|
 Some things never change - at least at the
fundamentals level.
Electric circuits is one of those things. I don't remember when I first became
interested in electrical apperati, but it must have been due to a natural affinity
to the science because nobody in my family or my circle of friends expressed any
interest. I was the odd man (or boy) out on my street, because while all the other
kids were playing baseball, basketball, and football, I was sticking forks in electric
sockets and disassembling flashlights, battery-powered toys, and building Erector
Set contraptions using the included electric motor. That's not to say I ever got
really good at it, but significantly better than I ever got at playing sports...
 You would be forgiven in this era of ubiquitous
cellphone usage for thinking maybe
Citizen Band (CB) radios are only used these days by techno-throwbacks
like myself, but the fact is many truckers still use them for convenience as well
as to avoid having all their communications intercepted, monitored, and recorded
by government agencies. It can be a deceiving sense of privacy though, because police
officers often monitor CB radio transmissions while in patrol cars, and even solicit
the assistance of other CBers in identifying and apprehending suspected transgressors
- an advantage of public, unencrypted conversation afforded law enforcement which
is not available with cellphones. Also, CB transmission, even though usually regarded
as "hearsay" in legal venues, has many times been admitted as evidence in cases
where "present sense impression," "excited utterance," or some other special...
 I have experienced the problem with low
precision AI calculations; however, it will use high precision if specifically instructed
to do so. "AI has driven an explosion of
new number
formats - the ways in which numbers are represented digitally. Engineers are
looking at every possible way to save computation time and energy, including shortening
the number of bits used to represent data. But what works for AI doesn't necessarily
work for scientific computing, be it for computational physics, biology, fluid dynamics,
or engineering simulations. IEEE Spectrum spoke with Laslo Hunhold..."
 This week's
Science & Engineering Crossword Puzzle, as is the case with all RF Cafe
crossword puzzles, has only words and clues related to science and engineering.
Each week for two decades I have created a new technology-themed crossword puzzle
using only words (1,000s of them) 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, find someone or something in the otherwise
excluded list directly related to this puzzle's technology theme, such as Hedy Lamarr
or the Bikini Atoll, respectively. Avid cruciverbalists amongst us: the gauntlet
has been thrown down.
 "And there is nothing new under the sun."
- Ecclesiastes 1:9, NKJV (did you know that is the origin
of the saying?). This 1930 editorial by Radio-Craft editor Hugo
Gernsback describes a coordinated scam perpetrated by
radio manufacturers to compel consumers to buy new sets rather
than have their existing sets repaired. In short, retail prices were inflated to
accommodate a built-in 'trade-in' allowance that far exceeded the repair cost or
used radio cost. Radio service shops were getting the short shrift because many
people who might have otherwise elected to have repairs made would instead trade
in the old set for a new one...
 It really wasn't all that long ago when
most people worked on computers with Color Graphics Adapter (CGA) that had just
16 colors (4-bit pixels). In the late 1980s (wow, maybe it really was a long time
ago), the luxury of a 256-color (8-bit pixels) Video Graphics Adapter (VGA) monitor
and video card would cost you around $300 each. I recall seeing ads for "16 million
color" displays by ViewSonic that ran north of a kilobuck. My first "real" monitor
was bought in 1987 and was 4-bit monochrome.
Televisions, as you know, began as black and white (actually a
infinite number of gray levels between black and white). When TVs first arrived
in people's homes, they were glad for any kind of display, but it wasn't long before
marketing gurus convinced the masses that...
![To Be, Or Not to Be [a Metal] - Do Astrophysicists Know the Difference?: Kirt's Cogitations™ #374 - RF Cafe](miscellany/homepage-archive/2026/images/big-bang-universe-creation-kirt-blattenberger-hp.gif) As a multi-decade-long amateur astronomer,
I have read countless articles written by
astronomers who refer to all elements heavier than helium (#2 on the periodic
table of the elements) as "metals." Ostensibly, the origin stems from early detection
of heavy elements in stars, based on heliographic spectrum investigations, where
iron - being the most abundant stable byproduct of supernova explosions - was most
readily observed. I wondered if the "metals" nomenclature came from the next heaviest
element, lithium (#3 in the periodic table), being a metal, thereby laying the foundation.
Not so, claims AI, since lithium is very rare overall in the universe, and not readily
observed. For clarity, I also procured the scientific distinction...
 I usually learn something new with each
episode of Mac's Radio Service Shop, but not necessarily related to electronics.
Such is the case this time where after Mac gives Barney a quick lesson in how to
determine a transformer's winding turns ratio when needing to create an impedance
match circuit. He then, while discussing whether "free" repair estimates are truly
free or of any real value at all, he uses the phrase "a horse on you." Maybe it is because I don't frequent bars that
I had never heard that, but after a little research I now know it refers to a bar
dice game called "'Horse." "A horse on you" is when you lose the final round of
a 2-out-of-3 challenge. "A horse apiece" is when you and your opponent each win
one round in a 2-out-of-3...
 "Data centers for AI are turning the world
of power generation on its head. There isn't enough power capacity on the grid to
even come close to how much energy is needed for the number being built. And traditional
transmission and distribution networks aren't efficient enough to take full advantage
of all the power available. According to the U.S. Energy Information Administration,
annual transmission and distribution losses average about 5%. The rate is much higher
in some other parts of the world. Hence, hyperscalers such as Amazon Web Services,
Google Cloud and Microsoft Azure are investigating every avenue to gain more power
and raise efficiency. The potential virtues of
high-temperature
superconductors..."
 Consumer grade
thermoelectric coolers have been around for so long now that most
people probably assume there is nothing wondrous about the discovery that makes
them possible. I still marvel at the process that allows the application of a current
through physical junction of two dissimilar metals (certain
types) to produce a cooling effect rather than the I2R heating normally associated
with conductors. This article from a scientist at Westinghouse Electric's research
laboratories provides a nice introduction to the subject of thermoelectricity from
both electric current generation based on the application of heat to a dissimilar
metals junction, and the aforementioned cooling effect possible from passing a current...
 FM radio has been in the news fairly frequently
in the last couple years as phone manufacturers and the
National Association of Broadcasters lobby the FCC and politicians
to mandate the inclusion of FM radio capability into every phone manufactured. In
a ploy to exploit the gullibility and egos of said bureaucrats and pols, their primary
argument that FM radio is a "first informer in times of crisis," assuming of course
that people will miss news of "the big one" when and if it occurs. To my knowledge,
successful reception of FM radio on a cellphone requires the listener wear a set
of wired ear buds since the wire from the phone to the ear buds functions as the
antenna. What percentage of cellphone users would bother to carry a set of ear buds?
I, of course, am a huge proponent of...
 Arthur Brach created many
crossword puzzles for Popular Electronics magazine in the 1950s and
1960s. Unlike the hundreds of RF Cafe Crossword Puzzles I designed over more than
two decades, the PE puzzles usually have a few words that are not specifically related
to electronics and/or technology. Still, they are a good source of a brief break
from the day's business. You will need to print out this crossword puzzle to work
it, since it is not interactive. Have fun.
 "Fair
Trade" was a policy established in the post-WWII era in response to what consumer
retail groups considered business-ruining cost cutting by dealers who offered to
sell products at or barely above cost in order to steal profit from other stores.
So-scheming stores planned to make up for the low profit margin with high sales
volumes. Doing so drove a lot of the local competition out of business, leaving
the crafty dirty dealers to later raise prices. Stores that had manufacturer-sanctioned
service shops often got screwed because they were obligated to repair items like
TVs and radios that were bought from another dealer who did not do service work.
Profit margins on repair work - at least from honest shops - were typically very
low, so the owners depended on new product sales...
 Yowza, yowza, yowza
(The Jazz Singer),
QentComm's stock will be rising soon! "Quantum technology is already alive and
well in telecom networks, and although security is the top-of-mind use case, telcos
are also looking at quantum to make networks more resilient and transmit information
more quickly. Comcast announced this week it completed a trial with AMD and Classiq
that leveraged quantum software to find independent backup paths for network sites.
Elsewhere, Deutsche Telekom and Qunnect successfully demonstrated
quantum teleportation over an existing fiber network in Berlin..."
 The persona of Scott Adams' "Dilbert" is
described exactly in the opening sentence of this article in a 1930 edition of
Radio-Craft magazine. It is amazing - if not frustrating - to realize how
long the perception of science-minded people being introverts has been around. Dilbert's
"pointy-haired-boss" is nailed in the second sentence.
Georg von Arco is celebrated here as a major contributor to the
advancement of early radio, particularly wireless telegraphy equipment development.
Interestingly, as brought to my attention by Melanie as she did the text clean-up
after OCRing the magazine page, von Arco worked at the Sayville radio transmission
station on Long Island, New York, where the Telefunken Company's Dr. K.G. Frank
was arrested and interred for the duration of the World War I for sending out
"unneutral messages...
 Lots of Hams still use this tried-and-true
system for
tuning antennas for efficient operation on a variety of bands.
There are plenty of multi-band designs that rely on traps to reactively isolate
portions of the antenna that properly resonate at the desired frequency, but there
is usually a price to be paid in VSWR. Poor VSWR; i.e., higher mismatch loss, can
be overcome with higher transmitter output power, but the real sacrifice for poor
matching is loss of receiving range. The utter simplicity of using an insulated
cord to vary the physical length of the antenna element(s) for tuning is hard to
beat. It could be impractical on a setup where access to the antenna mount is difficult,
but my guess is most people can make good use of it...
 In this 1958 Popular Science magazine
article titled "Russian
Proposes Global TV," Soviet engineer V. Petrov proposed a global TV relay using
three geosynchronous satellites at 35,800 km altitude, launched 120° apart from
the equator at ~6,000 mph to match Earth's 24-hour rotation. Fixed over sites like
the USSR, China, and USA, they would relay signals - uplink on meter waves, downlink
on microwaves - via inter-satellite links, enabling worldwide broadcasts beyond
line-of-sight limits with directional antennas mitigating solar interference. Each
would require 10-kW antenna power, potentially reduced via pulsed transmission (note
digital waveforms in the drawing). This closely mirrored Arthur C. Clarke's 1945
Wireless World article "Extra-Terrestrial Relays," which...
 Frequency crowding has evidently been an
issue since the early days of radio according to this 1930 article in Radio-Craft
magazine. The situation was really bad in the earliest times when unfiltered spark
type transmitters were the norm. Those pioneers could be credited, I suppose, with
being the first users of wideband communications, but it was not because they chose
to do so. Here author Clyde Fitch discusses the debate over whether there really
were such things as sidebands from modulation and makes an argument for their existence
based on analysis of various types of modulation. In particular, he predicts the
coming popularity of single sideband receivers with crystal-filtered channels, and
the need for matching SSB transmitters with... wait for it... carrier and sideband
suppression...
 "A new transceiver developed by electrical
engineers at the University of California, Irvine boosts radio frequencies into
140-gigahertz territory, unlocking data speeds that rival those of physical
fiber-optic cables and laying the groundwork for a transition to 6G and FutureG
data transmission protocols. To create the transceiver, researchers in UC Irvine's
Samueli School of Engineering devised a unique architecture that blends digital
and analog processing. The result is a silicon chip system, comprising both a transmitter
and a receiver, that's capable of processing digital signals significantly faster..."
 Somehow, after being in the RF business
for four decades, I have to admit to not being familiar with the term
"acceptance angle" for antennas. That is after having read scores
of articles on antennas. Maybe I did and just don't remember - embarrassing. Acceptance
angle is mentioned and explained in this article during the description of rhombic
antenna characteristics versus dipoles and multi-element designs. Although the author
focuses on television installations, information provided on signal reflections,
shadowing, ghosting, multipath, etc., is applicable to radio as well...
 Electrolytic capacitors have long been the
components that provide the highest capacitance density factor, that is, they have
the highest capacitance value for a given volume of space occupied. Anyone familiar
with electrolytic capacitors is aware of the polarization indicated on the package
(a marking or unique physical feature), indicating that there is required direction
for hookup; in fact, a backwards connection can lead to an explosive failure. While
physical construction of electrolytic capacitors have evolved over the decades since
this article was published, the fundamental operation has not. It is interesting
to note the reference to capacitors as "condensers," a name still commonly used
with internal combustion engine ignition systems and with some AC motors that use
them at turn-on for providing a starting coil phase shift...
 This 1959 Popular Science magazine
reprint of a 1925 Radio News magazine article focused is on visionary physicist
Robert H. Goddard's proposed Moon Rocket as a means to test
whether radio waves can traverse interstellar space, potentially enabling communication
with other planets. Amid recent radio achievements, including mysterious signals
during Mars' approach and solar disturbances recorded on Earth, the piece challenges
Oliver Heaviside's theory that radio waves are confined by Earth's atmosphere. Goddard's
innovative rocket, propelled by successive explosive charges to escape gravity and
reach the Moon, would carry a compact radio transmitter in its nose cone, broadcasting
signals throughout its flight. Astronomers would track...
 This week's
crossword puzzle, as with all RF Cafe puzzles, uses only words
pertaining to engineering, science, mathematics, mechanics, chemistry, astronomy,
etc. You will never find a reference to some obscure geological feature or city,
or be asked to recall the name of some numbnut movie star or fashion designer. You
will, however, need to know the name of a famous RF filter design software author.
Enjoy...
 "Broadband achromatic wavefront control
plays a central role in next-generation photonic technologies, including full-color
imaging and multi-spectral sensing. A research team led by Professor Yijun Feng
and Professor Ke Chen at Nanjing University has now reported a significant advance
in this field in PhotoniX. The researchers introduced a hybrid-phase cooperative
dispersion-engineering approach that combines Aharonov-Anandan (AA) and Pancharatnam–Berry
(PB) geometric phases within a single-layer metasurface. This strategy enables
independent achromatic control of wavefronts for two different light spin states..."
 As with the article in this month's issue
of Radio-Craft magazine (December 1937), the reference to a 200th anniversary
is understated by 88 years for 2025.
Luigi Galvani was sort of the Benjamin Franklin of biology in
that just as Franklin demonstrated that lightning was a form of electricity, Galvani
showed that signals sent from the brains to the appendages of animals were electrical
in nature. In my high school days in the 1970s, we duplicated his experiment by
making deceased frogs' legs twitch when motivated by a D cell. Today, such an exercise
would likely be met with demonstrations by animal rights people (whose lives, BTW,
have probably in some way been improved as a result of previous such experiments).
But, I digress. Mr. Galvani's name is...
 Superheterodyne receivers were originally
the sole domain of the Radio Corporation of America (RCA), which owned the patents
and refused to license them until around 1930. Hugo Gernsback, a contemporary editor
of the era, provides a little insight into the superregenerative receiver circuits
superheterodyne was about to replace, and why it was an important improvement in
technology. Sidebar: The question often
arises regarding the difference between a "heterodyne" circuit and a "superheterodyne"
circuit. The most popular answer that "super" refers to the IF being located above
the range of human hearing, which peaks at about 15 kHz. Doing so assured that
any IF leakage into the audio circuits would not be discernable by a radio...
|
 • FDA Clarifies
Wearable Device Rules
• Revisiting the
1996 Telecommunications Act
• China's
BeiDou Satellite (their GPS) Does Emergency Messaging
• How & When Will
Memory Chip Shortage End?
• At Age 25, Wikipedia
Refuses to Evolve
• Amazon Leo Asks FCC for
Satellite Launch Extension
 The
RF Cafe Homepage Archive
is a comprehensive collection of every item appearing daily on this website since
2008 - and many from earlier years. Many thousands of pages of unique content have
been added since then.
 Listen to the
RF Cafe Podcast. At the time this Mac's Service Shop episode appeared in
a 1957 issue of Radio & TV News magazine, electronics technicians were
beginning to see a lot of
transistorized radios, televisions, record players, and tape recorders showing
up in place of the very familiar vacuum tube models. It was a whole new ballgame.
To complicate matters, biasing, interstage coupling, and tuning circuits were in
many ways different requiring re-learning what a "typical" circuit looked like,
and the introduction of printed circuit boards in place of point-to-point wiring
made changing components more difficult. Delaminating metal traces was easy to do
on early PCBs when using the big, high thermal inertia soldering irons required
for larger and more heat-tolerant components. Author John T. Frye used these
Mac's Service Shop stories...
 The newest release of RF Cafe's spreadsheet
(Excel) based engineering and science calculator is now available -
Espresso Engineering Workbook™. Among other additions, it now has a Butterworth
Bandpass Calculator, and a Highpass Filter Calculator that does not just gain, but
also phase and group delay! Since 2002,
the original Calculator Workbook has been available as a free download.
Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is
also provided at no cost,
compliments of my generous sponsors. The original calculators are included, but
with a vastly expanded and improved user interface. Error-trapped user input cells
help prevent entry of invalid values. An extensive use of Visual Basic for Applications
(VBA) functions now do most of the heavy lifting with calculations, and facilitates
a wide user-selectable choice of units for voltage, frequency, speed, temperature,
power, wavelength, weight, etc. In fact, a full page of units conversion calculators
is included. A particularly handy feature is the ability to specify the the number
of significant digits to display. Drop-down menus are provided for convenience...
 John T. Frye was an electronics service
technician long before he began writing techno-dramas like "Mac's Radio Service
Shop" and "Carl & Jerry." His expertise and real-world experience evidenced
itself in the wide variety of situations and subjects covered in the stories. If
you have never read any of them, I whole-heartedly suggest that you sample a few
(or listen to one of my podcast readings of them). In this article from a 1949 issue
of Radio-Electronics magazine, Mr. Frye discusses what was evidently
a reluctance on the part of service men to acquire and/or use
printed service data when troubleshooting and/or aligning radios, televisions,
tape recorders, etc. The attitude of some elitists was that if you needed to consult
documentation that it was evidence of your ineptness; you were not a worthy electronics
technician. More than one episode of "Mac's Radio Service Shop" had owner Mac McGregor
admonishing young Barney about wasting time during troubleshooting by not consulting
the service data sheets he stocks in the shop. Even if a shop owner could not afford
the elite service literature from SAMS Photofacts...
 Joseph Ryerson (see 1976 award), of the Griffiss
AFB Air Development Laboratory was thinking in 1958 when this Radio-Electronics
article appeared about a method for exploiting
gravitational waves for communication purposes long before they were finally
detected for the first time in 2015. Even today, however, we are nowhere near being
able to control gravity waves. In fact, an Earth-based system is unlikely to ever
be developed due to the extraordinarily long wavelength of various kinds of gravity
waves with periods measured in minutes, hours, days, hours, weeks, and longer. Space-based
sun-orbiting interferometer satellite pairs (LISA) are in the planning stage to
more accurately measure gravity wave. I wonder if Mr. Ryerson was/is around
to witness the gravitational wave detection? Another major topic was the DIANA Moon
Radar project where the Army Signal Corps offered to send QSL cards...
 Proving once again what a visionary Hugo
Gernsback was regarding science and engineering, he published in his Radio-Craft
magazine this prognostication for the eventual supplanting of point-to-point wiring
with
printed circuit boards. Admittedly, by 1948 the electronics
industry had begun to outgrow hand-wired chassis assemblies with a rats nest of
wires, components, and terminal strips. It was in dire need of a new paradigm
that reduced labor costs and reduced the opportunity for wiring errors. Less
than a year earlier (December 1947) the trio of engineers at Bell Labs announced
their transistor invention, so Mr. Gernsback knew the world was about to change
significantly. Bulky transformers, vacuum tubes, and high voltage circuits would
soon be relegated - at least in the consumer product realm - to the newfangled
television products, so miniaturization would follow quickly. Even the smaller
fingers of women on the assembly lines...
 This
RF Cafe Engineering & Science Crossword Puzzle contains at
least 10 words from headlines posted on the homepage during the week of July 29
- August 2, 2019 (marked with an asterisk*). These custom-made engineering and science-themed
crossword puzzles are done weekly for the brain-exercising benefit and pleasure
of RF Cafe visitors who are fellow cruciverbalists. Every word and clue - without
exception - in these RF Cafe puzzles has been personally entered into a very large
database that encompasses engineering, science, physical, astronomy, mathematics,
chemistry...
 Amphenol has been around since 1932, when
founder Arthur Schmitt offered sockets for vacuum tubes, just 12 years before this
ad appeared in Radio News magazine. Now headquartered in Wallingford, CT, the company
began life in Chicago, Illinois. Amphenol was a major supplier of coaxial cable
in the days when most of the cable Americans used was produced in the country. Alpha
Wire, Amphenol, Carol Cable (now part of General Cable), and General Cable are the
names that come to mind that were around in the 1970s when I entered the radio-electronics
realm. The radar system I worked on in the USAF, and all of the defense electronics
electronics systems I worked on as a technician and engineer, used those four brands.
Today, of course, there is a seemingly unlimited number of coaxial cable suppliers,
many of which produce sub-standard products that do not hold up under even typical
operational environments. Caveat emptor...
 August 23rd's custom
Science & Engineering themed crossword puzzle contains only only words (1,000s
of them) 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, find someone or something in the otherwise excluded
list directly related to this puzzle's technology theme, such as Hedy Lamarr or
the Bikini Atoll, respectively. The technically inclined cruciverbalists amongst
us will appreciate the effort.
 Gray market electronic components are not
just a recent problem. Long before IC foundries were set up in China, Indonesia,
Vietnam, etc., to produce counterfeit semiconductor components, there were unscrupulous
manufacturers turning out bogus components of all sorts. Marking unauthorized microprocessor
and amplifier packages with an industry-leading brand name and part number is a
real problem, but such practices extend back to the vacuum tube era. This story
from a 1957 edition of Popular Electronics magazine tells the story of
how companies like General Electric and Sylvania dealt with the situation...
 This item from Tarek Mealy showed up on
my LinkedIn feed. He created a nifty software app called "SymMos" that allows
you to use a drag-and-drop interface to create a schematic using MOSFETs, resistors,
inductors, capacitors, bias voltages, and signal sources. Then, click on the appropriate
button to get the transfer function equation for input impedance, gain, transconductance,
or noise figure. SymMos is a work in progress and is available as a free download.
After unzipping the file, you need to change the SymMos.txt file extension to .exe.
Launch the executable and then you'll need to wait many seconds while the program
loads (a black screen is displayed while waiting). BTW, Norton flagged the file
as dangerous since it is new and hasn't seen it before, but I allowed it to run
anyway with no problems. I recreated the example shown in the YouTube video and
it works as advertised...
 Syzygy is a great word for a Scrabble game.
If you use it on a Triple Word Score (TWS) space where the "Z" sits on a Double
Letter Score (DLS) space, it will net you 105 points. About the only way to do better
is to use all 7 letters on a TWS play, where you earn 50 bonus points added to your
word score (I've done it twice in the last year).
Syzygy is an astronomical term referring to an alignment of three or more celestial
bodies - not necessarily in exact alignment, but within a few degrees. Astrologers
(not to be confused with astronomers) have since their knuckles no longer dragged
on the ground exploited such scenarios to predict various events both good and bad.
That was even before they knew those "wandering" orbs (planet means "wanderer")
were different than the (seemingly) stationary points of light. Until Galileo turned
his rudimentary telescope on the planets, the only celestial objects with a discernable
disk shape were the sun and moon, and possibly the earth. But I digress. It was
long thought that the vector sum of gravitational influences was responsible for
certain phenomena on our planet, including weather, tides, and earthquakes...
 Many years have passed since I sat in a college
classroom to learn about
transistor fundamentals. The industry had long moved past
germanium transistors and was solidly into silicon. Having been formally
introduced to transistors in the USAF, I was familiar with their functionality
from a technician's perspective of checking for gain, proper bias (as indicated
on "educated" schematics), and determining go-no-go health by performing a
front-to-back resistance measurement using an ohmmeter. Holes, energy bands,
gate widths, and doping levels were first encountered in solid state physics
class, however. This article does a nice job of introducing the terms and
concepts at a layman's level. I actually found the vacuum tube circuits in our
radar unit easier...
 My introduction to
passive intermodulation (PIM) issues was while working on a BTS switching system
back around the turn of the century (yes, this century), where because of high power
levels, the matrix had to be guaranteed to not generate PIM products greater than
a certain value. About 1/3 of the units were not passing test. The cause turned
out to be a high power attenuator in one of the paths. The manufacturer of the attenuator
was a very well established and reputable firm. The PIM levels were intermittent
and would come and go after removing and then replacing the interconnecting cables.
I fortunately noticed that the N-type connector on one end of the attenuator was
rotating slightly during the process. According to our specification to the manufacturer
(it was a custom design), the connector bodies were to be pinned to prevent movement
during torqueing. They appeared to be built properly because the small hole where
the steel pin was driven had been backfilled with conductive epoxy. When the company
was told that the connectors were rotating, they immediately blamed us (me, actually)
for abusing the connectors, since there was no way the connectors would move with
the pins in place...
 John T. Frye's "Carl & Jerry" technodramas
are always both eventful and instructive in the realm of electronics and physics,
but Mr. Frye really outdoes himself with this "A Low Blow" episode from the
March 1961 issue of Popular Electronics magazine. The gist of the story
is how they boys construct and use an
"infrasonic" microphone to detect low audio frequency sounds. Information provided
by the National Bureau of Standards (NBS, now the National Institute of Standards
and Technology - NIST) served as the basis for designing and implementing a measurement
system that ultimately resulted in a situation which provided the title "A Low Blow."
You might be surprised to learn that low frequency sound waves are subject to atmospheric
properties similar to radio waves, which can produce areal skipping and hopping
phenomena where reception is possible only in certain regions between the source
and the receiver. This is a very interesting read...
 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, Pennsylvania, which coincidentally is only a few miles 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 Röentgen made the world's first x-ray image...
 According to this promotion in a 1948 issue
of Radio News magazine, the Howard W. Sams company had published more
than 5,500
Photofact service data packs since beginning in 1938 - that's averaging 550
per year. There would have been many more if not for the cessation of domestic radio
production during the war years from 1942 through the middle of 1945. Once televisions
were being cranked out in huge numbers in the early 1950's, the number of data packets
quickly grew into the tens of thousands (including also phonographs, tape recorders,
and other electronics wonders for the home. In fact, by September of 1949 the magazine's
title was changed to Radio & Television News in order to reflect the
importance of servicing the burgeoning TV industry...
 Here is a fairly major treatise on
folded
and loaded antennas that appeared in a 1953 issue of QST magazine,
with "Suggestions for Mobile and Restricted-Space Radiators." It is not for the
faint of heart or anyone with math phobia or math anxiety. Integral calculus is
part of the presentation, although an understanding of calculus is not required
to get the gist of the article. Equations for calculating the antenna configuration
radiation resistances are given for the 3λ/4-wave folded dipole, the λ/8-wave folded
monopole, the bottom-, center- and top-loaded λ/8-wave monopole, the bottom-loaded
λ/16-wave monopole, and the λ/4-wave monopole folded twice, to name a few...
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weekday. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the world.
With more than 17,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images.
Your Banner Ads are displayed on average 225,000 times per year! New content
is added on a daily basis, which keeps the major search engines interested enough
to spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company
news to be seen, RF Cafe is the place to be... |
