Dealing with the problem of
lightning strikes was of concern long before electronic equipment needed to
be protected from its effects. Fires that were the result of lightning have always
been a problem in nature, but they were really catastrophic to civilization once
cities crowded with close-quartered wooden buildings became the norm. Benjamin Franklin
observed that when the many lightning-induced fires of Philadelphia were sparked
(pun intended), it was almost always the tallest structures in the area that were
hit. Those fire often spread to neighboring buildings and burned down entire city
blocks. It was a devastating and frequency...
"By observing
spintronic magnetic tunnel junctions in real-time, researchers found these devices
fail at unexpectedly low temperatures, offering valuable insights for improving
future electronic designs. Next-Generation Electronics Degradation A new study led
by researchers at the University of Minnesota Twin Cities is providing new insights
into how next-generation electronics, including memory components in computers,
breakdown or degrade over time. Understanding the reasons for degradation could
help improve efficiency of data storage solutions. The research is published in
ACS Nano, a peer-reviewed scientific journal and is featured on the cover..."
Arthur C. Clarke's writings and contributions
to science are vast and influential, intertwining his imaginative narratives with
profound scientific concepts. Clarke is credited with proposing the idea of
geostationary
satellites in a paper he published in the October 1945 issue of Wireless World
magazine. Titled "Extra-Terrestrial Relays: Can Rocket Stations Give Worldwide Radio
Coverage?," he described the concept of using a network of geostationary satellites
to provide global radio coverage. Geostationary satellites are satellites that orbit
the Earth at the same rate as the Earth rotates, so they appear to stay in the same
place in the sky relative to a fixed point on the Earth's surface. This makes them
ideal for telecommunications and broadcasting, as they can provide constant coverage
of a particular area without the need for multiple satellites or complicated ground
infrastructure...
Here we go with three new "What's
Your EQ?" challenges from the July 1961 issue of Radio-Electronics
magazine. Readers submit the problems, which typically involve creating a circuit
to perform a specified function, or determining how a given circuit works. The first
of these is more of a puzzle, since the author shows you how to go about arriving
at the answer. Since incandescent light bulbs are not overly familiar to a lot of
people these days, it might be to the advantage of pre-Millennials who grew up using
them and are acquainted with their properties. The second is an old-fashioned Black
Box challenge that some readers will solve without much...
"Japanese operator SoftBank announced that
the Sunglaider, its large-scale solar-powered uncrewed aircraft system (UAS) designed
for
High Altitude Platform Station (HAPS) stratospheric telecommunications, was
utilized in a field trial conducted by AeroVironment and the U.S. DoD in New Mexico,
the U.S. During the trial, carried out in early August, Sunglider succeeded in achieving
stratospheric flight, the Japanese operator said. With a wingspan of 78 meters and
the capability to carry payloads weighing up to 75kg, the Sunglider is larger than
other publicly announced HAPS UAS..."
Monday (any day, for that matter) is a good
day for Carl and Jerry stories, Mac's Electronics Service Shop sagas, Hobnobbing
with Harbaugh, electronics-themed comics, electronics quizzes, and other forms of
nerd entertainment. Here is another of Robert P. Balin's great challenges titled,
"Diagram
Quiz," this one from a 1966 issue of Popular Electronics magazine.
Most RF Cafe visitors will easily identify eight or nine of the ten diagrams. Relatively
few will be familiar with the Rieke diagram (hint: power amplifier designers will
know about it). The Biasing diagram is a bit misnamed IMHO, and could cause confusion...
Anatech Electronics 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 ceramic bandpass filters have
been announced for October 2024 - a 2275 MHz center frequency filter with a
bandwidth of 250 MHz, a 2275 MHz center frequency filter with a bandwidth
of 250 MHz, and a 6245 MHz center frequency filter with a bandwidth of
360 MHz. Custom RF power filter and directional couplers designs can be designed
and produced with required connector types when a standard cannot be found, or the
requirements are such that a custom approach is necessary.
When you read this 1963 Electronics
World magazine article's title, I doubt you immediately assumed it would be
about a vacuum tube circuit, or even one that uses discrete transistors to implement
the circuit. Rather you most likely though it would be about an integrated circuit
(IC).
Operational amplifiers (opamp) are building blocks characterized (ideally) by
their infinite input impedance, zero output impedance, infinite open-loop bandwidth
and gain, zero input offset voltage, amongst other defined parameters. The first
commercially produced integrated circuit (IC) opamp came to market in 1964 via Fairchild
Semiconductor (the µA702, brainchild of Bob Widlar)...
Nickel-cadmium (NiCad) batteries have a
long and significant history in energy storage, with their invention attributed
to Swedish engineer Waldemar Jungner in 1899. Jungner's work laid the foundation
for an electrochemical power source based on nickel oxide hydroxide and cadmium,
leading to the development of the rechargeable NiCad battery. It was a pioneering
breakthrough because it represented one of the earliest forms of rechargeable energy
storage systems. This battery technology found widespread use in various industries
due to its robust performance and ability to be recharged multiple times. At its
core, the chemistry of NiCad batteries involves the reaction between cadmium (the
negative electrode) and nickel oxide hydroxide (the positive electrode), with potassium
hydroxide as the electrolyte. During...
These two
tech-themed comics from the September 1969 issue of Electronics World
magazine are pretty good. I especially like the one where the guy's wife entered
his printed circuit board layout in an art contest. PCBs were just starting to gain
momentum in production electronics as they replaced the old point-to-point wiring
method. Also popular in that era was high fidelity stereo equipment. Owning a system
with speakers that operated from 1 Hz through 30 to 40 kHz was major evidence
of an audiophile's technical savvy, even though the human ear con only detect frequencies
in the 30 Hz to 20 kHz range. Dogs can hear frequencies up into the 45 kHz
range. Porpoises can hear up to 150 kHz. A ferret can hear from 16 Hz...
TotalTemp Technologies offers advanced
and innovative methods for meeting and optimizing your thermal testing requirements.
We specialize in benchtop thermal testing because small batches are typically the
most cost-effective approach. We offer heat transfer by conduction with thermal
platforms, forced convection as in traditional temperature chambers, combined systems,
and thermal vacuum for Space Simulation.
Thermal testing of Traveling Wave Tube Amplifiers and other devices with dramatically
uneven power dissipation can easily be achieved with a dual zone thermal platform.
Managing the heat produced by the electron gun side allows for the RF outputs side
to be tested at various required temperatures. The Dual Zone Thermal Platforms allows
the user to maintain safe controlling...
• Ham
Radio Serving Southeast U.S. Recovery Efforts
• Radio
"A Godsend for So Many" in Helene's Aftermath
• Estate
Planning for Hams
• Intel's Woes Damaging
U.S. Chip Indpendence
• Is
Gen-Z Low Car Ownership a Threat to Radio? (they
can't afford cars due to massive inflation - not because they don't want a car)
Amrad, American Radio & Research Corporation,
was based in Medford Hillside, Massachusetts and was founded in 1915 with funds
from J. Pierpont Morgan. The company's first manager, Harold James Power, was an
amateur radio enthusiast and built a research laboratory. In 1916, Amrad made its
first broadcast to J. Pierpont Morgan Jr., who was aboard the ocean liner "Philadelphia."
Amrad received orders for military radio equipment during World War I, but discontinued
these orders after the war ended. To keep the company afloat, Amrad produced items
such as electric egg beaters and cigar lighters. In 1919, Amrad was awarded a contract
to make 400 SE1420 receivers, and it began advertising components for amateur radio
enthusiasts...
This "Which
Dry Battery for You" article is a follow-on from the previous month's "Dry Cell
Battery Types" in Radio-Electronics magazine. It was a time long before the dominance
of rechargeable lithium batteries. In 1963, battery-powered devices were nowhere
near as widespread and diverse as they are nowadays. Hand tools like drills, saws,
routers, planers, and screwdrivers got their power either from a wall outlet or
the user's arm and hand muscles. Lawn mowers, grass and hedge trimmers, chain saws,
and snow blowers were powered mostly by gasoline, although some models plugged into
the wall. Those devices which did use batteries most often had no built-in...
"Researchers have developed a new architecture
for optical computing called
diffraction casting, offering power-efficient processing by using light waves.
This method promises better integration and flexibility for high-performance computing
tasks and could be used in fields like AI and machine learning. As artificial intelligence
and other complex applications demand ever more powerful and energy-intensive computers,
optical computing emerges as a promising solution to enhance speed and power efficiency.
However, its practical application has faced numerous challenges..."
The Atomic Energy Commission (AEC) was established
in 1946 as a result of the Atomic Energy Act, signed into law by President Harry
S. Truman. This legislative decision marked the United States' formal entry into
managing and controlling atomic energy, a rapidly advancing field that had been
essential in concluding World War II through the development and use of nuclear
weapons. The AEC was conceived to handle not only military applications of atomic
energy but also to develop peaceful uses, such as energy production, medical research,
and industrial applications. The creation of the AEC emerged from the Manhattan
Project, the secret wartime effort to develop atomic bombs. The Manhattan Project
brought together prominent scientists like J. Robert Oppenheimer, Enrico Fermi,
and Niels Bohr. After the war, however, the question arose...
Empower RF Systems, the technology leading
provider of high-performance RF amplifiers, is proud to announce the launch of the
Model 2221 X-Band Pulsed High Power Amplifier. The Empower RF 2221 amplifier
operates in the 9-10 GHz X-band, delivering an impressive 8000 W peak
output power with long and short pulse widths. Its applications encompass radar
systems, electronic warfare, HPM research, and electromagnetics effects testing.
With a rugged, modular design, the 2221 offers a reliable, high-performance solution
for applications demanding significant X-band power. Key Features and Specifications
The model 2221 amplifier operates in the 9-10 GHz X-band frequency range, delivering
an impressive 8 kW of peak pulsed output power...
Although not in the title as it used to
be, this 1964 Electronics World magazine piece by John T. Frye is
a "Mac's
Service Shop" story. If Mac and Barney are the stars of the saga, then it can
be none other. The story is about how the misdeeds of a few dishonest operators
can taint the reputation of an entire industry - nothing new there. Barney is telling
Mac about a "sting" ploy pulled by a consumer protection group whereby TV sets with
a specific easy-to-troubleshoot problem introduced to see how repair technicians
from a suspect company would bill the service. I'll not spoil the ending for you;
however, a comment mentioned that $10 would have been a reasonable price for a house
call that included the fix. According to the BLS's inflation calculator, $10 in
1964 was the equivalent of about $102 in 2024...
Ever the futurist, in 1962 Radio-Electronics
magazine editor Hugo Gernsback was making the case for occupying
millimeter- and submillimeter-wave bands. In fact, he first proposed the concept
back in 1959. He refers to it as "gap between the infrared (IR) and radio regions."
IR is generally understood to include wavelengths from around 750 nm (400 THz)
to 1 mm (300 GHz). Gernsback cites work done by Professor Gwyn O. Jones,
of Queen Mary College of the University of London, with the claim that among other
advantages of millimeter-wave (mm-wave) is an ability to penetrate certain wavelength
"windows" in the atmosphere where lower frequencies do not propagate efficiently,
more "channels" of communications can be accommodated, smaller antennas could be
used, and narrower focused transmission beams possible...
Werbel Microwave's WMRD10-7.2-S is a
10-way resistive splitter that covers up to 7.2 GHz with ultra-wide bandwidth.
This unique design accomplishes extremely flat frequency response in a small radial
package. Our unique design approach provides higher than expected isolation between
outputs at far ports than would be achieved in a typical star topology. It has applications
in markets such as CATV, test and measurement, and military radio. Its small size
makes it easy to integrate into compact systems. Designed, assembled, and tested
in the USA.
Hugo Gernsback, often heralded as the "Father
of Science Fiction," was an extraordinary figure whose influence extended beyond
the realm of speculative literature into the world of electronics, radio communication,
and futurism. His life, inventions, and publications shaped not only popular science
but also the practical development of radio and electronics, making him a pivotal
figure in early 20th-century technological advancements. Gernsback was born Hugo
Gernsbacher on August 16, 1884, in Luxembourg City, Luxembourg, to a wealthy family.
His father, Moritz Gernsbacher, was a winemaker and merchant, while his mother,
Bertha, came from a prominent local family. Hugo had several siblings, though details
of his early family life remain somewhat obscure. From a young age, Hugo showed
a strong interest in science and technology, particularly in electricity and wireless
communication. He attended local schools in Luxembourg and later pursued formal
education at the Technikum in Bingen, Germany...
These government programs take forever to
implement, then a major portion of the money gets wasted in bureaucracies, payoffs,
and misappropriations (e.g.,
8 EV charging stations after spending $7.5B). "If you know CostQuest at all
you probably think of it as the company that the FCC hired to clean up and refine
its national broadband map. But the company is also working with state broadband
offices on their
Broadband Equity, Access and Deployment (BEAD) programs. To give a little background,
CostQuest works with the FCC on its national broadband map. But it was also hired,
separately, by the National Telecommunications and Information Administration (NTIA)
to work with states..."
The
Radio Corporation of America (RCA) holds a significant place in the history
of American technology and business. Founded in 1919, RCA was initially created
as a government-sanctioned monopoly to manage the United States' growing interest
in wireless communication. During its peak, RCA was a dominant player across multiple
industries, including consumer electronics, communications, broadcasting, and defense
technology. Its influence extended through radio, television, radar, semiconductors,
and beyond. The inception of RCA was rooted in the growing importance of wireless
communication during and after World War I. The company was established by General
Electric (GE), which was pressured by the U.S. government to create a new entity
that would ensure...
When this was originally posted it was the
beginning of the IEEE's 2007
Microwave Theory and Techniques Society's (MTT-S) International Microwave Symposium
(IMS) in Honolulu, Hawaii. This advertisement from the January 1969 issue of Electronics
World magazine promoted Institute of Electrical and Electronics Engineers (IEEE)
annual symposium. Per the MTT.org website, the very first IMS show was held in 1995,
in Orlando, Florida. The 1969 IEEE International Convention & Exhibition, which
was not specifically a microwave electronics theme, was held in the New York Coliseum,
located in New York City...
If you have been wanting access to
nitrous oxide (N2O), aka laughing gas, in order to "encourage" someone
to divulge subconscious (or intentionally suppressed) information, but don't want
to pay the high cost of storage bottles and refilling, then here are instructions
in a 1949 issue of Popular Science magazine for brewing some on your own.
Purchase of N2O is legal, and is used, among other things, as an engine supercharger
which is injected into the intake manifold. I had a friend back in the 1970s with
such a system installed on his 1968 Camaro that had a 454 cu. in. big
block in it. It could easily pop the front wheels off the ground. Dentists and doctors
still use it as an anesthetic, food products like whipped cream...
The evolution of
Crosley
radio products is a fascinating journey through the golden age of radio, a period
marked by significant technological advancements and changing consumer preferences.
Powel Crosley Jr.'s genius lay in his ability to combine affordability with cutting-edge
features, making his radios highly desirable for the average American household.
Crosley Radio Corporation's products evolved rapidly, reflecting the company's commitment
to innovation and its response to market demands. Crosley's radio journey began
in 1921 when he created the Harko, an affordable crystal set that was small and
compact enough to sit on a tabletop. Early radios at the time were relatively...
It is amazing how some substrate layouts
look exactly like a block diagram of circuit they represent. "With increasing data
rates in mobile communications, the need for more powerful high-frequency electronics
is growing. This is particularly true for satellite-based global communication networks,
which must function reliably and securely in all weather conditions and at any location.
In the ESA Magellan project, researchers at Fraunhofer IAF, together with UMS and
TESAT, are therefore developing novel efficient
GaN transistors and high-power amplifiers for LEO and GEO communication satellites
to provide high..."
Allen B. DuMont, a pivotal figure in the
early days of television and electronics, was born on January 29, 1901, in Brooklyn,
New York. His contributions to the advancement of television technology, particularly
through his work on cathode-ray tubes, and the founding of the DuMont Television
Network, left a lasting mark on the broadcasting industry. DuMont's early years
were marked by adversity. As a young boy, he contracted polio, which left him bedridden
for several months. Despite the physical limitations imposed by the disease, DuMont's
intellectual curiosity flourished, and he turned to reading and tinkering with electronics
to occupy his time. This early exposure to electrical engineering would shape his
future. DuMont's passion for electronics was evident from an early age. By the time
he was a teenager, he had built his own radio receiver. He attended Rensselaer Polytechnic
Institute (RPI)...
Ever heard of "sferics?" That's a new word
in my technical lexicon as of right now. Sferics (aka spherics), is a contraction,
derived from "atmospheric" phenomena, specifically referring to the electromagnetic
signals generated by natural events in the atmosphere, such as lightning discharges.
Over time, its use has become specialized in the field of meteorology, physics,
and certain branches of electrical engineering, where it is used to describe specific
types of electromagnetic emissions. It was mentioned in this "News
Briefs" column in a 1961 issue of Radio Electronics magazine. Also
in the news was the decreasing conductivity of the atmosphere due to low sunspot
activity. Ham DX'ers love sunspots since by charging the upper atmosphere, it facilitates
long distance communications. Japanese color TV sets were deemed "impressive." Much
more...
"Recent advancements in
phonon laser technology, which utilizes sound waves rather than light, show
promising new applications in medical imaging and deep-sea exploration. A novel
technique enhances these lasers by stabilizing and strengthening the sound waves,
allowing for more precise and powerful outputs. This development not only improves
existing uses in medical and underwater applications but also extends potential
uses to material science and quantum computing. Scientists in China have made a
significant leap in developing lasers that use sound waves instead of light. These
'phonon lasers' hold promise for advancements in medical..."
Powel Crosley Jr., an American inventor,
entrepreneur, and industrialist, was born on September 18, 1886, in Cincinnati,
Ohio. He became one of the most prolific figures in American industry, with contributions
spanning from radios to cars, and from kitchen appliances to television broadcasting.
His innovative spirit, coupled with a keen business sense, enabled him to leave
an indelible mark on American consumer culture during the first half of the 20th
century. Crosley's early years were shaped by a supportive, middle-class family.
His father, Powel Crosley Sr., was a successful attorney, which afforded young Powel
and his siblings a comfortable upbringing. Crosley was drawn to mechanical and electrical
engineering from an early age, demonstrating an innate talent for tinkering. As
a boy, he built his own working model of a car...
"In these modern times, electronic systems
are usually operating within an
electromagnetic-interference (EMI) environment that contains many other electronic
systems. These systems need to exist and fully operate undisturbed while meeting
electromagnetic compatibility (EMC). EMC requirements are separated into two main
parts: Electromagnetic immunity - a system must not be disturbed by any other systems.
The electromagnetic interference in a system can't disturb any other system. Then,
if immunity and emission requirements are individually met, the electronic product,
such as an integrated circuit (IC), may be marketed from an EMC point of view. Measurement
methods for EMI and electromagnetic emission (EME) are fully described for ICs in
the IEC62132-4 (immunity) and IEC61967-4 (emission)..."
The
Space Race was one of the most significant geopolitical and scientific competitions
of the 20th century, driven by the rivalry between the United States and the Soviet
Union during the Cold War. It spanned from the late 1940s through the 1970s, with
a focus on achieving superiority in space exploration, a domain viewed as critical
not only for scientific advancement but also for military and strategic dominance.
Rooted in rocket technology developed during World War II, the Space Race transformed
the world's understanding of science and technology, culminating in the most dramatic
achievement: the landing of humans on the Moon in 1969. This treatise explores the
key milestones, the countries and key players involved, technological developments,
the interplay between military...
|
Antennas have been deployed in difficult environments
using many ingenious methods over the years both by professionals and amateurs.
The process typically involves first propelling a lightweight string or wire across
and/or up to a supporting structure (a tower, tree, building, whatever) and then
using that lead line to draw the antenna and its accompanying coaxial or twin lead
cable into its final position. Sometimes simply tying a line to a rock and tossing
it over a tree branch does the trick, but usually deployment requires a more powerful
launch such as a a bow and arrow or even a model rocket. Many years ago R/C
Modeler magazine reported on a large radio controlled airplane (Senior Telemaster)
that towed a lead line across a wide gulch...
The August 1958 issue of Radio News
marked the merging of All-Wave Radio with Radio News, both founded
by Hugo Gernsback. Radio News began publication in July 1919 (actually titled
Radio Amateur News for the first year) and All-Wave Radio debuted
in September 1936. "All-wave" radio referred to a class of radios popular at the
time which could tune in most of the worldwide commercial broadcast stations, spurring
the accompanying "short wave listening" craze. This instance of the monthly "Within
Earshot of the Editor" column received a lot of attention because it fired a shot
across the bow of the ARRL for not sufficiently lobbying the FCC for the
electromagnetic spectrum access rights currently enjoyed and the
serious threat of loss. Many people subsequently accused Radio News of
attempting to torpedo the ARRL and replace it with another organization of Ham operators...
Unlike many electronics enthusiasts including
hobbyists, salesmen, servicemen, and commercial and domestic users, Mac McGregor
was an early-on believer of the ultimate replacement of vacuum tubes by transistors.
Only a decade old and not yet adopted by a lot of manufacturers (to their ultimate
demise in some cases),
transistors were fighting a major battle to gain acceptance and trust by the
public. Not only were transistors still more expensive than an equivalent vacuum
tube, but the reliability was not as good - most times due to designers not properly
accounting for their special needs for protection against voltage extremes. Once
the price of transistorized products fell into parity with their predecessors, consumers
quickly adopted the products because of the markedly smaller sizes and lower power
consumption...
Well shazam, I found a radio service datasheet
that had been missed. This one for the
Sparton Selectronne Model 1068 brings the grand total to 220 that have been scanned
and posted here on RF Cafe. They appeared in various formats in Radio-Craft,
Radio News, and Radio & Television News magazines. It was in the
1930s that pushbutton tuning appeared in most radio sets, both tabletop and floor-sitting
console models. Those mechanical pushbutton tuner mechanisms were pretty impressive.
The Selectronne also sported a popular visual tuning indicator called the Viso-Glo
tube. It was not...
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...
That portion of the electromagnetic spectrum
which falls between 1000 megahertz and 100,000 megahertz is referred to as the
Microwave region. Before discussing the principles and applications of microwave
frequencies, the meaning of the term microwave as it is used in this module must
be established. On the surface, the definition of a microwave would appear to be
simple because, in electronics, the prefix "micro" normally means a millionth part
of a unit. Micro also means small, which is a relative term, and it is used in that
sense in this module. Microwave is a term loosely applied to identify electromagnetic
waves above 1000 megahertz in frequency because of the short physical wavelengths
of these frequencies. Short wavelength energy offers distinct advantages in many
applications...
RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running
series, RF Cascade Workbook. Chances are you have never used a spreadsheet
quite like this (click
here for screen capture). It is a full-featured RF system cascade parameter
and frequency planner that includes filters and mixers for a mere $45. Built in
MS Excel, using RF Cascade Workbook is a cinch and the format
is entirely customizable. It is significantly easier and faster than using a multi-thousand
dollar simulator when a high level system analysis is all that is needed...
"Micro" as applied to electronics is relative,
depending on which decade you reference. In the 1940s, a micro-size electronic assembly
might have included "peanut" vacuum tubes and even some sort of printed circuit
board. That was a huge step down in size from standard size tubes with point-to-point
wiring between tube sockets and solder lugs on switches, potentiometers, variable
capacitors, etc. Fixed value leaded resistors, capacitors, and inductors, and transformer
wires connected to those lugs as well as to many terminal strips installed specifically
for making connections. Once transistors came on the scene in the 1950s, a new round
of
miniaturization took place based on not just a significantly smaller size of
solid state transistors and diodes, but their lower voltage and current requirements
meant ancillary components could be made smaller as well due to lower voltage...
I don't know about you, but I really miss
the hard-wired POTS (Plain
Ordinary Telephone System) days of remote communications. Unless the conversation
was with an overseas telco system, there was never a noticeable delay where both
parties were constantly either 'stepping' on each other's words or having to consciously
wait before speaking to make sure the other guy has finished. Whether it be cellphone-to-cellphone
or cellphone-to-VoIP, nearly every conversation is annoying. Sometimes when one
party is on the POTS line with either a cell or Internet connection it can go well,
but if you want a hassle-free conversation (assuming the person you're talking to
is not a PiTA), you need a hard-wired connection on both ends. People loved to hate
Bell Telephone back in the day...
Those of us who have been working for a long
time around electricity with exposed circuit components are well aware that as little
as one-tenth of an ampere (1/10 A) can produce a lethal reaction, particularly
if the current path runs through the heart (i.e., hand-to-hand). Some of us (moi)
have even experienced a pretty significant jolt from a high voltage vacuum tube
power supply and/or from a 480 volt, three-phase supply to an industrial motor.
Fortunately, the worst damage done was to my ego and a feeling of utter stupidity
for allowing the occurrence to happen. If you are new to the concept of
electrocution, you might be inclined to wonder why, when the chart
below shows certain current levels with corresponding effects, would I mention exposure
to high voltages? The answer is that various current paths through your body...
This
Science Celebrity themed crossword puzzle for December 12th contains no
fewer than 18 names of notable scientists and engineers (marked with an asterisk
*) known famously to folks like you who visit RF Cafe. It took quite a while
to design. Elsewise, only clues and words which are directly to RF, microwave, and
wireless engineering, optics, mathematics, chemistry, physics, and other science
subjects. 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., Reginald Denny or the Tunguska
event in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort...
This week's RF Cafe crossword puzzle contains the
usual assortment of engineering and science related words and clues, but there are also
a few specific words commemorating our
Thanksgiving
Day holiday (indicated by a asterisk *) that is celebrated
each year on the fourth Thursday of November. Macy's 90th Thanksgiving Day Parade occurs
on the morning of November 24th and follows a route along Central Park West and 6th Avenue.
Interestingly, the parade was cancelled during the World War II years of 1942, 1943,
and...
An ancient legend tells us that nearly 5,000
years ago an Emperor of China had a small statue of a man mounted on his chariot.
This statue was pivoted at the base and one outstretched arm always pointed to the
south. In those ancient times, this action must have seemed truly miraculous - probably
the Emperor used his statue more to impress his subjects than he did to find his
way. This legend is the first report of man's use of a black or lead-colored stone
called
magnetite. About the time of Christ, magnetite was rediscovered
by a Grecian shepherd. He noticed that the iron of his staff was attracted to certain
stones. But for nearly another 1,000 years, no particular use was made of this discovery...
If you have seen many of the articles I post
from vintage electronics magazines, you know I often compare prices from the magazine's
era to today's prices. The online Inflation Calculator from the Bureau of Labor
Statistics (BLS) is as good as any, so it is used. This RCA advertisement in a 1946
issue of Radio-Craft magazine boasts of how drastically the
cost of
vacuum tubes has come down since 1923. It claims a $9 tube in 1923 costs a mere
80¢ in 1946; that is about 1/11th of the original price. Prior to around 1965, inflation
was very low, so the inflation-adjusted price for the $9.00 tube would be $9.80
in 1946 - a full 23 years later (a 9% increase, per the BLS). Therefore, the 80¢
price is an even better deal. Let us compare that to what a $9 item 23 years ago
(1998) from today (2021) would cost now. Per the BLS Inflation Calculator, it would
take $15.06 in 2021...
RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running
series, RF Cascade Workbook. Chances are you have never used a spreadsheet
quite like this (click
here for screen capture). It is a full-featured RF system cascade parameter
and frequency planner that includes filters and mixers for a mere $45. Built in
MS Excel, using RF Cascade Workbook is a cinch and the format
is entirely customizable. It is significantly easier and faster than using a multi-thousand
dollar simulator when a high level system analysis is all that is needed...
Those of us who have been around for six
or more decades have lived through two evolutions of video display types - raster
scanned
cathode ray tubes (CRTs) and digitally pixelated light-emitting diode (LED)
and liquid crystal (LCD) displays. Unlike with the latter display types that improved
in color depth, picture resolution and display size, the former had effectively
a fixed resolution of horizontal lines (525 vertical steps - only 484 visible, actually,
due to blanking). That meant for CRTs, designers needed to find ways to make images
appear in-focus while also looking continuous on larger screens. Doing so involved
cleverly adjusting the size and spacing of fluorescent color dots on the picture
tube face while also using special metal masks between the electron gun and the
tube. A lot of research that included panels of people rendering opinions...
Phased
vertical stacks of two or more antennas were fairly common in the television
realm - especially once color broadcasts became more dominant in the 1950s. Up to
3 dB per additional antenna is possible, but due to various non-ideal physical
parameters (summed phase angle, imperfect antenna geometry, etc.), realized gain
is typically in the 2.5 to 2.8 dB range. Higher signal to noise ratios were
needed to guarantee good color separation with the National Television System Committee
(NTSC) and stereo channel audio separation with the advent of Multichannel Television
Sound (MTS). As you might expect, companies appeared claiming to have invented physics-defying
antennas that "outperform all present antennas." This particular "Super 60"
model from All Channel Antenna Corporation further claims to outperform antennas
that use a mechanical rotator (see my Alliance U-100 Tenna-Rotor) by virtue of its
9-position electronic phase switching...
Not having ever applied for a patent, I do
not know how much of what appeared in this "Patent
Information for the Inventor" article from a 1962 issue of Electronics World
magazine is still valid. The fundamentals are probably about the same. One thing
that has changed since this article was written is the name change in 1975 from
the U.S. Patent Office to the U.S. Patent and Trademark Office (USPTO), which occurred
when ownership was passed from the Department of the Interior (1849-1925) to the
Department of Commerce (1975-present). The schedule of fees has grown to a very
complex table of definitions and requirements for various types of patents and services.
A Basic Filing Fee runs $320 for big businesses, $160 for smaller concerns ("Small
Entity"), and $80 for individuals with no more than four current patents ("Micro
Entity). That compares to $25 in 1962 ($220 in 2021 money per BLS). July 31, 1790,
the first U.S. patent was issued to Samuel Hopkins for an improvement "...in the
making of Pot ash and Pearl ash by a new Apparatus and Process...
Somebody get Al Gore on the phone - preferably
using Skype. It appears that maybe he did not invent the Internet after all. Sci-fi
writer William F. Jenkins, who went by the pen name "Murray Leinster," wrote
a short story entitled A Logic
Named Joe, that appeared in March 1946 issue of Astounding Science Fiction.
In the story, an amazingly prescient description of the modern Internet is laid
out. The works is copyrighted so I will not replicate the entire thing here, but
these are a few excerpts that sound a lot like Mr. Leinster was in cahoots with
DARPA during the development*. Before I forget, thanks to RF Cafe visitor Terry
W. for sending the link. My comments look like...
This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's Matchmakers"
Smith chart design. These would make excellent gifts for husbands, wives, kids,
significant others, and for handing out at company events or as rewards for excellent
service. My graphic has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. I only make a couple bucks
on each sale - the rest goes to Cafe Press. It's a great way to help support RF
Cafe. Thanks...
Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 visits each
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...
It was a lot of work, but I finally finished
a version of the "RF &
Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft
Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive
set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog,
antenna, and other commonly used symbols for system block diagrams and schematics
created for Visio™. Each of the 1,000+ symbols was exported individually from Visio
in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format
allows an image to be scaled up or down without becoming pixelated, so all the shapes
can be resized in a document and still look good. The imported symbols can also
be UnGrouped into their original constituent parts for editing...
A year has passed since I last posted a
Carl and Jerry high-tech saga. John T. Frye created the duo of teenage
sleuths in 1954 for the very first issue of Popular Electronics magazine. More than 100
adventures carried Carl and Jerry from high school through college. Their practical jokes,
crime solving, and mystery investigations incorporated microphones, timers, cameras,
Ham radio, transformers, metal detectors, remote controllers, home brew circuits, photodetectors,
and a host of other gadgets that could be pulled from a stash of parts in Carl's or Jerry's
basement workshop, or borrowed from a friend. In this story, Carl and Jerry, now students
at Parvoo University in Indiana, have an unexpected confrontation with a radio operator
while exploring a campus...
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...
The metal-oxide-semiconductor field-effect transistor
(MOSFET)
was patented in its present form by Bell Labs in 1959, following the original patent
by inventor Julius Edgar Lilienfeld, in 1925. It had only been on the open market for
designers to use for a bit over a decade when this article appeared in Popular Electronics.
Adolph Mangieri wrote a number of articles for the magazine in the early 1970s introducing
readers to the many new types of semiconductor devices coming out of research laboratories
and into the commercial marketplace; e.g., "Understanding the Junction Field Effect Transistor."
MOSFET's are nowadays the primary building...
It was a lot of work, but I finally finished
a version of the "RF &
Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft
Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive
set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog,
antenna, and other commonly used symbols for system block diagrams and schematics
created for Visio™. Each of the 1,000+ symbols was exported individually from Visio
in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format
allows an image to be scaled up or down without becoming pixelated, so all the shapes
can be resized in a document and still look good. The imported symbols can also
be UnGrouped into their original constituent parts for editing...
Plastic is one of those materials that seems
like it has been around since the dawn of time - like metal. There was an Iron Age
in the 1,000 BC timeframe (depends on location), but the Plastic Age - not
that there officially was one - did not begin in the commercial world until World
War II. If you note in older photos and films, there was not much, if any,
in the way of objects made of
plastic before the 1940s. In fact, the formulation and production of some types
of plastic like Plexiglas and polycarbonates was considered a matter of national
security for a while both for Allied and Axis powers. Bomber and fighter aircraft
windshields were made of the material. After the war, use of plastics for industrial
and consumer products exploded due to the much easier manufacturing of product enclosures,
knobs, and parts with complex shapes. Lighter weight, lower cost, easy application
of color, and in some cases greater robustness made plastic very popular with consumers.
Plastic does have its drawbacks compared to the wood, metal, and phenolic materials
previously used for radios, TVs, and phonographs, and Barney experienced one of
them...
"Electrical
Pipeline" is as apt a layman's description for waveguide as "electrical hose"
is for coaxial cable. What would be a good commoner's name for twin lead? "Ladder
Line" and "Window Line" are descriptive of the type with open regions between supports,
but neither relates to a water analogy that would be familiar to Joe Six-Pack. I'm
open to suggestions. Module 11 of the Navy Electricity and Electronics Training
Series (NEETS), entitled "Microwave Principles," does a very nice job introducing
and explaining how waveguide works. It discusses rectangular, elliptical, and circular
waveguide. Bell Telephone Laboratories, which was responsible for some of the most
profound and world-shaping innovations of the 20th Century, pioneered the use of
waveguide in commercial telecommunications systems...
Electronics symbols
for schematics and wiring diagrams have remained amazingly consistent for the last
hundred years, although obviously many new ones have been added. You can see from
this set of standardized wiring diagram and schematic symbols from a 1955 edition
of Popular Electronics what I mean. Even symbols for newly introduced devices tend
not to change. There are some variations such as whether or not to draw a circle
around a transistor or how many lightning bolt lines to use with photon emitters
and detectors, but that's about it. The digital world adopted IEEE Standard 91-1984
for logic and microprocessors, although you will still occasionally see variants
in symbols, especially in early digital circuit schematics. The ARRL publishes its
own version of standardized electrical schematic symbols, but even the ARRL
Handbook, in which the symbols are printed, does not strictly conform to its
own standards.
Proper soldering is almost as much of an
art form as it is a technical skill. Having been through numerous soldering classes
in my career, starting with electrical vocational courses in high school, then again
in USAF technical school, and other times while working as a technician and engineer,
I always exercise care in
making solder joints. Proper preparation - including both tinning of mating
surfaces and a means to prevent the joint members from moving during cool-down -
is of utmost importance for assuring a nice, smooth, shiny joint with just the right
amount of solder. Lead-free solders do not tend to produce the level of shininess
as do the good old 60-40 type tin-lead solders, but you can still make a nice looking
joint. This might be more information than you want to know about me, but I even
strive for perfection in solder joints in copper pipes and fittings used in plumbing
work...
This quiz is based on the information presented
in Conquer
Radio Frequency, by Francesco Fornetti. See my review for the online version.
This material, which includes a full-color textbook and over 12 hours of video tutorials
(in mp4 format on enclosed DVD-R), provides a comprehensive guide for the RF and
Microwave engineering student or junior professional. It allows the reader to achieve
a good understanding of the foundation theory and concepts behind high frequency
circuits as well illustrating the most common design and simulation techniques for
passive and active RF circuits. A preview of the textbook, a comprehensive description
of the content of the video tutorials and sample video tutorials are available on
the Explore RF website. |