|
 Transcat | Axiom Test Equipment, an electronic
test equipment rental and sales company has published a new blog post entitled "The
Role of Temperature Calibration in Protecting Food Safety" that covers how temperature
calibration tools such as dry blocks and calibration baths are precise, accurate
tools for measuring temperatures during food production cycles. Complying with food
temperature safety regulations helps deliver safe foods with long shelf lives, while
noncompliance can result in health issues with serious legal consequences. Dry blocks
and temperature calibration baths are both capable of measuring wide temperature
ranges with high resolution and accuracy although they work in much diverse ways.
A temperature dry block heats or cools a metal block to a precise temperature...
 My long-established collection of soldering
aid and tuning wand tools still gets a fairly regular workout - but not necessarily
for soldering tasks. Most are non-metallic, meant for bending and poking, and are
very strong and heat resistant. The metal types are still required for direct contact
with molten solder. One of the best tips offered in this 1959 Electronics World
magazine article is for when
replacing a leaded component on a PCB. If possible, rather than heating the
landing pad and plated through-via to remove the leads, just clip the leads far
enough from the PCB surface to create a post or loop to solder the new component
to. Doing so creates a mechanically sound solder joint without undue risk of damage
to the PCB metal or laminations. Interestingly, the PCB in this article contains
a vacuum tube plug-in socket...
 "Multichannel light highways for communications
are still far from realization. But with continuous sources of coherent light available,
it becomes possible to explore the problems of modulating, transmitting, detecting,
amplifying and, in general, controlling light for possible communications applications."
That claim was made in a 1962
Bell Telephone Laboratories (Bell Labs) info ad in Radio-Electronics
magazine. More than six decades later, the job is being handled by microcircuits
with integrated laser transmitters and receivers. High quality optical fiber provides
information transport across the neighborhood, city, state, country and world. A
big list of other Bell Labs innovations is at the page bottom. Created a century
ago in 1925, Bell Telephone Laboratories' name has been Nokia Bell Labs...
 Wilhelm Conrad Röntgen, a luminary in the
field of physics, was born on March 27, 1845, in Lennep, a small town in the Rhine
Province of Prussia, now part of Germany. His father, Friedrich Conrad Röntgen,
was a cloth manufacturer, while his mother, Charlotte Constanze Frowein, hailed
from an affluent and distinguished family of Dutch descent. Wilhelm spent his early
childhood in Lennep before the family moved to Apeldoorn, the Netherlands, when
he was three years old. His education began at the Institute of Martinus Herman
van Doorn, a technical school in Utrecht. However, Wilhelm was expelled at the age
of 18 after being falsely accused of sketching a caricature of one of his teachers,
an injustice that deeply affected his academic trajectory. Röntgen's early academic
path was unconventional...
 Shortly before Christmas, 1947, the experimental
work of Bell Laboratories scientists John Bardeen, Walter Brattain, and William
Shockley resulted in the world's first
semiconductor transistor. With proper biasing, the germanium transistor demonstrated
an ability to produce signal gain. The signal fed to the base resulted in a higher
amplitude signal at the collector. Voila, the device which would ultimately replace
the vacuum electron tube had been invented. The rest, as they say, is history. Aside
from a few high power applications, the only new equipment produced that uses vacuum
tubes are retro things like audio amplifiers and simple receivers. Of course, there
is still a large cadre of vacuum tube users in the Amateur Radio real and vintage
equipment restorers...
 In Compliance magazine has an article entitled,
"The
Growing Use of Generative AI Will Generate More E-Waste." I queried ChatGPT
about whether the claim is true. Summarizing its reply, ChatGPT admits is is a polluter.
To wit: "Yes, the growing use of generative AI has the potential to contribute
to an increase in electronic waste (e-waste). This stems from multiple factors related
to the infrastructure and hardware required to support AI development and deployment.
Here's how generative AI contributes to the problem and the broader implications: •
Hardware Demand • Shorter Hardware Lifespan • Increased Energy Consumption • Consumer
Devices • Recycling Challenges. To mitigate the e-waste impact of generative AI
include designing hardware with a longer lifecycle, improving recycling technologies,
adopting modular designs for easier upgrades, and using energy-efficient models
that reduce the need for frequent hardware replacements. Additionally, promoting
circular economy practices and enforcing e-waste regulations can help address the
issue. Generative AI offers immense potential but addressing its environmental footprint,
including e-waste, is essential for sustainable development."
• U.S. Pressures
Japan for Selling Chip Kit to China
• Record
September IC Exports for Korea
• FCC Issues Notices to
Pirate Radio in NYC, Miami
• TSMC
Posts Sharp Rise in Q3 Net Profit
• Nearly
40% of SMBs using AI
 FM radio noise immunity testing. 1940 was
a big year in the commercial broadcast industry because it was when the FCC began
licensing stations for FM operation. Amazingly, that was only four years after Edwin
Armstrong first came up with his frequency modulation scheme - fast moving for the
government. Simultaneously, equipment manufacturers were cranking out transmitters,
receivers, antennas (new frequencies), writing installation and operation guidelines,
training servicemen, and doing scores of other vitally important tasks. The advent
of FM was considered a very significant technical improvement because of immunity
to electrical noise interference. If for no other reason, you should look at this
National Radio News magazine article...
 During the early era of color television,
much editorial ink was spilled on the topic of
x-radiation emitted from the high voltage power supplies within. This 1967
Radio-Electronics magazine article appeared toward the end of the problem.
Those of us who were around for the excitement remember being told as children "Don't
sit so close to the TV; it'll ruin your eyes." The ignorant among us thought the
admonition was because focusing so close-up would be bad training for eye muscles.
The real reason was danger of absorbing too much ionizing x-radiation from the high
voltage vacuum tubes. Achieving bright, vibrant color with early tri-color cathode
ray tubes (CRTs) required blasting the red, green, and blue phosphorescent dots
on the back of the display...
 "A research team headed by Prof. Karl Leo
at TUD Dresden University of Technology have developed an innovative, nature-inspired
solution that could revolutionize the electronics industry:
Leaftronics." This innovative approach leverages the natural structure of leaves
to create biodegradable electronic substrates with enhanced properties and offers
a sustainable, efficient, and scalable solution to the global-waste problem. These
findings have now been published in the journal Science Advances. Electronic devices,
from toys to smartphones, consist of circuits. Specific substrates are used to manufacture
these circuits..."
 San Francisco Circuits, a premier provider
of leading edge technology printed circuit boards, has published a new article on
ENEPIG (Electroless Nickel Electroless Palladium Immersion Gold) PCB Surface
Finish. ENEPIG is one of the most popular PCB surface finishes due to reduced palladium
prices and its advantages over finishes like ENIG. Composed of four metal layers
- copper, nickel, palladium, and gold - ENEPIG offers excellent protection against
corrosion and the infamous "black pad" issue. ENEPIG: Ideal for Demanding Requirements
ENEPIG supports various package types, including BGA, SMT, wire bonding, and press
fit. With a thin gold layer (0.05μm - 0.1μm), it simplifies assembly and provides
improved reliability...
 On a whim, I did a search for the earliest
appearance of Nikola Tesla's name in U.S. newspapers included in the NewspaperArchive.com
database. This story from Mr. George Grantham Bain appeared in multiple newspapers
within a few days of this March 5, 1896 edition of The Warren Times in Warren, PA,
which coincidentally is not far from me here in Erie. The article reports on the
role that Tesla's high voltage generators played in the development of x-ray images
on fluorescent displays and on film (which Tesla termed "cathode photography").
It mentions how the term "cathode" is relatively new to the general public even
though it had been around since 1832 when Michael Faraday introduced it in his work.
Wilhelm Röntgen made the world's first x-ray image - of his wife's hand...
 Michael Faraday, one of the most revered
experimental scientists in history, was born on September 22, 1791, in Newington
Butts, a small village near London. His humble beginnings were in stark contrast
to his towering achievements. Faraday's father, James, was a blacksmith of modest
means, and his mother, Margaret Hastwell, managed the household despite financial
difficulties. The family belonged to a small Christian sect known as the Sandemanians,
whose values of humility, simplicity, and a focus on practical service profoundly
influenced Faraday throughout his life. Faraday's early education was rudimentary,
consisting mostly of reading, writing, and arithmetic. At the age of 14, he was
apprenticed to a London bookbinder named George Riebau. This apprenticeship proved
transformative, as it allowed young Faraday...
 A neighbor approached me the other day regarding
a strange occurrence with the electrical supply to his workshop, which is not attached
to the house. The overhead lights were dim, and his small refrigerator was straining.
Turning on or off various tools and lights caused changes in everything else. This
guy is one smart cookie (and an excellent woodworker), and has handled all his own
household electrical and plumbing issues for many decades, but he had never experienced
such a situation. Fortunately, I have. Upon hearing his description, I immediately
recognized it as a case of an
open neutral in the circuit breaker panel. I have seen that before. Understanding
what is happening can be made simple by realizing that once the neutral reference
is gone, the two "legs" (phases) are in series with each other rather than in parallel...
A neighbor approached me the other day regarding
a strange occurrence with the electrical supply to his workshop, which is not attached
to the house. The overhead lights were dim, and his small refrigerator was straining.
Turning on or off various tools and lights caused changes in everything else. This
guy is one smart cookie (and an excellent woodworker), and has handled all his own
household electrical and plumbing issues for many decades, but he had never experienced
such a situation. Fortunately, I have. Upon hearing his description, I immediately
recognized it as a case of an
open neutral in the circuit breaker panel. I have seen that before. Understanding
what is happening can be made simple by realizing that once the neutral reference
is gone, the two "legs" (phases) are in series with each other rather than in parallel...
 Three more
electronics-themed comics here, these from a 1962 issue of Radio-Electronics
magazine. They represent a good spectrum of consumer electronics service issues
of the era. The page 41 comic scenario is not likely to occur with a television
today; it's more likely with a Li-Ion powered cellphone sitting in your pocket.
The page 60 comic, on the other hand, is more likely to happen today with all the
anti-theft devices used on in-dash devices like radios, GPS navigation units, and
Ham (Amateur) and CB radios. Even without the anti-theft devices, good luck getting
the dashboard apart enough to service the device. I recently replaced an in-dash
air vent valve motor in my daughter's truck...
 "A team of scientists from the Korea Institute
of Materials Science (KIMS) has developed the world's first ultra-thin film composite
material capable of
absorbing over 99% of electromagnetic waves from various frequency bands, including
5G/6G, WiFi, and autonomous driving radar, using a single material. This novel electromagnetic
wave absorption and shielding material is less than 0.5mm thick and is characterized
by its low reflectance of less than 1% and high absorbance of over 99% across three
different frequency bands..."
 Part 1 of this "All About IC's" series titled,
"What Makes Them Tick," author Bob Hibberd introduced the concept of semiconductor
physics and doped PN junctions. It appeared in a 1969 issue of Radio-Electronics
magazine. In Part 2, he discusses methods used to
fabricate monolithic, integrated circuits (IC's) on silicon chips. Transistors,
diodes, resistor, capacitors, and to some extent, inductors, can be built using
a combination of variously doped junction regions, metallization, and oxidation
(insulators). Technology has come a long way since 1969, including mask techniques,
3-D structures, doping gradients, feature size, dielectric breakdown strength...
 Before the Emergency Alert System (EAS)
was activated on January 1, 1997, which followed the August 5, 1963 activation of
the Emergency Broadcast System (EBS), there was the 1951 implementation of the
CONtrol
of ELectromagnetic RADiation (CONELRAD). Born out of the Cold War era, CONELRAD
was devised in order to not just provide timely forewarning of enemy nuclear and/or
bomber and/or submarine-based attacks, but also to silence all commercial broadcasters
whose transmitting installation could potentially be exploited as homing signals
for the aforementioned bad guys. The Germans had used just such a scheme during
the recently concluded...
 As was customary for U.S. businesses,
Hallicrafters ran a Christmas advertisement in the January issue
of magazines where they appeared. The January edition, as is common even now, is
typically mailed in early December, getting it in the hands of readers in time for
Christmas. This "Here's to a Good Old Fashioned Christmas" (which many state governors
want to end beginning this year) message appeared in the January 1942 issue of
QST magazine. Halli(gan) and (hand)crafters was founded in Chicago in 1932
by William J. Halligan. The company designed and manufactured radio equipment for
hobby, commercial, and military applications and quickly became very popular amongst
their users...
 Guess we'll just need to start mining our
own again, and stop exporting our technology to them: "China announced Tuesday it
is banning exports to the United States of
gallium, germanium, antimony and other key high-tech materials with potential
military applications, as a general principle, lashing back at U.S. limits on semiconductor-related
exports. The Chinese Commerce Ministry announced the move after the Washington expanded
its list of Chinese companies subject to export controls on computer chip-making
equipment, software..."
 For the last two centuries our wars have
been fought to secure freedom from oppressive regimes, either for our own citizens
or for citizens of allied countries requesting our assistance. In the entire history
of the United States, no land has ever been claimed during or after the conclusion
of the conflicts. Although the human cost has been tragic - especially for those
who have lost family members or suffered injuries - one undeniable benefit has been
the advancement of technology. "Necessity," it has been said, "is the mother of
invention." World War II resulted in significant advances in wireless communications,
and the
civilian radio industry was quick to exploit the new devices and methods. Futurists
wasted no time prognosticating about how the postwar technology world would shape
up, and of course radio figured significantly into the vision. This 1945 article
from Radio-Craft magazine is an early example...
 Empower RF Systems is the technological
leader in RF & microwave power amplifier solutions for EW, Radar, Satcom, Threat
Simulation, Communications, and Product Testing. Our air and liquid cooled amplifiers
incorporate the latest semiconductor and power combining technologies and with a
patented architecture we build the most sophisticated and flexible COTS system amplifiers
in the world. Solutions range from tens of watts to hundreds of kilowatts and includes
basic PA modules to scalable rack systems.
 Amongst the noteworthy items announced in
the July 1962 "News
Briefs" column in Radio-Electronics magazine was the impending end
of the DoD's CONELRAD early warning defense system. It was being replaced with the
Emergency Broadcast System in 1963, which was later replaced by the Emergency Alert
System in 1997. Changing names for essentially the same service was - and remains
today - a shining example of government waste. Westinghouse debuted its slow-scan
TV system for transmitting still images via telephone wires - sort of an early Internet
means of downloading pictures that could be stored on magnetic tape...
|
 Installing commercial broadcast radio receivers
in cars and trucks was a big deal in the 1930s - even bigger than having one in
your home. Having an ability to receive the popular shortwave bands was a real sign
of success (as was merely owning a car). An advantage to auto radios was not needing
an AC-to-DC rectification circuit like in-home models that required at least one
additional vacuum tube and a hefty transformer - although many people in non-electrified
rural areas had DC radios in their homes as well (the Rural Electrification Act
wasn't passed until 1936). In its service instructions,
Remler suggested to owners that if poor reception was experienced,
the auto should be parked somewhere that a 50-foot secondary aerial couldn't be
deployed. I could locate any examples of restored...
 Basic
transformer circuits have not changed in the more than sixty years since this
article was published in Popular Electronics magazine. The applications
have definitely changed, though, since active circuits of the day required a
relatively low voltage (step-down) for vacuum tube cathode heaters, and at least
one relatively high voltage (step-up) for biasing the tube plate. Most
transformers for today's consumer applications perform a single step-down
operation for 3.3 V, 5 V, 12 V, etc. In many applications, transformers are done
away with altogether in favor of solid state rectifiers and regulators. A
5-question quiz is provided at the end. There is also a short tutorial on
electrostatic speakers and some analog and digital signal info. Digital circuits
were still a relatively new (and scary) concept to most people at the time...
 One very satisfying aspect of 'rolling your
own'
audio frequency coils (aka chokes, aka inductors), is how well the simple inductance
equations match measured end results. Unless you really manage to mangle the job,
if you use the right equation and are reasonably careful to observe wire size, spacing
(including insulation), and core diameter, you will be amazed at how close practice
matches theory. Although strictly speaking audio frequencies run from a few Hertz
up to maybe 15 kHz for people with really good hearing. My experience is that
similar success can be had even into the low MHz realm with just a little tuning
required. It's not until you get into the realm of self-resonance that everything
starts falling apart with basic equations...
 Hugo Gernsback wrote this editorial about
the state of the art of
radio astronomy in a 1953 issue of his Radio-Electronics magazine.
He cites Dr. Jansky's discovery of radio frequency signals emanating from
the center of our Milky Way galaxy, and the subsequent work done by radio
astronomers in the interim. Little did Gernsback know that a mere decade later
later, Bell Telephone Labs engineers Dr. Wilson and Dr. Penzias would
serendipitously discover, using the company's "sugar-scoop" antenna, the
ubiquitous cosmic microwave background radiation (CMBR) believed to be a
signature of the "Big Bang" era. He predicted that, as is true for most realms
of theoretical research, much collateral technology would be created as a
result. Ultra low noise, cryogenically cooled receivers are an obvious
example...
 Listen to this
on the RF Cafe Podcast. 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 hair
clippers running...
 For two decades, I have been creating custom
engineering- and science-themed crossword puzzles for the brain-exercising benefit
and pleasure of RF Cafe visitors who are fellow cruciverbalists. This November 24,
2019, puzzle has a holiday message for you. A database of thousands of words is
used which I have built up over the years and contains only clues and terms associated
with engineering, science, physical, astronomy, mathematics, chemistry, etc. You
will never find a word taxing your knowledge of a numbnut soap opera star or the
name of some obscure village in the Andes mountains. You might, however, encounter
the name of a movie star like Hedy Lamarr or a geographical location like
Tunguska, Russia, for reasons which, if you don't already know, might surprise
you. The jury is out on whether or not this type of mental challenge...
 For a given semiconductor compound, the maximum
operational speed of a transistor is governed pretty much by its gate thickness.
Capacitance and impurities along with lithography precision and accuracy are the
culprits. Shrinking gate sizes and growing crystals with greater purity has driven
operational speeds upward significantly over the years. An equivalent set of issues
plagued vacuum tube development a century ago. The physical spacing of grid elements
wrt each other as well as to the cathode and plate placed an
upper limit on amplification bandwidth. As always, judicious study of the underlying
causes led to the development of new designs that, along with improved manufacturing
techniques, overcame existing barriers and, also as always, exposed yet a new set
of limiting criteria for conquering...
 Each week, for the sake of all avid cruciverbalists
amongst us, I create a new
technology-themed crossword puzzle using only words from my custom-created
lexicon related to engineering, science, mathematics, chemistry, physics, astronomy,
etc. You will never find among the words names of politicians, mountain ranges,
exotic foods or plants, movie stars, or anything of the sort. You might, however,
see someone or something in the exclusion list who or that is directly related to
this puzzle's theme, such as Hedy...
 Success won in the realm of
space-based communications has been fraught with many failures.
As with most endeavors, it is thanks to the relative few who have sacrificed and
endured against overwhelming odds to bring significant technological advances in
communications to the many. Space presents a particularly difficult venue because
of the harsh deployment and operational environment, and inaccessibility after deployment.
Personal sacrifice has taken the form of depression, financial ruin, lost opportunity
for other endeavors, broken families, sickness, substance abuse, and other maladies
brought on by an obsession with success. Such sacrifice has built the modern world...
 Have you ever used any of these
voltage-variable capacitor (VVC) types: varicaps, epicaps, minicaps,
voltacaps, capistors and varactrons? If you answered "no, but I have used varactor
diodes," then the more correct answer would have "yes, I have, but by a different
name." Construction was similar for all variations. This article from a 1969 issue
of Radio-Electronics magazine reports on some of the earliest forms of
diodes specifically designed to use a reverse bias on the PN junction to control
the effective capacitance of the device for use in frequency tuning circuits. The
first uses were for electronically tuning local oscillators in mixing stages, and
then for making tunable filters. Capacitance ratios greater than 10:1 with some
VVCs allowed tuning over a very wide range. At the time the article was written,
there was not universally agreed upon schematic symbol for the VVC, as illustrated
in Figure 2. Varactor-tuned television channel selectors...
 In my daily routine of perusing the WWW (World
Wide Web - remember that?) for good information to post, I need to copy images into
which thumbnail versions are made. A very recent trend has evolved for the sake
of mobile device displays which appends some sizing directives to the end of the
otherwise normal URL, and that prevents doing a copy and paste with right-click
-> Copy Image, and then paste it into a graphics editor. Instead, do
a right-click -> Copy Image Location
and then paste that URL into your browser. Click the thumbnail image above for an
example. Note the appendage after the ".png" file extension:
?auto=format&fit=crop&h=432&w=76"
That prevents the normal Image Copy from working. Delete everything after .png and
then hit enter. You should now be able to copy and paste the image into your editor.
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils
available for RF, analog, and digital system and schematic drawings! Every stencil
symbol has been built to fit proportionally on the included A-, B-, and C-size drawing
page templates (or use your own page if preferred). Components are provided for
system block diagrams, conceptual drawings, schematics, test equipment, racks, and
more. Page templates are provided with a preset scale (changeable) for a good presentation
that can incorporate all provided symbols...
 Bell Telephone Laboratories used to run some pretty
interesting advertisements in magazines back in the 1940s through 1960s that touted the
many communications innovations coming from their scientists and engineers. They built
what was indisputably the worlds best, most reliable telephone network. It, along with
the Interstate Highway System, is credited for a large part of what fueled America's
growth so significantly after World War II. This ad from a 1949 issue of Radio &
Television News magazine tells how repairmen used a specially designed
sensor to trace out faulty phone lines by listening for a test signal sent out
by the central office. What caught my attention about this ad was the uncanny
resemblance the man in the photo has to Melanie's father - especially with the
ball cap and glasses...
 If you read through this "Dots
and Dashes" column from the July 1934 issue of Radio News, you will
find many familiar topics -- and a couple weird ones. Among the familiar are
transmitting electrical power via RF waves, an electronics industry convention
and exposition being held in Chicago, elevator control with electric sensors to
assure the cars stop at floor level, global communications, the closing of a
historic radio station (how 'historic' can a radio station be in 1934?),
earth-moon-earth (EME) experimentation, and remote control of beacon stations
with radio signals. The weird ones? How about an "electric woman" with glowing
breasts and a "queer-acting" radio microphone, do they qualify?...
 I recently created a new reference page titled
"Resistivity (ρ) & Conductivity
(σ) of Metals, Alloys, Rocks, and Soils." Values for materials are pulled from my
copy of Reference Data for Radio Engineers, Sams Publishing. Resistivity, also
referred to as specific resistance, is dependent on the nature of the material as well
as its volume definition (shape and size). Resistivity is expressed in units that are
the product of resistance and length; e.g., Ω·cm. As an example of calculating a volume's
resistance, consider the drawing to the left. Assume 12 AWG copper wire with a resistivity
of 1.72x10-6 Ω·cm, a cross-sectional area...
 Mac McGregor, owner of
Mac's Radio Service Shop, can always be counted on to provide
his apprentice technician, Barney, with a lesson from his own life-long attendance
at the School of Hard Knocks. Barney is your stereotypical young buck whose level
of seriousness needs occasional alignment, just as do the radio and television sets
he services. In this episode, I can't find where Mac actually solved the intermittent
electrical condition believed to be causing the problem - weird. The "Mac's Radio
Service Shop" series ran in Radio & Television News magazine for many
years prior to a similar electronics story series called "Carl & Jerry" that
appeared in Popular Electronics. Both were created by consummate storyteller
John T. Frye.
 This
Engineering Theme crossword puzzle for August 8th, 2021, contains only words
and clues related to engineering, mathematics, chemistry, physics, and other technical
words. As always, this crossword contains no names of politicians, mountain ranges,
exotic foods or plants, movie stars, or anything of the sort unless it/he/she is
related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini Atoll).
The technically inclined cruciverbalists amongst us will appreciate the effort.
Enjoy!
 If you have not yet discovered the Engineering
and Technology History Wiki (ETHW) website, now would be a good time to surf on
over and take a look at the vast resources there - particularly the "Oral-History"
series of in-person interviews of our field's top scientists and engineers. Among
them are Dr. Harold Beverage, Dr. Ulrich L. Rohde (N1UL), Harold S.
Black, Harold A. Wheeler, Dr. Irwin Jacobs and Dr. Andrew Viterbi,
and of particular significance to me,
Dr. David B. Leeson (W6NL), founder of California Microwave and Ham
radio contesting champion. Many of the oral interviews were conducted in the pre-Internet
era and some of the people are no longer with us. A few days ago, I had the honor
of being contacted Dr. Leeson as part of his search for information he wants
for some work he is doing. His name is familiar to amateur radio contesters who
participate in DX (long distance) events. Most Hams do their part from home-based
"shacks" while others join in during Hamfest gatherings. Some adventuresome and
hardy souls set up temporary (and sometimes fixed) stations in remote locations
around the world in order to provide rare and exotic contact opportunities, where
coveted QSL cards can be collected...
 Establishing a
good ground connection is more important than ever with all the
vulnerable electronics devices connected to house wiring for the Internet of Things
(IoT). The old saying of "Ground is ground the world around" is only true if you
actually have a good path to that ground potential. This article discusses methods
for determining whether or not you have a low resistance ground interface, and how
to establish one if needed. However, that is only the below-grade part of the equation
[ground rod(s) and possibly conduction-enhancing chemicals]. Installing a low resistance
and equally important low inductance path above grade to the below grade component(s)
is essential for maximum protection. Lightning is a transient phenomenon, so the
di/dt part of the v(t) = L * di/dt equation governing voltage across an inductor...
 At the end of the last century (the 20th),
aside from the impending total collapse of the world's electrical infrastructure
due to Y2K computer date issues, technovisionaries (a word I just made up)
predicted the near-term demise of local over-the-air (OTA) broadcasting of both
commercial radio and television. Cable and satellite was going to supplant it
all. For a short while things seemed to be going that way, particularly as both
forms of media (radio and TV) began being available via smartphones. The FCC
(Federal Communications Commission) was so sure OTA television was dead that it
wanted to reallocate unused spectrum (white space) for other uses. It also
mandated a conversion of all TV broadcasting to be done in digital form. The
plan forced either trashing of existing television sets and purchase of new
models or the purchase of analog-to-digital conversion boxes. The compliant
public folded like a cheap suit...
 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... |
