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Friday the 30th
 Bill Woodbury, president of Sprague Products
Company, addressed the National Electronics Association's (NEA) National Convention
in 1969, praising his firm's commitment to high-quality replacement components for
electronic service technicians while flipping the topic to solicit their input on
manufacturer support. He candidly criticized the independent service industry for
failing to unite, with only 15-25% of 125,000 technicians in
fragmented trade associations that waste energy fighting each other. Woodbury
urged forming one powerful national body like NEA through mergers, warning that
disunity has cost billions in missed opportunities like garage doors...
 While reading through this article on
copper-oxide rectifiers, I am once again reminded of how much
we take for granted the conveniences of electrical test equipment on today's shop
benches. The advent of FET-input multimeters was a huge step forward because the
meter input impedance is so high that it has practically no impact on the circuit
being measured. Prior to that, most simple meters drew their power from the circuit
under test, thereby altering the true value of current or voltage being measured.
Of course there were vacuum tube voltmeters (VTVM)
with high input impedances, but few hobbyists or laymen could afford them. This
piece reports on how the advent of a non-tube-based rectifier permitted AC measurements
to be made by DC-driven d'Arsonval meter movements so as to not excessively...
 "[Bill
Schweber has] always been interested in innovations that are pursued for years without
wide adoption, yet proponents keep working on them. Sometimes, these advances just
fade away. Other times, they contribute to progress in a more-general way and, in
some cases, the necessary pieces -- technologies, manufacturing, market needs --
finally converge, and the years of laboring in semi-obscurity final pay off. That's
one of the reasons [he has] been following the efforts to use
laser-based spark plugs in place of the classic spark plug as the igniter of
gasoline and other volatile fuels in the internal combustion engine (ICE). There
have been innovations in the plug itself over the years...
 The basics of
power transistor specification and selection have not changed
much since they became widely commercially available in the 1960s. Although available
package shapes, power handling, cutoff frequencies, and other parameter options
have been greatly expanded, still the most important aspect is not just selecting
a power transistor but properly mounting it to ensure that the rated heat dissipation
capacity will be realized. This article touches on some of those considerations
and how to effectively deal with them...
 Fellow cruciverbalists, here from a 1963
edition of Electronics World is an
electronics-themed crossword puzzle for your end-of-the week enjoyment.
You can click on the grid for a larger, printable, write-on-able paper version.
If you are an avid worker of crosswords and don't already know it, I have created
hundreds over the last decade+ that are available
here. Unlike this
crossword from Electronics World magazine (and most others for that matter),
my puzzles have only hand-picked words related to engineering and science...
 Boonton, Holzworth, and Noisecom brands
are part of Maury Microwave (formerly WTG), a global designer and manufacturer of
advanced RF and microwave components, modules, systems, and instruments. Serving
the wireless, telecommunication, satellite, military, aerospace, semiconductor and
medical industries, Wireless Telecom Group products enable innovation across a wide
range of traditional and emerging wireless technologies. A unique set of high-performance
products including peak power meters, signal generators, phase noise analyzers,
signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable
noise generators.
Thursday the 29th
 The monthly "Radio &
Television News" column in Electronics World magazine always contained
an interesting mish-mash of industry happenings. As mentioned many times before,
the 1960s was an era of huge transitions in the electronics and communications fields,
in all aspects including military, automotive, aerospace, domestic, commercial,
industrial, and hobby. It was a heyday for just about all involved - designers,
manufacturers, customers - except the poor service guys who had to keep everything
working. Homeowners with problematic television sets - particularly the expensive,
newfangled color sets - notoriously made technicians' lives Heck. Some outfits deserved
the grief, but most could barely turn a profit because if the manufacturer wasn't
cheating the serviceman out of payment for warranty work, housewives and husbands
would try...
 Benjamin Franklin is famous for his kite-flying
experiment whereby he "discovered" not electricity (as many people believe), but
that lightning is a form of electricity (most people thought it was a jet of gas).
A lesser known fact about Mr. Franklin is that he invented the
lightning rod after realizing the electrical nature of lightning.
His understanding of electric fields facilitated a implementation whereby hefty
iron cabling interconnected a tall, pointed rod installed at the tallest point on
a building and a spike driven into the ground. Lightning typically strikes the object
that is the shortest distance (in terms of electrical field strength) from it because
the discharge can begin at the lowest voltage. The presence of the grounded lightning
rod above the highest point on a structure effectively brings that point all the...
 Tiny molecules that can think, remember,
and learn may be the missing link between electronics and the brain. For more than
half a century, researchers have looked for ways to move past silicon by
building electronics from molecules. The idea sounded simple and beautiful,
but real devices turned out to be messy. Inside a working component, molecules do
not act like neat, isolated pieces from a textbook. Instead, they form crowded,
interactive networks where electrons move, ions shift position, interfaces change
over time, and even tiny differences in structure can trigger strongly nonlinear
behavior. The potential was exciting, but reliably predicting and controlling what
a molecular device would do remained out of reach.
 What better way is there to resuscitate
a challenging work day than to kick back and enjoy these electronics-themed comics
from a vintage edition of Radio & Television News magazine? Seeing
a comic panel in any modern technical magazine these days is rare, if for no other
reason than a fear amongst publishers (and their lawyers) that somebody, somewhere
might be offended. You have my invitation to create a good-humored cartoon about
me or RF Cafe anytime you wish, and I promise not to sue you. I'll even post it
here on the website if you like. BTW, these comics make great fodder for the front
page of your technical presentations...
 Potassium sodium tartrate (Rochelle salt) was used in commercial speakers for a while in
place of electromagnetic driver coils. The relatively large mechanical deformation
produced when subject to an electric field made them attractive as coil alternatives
because a separate energization circuit was not required. The drawback, at least
early on, was unavailability of crystals large enough to drive anything other than
a headphone size speaker cone. This article tells of the time when a process was
created to grow large crystals from a seed, similar to how silicon, gallium-arsenide,
and other modern semiconductors are grown...
Wednesday the 28th
 Galvanic corrosion is a potential problem
(get it - potential?) for just about any scenario where two metals of differing
nobility (position the galvanic table) come into contact with each other. This 1969
Electronics World magazine article explains corrosion as an electrochemical process
akin to electronics, involving anodes, cathodes, electrolytes, and electron flow,
particularly in marine environments. Galvanic corrosion occurs with dissimilar metals
like zinc (anode) and copper (cathode) in water, accelerated by oxygen depolarizing
the cathode. Factors include galvanic/activity series rankings, electrolyte pH,
chloride content, humidity, and oxygen differentials...
 GeAs was the semiconductor substrate material
of choice long before the III-V series like GaN and GaAs came along. GeAs would
be considered a III-IV semiconductor since Ge is in group IV of the
periodic table
(Ga is group III, As is group V). It is actually know simply as germanium. 1954,
when this advertisement from Bell Telephone Laboratories appeared in Radio &
Television News magazine, was the same year that Texas Instruments (TI) introduced
the world's first commercially available silicon (Si) transistor. The GeAs boule
photo in the ad was printed "life size," which makes it around 2" in diameter. Compare
that to 12" diameter wafers standard today for Si. Gallium nitride GaN), a more...
 "Induction is a hazard that occurs when
an electric or magnetic field causes current to flow through equipment whose intended
power supply has been cut off. Safety practices seek to prevent such induction shocks
by grounding all conductive objects in a work zone, giving electricity alternative
paths. But accidents happen. In [one lineman's] case, his platform unexpectedly
swung into the line before it could be grounded. Adding a layer of defense against
induction injuries is the motivation behind Budapest-based Electrostatics' specialized
conductive jumpsuits,
which are designed to protect against burns, cardiac fibrillation, and other ills.
'If my boy had been wearing one, I know he'd be alive today,' says the elder Kropp,
who purchased a line-worker safety training business..."
 This article was written in 1932, before
anyone had in-situ empirical measurements of the
ionosphere, since suitable instrumented sounding rockets were
not yet available. It had only been 30 years since Oliver Heaviside and Arthur Kennelly
first proposed their theory of the ionized layer that encompasses the Earth. It
turned out that the ionosphere is composed of multiple layers of ionized regions
whose intensities are dependent on solar surface activity, time of day and night,
time of year, and even on terrestrial events like large volcanoes. Large network
communications have been built so as not to be held hostage by atmospheric conditions
by utilizing...
 In this episode of John T. Frye's "Carl & Jerry" series, the intrepid pair of teenage electronics
hobbyists and Ham radio operators are experimenting with an audio amplifier rig
that uses a parabolic dish for concentrating sound waves at a focal point where
they have a microphone mounted. Aside from picking up bird noises and a neighbor
lady scolding her husband for not properly washing the windows during a round of
Spring cleaning, Carl imposes upon Jerry for a lesson in
feedback techniques - both positive and negative - and the reasons
one is preferred over the other. The story winds up with a clever double entendre
comment referring to "osculation..."
 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.
Tuesday the 27th
 After learning the fundaments of Ohm's law,
for calculating simple relationships between voltage, current, power, and resistance,
the next area of study is capacitors and inductors. Anyone who might have had trouble
grasping the concepts of Ohm's law will certainly be considering another career
line when encountering these two components. Fortunately, an introductory course
does not immediately deal with complex math -- involving real and imaginary parts.
Rather tidy equations relating common
combinations of L's (inductors), R's (resistors), and C's (capacitors)...
 In 2015 we would hardly think of electromagnetic
radiation in the 5 cm wavelength realm as being "quasi-optical" as far as circuit-based manipulation is concerned.
Optical wavelengths begin at around 6,300 Å for red light, which is 6.3x10-5 cm,
or 630 nm. The 5 cm wavelength used an example in a 1932 article in
Short Wave Craft magazine is equivalent to 6 GHz. 6 GHz was an
extraordinarily high frequency to be using for communications back then, and the
author did not intend to liken it to anywhere near visible light. Instead, his terming
its properties as "quasi-optical" referred to how the waves interacted with physical
objects; e.g., reflection, refraction, absorption, and scattering. Barkhausen
oscillations were a popular subject of the era...
 "On a blustery November day, a Cessna turboprop
flew over Pennsylvania at 5,000 meters, in crosswinds of up to 70 knots -- nearly
as fast as the little plane was flying. But the bumpy conditions didn't thwart its
mission: to wirelessly beam power down to receivers on the ground as it flew by.
The test flight marked the first time
power has been
beamed from a moving aircraft. It was conducted by Overview Energy, which emerged
from stealth mode in December by announcing the feat. But the greater purpose of
the flight was to demonstrate the feasibility of a much grander ambition: to beam
power from space to Earth..."
 Before there were electric generators onboard
airplanes to power communications equipment, aviators relied on storage batteries
to operate their radios. Before that, there were no radios at all aboard airplanes.
Although Wilbur and Orville Wright first piloted their Wright Flyer in 1903, by
the end of the decade airplanes were becoming a common sight across the country
and across the civilized world. By the middle of the second decade experiments were
being done with airborne radio. They were heavy vacuum tube units with heavy
lead-acid batteries. Antennas sometimes hundreds of feet long
needed to be reeled out and in once at altitude. The earliest transmitter (for 2-way
communications) were spark gap types, meaning of course Morse code was the medium...
 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. The
WMHPC-80-520M-6dB-N is a high-power coupler that operates over the 80 to 520 MHz
band, covering FM radio, upper VHF and lower UHF applications. Conservatively rated
for 100 watts CW. Useful for amplification and signal distribution applications
including radio and television broadcasting, public safety and emergency broadcasting
and distributed antenna systems. Mainline loss 1.2 dB typical, directivity
24.5 dB. Assembled and tested in USA. "No Worries with Werbel!"
 Whoa, it's a good thing I read these articles
prior to publishing them, lest some uninitiated soul be lead to the wrong conclusion!
Keep in mind that this article was written in 1932, prior to the development of
the quantum mechanical model of the atom, but on the other hand, Ernest Rutherford
and Niels Bohr developed their model in 1913, so the information was available.
The
Rutherford-Bohr model of the atom suggested a nucleus comprised
of positive masses called protons, each of which carries a charge of +1 unit, and
neutrons with no net charge. Surrounding the nucleus were orbiting masses called
electrons, each of which carries a charge of -1 units. Accordingly, the net charge
of an atom was the sum of protons and electrons, with unionized atoms having a net...
Monday the 26th
 I have always found it annoying when an
author uses a symbol or subscript in an article without explaining or somehow making
obvious what it is. In this "Resistivity:
Some Definitions" piece from a 1969 issue of Electronics World magazine,
the author's stated purpose is to define terms related to resistivity, which he
does well, but there are a couple instances where subscripts for resistivity, rho
(ρ), are left for the reader to figure out.
ρsp, ρs,
and ρv have been replaced with
ρspecific, ρsheet,
and ρvolume , respectively, where needed.
Sure, a careful reading of the surrounding content clarified the intent, but you
are not supposed to work that hard. Otherwise...
 Carl and Jerry found the appearance and
construction of 2400 megacycle transmitters and receivers to be quite odd compared
to the equipment they were used to dealing with. It's sometimes hard to believe
such an attitude of wonder when our world today is utterly filled with wireless
devices operating in the 2.4 GHz ISM band. Author John T. Frye could never
have imagined that such a reality would would exist half a century after his story
of the pair of teenage electronics sleuths. Unlike our postage stamp size integrated
assemblies that cost a few dollars, they speak of "special ultra-high-frequency
"light-house" tubes with...
 Say goodbye to Earth-based astronomy if
this trend continues! Elon Musk's Starlink 10,000-satellite constellation pales
in comparison to this ambitious, dominating system. Isn't it amazing how Green warrior
funders are willing to ignore things like and nuclear power plants when it serves
their financial and influence purposes? "China
files to launch 193,448 satellites. The CTC-1 filing is for a single notional
Non-Geostationary Orbit (NGSO) system. The CTC-2 filing is still at the Advanced
Publication Information stage. CTC-1 and CTC-2 are early-stage ITU regulatory filings
but don't authorize launches. [They] form part of a single strategic effort to secure
spectrum and orbital priority for a future next-generation Chinese megaconstellation..."
 In an effort to promote entry of women and
girls into the amateur radio hobby, Short Wave Craft magazine ran a few
contests for Best "YL" Photos. Amazingly - and maybe there are still instances
of it today - many (if not most) of the YLs featured had built their own equipment.
In 1935, most people built their own equipment, so that is not too surprising. The
winner for this month was a 16-year-old young lady i.e., "YL") who in fact built
her rig. Another winner was an 83-year-old grandma who was born before Marconi,
Maxwell, and Hertz did their best work! The third winner was a girl who earned her
Ham license at age 6, which back in the day required sending and receiving 5 words
per minute (WPM) in Morse code...
 Coaxial cable is the most familiar form
of
RF transmission line for most people these days. Up until 2009
when the U.S. switched to digital television (DTV), there were still a fairly large
number of people who had the old 300 Ω twin lead cable running from roof-top
antennas to TV sets. Over-the-air reception has petered off precipitously since
then. Coaxial cable is undoubtedly more convenient and forgiving regarding routing
since proximity to structures - particularly metallic components - than twin lead.
Good quality 300 Ω twin lead cable (~30¢/foot today)...
Friday the 23rd
 Certainly my high school, Southern Senior
High (class of '76), in Harwood, Maryland, had a JROTC program in the 1970s, but
I have no recollection of it. Maybe because of the Vietnam War, not as many ROTC
groups were being formed. In fact, I don't think there was anything about ROTC in
my yearbook. This 1962 Carl and Jerry adventure titled "ROTC
Riot" took place at the semi-fictional Parvoo University, where the electronics
and technology pair was attending for electrical engineering. ROTC upperclassmen
were famously difficult to tolerate due to their attitude of superiority -- and
desire to do unto others as was done unto them...
 Mrs. Helen McKee knew exactly what she was
signing up for when she agreed to marry Mr. McKee. After all, she met and got familiar
with the guy over the air during some rag chewing sessions. This story is a humorous
(and true) account of what life can be like for the spouses of enthusiastic Ham
radio operators. We all hope for such an understanding "significant other." Melanie
has certainly endured and supported a lot of
my pastime endeavors
over the past 32 years. It's a short read, so take a break and put a smile on your
face...
 "SatVu has released a 3.5m high-resolution
thermal image revealing near-real-time activity inside one of the USA's largest
data centres. The image provides a heat-based look at cooling systems, substations
and high-load infrastructure of the data centre of a bitcoin mining company in Rockdale,
Texas. Demand for AI, cloud computing and crypto mining has made data centres some
of the world's most energy-intensive facilities. They are expanding fast, often
outpacing the ability of regulators, grid operators, analysts and communities..."
 As mentioned many times in the past, some
things never change regarding the
basics of electricity and electronics. Resistance, inductance,
and capacitance are examples. When first starting out in this science, an effective
introduction to the fundamentals can often determine whether a person sticks with
it or finds another area of interest to pursue as a hobby and/or vocation. Analogous
examples of voltage and water pressure, resistance and the diameter of a water hose,
inertia in a spinning mass opposing a change in rate and an inductor opposing a
change in current, etc., are presented along with some good sketches of...
 How is this for a prescient prediction from
the early 1960s? "As a result of modular and
integrated circuitry techniques, all future circuit design work,
regardless of degree, will become the responsibility of the component manufacturer
instead of the equipment producer." Texas Instruments' (TI) Jack Kilby is credited
with designing the first integrated circuit in 1958. The first commercial IC, Ti's
Type 502 flip-flop, had just hit the market in early 1960, and already pundits were
prognosticating and ruing the disappearance of circuit designers. Maybe it was concerns
over job security that they seem to favor forever building every circuit...
 Werbel Microwave is a manufacturer of RF
directional and bidirectional couplers (6 dB to 50 dB) and RF power dividers
/ combiners (2- to 16-way) with select models operating up to 26.5 GHz and
100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are
designed and manufactured in our Whippany, NJ, location. Custom products and private
label service available. Please take a couple minutes to visit their website and
see how Werbel Microwave can help you today.
Thursday the 22nd
 John R. Collins' 1967 Electronics World
magazine "Advances
in Magnetic Materials" article captures the essence of magnetic materials leaping
from incremental tweaks to revolutionary shifts, like grain-oriented steels that
aligned crystals to slash transformer losses and shrink massive power gear for aviation
and grids. Alnico alloys ditched bulky speakers for sleek permanent magnets, while
ferrites -- ceramic wonders -- tamed high frequencies with non-conductive ease,
spawning compact motors, tools, and early computer memories. Superconductors, then
lab novelties generating intense fields with zero resistance, hinted at sci-fi applications
from particle physics to space. Fast-forward to today, and they've exploded, proving
Collins' "quantum jumps" birthed today's...
 Crowded frequency bands have been a problem
since the beginning of radio because technology is constantly not only filling available
bandwidth, but also pushing the frontiers higher. The advantage of going higher
in frequency is that required bandwidths for existing modulation schemes represent
a smaller percentage of the center frequency. For example, an 802.11b WiFi signal's
22 MHz bandwidth represents roughly 1% of its 2.4 MHz center frequency.
802.11a does 20 MHz at 5 GHz for 0.4%. Extend that center frequency up
to 50 GHz and the channel occupancy is a mere 0.04%. That means for the same
total band occupancy of 1% as with 802.11b, you can fit in 25 equivalent slots.
The problem with going higher in frequency is that components...
 "Researchers have used a new nanowire fabrication
technique to produce flexible electronics virtually impervious to electromagnetic
interference. Developed at Glasgow University [that's "UoG" in the image], the method
involves imprinting ultra-thin nanowires onto bendable and transparent polymer substrates.
A process called
interfacial-dielectrophoresis (i-DEP) uses electrical fields to arrange the
nanoscale materials with high accuracy, enabling the creation of precise patterns.
The Glasgow team used i-DEP to create gaps in the nanowire network that act as capacitors..."
 For the sake of avid cruciverbalists amongst
us, each week I create a new
crossword
puzzle that has a theme related to engineering, mathematics, chemistry, physics,
and other technical words. You will never be asked the name of a movie star unless
he/she was involved in a technical endeavor(e.g., Hedy Lamar). Enjoy...
 San Francisco Circuits (SFC) has been a
trusted U.S. provider of advanced PCB manufacturing and assembly solutions for R&D
innovators, prime contractors, and integration experts. SFC has published a white
paper entitled, "PCBA
Press Fit Connector Reliability: Strain Thresholds and Best Practices," to help
inform you on issues that can mean the difference between success and failure. "Press
fit connectors are common in high-density PCB designs - powering 5G infrastructure,
electric vehicles, aerospace systems, and advanced medical devices. Their ability
to deliver high I/O counts without the heat risks of soldering makes them indispensable
for modern electronics. But here's a hidden risk: If strain during insertion isn't
properly managed, it can lead to latent solder joint..."
 As a case in point about my claim with today's
earlier post featuring Bob Berman's factoids on astronomy, this article from a 1956 edition
of Popular Electronics illustrates how vital electronics are in the various
fields of science. It has only been fairly recently that astronomers have been 'looking'
at stars and planets outside of the visible wavelengths. Renditions of the sky in
both shorter and longer wavelengths show in some regions a vastly different universe.
Earlier this year, a comprehensive mapping of the entire known universe in the microwave
realm revealed the largest contiguous feature ever detected - dubbed "The Cold Spot"...
Wednesday the 21st
 Of the scores of Mac's Service Shop stories
I have read and posted here on RF Cafe, this is the first that deals with a subject
near and dear to author John Frye - the plight of handicapped people. If you don't
know, Mr. Frye had been confined to a wheelchair for most of his life. "Electronics
and the Handicapped" is essentially the story of his life, though he does not
say so. Mac: "When I was a kid growing up in a little Arkansas town, I knew a crippled
boy whose dad ran the local garage." Guess where John grew up? His father owned
a machine shop, and made gadgets to help his crippled son. "I had never heard the
term 'respo' until you told me about a month ago it was the nickname for a victim
of respiratory polio." He had polio at 18 months old...
 Very few items from my early days here on
Earth have escaped destruction or disposal. A couple dozen household moves in the
last half century have been responsible for some of it. Oddly, one thing that survived
is a box full of old letters and greeting cards - dating back to the late 1960s.
Melanie has been scanning her and my items for a more permanent record, and ran
across this letter of praise written from the administrator of the
Annapolis Vocational Technical Center, where I studied for the electrical trade
in high school. The linked page has information on the AVTC and my time there...
 "With $800 of off-the-shelf equipment and
months' worth of patience, a team of U.S. computer scientists set out to find out
how well geostationary satellite communications are encrypted. And what they found
was shocking. Close to half of the communications beamed from satellites to the
ground that the researchers were
able to listen in on were not encrypted. This included sensitive data including
cellular text messages, voice calls, as well as sensitive military information,
data from internal corporate and bank networks, and the in-flight online activity
of airline passengers. The research team, led by Aaron Schulman and Nadia Heninger,
then set out to find out which companies and government agencies were failing to
encrypt data in order to contact them and disclose the vulnerabilities..."
 This is one of the earliest examples I have
seen (and I've seen many) of an electronics article that was written in a conversational
tone rather than in the heretothen[sic] stoic, all-business type prose. In fact,
you would be hard pressed to discern it from a contemporary article in QST
magazine. Author Davis describes his process of interfacing 52 Ω coaxial
cable to his multi-element beam antenna. The
gamma match has the advantage in such an application of being
usable when the center of a driven element is directly grounded to the antenna boom. Most
other types of feed systems...
 According to the
RadioMuseum.com website, B.F. Goodrich manufactured the
Mantola line of radio receivers. It was evidently a low quality,
low price, short-lived run of models. The simplicity of the schematic shows the
low parts count. A lack of multipole filter circuits likely means selectivity was
fairly marginal. One good feature is that unlike many earlier radios and TVs, the
AC line connection to the chassis is DC-isolated through a 150 kΩ resistor.
Look at the schematics of older sets and it is not uncommon to see one line of the
AC supply tied directly to the metal electronics chassis. An isolation transformer
right at the input is the safest way to do it...
Tuesday the 20th
 This article describes an
electronically steerable aperiodic loop antenna developed that claims superior
beam pinpointing on targets with high gain in minimal space for high-frequency signals
(2-32 MHz) via ionosphere, akin to linear arrays. Comprising 36 untuned balanced
loops, each about 1 meter in diameter with transistorized preamplifiers, arranged
on a 150-foot circular perimeter, the system weighs roughly 12 pounds per element
and withstands 100 mph winds. Phase shifts enable simultaneous beams every 10° through
360°, or commutator scanning for direction finding, equating to 18 rhombic antennas
at 10° intervals...
 Although this "Algebra
in Electronic Design" article in the February 1952 issue of Radio-Electronics
magazine does not claim to be the second part of author Edmund Berkeley's "Light
Sensitive Electronic Beast" article from the previous December's issue, it does
help to know that the "Squee" mentioned here came from there. Squee is a Robot Squirrel
which has four sensing organs, three acting organs, and a small electronic and relay
brain. "Although Squee is not a very clever robot, he does have a small amount of
memory and of reasoning ability." Boolean logic (aka Boolean algrbra), a common
part of modern electronic circuits and systems...
 Sam Benzacar, of Anatech Electronics, an
RF and microwave filter company, has published his January 2026 Newsletter that,
along with timely news items, features his short op-ed titled "The
Internet of Things Has Finally Grown Up." Sam points out how the expectations
of wireless connectivity to all aspects of our everyday lives have transitioned
from a science fiction daydream to a reality that now constitutes a critical aspect
of modern-day existence. The Dick Tracy wristwatch is no longer a comic prop; it
is reality. In fact, so commonplace are such technological wonders that young kids
even wear them to school - not just super cops. Factory automation no longer relies
on massive bundles of wires, but on high-speed, ultra-reliable wireless...
 Technological prescience refers to the rare
ability to accurately foresee or anticipate future technological developments, inventions,
or trends well in advance of their realization. It combines deep technical insight,
pattern recognition from historical precedents, and intuitive leaps about scientific
trajectories. In practice, it's undervalued today amid hype cycles (e.g., metaverse
flops vs. steady AI progress). True prescience demands skepticism of short-term
trends and focus on exponential laws like computing power doubling. Few possess
it; most "futurists" recycle buzzwords. The comic artist who drew this comic for
a 1968 issue of Electronics World magazine probably had no idea how spot-on
he was.
 Anritsu has just released an application
note entitled, "Basics of Eye Pattern
Analysis." It is available as a free download on their website, but you do have
register for it. "Eye pattern analysis using the sampling oscilloscope is an effective
method for evaluating signal quality in the physical layer of high-speed digital
systems. This application note explains the basic terms used for eye pattern analysis
and methods for evaluating the performance of optical modules...
 Belmont Radio Corporation was located in
Chicago, Illinois. Founded independently sometime the 1920s, it became a subsidiary
of Raytheon Manufacturing after World War II in an effort to quickly launch
the Raytheon into nascent consumer FM radio and television markets. Belmont advertisements
were prominent in electronics trade magazines throughout the 1940s to promote their
war efforts. A schematic and parts list for this
Belmont Model 5240 receiver appeared in the July 1948 edition
of Radio News magazine...
Monday the 19th
 Recent in 1967, that is. These half dozen
developments made the headlines in Electronics World magazine in February
of the year. Solid-state electronics was rapidly gaining on the traditional vacuum
tube, and the
new technologies were glomming onto the trend. Lasers, integrated circuits,
computer-aided design, superconductors, and similar technologies were moving from
the realm of science fiction to reality. Operational power levels were still relatively
low, and physical sizes were still rather large and heavy, but as history has shown,
incremental improvements happen quickly. More than half a century later, compare
these news items to their modern equivalents or descendants. ICs have...
 Did you know that some radio service equipment
can be financed by the Federal Housing Administration (FHA)?
That's right, if your business needs a new tube tester or maybe an oscilloscope,
Uncle Sam is there to help. That was in 1936, anyway, per this
Radio-Craft news blurb. Today, of course, the FHA no longer
makes loans for business equipment - the Small Business Administration (SBA) takes
care of that. Nowadays the FHA restricts itself to home loans - including to illegal
residents and otherwise traditionally unqualified. Also reported, among lots of
other interesting stuff, is some early instances of RFI (radio frequency interference)
emanating from...
 Nothing to see here, folks; conspiracy theorists
just move along. This article appeared in the UK Telegraph on 1/12/2026.
"Uncovered: Secret room beneath Chinese embassy that poses threat to City Telegraph
obtains unredacted plans showing how close the underground complex will come to
cables carrying sensitive British financial data. China is to build a hidden chamber
alongside Britain's most sensitive communication cables as part of a
network of 208 secret
rooms beneath its new London 'super-embassy.' This newspaper has uncovered detailed
plans for an underground complex below the vast diplomatic site in central London.
Despite the apparent security risk, Sir Keir Starmer is expected to approve the
embassy..."
 How often have we all mistaken "spooks"
for
Barkhausen oscillations? Yeah, it's embarrassing, but we've all
done it. I can't tell you how many times as a kid I saw the tell-tale effects on
our old black and white TV and said, "Mom, can you remind Dad to do something about
those dang Barkhausen oscillations when he gets home from the newspaper office?"
If you believe that line of bull hockey, I've got some waterfront property in the
Sahara Desert to sell you. The only thing close to 'Barkhausen' I might have known
back then was the name of a German beer house on Hogan's Heroes. Anyway, this article,
written in the days of over-the-air television broadcasts, presents a solution to...
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Exodus'
AMP20175 pulse amplifier is designed for Pulse/HIRF, EMC/EMI Mil-Std 461/464,
and Radar applications. Providing superb pulse fidelity 4.0-8.0 GHz, 6 kW
typical, and up to 150 µsec pulse widths. Duty cycles to 10% with a minimum
68 dB gain. Available monitoring parameters for Forward/Reflected power in
watts and dBm, VSWR, voltage, current, and temperature sensing for outstanding reliability
and ruggedness in a compact configuration...
 Arthur Collins founded the
Collins Radio Company in 1933 to enter the fledgling domestic
AM broadcast market. His equipment instantly became renowned for high quality and
reliability. Collins gained early notoriety as the result of being selected by Admiral
Richard Byrd for his South Pole expedition. The U.S. military took notice and the
company quickly earned a reputation as a preferred supplier of aviation communications
equipment both for commercial and military aviation. As seen in this 1946 advertisement
in Radio News, Trans World Airlines proudly employed Collins radio equipment
in its fleet of Lockheed Constellation (aka "Connie")...
 Alliance Test Equipment sells
used / refurbished test
equipment and offers short- and long-term rentals. They also offer repair, maintenance
and calibration. Prices discounted up to 80% off list price. Agilent/HP, Tektronix,
Anritsu, Fluke, R&S and other major brands. A global organization with ability
to source hard to find equipment through our network of suppliers. Alliance Test
will purchase your excess test equipment in large or small lots. Blog posts offer
advice on application and use of a wide range of test equipment. Please visit Allied
Test Equipment today to see how they can help your project.
Friday the 16th
 In this 1968 "Macs Service Shop" entitled
"The
Laser - Toy or Tool?," Mac educates Barney on lasers, from Einstein's 1917 stimulated
emission theory and Townes & Schawlow's 1958 optical maser to Maiman's 1960
ruby crystal laser using a mirrored rod pumped by flash tubes for coherent, narrow-beam
red light. He highlights properties like focusability (1/10,000th cm spot), minimal
divergence (200 ft at 25 miles), and applications: surgery (retina welding, scalpels),
metal cutting, ICBM/satellite defense, precise ranging, gyroscopes, altimeters,
auto modeling, 118-mile / 10-TV-channel communications, high-speed...
 "2025 saw telecom giants accelerate their
integration efforts of non-terrestrial networks (NTNs) to bridge connectivity gaps
and future-proof the sector. As the industry further shifts from viewing satellites
as standalone solutions to critical components of
hybrid terrestrial-NTN architectures, here we look back at some of the top stories
and key developments over this past year. Satellite and terrestrial integration
A 2025 survey showed that NTNs are viewed by the telecom industry as reinforcing
service reliability and adding an extra layer of network redundancy to 5G. This
view increasingly makes the convergence of satellites..."
 Before the current generation began destroying
its hearing with smartphone earbuds, their parents and grandparents (that includes
me) destroyed our hearing* with ridiculously powerful loudspeakers, often in boom
boxes perched on shoulders right next to the ears (not me). The "concert hall" -
or concert auditorium - experience has been long sought-after since recorded music
has been available, which has only been about a century. As evidenced by the sudden
increase in articles and advertisements in my growing collection of
vintage electronics magazines, the early and mid 1950s saw a sudden
swell of articles promoting the equally swelling supply of high fidelity (hifi)
recording and playback...
 As with most things of consumer, commercial,
and industrial nature, the battery - more correctly "cell" - science has come a
long way in a relatively short time. Alessandro Volta invented the eponymous
voltaic pile in 1799; it consisted of zinc and copper electrodes
immersed in a sulfuric acid electrolyte, thereby being a wet cell. The first dry
cell was the zinc-carbon type invented by Guiseppe Zamboni (not the guy who invented
the ice rink resurfacer) in 1812. Rechargeable dry cells of the NiCad variety hit
the scene in 1899. Then, it wasn't until 1991 - a century later - that Sony commercialized
the Li-Ion cell (and varieties thereof) that now dominates...
Thursday the 15th
 Johanson Dielectrics and
Johanson Technology, located in
Camarillo, CA, are now supporting RF Cafe's publication. Johanson Technology designs
and manufactures RF & microwave ceramic chip capacitors, inductors and integrated
passives. These includes chip-format antennas, capacitors, lowpass, highpass, and
bandpass filters, couplers, inductors, baluns, power dividers, substrates, chipsets.
 Johanson Dielectrics has produced ceramic
chip capacitors for over 60 years. They design and manufacture capacitors that include
standard and high-voltage SMT ceramic chip capacitors, as well as a variety of standard
and custom high voltage & high capacitance value ceramic capacitors.
Please return the favor by exploring their offerings when planning your projects!
 Allen Kushner's (Times Wire and Cable) 1968
Electronics World magazine article portrays
coaxial cables as essential microwave components with impedance, power-handling,
attenuation, time-delay, and shielding traits that must hold steady over broad frequency,
temperature, and harsh environmental conditions like moisture, corrosion, and flexing.
Optimal use demands impedance matching for maximum energy transfer, minimizing VSWR,
radiation losses, and delays; dielectric selection -- solid polyolefins/PTFE for
moisture resistance versus low-loss foamed or air-spaced types with aluminum sheaths
reducing attenuation by 20%; and superior shielding, from ~80 dB in single-braid...
 I have to admit to not recalling ever having
heard of Dagmar; have you? Crack electronics technician "Red" mentioned her in this
episode of "Mac's Radio Service Shop" appearing in the March 1952 edition
of Radio & TV News. I thought Prince and Cher were the first man (ostensibly)
and woman, respectively, to use a single-name public moniker, but evidently Dagmar
beat them to the punch ...but I digress. John T. Frye, author of the popular
Carl & Jerry series that appeared later in Popular Electronics magazine,
wrote this series before that time. On this cold and wintry day, Red and Mac are
discussing troubleshooting methods and how looking for and interpreting certain
symptoms...
 "Finding accurate positions in dense urban
areas remains difficult for satellite-based navigation systems, where high-rise
buildings and signal blockages can cause large errors or complete loss of service.
A recent study outlines a deeply integrated positioning method that combines commercial
5G New Radio (NR) signals with Global Navigation Satellite Systems (GNSS) to
address these issues. By reinforcing 5G signal tracking and tightly merging it with
satellite measurements, the approach improves both ranging stability and overall
positioning accuracy in demanding city environments..."
 Even with the ready availability of programmable
calculators and smartphone apps, there are still times when having a handy-dandy
nomograph printed out and hanging on the wall for quick reference can be a great
asset. This nomograph which appeared in a 1965 issue of Electronics World
magazine provided ready conversion between two different (input and output) voltage
and power values to equivalent decibel values. It seems strange that the watts and
voltage scale is on the left and the milliwatts and millivolts scale is on the right.
That might be more intuitive for a nomograph of attenuation, but not - at least
to me - for positive gain as through an amplifier...
 Seamless
integration of wireless communications with wired communications
has not always been a yawn in technical strategy discussions. It has really only
been since the early 1990s with the introduction of ubiquitous cellphone systems
that someone on a wireless device could connect directly with a wired contact and
not need an intermediary operator to facilitate. Some military comms, the Inmarsat
system and a few other proprietary systems were available, but not to the public
at large. This article reports on some of the Army's early attempts at implementing
wireless-to-wired communications, specifically as implemented during the Normandy
Invasion on D-Day (June 6, 1944). Unlike present...
Alliance Test Equipment sells
used / refurbished test
equipment and offers short- and long-term rentals. They also offer repair, maintenance
and calibration. Prices discounted up to 80% off list price. Agilent/HP, Tektronix,
Anritsu, Fluke, R&S and other major brands. A global organization with ability
to source hard to find equipment through our network of suppliers. Alliance Test
will purchase your excess test equipment in large or small lots. Blog posts offer
advice on application and use of a wide range of test equipment. Please visit Allied
Test Equipment today to see how they can help your project.
Wednesday the 14th
 Proper grounding often makes the difference
between success and failure in a circuit - from DC to light. I recently fix an intermittent
hum in a vintage cassette tape deck by discovering and repairing a cold factory
solder joint on the shield connection of an input RCA plug. Improperly grounded
shields in electronic circuits cause coupling and interference issues, addressed
via single-point or multi-point grounding based on interference frequencies, cable
length, and circuit sensitivity to high- or low-impedance fields. Single-point grounding
suits short shields (L/λ < 0.15, where L is length and λ is wavelength of highest
frequency), with each insulated shield grounded individually, effective for low
frequencies like audio but failing against magnetic...
 "Researchers based in France, USA and Italy
claim the first demonstration of avalanche breakdown behavior in
quasi-vertical gallium nitride (GaN) diodes fabricated from selective area growth
(SAG) material on silicon (Si) substrate. The advantage of avalanche breakdown is
that it is non-destructive. The breakdown of the diodes was 720V at room temperature.
The team, from Université Grenoble Alpes in France, Stanford University in the USA,
and University of Padova in Italy, believes that the performance of the devices
can be improved “through the optimization of the design geometry..."
 Narrow-band frequency modulation (NFM) was
a relatively new technology in 1947, having been advanced significantly during World
War II. Amateur radio operators were just getting their gear back on the air
after having been prohibited from transmitting for the duration of the war. Few
were probably thinking about adopting and exploiting new modulation techniques,
but for those who were and recognized FM as the path to the future of radio, QST
published this fairly comprehensive treatment of both frequency modulation (FM)
and phase modulation (PM). Mathematically, FM is the time...
 The advent of
FET-input multimeters greatly reduced reading accuracy errors
due to not taking into account the impedance of devices being measured. A certain
amount of familiarity with how to interpret the indication on a meter movement on
analog meters is still required based on the multiplier switch position and scale
selected, but for most users simply reading the number beneath the pointer - or
interpolating its position between two numbers - is good enough. Mirrored scales
take the some of guesswork out of that by reducing parallax issues. Finally, digital
multimeters (DMMs) hit the scene and made slackers out of just about all of us when
it comes to making voltage, current, and resistance measurements. With few...
 Withwave manufactures an extensive line
of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch,
board edge, panel mount), calibration kits (SOLT), a
fully automated 4-port vector
network analyzer (VNA) calibrator,, between- and in-series connector adaptors,
attenuators, terminations, DC blocks, torque wrenches, test probes & probe positioner.
Special test fixtures for calibration and multicoax cable assemblies. Frequency
ranges from DC through 110 GHz. Please contact Withwave today to see how they
can help your project succeed.
Tuesday the 13th
 The "Recent
Developments in Electronics" column in a 1968 issue of Electronics World
magazine featured among other topics, a six-foot McDonnell-Douglas DC-10 jet model
tested inside a charged wire enclosure generating controlled electromagnetic fields
to evaluate communications and navigation antennas across flight attitudes on the
179-foot tri-jet led to modern anechoic chambers for 5G and aircraft testing. An
all-solid-state bright radar display provided daylight air traffic control to enhance
monitoring and safety to replace dim scopes. A nuclear reactor attained criticality
with 211 fuel elements for 600 kW thermal power in a 66-lb flight unit convertible
for moon/orbit craft, inspiring RTGs in Voyager and Perseverance rover...
 Not sure what the image has to do with the
subject, but... "Electromagnetic
compatibility (EMC) and compliance engineering are critical fields in ensuring
that electronic devices operate without causing or being affected by electromagnetic
interference (EMI). As technology advances, new challenges and opportunities arise
in EMC and compliance engineering. This article explores emerging technologies,
innovations in EMC testing, and potential future challenges in the field. Emerging
Technologies..."
 It is a pretty good bet that most multi-element
TV aerials you find on rooftops and even on ancient towers were decommissioned years
ago. They have been replaced either with cable (whether via CATV or Internet) or
satellite dishes. A few hold-outs still use them for local over-the-air broadcast
stations and/or even FM radio reception. There was a time, though, that photographs
taken looking across a vast expanse of house roofs showing an endless array of antennas
and guy wires was a sign of 'modern' living. Most were erected by Harry Homeowner
types or minimally qualified service technicians, and were well-known for toppling,
twisting, bending or un-aligning when stiff winds were imposed upon them. This story-lesson
from the March 1953 edition "Mac's Radio Service Shop...
 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. Our
WM2PD-0.45-7.5-S is a 2-way in-line power splitter covering the continuous bandwidth
of 450 MHz to 7.5 GHz in an enclosure measuring 5.75 x 2.80 x 0.55 inches
with versatile mounting options. The device is RoHS compliant. This part has versatile
mounting options. Through holes allow for mounting to chassis on the broad side.
Threaded holes on the connector edges allow for through-panel mounting. No worries
with Werbel...
 A mere five years had elapsed from the time
Echo, a gas-filled metallized plastic sphere that passively reflected radio signals
back to Earth, was launched and the time that 35
television cameras had been launched into space. The Space Race
was at a fever pitch. Although the Ruskies beat us in being the first to launch
both an active satellite (Sputnik) and a man (Yuri Gagarin) into space, America's
deep pool of intellectual resources, consisting of both native scientists and many
of the world's top scientists who chose to flourish in freedom here rather than
oppression behind the Iron Curtain, fostered the advantage that in short order established
the United States as the leading super power both in space and on terra firma. TIROS
satellites began providing real-time visual data on the Earth's weather in 1960.
Not only were cameras transmitting images of the Earth...
Monday the 12th
 In his 1968 Electronics World magazine
article, Amphenol RF Division VP Tore Anderson emphasizes that
selecting coaxial connectors is as crucial as choosing the cable itself for
optimal RF transmission system performance, maintaining constant impedance despite
dielectric transitions and withstanding power without disrupting VSWR. Engineers
often prioritize familiarity over suitability, leading to problematic adapters and
system degradation, while even manufacturers misuse inexpensive types for high-power
applications, risking damage. Connectors are classified by cable size, coupling
methods (bayonet, threaded, push-on)...
 Arthur Steele is probably enjoying retirement
from
Littelfuse by now. In 1965 he had an article published offering
guidelines on how to select the proper type fuse for protecting the circuit at hand.
The correct choice is seldom a simple matter of adding a margin of some amount onto
the known maximum current draw, especially if you are designing for a commercial
or defense electronics project. Applied voltage, expected current surges, operational
temperature and mechanical stress (vibration & shock, etc.), applicable design
regulations (UL, Mil-Spec, etc.), serviceability, and available space are among
the factors that need consideration. Do you need a fast-blow, medium-blow, or slow-blow
fuse for that circuit? You'll have...
 Anatech Microwave Company (AMC) offers the
industry's largest portfolio of high-performance standard and customized
RF and microwave filters and filter-related products for military, commercial,
aerospace and defense, and industrial applications up to 40 GHz. Three new
models have been added to the product line in November, including a 20 dB directional
coupler with an insertion loss of 0.5 dB over a 2-18 GHz range, a 1 dB
attenuator for 1 kW peak pulse at up to 4 GHz, and an 8-way power divider
with 3° phase balance over 0.5-150 MHz. Custom RF power filter and directional couplers
designs can be designed...
 This week's
crossword puzzle has a "directional coupler" theme in that many
of the words are related to the devices. All of the other words are, as usual, pulled
from a custom-built dictionary containing only terms pertaining to engineering,
mechanics, astronomy, mathematics, chemistry, and names of companies that make components
for the aforementioned fields. Even Dilbert characters appear sometimes. You will
not, however, find names of numbnut Hollywierd celebs or TV shows here...
 Longtime RF Cafe visitor Steve M. sent
me a note about his new RFGraph system modeling
software. It is an online cascade calculator with a drag-and-drop user interface.
Standard or custom components can be placed on the drawing grid, and all system
parameters -- gain, NF, IP, P1dB, etc., can be viewed at any point in the chain.
Your design is stored in the cloud and can be easily shared with other users or
exported to PDF for inclusion in presentations and white papers. A Basic account
with limited capability is free, and a full-featured Pro account is a mere $9.99/month
or $99/year. Try it today!
 May 6, 1937, is the date of the
Hindenburg disaster at the Naval Air Station in Lakehurst, New Jersey, and is
the RF Cafe logo theme for that Day in History . While looking through the July
1936 edition of Radio-Craft magazine, I saw this news article reporting
on preparations being made in the onboard radio and direction finding equipment
for Hindenburg's maiden voyage from its home base in Frankfurt, Germany to North
America. No one at the time of this article suspected such a terrible fate was looming
les than a year later. Theories abound regarding the cause of the fatal fire, but
there is no doubt that a combination of highly flammable hydrogen gas and an also
highly flammable graphite dope...
Friday the 9th
 Log-periodic dipole array (LPDA) antennas
have been a favorite of homeowners and hobbyists since they were first invented
back in the late 1950s by Dwight Isbell and Raymond DuHamel at the University of
Illinois. In this 1967 Electronics World magazine article, Harold D. Pruett,
an assistant physics professor at Colorado State University, outlines DIY zig-zag
designs for FM and TV reception, costing under $5 in materials. The FM-only and
VHF TV-FM antennas provide 10-12 dB gain, 5° beamwidths, and over 20 dB
front-to-back ratios, enhancing signal-to-noise by focusing on transmitters and
rejecting noise, multipath distortion, FM stereo hiss, and TV "snow" or ghosts...
 Effective January 19, Innovative Power Products
(IPP), an RF Cafe advertiser, will be relocating our operations from Holbrook, NY
to a
new facility at 90 Davids Drive, Hauppauge, NY 11788. This important step
for IPP will allow us to better support our customers, giving us more capacity in
a newly-renovated manufacturing location. All shipping, receiving, and in-person
visits will transition to the new site. Our team, ownership, and commitment to quality
and service, phone numbers, emails, and primary points of contact all remain the
same!
 James Kilton Clapp in 1948 first published
details on an oscillator that used positive feedback obtained from an LC (capacitive &
inductive) voltage divider to initiate and sustain oscillations. Thus was born the
now familiar Clapp oscillator. It had an advantage over both the Colpitts and Hartley
oscillators because the feedback, not being dependent on a simple capacitive or
inductive voltage division, respectively, made it more reliable as a variable frequency
oscillator (VFO). This article does a nice job of explaining the operation of the
Clapp oscillator. Just as the Colpitts and Hartley oscillators handily provide an
easy mnemonic for being based...
 ARRL
The National Association for Amateur Radio® is launching a year-long celebration
that puts the spotlight squarely where it belongs -- on radio clubs. Beginning January
1, 2026, ARRL officially recognizes the
Year of the Club, an initiative designated by the ARRL Board of Directors to
honor the vital role clubs play in sustaining, growing, and energizing amateur radio.
Radio clubs are the backbone of ARRL and of the Amateur Radio Service itself. For
countless hams, a club is the first welcoming doorway into the hobby -- a place
to learn, to operate...
 Magnetic ceramics have been with us for
a long time - probably forever as far as most people that use them these days are
concerned. When this article was published in 1953, ferrites for use at RF frequencies
were a new, breakthrough phenomenon. Take a look at inductors used in vintage radio
equipment and you will find either air or solid iron as the permeable filler elements
in most instances. Whereas iron might have a permeability of 100-150, the new magnetic
ceramics exhibited permeabilities up to 4,000 at 1 MHz, and even higher for
lower frequencies. Modern alloys and compounds provide permeabilities of more than
50,000 for special applications. Such high values allow physical size and weight
of inductors and transformers...
 When I first saw this article from a 1946
edition of
Radio News, I did a double-take on the author's name, thinking
it was written by long-time model aviation author and magazine editor William "Bill"
Winter. It was actually done by a fellow named Winters, not Winter. An enthusiastic
radio control (R/C) evangelist in his day, Bill Winter wrote many pieces for electronics
magazines such as
Popular Electronics. As I have noted in the past, hobbyists in
the electronics realm, as well as in the fields of aircraft and rocket design, contribute
mightily to the state of the art. Such is also the case in many other arts and sciences.
Here we have a report of some of the earliest radio controlled flying "drones,"
as we call them today. They are a far cry from the...
Thursday the 8th
 This 1967 Electronics World magazine
article detailed the FCC's at-the-time
incentive licensing program that established a strict hierarchy where exclusive
frequency blocks were reserved solely for Advanced and Extra Class operators, creating
clear privileges based on examination proficiency. This system mandated Morse code
testing at 13 wpm for General class and beyond, with the explicit goal of pushing
hams toward technical excellence by restricting prime DX and phone segments. Today's
licensing structure retains a modified version of class-based frequency assignments,
but the distinctions are far less restrictive. While some band segments remain allocated
to specific license classes like Technician, General, and Extra, the partitions
are more permissive and designed for operational convenience rather...
 Just as modern high power semiconductor
amplifiers are composed of cascoded (connected in parallel) lower power amplifier
units, so too a
super-high-power vacuum tubes. In the case of tubes, a requisite
number of triodes (typically) are arranged around the perimeter of the tube enclosure
with the inputs and output connected to power dividers and combiners, respectively.
Vacuum tubes are still used in high power applications, although it is rare that
you will find them with glass enclosures; most are metal and/or ceramic. Over-the-air
radio and television broadcasting stations are major users. Richardson Electronics
is a major distributor for...
 "'AI is not going to take your job.
The person who uses
AI is going to take your job.' This is an idea that has become a refrain for,
among others, Nvidia CEO Jensen Huang, who has publicly made the prediction several
times since October 2023. Meanwhile, other AI developers and stalwarts say the technology
will eliminate countless entry-level jobs. These predictions have come at the same
time as reports of layoffs at companies including IBM and Amazon, causing anxiety
for tech workers - especially those starting their careers, whose responsibilities
are often more easily automated. Early reports have borne out some of these anxieties
in employment data..."
 Side-looking airborne radar started out using
a narrow beam formed by reflectors, like traditional radars, as opposed to the synthetic
aperture type most often (maybe even exclusively) used today. Both types of side-looking
radars rely primarily on the physical movement of the airborne platform for effective
azimuthal scanning rather than steering the beam either mechanically or electronically.
Modern computer-controlled synthetic radar beams can be segmented and directed off-axis
for detected areas of interest as required, but the early systems simply gathered
radar return data and presented it real-time, with some level of analog processing,
to operators...
 This is one of a multi-part series of articles
that appeared in Popular Electronics magazine on using an
o-scope to analyze signal waveforms. An introduction to square
waves and how to accurately measure them is covered here. Frequency-compensating
the o-scope probe is always an important step prior to sampling just about any waveform
other than a pure sinewave, because per Fourier series analysis, every periodic
waveform can be defined by a series of sinewave and various frequencies, phases,
and amplitudes. The author demonstrates with a square wave being composed of the
fundamental frequency and its odd harmonics. I remember being amazed to learn whilst
in engineering school that...
Wednesday the 7th
 In this "Mac's Service Shop" article entitled
"Technical
Writing," John Frye presents a critical dialogue on technical journalism, where
Mac contrasts self-aggrandizing writers with true professionals who prioritize substance
over style. The article outlines the essentials of effective technical writing:
originality, clarity, proper organization, and the ability to inspire action, all
while avoiding the insertion of the author's personality between the reader and
the subject. This critique finds a parallel in the automotive journalism of the
1970s, as with figures like "Mechanix Illustrated" magazine's Tom MacCahill...
 Ironically, an RF Cafe visitor just within
the last couple days wrote about possibly getting his Amateur radio license in order
to permit live broadcasting of his
kite-borne video camera system (known as "Kite Aerial Video" [KAV]),
or Kite Aerial Photography [KAP]). Slow scan television SSTV has long been a popular
facet of Ham radio since prior to broadband Internet connections, it was the only
practical method available. Older equipment was large, heavy, power hungry, and
relatively expensive, but today you can buy a much improved camera for a few bucks
that transmits real-time via an unlicensed 2.4 GHz wireless link. That data
stream can be recorded for later use of streamed real-time to the Internet. As with
so many other things, easy availability take some of the challenge out of it, but
the world benefits from...
 "By now, it's no secret that utility companies
are struggling to meet the unprecedented surge on North America's aging power grids,
particularly due to rapidly rising demands for AI-based services from new data centers
popping up across the country. New energy plants, transmission lines, and faltering
coal plants are all leading to increased utility bills for ratepayers. In addition,
the AI boom is creating a second, less well-known crisis: The
data centers' thirst for cooling water strains the water supplies and water-related
infrastructures in many areas. It turns out that data centers' steadily growing
appetite for energy and water..."
 As radio frequencies moved up into the UHF
realm of 30 MHz (through 3 GHz), designers noticed that the old methods
and equations for winding inductors (aka coils and chokes) no longer performed as
predicted. The culprit was
stray capacitance created by the wire itself and the insulation
between windings. To some extent, the length of leads running from the inductor
windings to connection points (terminal strips and lugs at first and then later
printed circuit boards) generated enough extra inductance to add noticeably to total
inductance. New methods were developed to help mitigate the effects of these stray
(aka parasitic) reactances. Much new knowledge in this area was gained through the
war efforts with many radar...
 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...
 KR Electronics has been designing and manufacturing custom filters
for military and commercial radio, radar, medical, and communications since 1973.
KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop,
equalizer, duplexer, diplexer, and individually synthesized filters for special
applications - both commercial and military. State-of-the-art computer synthesis,
analysis, and test methods are used to meet the most challenging specifications.
All common connector types and package form factors are available. Update: KR Electronics
has been acquired by NIC, where KR Electronics'
legacy of quality and innovation will continue to thrive, offering the same trusted
products and services under NIC's leadership. For over three decades, NIC has delivered
high-quality component performance and reliability, ensuring the successful deployment
and operation of our clients' mission-critical solutions. Designed and manufactured
in the USA. Please visit NIC today to see how
we might be of assistance.
Tuesday the 6th
 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...
Monday the 5th
 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...
Friday the 2nd
 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...
|
 Here are three
electronics-themed comics from vintage issues of Electronics World
and Popular Electronics magazines. My favorite is the page 84 comic where
the sign on the Telco Rectifier Components president's wall is apropos. Maybe one
of the interview questions for job applicants was #1: "Did you notice the sign on
the wall in the waiting room," and #2: "Did you 'get it?,' and please explain."
In 1956 when that comic appeared, AC-to-DC power supplies used high voltage vacuum
tubes, typically 300 volts or more. Hefty capacitors were needed to remove
enough ripple from the "top" of the DC to render it undetectable in the circuit
output - especially if the output was audio where a 60 or 120 Hz (50 or 100 Hz
in Europe) "hum"...
 LadyBug Technologies was founded in 2004
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 It seemed weird to read of
microelectronics device density expressed in parts per cubic foot
of semiconductor substrate. Describing density that way makes some sense when considering
3-dimensional devices with vertically stacked elements, but this was in a 1963 article
in Electronics World, so that could not have been the case. The motivation, evidently
was to be able to compare microcircuit density with that of the human brain in terms
of neuron density. In fact, there is an interesting chart presented that shows the
evolution in circuit density beginning with vacuum tube circuits, progressing through
the state of the art in 1963, projecting for future years, and finally peaking with
the brain's density. Interestingly, the brain density shows as about 5x1011/ft3,
while the "nonredundant semiconductor device" limit is...
 In the late 1960s, there was evidently a
brewing consumer revolt against
shoddy merchandise, worthless warranties, and sloppy service. Mac attributed
this to a post-WWII seller's market fueled by wartime shortages, black markets,
and inflation. Many workers had pent-up money to spend on products not readily available
during the war. Ensuing conflict eras like Korea and Vietnam prioritized volume
production and advertising over quality. Demand escalated prices. Customers, once
kings in a competitive free-enterprise system, became expendable amid abundant demand.
By 1969, when this story appeared in Electronics World magazine...
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2015 July - 2
 "Future lunar missions face a fundamental
challenge: the high cost and difficult transport of materials from Earth. Now, a
new project supported by the European Space Agency (ESA) will demonstrate how lunar
soil -- after releasing its oxygen for rocket propulsion and potentially air for
astronauts -- can also be converted into metal-rich compounds which can conduct
electricity. This compound can either be transformed to inks for
printing electronic circuits or powder for 3D printing of larger components.
Danish Technological Institute..."
 "Isolation dictates where we go to see into
the far reaches of the universe. The Atacama Desert of Chile, the summit of Mauna
Kea in Hawaii, the vast expanse of the Australian Outback -- these are where astronomers
and engineers have built the great observatories and radio telescopes of modern
times. The skies are usually clear, the air is arid, and the electronic din of civilization
is far away. It was to one of these places, in the high desert of New Mexico, that
a young astronomer named Jack Burns went to study radio jets and quasars far beyond
the Milky Way. Could there be a better, even lonelier place to put a
radio telescope? Sure,
a NASA planetary scientist named Wendell Mendell, told Burns: How about the moon..."
 "An international team of astronomers has
developed a new way to extract
solar polar magnetic information from more than a century of historical observations,
improving prospects for predicting future solar cycle activity. The work combines
data from the Kodaikanal Solar Observatory in India with modern measurements to
reconstruct the behavior of the Sun's polar magnetic field over more than 100 years.
Researchers from Southwest Research Institute, the Aryabhatta Research Institute
of Observational Sciences and the Max Planck Institute used archival Calcium K (Ca
II K) images..."
 "A UCLA-led, multi-institution research
team has discovered a metallic material with the
highest thermal conductivity measured among metals, challenging long-standing
assumptions about the limits of heat transport in metallic materials. Published
in Science, the study was led by Yongjie Hu, a professor of mechanical
and aerospace engineering at the UCLA Samueli School of Engineering. The team reported
that metallic theta-phase tantalum nitride conducts heat nearly three times more
efficiently than copper or silver, the best conventional heat-conducting metals..."
 "A new type of circuit board which is almost
entirely biodegradable could help reduce the environmental harms of electronic waste,
its inventors say. Researchers from the University of Glasgow have developed a new
method of printing
zinc-based electronic circuits on environmentally friendly surfaces including
paper and bioplastics. Once the circuits are no longer needed, 99% of their materials
can be disposed of safely through ordinary soil composting or by dissolving in widely
available chemicals like vinegar..."
 "A research team affiliated with UNIST has
introduced a novel, high-performance, and thermally stable polymer-based non-volatile
analog switch. This next-generation device is as
thin and flexible as vinyl, yet capable of withstanding high temperatures. Professor
Myungsoo Kim and his team from the Department of Electrical Engineering at UNIST,
in collaboration with Professor Minju Kim from Dankook University, have developed
this robust, flexible radio-frequency (RF) switch. Such technology could enable
reliable 5G and 6G wireless communication in demanding environments -- such as wearable
devices and the Internet of Things (IoT)..."
 "Apple has published a patent application
describing a method to detect user gestures on wireless earbuds by measuring changes
in RF antenna impedance, potentially reducing the need for dedicated touch-sensing
hardware. The filing, titled 'Gesture
Detection Based on Antenna Impedance Measurements,' published on January 8,
2026 as US 20260010234, describes using antennas already present for wireless communication
as dual-purpose components that can also detect user input..."
 "A new metasurface lets scientists flip
between ultra-stable light vortices, paving the way for tougher, smarter wireless
communication. Scientists have developed a new optical device capable of producing
two different types of vortex-shaped light patterns: electric and magnetic. These
unusual light structures, called
skyrmions, are known for their exceptional stability and resistance to interference.
Because they hold their shape so reliably, they are strong candidates for carrying
information in future wireless communication systems. 'Our device not only generates
more than one vortex pattern in free-space-propagating..."
 "Scientists have shown that
twisting a crystal at the nanoscale can turn it into a tiny, reversible diode,
hinting at a new era of shape-engineered electronics. Researchers at the RIKEN Center
for Emergent Matter Science, working with collaborators, have created a new technique
for building three-dimensional nanoscale devices directly from single crystals.
The approach uses a focused ion beam instrument to precisely carve materials at
extremely small scales. Using this method, the team shaped tiny helical structures
from a topological magnetic material made of cobalt, tin, and sulfur, known by its
chemical formula Co3Sn2S2..."
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