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 Are you having a rough week? If so - and
even if not - take a few minutes to get a laugh from these
electronics-themed comics from the pages of vintage Radio
News magazines. Beginning sometime in the late 1930s and early 1940s, single-panel
topical comics began appearing frequently in many hobby and even professional magazines.
Sure, comics showed up in magazine before that time, but they generally did not
necessarily have to do with the main subject of the publication. The Saturday
Evening Post, for example, had many single-panel comics, but they were on any
random theme. The Saturday Evening Post, for example, had many single-panel
comics, but they were on any random theme. I can't go without commenting on the
April 1946 comic since it reminds me of a situation...
 Arthur Hackman's 1967 Electronics World
magazine article provides a systematic guide for
selecting mechanical and manual switches, beginning with specifying the required
function through poles (circuits controlled) and throws (positions connected, excluding
"off"). Voltage and current ratings must not be exceeded to prevent contact welding
or catastrophic dielectric failure. Mechanically actuated switches include pressure-sensitive
types (with defined proof and burst pressures), temperature-sensitive switches,
and various limit switches (plunger, lever, roller), which require consideration
of mounting and environmental sealing for harsh conditions. Manually...
 Isn't an anagram a word game where letters
of one word are rearranged to spell another word or series of words? For instance,
an anagram for "microwave" is "warm voice," one for "resistance" is "ancestries,"
and for "vector" is "covert." If so, then this puzzle is misnamed; it is really
a crossword puzzle. Maybe back in 1961 the word anagram included this type of puzzle.
Regardless of the naming error, I did learn a new word: "inertance," which means "the effect of inertia in an acoustic
system, an impeding of the transmission of sound through...
 "Electronics have long been defined by their
permanence. Even when their useful life ends, their materials persist in landfills
for years or decades.
Transient electronics embrace impermanence with devices that are deliberately
engineered to function for a set period of time and then disappear, dissolving into
safe byproducts when exposed to water, heat, or light. Advances in electronics technology
moving at a faster pace than ever before, and, thus, older electronics become obsolete
or undesirable quickly. While there are obvious benefits to developments in electronic..."
 Magnetostriction is a term not seen very
often these days. It describes the physical shape change that takes place in certain
ferrous materials when subject to a magnetic field, and is responsible for most
of the familiar "hum" that comes from transformers. The effect is used in mechanical
filters as transducers between the electronic circuit and the mechanically resonant
disks that define filter bandpass characteristics. Elemental cobalt exhibits the
highest room temperature magnetostriction (units are "microstrains"). Nickel, with
about half the value as cobalt, is cheaper and more abundant and is therefor more
commonly used in modern magnetorestrictive transducers. Way back in the 1980s while...
 RF Cafe's spreadsheet-based engineering
and science calculator,
Espresso
Engineering Workbook™, is a collection of electrical engineering and physics
calculators for commonly needed design and problem solving work. A Transformer
Calculator worksheet has just been added, making for a total of 45 calculators.
It is an excellent tool for engineers, technicians, hobbyists, and students. Equally
excellent is that Espresso Engineering Workbook™ is
provided at no cost, compliments of my generous sponsors...
 There was a time when having a career in any
field of electricity or electronics work was an enviable mark of a person's technical
prowess that conveyed a degree of respect. The whole
controlling of electrons thing boggled the minds of most people,
whether it meant wiring homes and buildings for lights, receptacles, and motors,
or designing "all wave" radio sets for listening to the evening broadcast of "The
Lone Ranger." Today, with nearly everyone alive having grown up with such conveniences,
the "wow factor" is pretty much gone, except maybe with those of us who still chose
to engage. If an electronics appliance...
 Substitute "cellphone" for "radio" in this
title ("Money
in Radio Gadgets"), and editorial by Hugo Gernsback and it would fit right in
with today's market of wondrous gadgetry. Prescient as always, Mr. Gernsback describes
in this 1933 issue of Radio-Craft magazine, among other things, what we now refer
to as energy harnessing to power ancillary devices and props. He also recommends
a scheme for causing "dancing dolls" on the surface of a table vibrated and mobilized
by the sonic waves of a large speaker - a lot like the way years later vibrating
football games were made (remember them?) where the men danced randomly across the
painted metal playing field. It sounded like a pair of electric...
 "Researchers at the Hebrew University of
Jerusalem have found that the
magnetic
component of light plays a direct part in the Faraday Effect, overturning a
180-year belief that only light's electric field was involved. Their work shows
that light can exert magnetic influence on matter, not simply illuminate it. This
insight could support advances in optics, spintronics, and emerging quantum technologies.
The team's findings, published in Nature's Scientific Reports, show that
the magnetic portion of light, not only its electric one, has a meaningful and measurable
influence on how light interacts with materials. This result contradicts..."
 This
passive
RF limiter is a simple combination of cascaded "T" type resistive attenuators
that are switched in and out of the circuit based on the power level in the line.
The design takes a bit of thinking due to needing to retain a reasonable impedance
match at the input and output throughout various stages' conduction states. Arriving
at an optimal value for resistors would require a circuit simulator with a mathematically
based optimizer, but, especially for amateur radio work, close is good enough. That
is not to say Hams are a bunch of slackers - they're not - it's just that component
and software resources are not as readily available (aka "prohibitively expensive")
for doing the analysis and testing. In 1966 when...
 This
Electronic Crosswords puzzle appeared in the October 1963 edition of Electronics
World magazine. About half the words used are related directly in some way
to electronics or physics. It's a fairly small puzzle so it shouldn't take you too
long to complete. My RF Cafe crosswords, by the way, have 100% of the words directly
related to the sciences, from a custom lexicon I have created over 20 years of making
puzzles. Enjoy...
 Avalanche breakdown in semiconductors, initially
viewed by engineers as a destructive limitation, was later discovered to be nondestructive
when peak power was controlled through external circuitry. This 1967 Electronics
World magazine article explains how
avalanche transistors evolved from being considered problematic to becoming
valuable components for high-speed pulse generation. Early adoption was hindered
by inconsistent performance between transistors, requiring careful selection for
reliability. Improved fabrication techniques reduced surface leakage currents, enabling
modern avalanche transistors to operate at high collector voltages...
 Until maybe 30 to 40 years ago, there was
still a certain amount of awe associated with new applications of technology. It
seems anymore people are so accustomed to new and amazing things - usually at affordable
prices - that the wonder is gone. Advancements are expected. The world is moving
so fast that it is difficult to absorb and fully appreciate all the work being done.
In 1947 when this "Sound
Broadcasting from Airplanes" article appeared in Radio News magazine,
both airplanes and electronics were still relatively new to a lot of people, especially
in more rural areas, so a whiz-bang scheme like broadcasting messages from an airplane
was a big deal to many. It was an area of science that had not yet been explored
to a large degree. BTW, the spell checker flagged a new word (for me, anyway): genemotor
which, as it turns out, is the generic name for the line of dynamos, generators,
engines, and motors manufactured by Pioneer Gen-E-Motor Corporation of Chicago,
Illinois...
 "Inside a secure facility overseen by the
Central Science and Technology Commission, Chinese engineers have activated an
Extreme Ultraviolet (EUV) lithography machine - a technology the U.S. spent
years attempting to block. A recent Reuters investigation confirms the EUV prototype
is now operational in Shenzhen. This development is not just a technical milestone;
it is a seismic structural realignment that effectively marks the end of the unified
global semiconductor market. Lack of access to the leading edge technology of ASML's
EUV lithography machines. Strict 'small yard, high fence' restrictions would keep
China several generations behind in technology..."
 Remember when you could hold a telephone
conversation without having to allow a moment of time at the end of a sentence before
responding in order to keep from "stepping on" the person on the other end? It used
to be only overseas phone calls or maybe communicating to astronauts on the moon
suffered such inconveniences, but talking to someone across town was like having
a face-to-face discussion. More often than not - or so at least it seems - there
is a noticeable delay between the time someone actually stops talking on the transmitter
end and the time the audio stops at the receiver end. People who have never known
otherwise accommodate the delay with no appreciation for how good phone calls used
to be. This promotion by
Bell
Telephone Labs which appeared in a 1946 issue of Radio News magazine
extolls the virtues of its "scientific quality control" innovation that produced
repeatable...
 In 1935,
not much was yet known about the
ionosphere. Its existence was first theorized in 1902 by Arthur
Kennelly and Oliver Heaviside, and Edward Appleton proved its presence in 1924 by
conducting a series of broadcast experiments, but no direct measurements were possible
until rocket-borne instruments could be launched. An Aerobee-Hi sounding rocket
was launched in 1956 as part of the International Geophysical Year (IGY) project
that made the first actual detection of ionized particles in what is now referred
to as the D-layer. It is therefore forgivable that Hugo Gernsback, normally spot-on
in his theories and postulations regarding RF propagation, incorrectly suggested
in this editorial that based on observed time...
 This 1967 Electronics World magazine
article highlights a potential revolution in microwave technology through new semiconductor
devices that could miniaturize and drastically reduce the cost of microwave sources.
The focus is on two promising devices: the Read p-n junction diode and the
Gunn bulk gallium arsenide oscillator. The Gunn device, discovered accidentally
by Dr. J.B. Gunn at IBM, operates on a radical principle - a bulk semiconductor
material oscillates at microwave frequencies without external tuned circuitry when
a threshold voltage is applied. Key to the Gunn effect is the unique property of
gallium arsenide, which features a second conduction band. Electrons entering this
high-energy, low-mobility band create "domains" that drift slowly from cathode to
anode, causing current...
 Most people have heard of the incredibly
accurate
Norden bombsight that was credited for revolutionizing accuracy
of heavy bombers like B-17s, B-25s, and B-29s. It was an electromechanical device
that took bombardier inputs of altitude, airspeed, heading, and wind speed and direction,
then calculated the impact point of the bomb. An accuracy of 75 feet was claimed
under ideal conditions - provided by a mechanical computing device. By 1956 when
this article was published, the Norden had been replaced by radar-integrated bombing
systems. Additionally,
ground-based radar measurement systems were...
 "On
Monday, December 22, 2025, the FCC released
DA 25-1086,
which adds
foreign-made drones and some components to security risk list. What the decision
actually means: "If you already own a DJI or other foreign-made drone, you can still
fly it. Stores can still sell previously approved models while inventory lasts.
New foreign-made drones and key components can no longer get FCC approval. In practical
terms, future DJI models are now cut off from the U.S. market. There are no true
low-cost, one-for-one replacements available today..."
Most people have heard of the incredibly
accurate
Norden bombsight that was credited for revolutionizing accuracy
of heavy bombers like B-17s, B-25s, and B-29s. It was an electromechanical device
that took bombardier inputs of altitude, airspeed, heading, and wind speed and direction,
then calculated the impact point of the bomb. An accuracy of 75 feet was claimed
under ideal conditions - provided by a mechanical computing device. By 1956 when
this article was published, the Norden had been replaced by radar-integrated bombing
systems. Additionally,
ground-based radar measurement systems were...
 If you need a cheap, quick
lightning arrestor for your antenna or just about any type of
wired system, this idea from Mr. Burgess Brownson looks like a good option.
He used an automotive spare plug. Voltage breakover points can be set by varying
the spark gap distance. The old vacuum tube transmitters and receivers had a better
of chance of surviving a lightning strike because the components were able to handle
much more of a shock than our modern semiconductor sets with miniature, closely
spaced components. Still, the spark plug setup is better than nothing, if for no
other reason than to protect the shelter. it should suffice. This and many
...
 Aircraft electronics has always been on
the bleeding edge of technology because of the ever-increasing need to fly in the
widest range of atmospheric conditions possible. Accordingly, skills needed by avionics
servicemen are amongst the highest required in any electronics field. There are
still many pieces of vintage equipment in service that need to be maintained, but
even 20- to 30-year-old airborne radars and navigational units require top-notch
techs to troubleshoot and align. One topic in particular that plagues electronics
operation even in modern airframes is that of static electricity build-up and lightning
strikes. We all face those kinds of static discharge hazards in non-aviation environments,
but for the most part a failure on the ground or water is not as imminently...
|
 • U.S.
Cuts EV Plans as Tax Credit Ends
• Fragmented 6 GHz Policy
Shapes Wi-Fi 8 Adoption
• Big 3 Have
Room for 32M FWA Customers
• FCC Simplifying
Broadband "Nutrition Labels"
• GSMA Pleads for
Yet More 6G Spectrum
 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.
 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...
 One of the major advantages of the age of powerful
personal computers - be they in the form of desktop systems, tablets, or smartphone apps
- is that for most
computation-intensive tasks there only needs to be one or maybe at most a
few people smart enough to know how to do them. Everyone else who has to perform
the task just needs to be able to input the proper parameters to ensure a useful
output. That is a significant statement, because in the days before ubiquitous
computer availability and incredible computing power, highly capable engineers,
scientists, analysts, and mathematicians either had to be on staff or an expert
external resource was used for difficult and/or time-intensive tasks. Over time,
fewer and fewer people are needed to produce very precise and reliable results.
In many ways, other than the creative intuition involved in concept, creation,
and execution, a large part of the product design and planning phases have been
automated...
 Like a fool, many years ago I donated a perfectly
fine
vacuum tube tester that had been given to me by an über-engineer/ham I worked
with during the time (nearly 35 years ago) I was restoring my first vintage tube
radio. Big mistake. It was a really nice tester: a B&K Model 650 Dyna-Quik Dynamic
Mutual Conductance Tube & Transistor Tester. It was sold shortly after I had
also given away as a wedding gift the Crosley floor console radio that I restored.
Another bad move. Now, many moons later, I am working to restore yet another Crosley
tube radio and I sure wish I had held on to it. Similar tube testers are routinely
selling on eBay for $100-$200. I finally found a really nice B&K Model 650 on
eBay and got it for a decent price. Mistake corrected...
 The 1940s and 1950s was an era of much advancement
in our knowledge of Earth's upper atmosphere and its affects on
radio communications - both good and bad as reported by this 1947 issue of
QST magazine. Industry, government, academic, and amateur groups all played
major roles in conducting experiments and publishing findings for the interested
community to share and build upon. Still today a huge amount of research is being
carried out to better understand how the various layers of the atmosphere - from
ground level to space - are affected by extraterrestrial influences. A year ago
I posted an article, along with a bit of editorializing, from the July 1958 edition
of Radio-Electronics entitled..."
 Preparing for a
technician career in electronics today is not so different than it was in 1970,
when this article on resume preparation appeared in Popular Electronics
magazine. Sure, particular job descriptions have changed, but the basics are pretty
much the same. In 1970, being able to list television and radio repair on your resume
was a valuable indication of your schematic reading and troubleshooting prowess.
The keywords Sams Photofacts would jump right off the page at a knowledgeable interviewer
(you can still buy documentation packages from Sams Technical Publishing). Then,
as now, having a two-year college electronics degree or a stint in the armed forces
as an electronics technician - or both, preferably - is almost a requirement for
landing a job at a defense or aerospace electronics company...
 Unlike even the vacuum tube type AM radio
in the dashboard of my parents' car in the early 1960s that were self-contained
units, even earlier radios designed for cars and trucks had their bulky electronics
mounted under the sea or in the trunk, with a remote volume and tuning control mounted
in the dashboard. That greatly complicated the installation as well as the design
of the radio. This circa 1940
Belmont Model 678 Auto-Radio is a prime example. Note the unique cylindrical
shape of the radio chassis, and that the remote control is a pushbutton assembly
with rotating knobs for tuning and volume. Operating from a 6 volt DC car battery
(12 volts came later), these radios required a "vibrator" circuit to convert DC
to AC (and back to a higher level DC) in order to transform to a couple hundred
volts for the plate voltage of the tubes...
 This is part 8 of a series authored by Milton Kiver
entitled, "Theory
and Applications of UHF," that appeared in Radio News magazine in the
mid 1940s. As you might expect it is a very extensive delve into the relatively
new realm of UHF generation, transmission, propagation, and reception. You might
not know that up through the 1930s, UHF circuit and practice had been relegated
to the amateur radio operators because those frequencies from 300 MHz to 3 GHz
were considered too unexploitable for professional use. It was not until Hams
did the hard work of figuring out practical methods of building circuits and
antennas and characterizing geographical and atmospheric conditions that
affected propagation that suddenly industry and government decided UHF might be
useful after all...
 A few years ago I was in a second-hand shop
in Erie, Pennsylvania, and happened to spot a Hewlett-Packard model HP 5212A Electronic
Counter stashed in a cardboard box with a bunch of other electronic stuff. It was
a little dirty, but otherwise appeared to be in pretty good condition. I took it
to the counter and asked the lady what she'd take for it, and we agreed on $15,
provided when I plugged it in the front panel display would light up and no smoke
came from the chassis. It did and it didn't, respectively. Once at home, I fired
it up and ran some functional tests on it, and all seemed to be working properly.
After performing some major clean-up to nearly like-new condition, I decided it
should go to someone who could put it to good use, so it went up for sale here on
RF Cafe. Believe it or not, the best offer received was $125. It deserved more respect
than that, but the guy was a collector of vintage test equipment, so at least it
went to a loving home. This 1962 "The
Counter as a Test Instrument" article in Electronics World magazine article
shows both the HP 5212A (300 kHz) and the HP 5243L (500 MHz)
electronic counters...
 Radio-Craft magazine ran a monthly series
of short articles paying tribute to some of the shakers and movers in the field
of science - this time it was
Sir Oliver Lodge. "While Hertz was discovering radio waves in
air, Lodge was determining the laws of the corresponding activity which takes place
in electrical conductors. It was Lodge who demonstrated the possibility of radio
communication, experimentally, as Marconi did its commercial value - just as Henry
created the telegraph and Morse made it of practical utility." See other "Men Who
Made Radio" features on...
 FM (frequency modulation) radio certainly
was a hot topic beginning in the middle to late 1940s. With the war out of the way,
energies and resources were being redirected back to peacetime production. Major
Edwin Armstrong announced his FM scheme in 1935, and as with many new inventions,
it was met with skepticism by many who doubted his claim of static interference
immunity. For many, it was a lack of understanding that caused the negative reaction,
caused primarily by the increased level of sophistication of the transmitter and
receiver circuitry. Amplitude modulation (AM) was so easy even a caveman could understand
it, but adding phase relationships into the equation (literally) left many in the
dust. This
FM Radio Quiz from a 1950 issue of Radio & Television News magazine
tests your grasp of frequency modulation principles.
 The
Underwriter's Laboratory (UL) is an entity that seems to have been around forever.
A lot of people - maybe most people - assume that it is a government entity. In
fact, it is a non-profit organization sponsored by the National Board of Fire Underwriters.
Its roots are traceable back to the Chicago World's Fair in 1893. Concern over the
potential fire hazard of Edison's light bulbs was the impetus for the effort. Another
aspect of the UL that a lot of people don't know is that the UL label of approval
is no guarantee that the device works properly, only that is passes standards of
safety as it relates to fire hazards. This article in the August 1955 edition of
Popular Electronics magazine gives a brief history...
 Without presenting a single equation, author
Cyrus Glickstein discusses the affects of
resistor-capacitor interaction in circuits, aka R-C time constants. This 1953
Radio-Electronics article is directed mostly toward a repair technician poking and
probing circuits while referring to schematics during troubleshooting sessions.
Being in the age of vacuum tubes without integrated circuits with built-in biasing
and interstage coupling circuits, there were plenty of discrete resistors, inductors,
and capacitors strewn throughout the chassis with point-to-point wiring and components
soldered directly to binding posts and terminal lugs on sockets, stacked wafer switches,
transformers, etc. Cold solder joints and broken wires were a fairly common occurrence...
 If this article had appeared in the New
York Times in the year 2020, its author, Glenn Ellsworth, would have been labeled
a 'Depression
Denier!' Don't be confused by the word 'denier,' which most often prior to about
1999 was used to refer to a type of silver coin or a measure of fineness of silk
cloth. Today, it is seen most often as describing one who would deny something.
'Denyer' is the alternate spelling used by some authors to avoid confusion, and
since the level of spelling knowledge is so low, most people never notice. But,
I digress. The reason I bring up the point is because this article was published
in 1933, little more than three years after the Stock Market Crash of October 29,
1929 (aka 'Black Tuesday')...
 "Ignitron"
sounds like a contemporary pejorative term for someone who blindly follows orders.
In the 1940s, though, it was a type of steel-jacketed vacuum tube manufactured by
General Electric for use in conversion from alternating alternating to direct current
(AC-DC) power supplies. According to this GE document, "Ignitrons are gas-discharge,
pool-type cathode tubes in which the arc is started for each conducting cycle by
means of a starting or ignition electrode. The tubes are of the half-wave type in
which the current is carried through the tube during only the positive part of the
cycle. During the remainder or non-conducting part the residual ionization reaches
very low values in comparison with the ionization present in the multi-anode type
of pool tube where it is proportional to the load current carried. As a result of
the so-called dark, negative half-cycle, the shielding required in half-wave tubes
is greatly reduced from that in the multi-anode tube. Reduction in shielding in
turn lowers the arc voltages so that tubes of this type may be efficiently applied...
 Author Edward Tilton discusses here the tradeoff
between
bandwidth and sensitivity in receivers, given that broadband noise power follows
bandwidth in a 10 log BW fashion. Pulling in the most distant stations requires
very low noise in able to get the SNR as high as possible, which requires the minimum
bandwidth possible. Prior to highly stable local oscillators, operating successfully
in a narrow bandwidth for voice (phone), and particularly for CW (Morse code), dictated
the use of a fixed frequency crystal to keep from having to constantly re-tune the
station. Nowadays, of course, what used to be considered a metrology grade oscillator
can be bought for tens of dollars...
 It took a couple times reading through this
"Rectifying
Without Rectifiers" article to get the gist of what author H.B. Conant
was talking about. He begins by pointing out the negative aspects of using nonlinear
metallic rectifiers in a bridge circuit for an electric meter, then goes on to describe
an improved "translator" circuit that uses - wait for it - nonlinear metallic rectifiers
(or nonlinear resistors made of Thyrite material). If my interpretation is correct,
basically the new and improved circuit incorporates a bias voltage that forces the
nonlinear element (be it a metallic rectifier or a nonlinear resistance) to operate
in a region which passes a higher current level to the meter movement when low values
are being measured. One of the drawbacks mentioned of a traditional (at the time)
bridge circuit was the need for separate calibration / marking of the meter's scale
on the front panel, but then he says the translator meter also does not have uniform
scales on all voltage ranges. I are a bit confused...
 Everyone who is interested enough in microwave
diodes to read this article surely knows* what IMPATT, GUNN, and PIN diodes are, but
have you heard of Read-effect, TRAPATT, LSA, or QMD diodes? If not, it is likely because
you entered the microwaves field long after 1969 when this edition of Electronics
World was mailed to subscribers. Device improvement and obsolescence accounts for
familiarity with the former and unfamiliarity with the latter, respectively. The article
below by two Sylvania Electronic Products engineers describes the properties of various
up-and-...
 Don Hoefler, widely credited for being the
first author to use the term "Silicon Valley" in print* to refer to the rapidly
building semiconductor region of the San Francisco Bay area, published a series
of articles in the 1944-1945 timeframe in Radio-Craft magazine about radio
and television broadcast equipment. This particular installment is part XII, covering
broadcast antenna towers. At the time, commercial installations were few and
far between as priority was given to scarce resources for military applications.
He discusses the tradeoffs involved in various vertical antenna designs, including
the tower structures: top-loading, center-loading, etc. When I first looked at the
traditional tapered tower design I thought about how labor-intensive such calculations
might be and sure enough, he mentions that constant-cross-section towers were gaining
favor due to the relative ease of computations for predicting radiation patterns
and impedance matching. Still, it required a lot of slide rule work... |
