the impact of ChatGPT - and of the generative AI industry in general. OpenAI's actions
also provide hints. As part of the U.S.'s Stargate Project, OpenAI will collaborate
with other AI titans to build the largest data centers yet. And AI companies expect
to need dozens of 'Stargate-class' data centers to meet user demand ... report estimates
that all generative AI queries consume 15 TWh in 2025 and will use
347 TWh by 2030..."
 Since 2000, I have been creating custom
technology-themed crossword puzzles for the brain-exercising benefit
and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury is out
on whether or not this type of mental challenge helps keep your gray matter from
atrophying in old age, but it certainly helps maintain your vocabulary and cognitive
skills at all ages. A database of thousands of words has been built up over the
years and contains only clues and terms associated with engineering, science, physical,
astronomy, mathematics, chemistry, etc. You will never find a word taxing your knowledge
of a numbnut soap opera star or the name of some obscure village in the Andes mountains.
You might, however, encounter the name of a movie star like Hedy Lamarr or a geographical
location like Tunguska, Russia, for reasons which, if you don't already know, might
surprise you...
 Chapter 16 of the "Electricity - Basic Navy
Training Courses" introduces concepts of
alternating current (AC) motors, their electric supply, and controls.
It is part of the NAVPERS (Navy Personnel) 10622 series which is highly regarded
both in and out of the military. The manuals were first written in the middle of
the last century and have been upgraded a few times since then, but if you compare
the sections this one on AC motors in both the original and most modern versions,
not much - if anything - has changed. If you have an interest in motors and want
to understand the basics of how they work both as motors and generators (AC and
DC), then there is not a much better source from which to start...
Thursday the 16th
 David Moore's 1962 poem "CQ
DX 11" which appeared in Popular Electronics magazine, captures the vibrant
culture of amateur radio operation during CB radio's golden age. The poem meticulously
documents the technical jargon and operational procedures of ham radio enthusiasts
like "Gus," celebrating homemade equipment, signal reports, and international contacts
("DX hauls"). The final stanza's twist reveals regulatory intervention - "The FCC
has seen to that" - hinting at growing government oversight that would eventually
constrain the freewheeling CB community. This work perfectly encapsulates the early
1960s amateur radio scene when citizens band radio represented...
 "'Based on our previous research on high
refractive index polymers, we hypothesised that replacing oxygen with sulphur in
certain polymers such as PPO, could significantly reduce the dissipation factor,'
said Waseda University chemist Professor Kenichi Oyaizu. 'Using this strategy, we
succeeded in developing a new class of
ultralow dielectric loss polymers. PPO is poly(2,6-dimethyl-1,4-phenylene oxide),
a benchmark material for its balance of dielectric constant and dissipation factor.
By replacing oxygen with sulphur in PPO, the researchers created PMPS – poly(2,6-dimethyl-1,4-phenylene
sulfide), and to further understand..."
 Operators didn't know how good they had
it in 1967. The story talks about the nuisance of having to sift through "hundreds"
of satellites, old rockets, and assorted space junk" in order to search for and
track potentially threatening objects in orbit around the Earth. We're into the
millions of objects in 2019, and the potential threats are infinitely larger. The
article mentions the use of an
AN/FPS-16 radar operating in C-band to detect and measure the
returns and then the results were analyzed in an attempt to determine the character
of the object. Open air test sites and anechoic chambers were used to measure the
radar cross section and characteristic signature of many shapes to populate a database
of recognizable returns that would help to determine whether the space object was
friend or foe...
 San Francisco Circuits announces its
Heavy Copper PCB Manufacturing & Assembly Capabilities, and why it matters.
As electronic systems demand higher power and improved thermal performance, heavy
copper PCBs have become essential for high-current, high-reliability applications
across industries. San Francisco Circuits latest capabilities page on heavy copper
outlines how increased copper thickness enhances current capacity, thermal conductivity,
and mechanical strength in demanding environments. Why Heavy Copper Matters
By utilizing copper weights from 4 oz. to 10 oz. per square foot, heavy
copper PCBs...
 Studies of motors usually begin with the
direct current (DC) type - maybe because most students have already
had hands-on experiences with motors in models (cars, boats, airplanes) and/or electricity
experimenter kits. They are small, cheap, and a simple flashlight battery (the ultimate
in safety) makes them run. An alternating current (AC) motor requires either a direct
connection to the house current or use of a step-down transformer, which still carries
with it a high risk factor. This chapter of the U.S. military's Basic Navy Training
Course (NAVPERS 10622) conforms to the tradition, and follows in the next chapter
with AC motors and generators. While reading through the text, I ran across the
unfamiliar term "kickpipe" and wondered...
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.
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