|
 A popular meme on chat websites these days
is the posting of some items or scenes indicative of times many moons ago, with
a comment something like, "If you know what this is, you are probably wearing reading
glasses." I recently saw one with a picture of an old cube type flash bulbs that
went on Kodak Instamatic cameras. In fact, I still have my Kodak Instamatic 40
camera and a couple of unused flashcubes. Those flashcubes were expensive for a
guy who never had much pocket cash; maybe that's why I have so few pictures from
back in the day. Anyway, I mention all that because some of the topics of these
electronics-themed comics from a 1962 issue of Electronics Illustrated
magazine would be likely candidates for the meme...
 A new word has been added to my personal lexicon:
"sphenoidal." Author John Kraus used it to describe the wedge shape
of a corner reflector. The Oxford Dictionary defines "sphenoid" thusly: "A compound
bone that forms the base of the cranium, behind the eye and below the front part
of the brain. It has two pairs of broad lateral 'wings' and a number of other projections,
and contains two air-filled sinuses." This "square corner" configuration - essentially
a "V" shape, is shown to exhibit up to 10 dB of gain while being relatively (compared
to a parabolic reflector) insensitive to physical size and driven radiator placement
across a wide band when made sufficiently large. No radiation pattern was...
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- and don't miss the blog articles!
 As you might know, particularly if you are
a frequent RF Cafe visitor, amateur radio operators (Hams)
were prohibited from broadcasting during the entirety of World War II,
(see
War
Comes) ostensibly as a security measure. The concern was that people
might unintentionally (or intentionally) convey information on troop positions and
family names, domestic factory locations and activities, and the general state of
the nation in regards to attitude and finance. Unlike today, that type of data was
not easily gathered even by a dedicated deployment of internal spies. In the early
1940s, the majority of amateur radio activity was carried out in the form of Morse
code, and operators were understandably concerned...
 Here is a fascinating story from a 1946
issue of the ARRL's QST magazine of the ordeal one Catholic priest
experienced while serving in the Philippines during the Japanese occupation in World
War II. Father Visintainer exploited his personal interest in
radio communications
to help keep local residents apprised of the war's progress and talk to the outside
world. Japanese troops confiscated all the existing shortwave radios and converted
them to their own frequencies. Some were re-converted by daring servicemen and then
hidden. Batteries were recharged using covert water wheel powered generators located
in the woods. Drama hit a peak one day when an attempt to formulate a make-shift
battery electrolyte resulted in an explosion that brought Japanese running to the
church lab...
 For decades, the engineering community has
viewed space as the ultimate frontier (Captain Kirk declared it) - a clean, vacuum-sealed
environment that offered a solution to the terrestrial limitations of bandwidth,
range, and latency. Nations and industries have long championed the
democratization of global communications, seeing Direct-to-Device (D2D) connectivity
as the next logical step in our technological evolution. But as we move from the
era of rare satellite backhaul to the age of the "mega-constellation," the engineering
paradigm has shifted. We are no longer just looking at the sky; we are beginning
to occupy it with such density that we risk creating a perpetual "noise floor" for
the rest of humanity. This article examines the thermodynamics, the mechanics of
orbital mesh nodes, and the sheer volume of material required to shift our compute
infrastructure into the heavens...
 Just the other day I saw a greeting card
with a sailboat on the front with the words "Anchors Away," on it. It was not meant
to be a pun on "anchors aweigh;" the card writer didn't know any better. This
episode of "Carl & Jerry" has our teenage Ham radio operators and electronics
hobbyists running a newly built model tugboat powered by a steam engine and navigated
via a radio control system. As is always the case, no activity of the pair goes
without drama of some sort. Author John T. Frye used his writings to present
technical topics within the storyline, both in the "Carl & Jerry" series here
in Popular Electronics magazine and his earlier "Mac's Radio Service Shop"
series that appeared...
 For the sake of all the avid cruciverbalists
amongst us, this
technical-term-themed
crossword puzzle 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)...
 Sam Benzacar, of Anatech Electronics, an
RF and microwave filter company, has published his May 2026 Newsletter that, along
with timely news items, features his short op-ed titled "The
Math of LEO No Longer Adds Up." Sam runs the numbers on Low-Earth-Orbit satellites,
and assesses future plans. "SpaceX now operates more than 10,000 Starlink satellites,
roughly two-thirds of everything in orbit. The next-largest operator, OneWeb, has
fewer than 700." They roam the nighttime sky, with small dots of light tracking
across our already light-polluted skies. The ITU coordination process now confronts
filings for more than a million LEO spacecraft, with half a million projected to
be in orbit by 2040. Now that Internet coverage and even Direct-to-Device (D2D)
networks...
 Meteor scatter communications is an excellent
example of where hobbyists - in this case amateur radio operators - have contributed
mightily to technology. It could be argued that a big part of the reason for such
occasions is that many people involved in science type hobbies are employed professionally
in a similar capacity, and their extracurricular activities are a natural extension
of what pays for the pastimes. It seems amazing to me that
meteor
scatter as a means of achieving upper atmosphere reflections of radio signals
went undiscovered until 1953, but evidently that is the case. Meteor scatter is
a very popular form of amateur radio challenge...
 "Make the most of your time at
Dayton Hamvention® with the free ARRL Events phone app. Hamvention is the world's
largest annual gathering of radio amateurs, and will be held May 15-17 in Xenia,
Ohio. There is a lot to do and see. Use the ARRL Events app to make sure you don't
miss a beat and plan out your visit now. The ARRL events app is produced by ARRL
The National Association® for Amateur Radio in partnership with Dayton Hamvention.
The app includes Hamvention's full program, so you can browse and schedule forums,
preview the extensive list of exhibitors, and find affiliated events. During the
event, attendees can use..."
 Here's a topic that never goes out of style.
Without bothering to worry about source and load impedances, this brief tutorial
on the fundamentals of
power supply filter design using series inductors and parallel
capacitor combinations. The author offers a rule-of-thumb type formula for guessing
at a good inductor value based on peak-to-average expected current. This is by no
means a comprehensive primer on power supply filter design and is directed more
toward someone new to the concept...
 Werbel's new
WMC-0.5-2-6dB-S, 6 dB directional coupler provides precision attenuation
where it matters most. It covers 500 MHz to 2 GHz with broadband flat coupling response,
high directivity, and excellent return loss performance. The device covers the upper
portion of the UHF band as well as L band in a single unit measuring just 3.60 x
0.60 x 0.38 inches. Minimized reflections increase accuracy of the measurement.
Mainline insertion loss of 1.2 dB (typical) includes coupling factor. The 6 dB coupling
ratio gives an approximate 75/25% splitting ratio and may be used as such to distribute
signals unequally where required, often to make up for asymmetrical losses elsewhere
in a system...
 Connecting a diode backwards across a solenoid
coil to shunt potentially damaging current and/or voltages when the supply is turned
off is a common trick for saving connected circuitry. Depending on the magnitude
of the magnetic field and how quickly the field collapses, some really high voltages
can be produced. In fact, the ignition coil and point (now
solid state) system in exploits exactly that principle to turn the 12 volts
from your car battery into 20-40 kV for firing the spark plugs. Engineers that
designed this early
cyclotron
had limited options for what to use given the state of the art in the early 1940s,
and chose to keep the generator permanently connected to the coil (no switch) so
that if the controller failed, the coil's energy...
 In the opening scene of "Gladiators," Quintus
remarks to Maximus (Russell Crowe), "A people should
know when they've been conquered." Such truth is applicable to society today regarding
ubiquitous surveillance. Less than two decades ago the media was
filled with stories of outrage over the discovery of some new form of monitoring
and reporting system having been installed on highways, in shopping malls, along
sidewalks, even bathrooms. Since the 9/11 terrorist attacks, anything goes with
government snooping. Count the numbers of freedoms you have lost and the inconveniences
suffered because of those 19 men with no identifiable common cause
(wouldn't want to profile). This story from 1956 shows
how long stealth installation...
 I wonder why today's editions of the ARRL's
QST magazine does not have a column dedicated to the "YL" (Young Lady,
or female in general) contingent of the amateur radio realm? Ham radio, as most
-if not all - historically male-dominated hobbies has fairly significant outreach
efforts to try attracting women into activities. My Model Aviation magazine
has a monthly column written by a lady whose enthusiasm for model airplanes equals
that of most males - and she's funny to boot! - but it is not dedicated to female
modelers. If there is a girl or woman present at a competition, she is almost guaranteed
to receive coverage...
 The December 1947 issue of Radio News
and the February 1954 issue of Radio & Television News published these
electronics-themed comics. Humor evolves over time, which is apparent when you
look over these and many of the other comics from these vintage electronics magazines.
The AVC comic is the best, IMHO. For those of you not around in the olden days of
vacuum tubes, tapping on a tube would often make it work properly again, either
because of a dirty contact in the socket or crud that had accumulated on the screen
grid. I give this batch a score of about 7 out of 10, but you might think otherwise.
There is a growing list of other comics at the bottom of the page. Enjoy...
 How RF circuits work have long been referred
to as "black magic,... even sometimes by people who fully understand
the theory behind the craft. To me the ways in which a transmission line - be it
coaxial cable, microstrip, or waveguide - can be manipulated and controlled with
various combinations of lengths and terminations is what most qualifies as "magic."
Sure, I know the equations and understand (mostly) what's happening with incident
and reflected waves, etc., and how the impedance and admittance circles of a Smith
chart graphically trace out what's happening, but you have to admit there's something
wonderfully mystical about it all...
 I remember hearing a long time ago about
"The Thing"
- a passive bugging device discovered within a wooden Great Seal gifted to the U.S.
Embassy in Moscow. This 1962 Electronics Illustrated magazine feature explores
the ingenious, battery-less Soviet listening device. Far from a conventional electronic
bug, this passive device utilized a specialized resonant cavity and a diaphragm
that modulated an external 1600 MHz radio beam, essentially acting as an echo-based
microphone that was incredibly difficult to detect. While the article highlights
the device's diabolical simplicity and sensitivity, it contains no mention of the
U-2 incident or Gary Powers; notably, historical records clarify that Ambassador
Lodge displayed the device in 1960 to expose Soviet espionage...
 Based on beleaguered wife Sylvia Kohler's
mention of GE's Electronics Park in this story (surely a fable... or not), she and
unintentional antagonist, superheterodyne hubby (aka "Happy Boy," but we know him
as Popular Electronics cartoonist
Carl Kohler) probably lived in the Syracuse, NY, area. Electronics
Park existed during the hey days of General Electric when the sprawling campus ,
just north of I-90, designed and manufactured a plethora of both household and military
electronics products. GE's Electronics Laboratory ("E-Labs") was the company's pride
and joy. Today, a tiny portion of Electronics Park is still occupied by Lockheed
Martin, who bought that GE division in the 1990s, and the rest belongs the city.
But I digress... enjoy the story (her reason for referring to hubby as a Superheterodyne
is highlighted)...
 Multielement quad antennas are as popular
today as they were in 1967 when this article appeared in the ARRL's QST
magazine. That is not to say they are common. This particular design is for the
10-, 15-, and 20-meters bands, all three
of which are still in use today. If you build a multielement quad as shown here,
you might want to find a substitute for the bamboo frame members; aluminum tubing
is pretty cheap, but if you use metal, you'll need to use insulators at the connection
points. Formulas are provided for determining element lengths and director and reflector...
 There is something about these proposed
shorthand circuit symbols that reminds me of the IEEE digital
logic symbols using the distinctive shape (the traditional format) versus the newer
rectangular shape format. The set is quite extensive when all the different flavors
of combinatorial blocks - flip-flops, timers, counters, shift registers, encoders,
decoders, etc. - are included. My personal preference, you might guess, is the original
format with distinctive shapes. Although I do not do a lot of digital work, it is
easier for me to follow the signal flow and mentally perform the logic operations
with the distinctive shapes. But I digress. This article from a 1947 issue of
QST magazine introduces...
|
 • Europe's
Electronics Sector Picks up Speed
• Top
5 Companies Granted U.S. Patents in 2025 (one American)
• Shape-Shifting
Semiconductors Activated by Light
• UK Teachers Say
AI Eroding Critical Thinking
• FCC
Approves Charter's $34.5B Acquisition of Cox
 The
RF Cafe Homepage Archive
is a comprehensive collection of every item appearing daily on this website since
2008 - and many from earlier years. Many thousands of pages of unique content have
been added since then.
 This custom RF Cafe
electronics-themed crossword puzzle for March 19th contains words and clues
which pertain strictly to the subjects of electronics, mechanics, power distribution,
engineering, science, physics, astronomy, chemistry, etc. If you do see names of
people or places, they are directly related to the aforementioned areas of study.
As always, you will find no references to numbnut movie stars or fashion designers.
Need more crossword RF Cafe puzzles? A list at the bottom of the page links to hundreds
of them dating back to the year 2000. Enjoy.
 If you believe this 1969
Sylvania General Telephone & Electronics advertisement, you needed only
to stock their specially-designed 60 components to be able to replace every
other component made anywhere in the world. Even in 1969 when semiconductors
were becoming the majority active devices in electronics (replacing vacuum
tubes), the claim is a bit of a stretch. I have my doubts. The ad probably got
posted on a few engineering lab bulletin boards (the physical kind of yore, not
computer BB's) to elicit a few laughs. It reminds me a little of the episode of
M.A.S.H. where a war correspondent asked Captain Hawkeye Pierce what he brought
with him from home, and he responded that he only brought...
 Around since 1934,
Newark Electric is one of the longest-surviving electronic component mail order
businesses. In the days before Digi-Key (founded in 1972), Newark was my go-to source
for parts I needed ASAP. Allied Electronics (earlier Allied Radio), around since
1928, was my second choice. There was no Internet, so the fastest service was had
by calling in your order - while paying a long-distance toll. U.S. Post Office and
United Postal Service (UPS, since 1907; my Uncle Brian drove their trucks from Buffalo
to/from Cleveland for 40 years) were the two prime delivery service of the era (FedEx
came online in 1973). Reportedly, its first paper-format catalog was mailed out
in 1948, two years after this full-page ad appeared in Radio-Craft magazine. Newark
now goes by the name of Newark element14 (the 14th element in the periodic table
happens to be silicon). The "About Us" webpage shows Newark and Newark element14
(in Asia) as being Avnet companies. In 1946 there were many hometown electronics
parts outlets that included repair shops, hardware stores, and department stores,
so much of what a person needed was available locally...
 When I saw this first
electronics-themed comic in the May 1959 issue of Electronics
World, my first thought was how most people today probably cannot relate to
the task of installing and adjusting a rooftop antenna for televisions. Ditto for
FM antennas. Most people who still watch TV use cable, although some have satellite
TV. Then I thought about how Ham radio operators are the last vestige of civilians
who rely on antennas and over-the-air radio communications (other than the world's
4.5 billion cellphone users who don't realize their phones are radios). Television
antenna design and installation was never a high-tech sport for typical homeowners
as it is for Amateurs; it was just a necessary nuisance. Finally, it occurred to
me than for a growing number of Hams...
 Hugo Gernsback (1884-1967) was a Luxembourgish-American
inventor, writer, editor, and publisher who is often referred to as the "Father
of Science Fiction." Gernsback was also an inventor and entrepreneur, and was awarded
many patents, including for early television systems. He founded several companies,
including the Gernsback Publications, which published a variety of magazines that
included this one, Radio-Electronics, and its predecessor, Electronics World, and
before that, Radio Craft. Mr. Gernsback was undeniably qualified to pontificate
and prognosticate on the
future of the electronics industry, as he does in his February 1960 editorial
in Radio-Electronics magazine...
 It was a lot of work, but I finally finished
a version of the "RF &
Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft
Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive
set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog,
antenna, and other commonly used symbols for system block diagrams and schematics
created for Visio™. Each of the 1,000+ symbols was exported individually from Visio
in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format
allows an image to be scaled up or down without becoming pixelated, so all the shapes
can be resized in a document and still look good. The imported symbols can also
be UnGrouped into their original constituent parts for editing...
 Finding any photos of vintage vacuum tube
type car / truck radios is usually very difficult. That is probably because they
are not housed in attractive wooden or phenolic cases, and most likely ended up
rusting out inside a vehicle sitting in a junk yard. A few manage to survive, such
as this United Model 980744, but it is a new enough design (c1947) that it is all
contained within a single chassis. Older car radios like this c1936
General Electric Model N-60 had the electronics in a metal or sometimes wooden
box that was mounted in the trunk or under a seat, and then a "control head" wired
remote control was mounted in or under the dashboard. Just in case someone out there
manages to acquire a GE Model N-60 auto radio, I am posting the schematic &
parts list, which appeared in a 1936 issue of Radio-Craft magazine. There are still
many people who restore and service these vintage radios, and often it can be difficult
or impossible to find schematics and/or tuning information...
 Forgive me if I sound like a broken record
(a scratched record, actually), but when 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...
 This line from the Basic Navy Training
Courses is very important when considering electrical machines: Many electrical
devices and machines operate on the principle of "transformer
action." They in fact are not transformers - but the theory of their operation
is best explained by considering them as if they were transformers. It is part of
chapter 21, entitled, "Some Electrical Machines - Transformer Action," which provides
a simple introduction to induction motors and generators, regulators, frequency
converters, and synchros. If you are a newcomer to the field of electricity
and/or electronics, or if you just want to brush up on old knowledge to be
conversant at office parties, this is a great short read. A quiz is provided at
the end...
 The world is full of geniuses who have ideas
with the potential to introduce history-making products and services to mankind.
Thankfully, many of them manage to draw the attention to themselves and make their
contributions available. Some of those same people have the talent to prepare their
inventions and concepts for distribution, while others require the know-how of others
- nowadays known as manufacturing engineers - to figure out how to mass produce
a product with enough efficiency to make things affordable. Thomas Edison, Henry
Ford, George Westinghouse, Lee de Forest, and other recognizable inventors
depended on assistance for ultimate success. I will soon be posting stories of de Forest's
long, hard-fought path to success with his Audion tube which will make you wonder
how people can have the fortitude to continue...
 Here is the final installment in the "Basic
Digital Electronic Course" series that ran in three issues of Popular Electronics
magazine. The first two parts laid the groundwork with an introduction to binary,
octal, and hexadecimal arithmetic, Boolean logic, AND, OR and NOT gates, and some
truth tables. Armed with those fundamentals, the authors now dive into flip-flops,
encoders and decoders, debouncing circuits for switch inputs, integrated circuit
(IC) types, and interconnect methods to design and build a simple digital computer
with a 7-segment LED display. Don't expect too much from the computer since it was
only three years earlier, in 1971, that Intel introduced the world's first integrated
microprocessor - the 4-bit model 4004 central processing unit (CPU)...
 Before I forget, let me remind you while
on the subject of antenna design that beginning January 1, 2022, EZNEC Antenna Software
by Roy Lewallen (W7EL) is being offered free of charge. It is inarguably the world's
premiere package for amateur radio enthusiasts and is used by many professionals.
QST's Joel Hallas (SK) used it extensively as part of his monthly "The
Doctor Is In" column. This "ABCs
of Antenna Design" article appeared in a 1948 issue of Radio News magazine
in an era when nomographs, slide rules, and empirical testing and adjusting were
the primary tools of all designers. Digital and analog computers occupied entire
wings of buildings and could not calculate results nearly as well as EZNEC can on
even a low end Windows 10 computer...
 The
stacked halo antenna is a compact configuration for obtaining a nearly omnidirectional
radiation pattern with nearly 8 dB of gain. An ideal half-wave dipole antenna
provides 2.15 dB, so adding 5 to 6 more decibels by merely stacking two halo
antennas (which are essentially curved half-waves) might seem like getting more
than the sum of the parts. That extra gain is obtained by concentrating the vertical
radiation pattern lower to the horizon as compared to a straight half-wave, even
though the horizontal pattern loses a bit of gain contribution from the translation
to a nearly omnidirectional nature. There is nowadays a plethora of information
available on the Internet regarding stacked halo antennas, but in 1965, this
Popular Electronics magazine article was one of only a few readily accessible
sources other than college textbooks and scholarly papers (of course the ARRL
Antenna Handbook was and still is a prime source)...
 It is understandable if, based on this article's
title, "Holes and the Service Technician," you thought maybe it had to do with semiconductors.
Silicon was beginning to overtake germanium as the substrate of choice it appeared
in a 1963 issue of Radio-Electronics magazine. Electron conduction seemed
intuitive to most people involved in electronics; however, the concept of hole conduction
caused a lot of head scratching. But, I digress. This article discusses how to
create various types of holes in metal. It might seem like a no-brainer task,
if you have ever needed to make precisely shaped and dimensioned holes in metal,
you know it is not always such a simple task - especially in soft sheet metal. Achieving
a truly round hole - especially of large diameter - in an aluminum chassis requires
securely clamping the work piece to the table and using a sturdy drill press. Otherwise,
you almost always get an oblong hole. A machinist at Westinghouse showed me one
day back in the 1980's how he would get the chassis secured and drill press positioned,
then place a couple layers of paper towel on the metal before lowering the drill
bit onto the chassis. It helped fill the space between drill bit flutes to prevent
it from "walking" before both sides of the bit had a bite on the metal. It works
like magic, even when using a hand drill. To this day I still do that...
 Magnetron, photomultiplier, traveling wave,
compactron, klystron, backward wave, pencil, lighthouse, cathode ray, indicator,
nuvistor, acorn, peanut, T-R, electrostatic, cat's-eye, orithon, and loctal, are
just a few of the many types of vacuum tubes that have been and in some cases still
are in use in various types of electronic equipment. Some you have heard of, others
you probably have not. All are discussed in a series of three articles published
in Popular Electronics magazine. This is part 3, which includes operational
descriptions of
klystrons, magnetrons, and traveling wave tubes (radar & satellite communication),
all of which are still designed into new products today... |
