|
 Charles Babbage, born on December 26, 1791, in London, England, was one of the foremost mathematicians and inventors of the 19th century, best known for his pioneering work on the concept of a programmable computer. He was the son of Benjamin Babbage, a banker, and Betsy Plumleigh Teape, who hailed from a relatively affluent family. His upbringing was comfortable, allowing him access to an education that would later foster his intellectual pursuits. His father's wealth enabled Charles to attend some of the finest schools of the time, although his formal education started somewhat later than usual due to early childhood illness.
Babbage's schooling began at a local academy in Alphington and later at the King Edward VI Grammar School in Totnes,
Devon. He was a highly curious child...
 "Yesterday, NASA successfully launched the
Europa Clipper, the largest spacecraft the agency has ever built for a planetary
mission. Clipper is now successfully on its multi-year journey to Europa, bristling
with equipment to study the Jovian moon's potential to support life - but just a
few months ago, the mission was almost doomed. In July, researchers at NASA found
out that a group of Europa Clipper's
transistors would fail under
Jupiter's extreme radiation levels. They spent months testing devices, updating
their flight trajectories, and ultimately adding a warning “canary box” to monitor
the effects of radiation as..."
 The October issue of Electronics World
magazine included many articles written by
printed circuit board (PCB) industry leaders regarding the state of the art.
Multi-layer PCB technology was still in its infancy at the time, with most prototype
and production boards being 1- or 2-sided. As with the switch from vacuum tubes
to transistors, there were hold-outs who resisted the change to PCBs - for good
reason in some cases. A list of advantages and disadvantages is presented both for
and against, respectively, use of printed circuit boards. One of the biggest advantages
to point-to-point wiring (i.e., in the PCB disadvantage list) was that circuit modifications
in production was more easily accommodated, unless the change was simply...
 Along with the advent of FM (frequency modulation)
radio came an entirely new variety of
antenna shapes and configurations, compared to primarily a simple long, straight
wire for AM (amplitude modulation) radio antennas. Amateur radio operators (Hams)
of course had been designing, tuning, and using such antennas (as FM) for decades,
but the average radio listener was facing a whole new world of options for getting
the most out of his receiver. It is not that AM radio cannot benefit by similar
antenna configurations, it is just that the relatively long wavelength of AM station
frequencies (540 to 1,700 kHz) compared to FM station frequencies (88 to 108 MHz)
represents a two-order-of-magnitude...
 "Researchers have developed a novel
graphene-germanium hot-emitter transistor using a new hot carrier generation
mechanism, achieving unprecedented performance. This advancement opens new possibilities
for low-power, high-performance multifunctional devices. Transistors, the fundamental
components of integrated circuits, encounter increasing difficulties as their size
continues to shrink. To boost circuit performance, it has become essential to develop
transistors that operate on innovative principles. Hot carrier transistors, which
harness the extra kinetic energy of charge carriers, offer the potential to enhance
transistor speed and functionality..."
 When this was originally published, it was
Labor Day in the USA, so most people were off work (which seems antithetical to
the "labor" part of the holiday name). For those unfortunate enough to be at work,
here is a bit of vintage electronic comic relief from a 1969 Electronics World
magazine for your office-bound condition. Actually, during my years of working for
someone else, I used to work the holidays (except Christmas) if I could get another
day off instead. With very few managers around, those of us at work would enjoy
what we termed "IPV," or "In-Plant-Vacation." Very little work got done on those
days, and lunches and break-times were pretty long. I was always surprised the scheme
never caught on more widely...
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. We are pleased to announce
the model
AMP2083P-2KW solid state pulse amplifier (SSPA) is designed for Pulse/HIRF,
EMC/EMI Mil-Std 461/464 and radar applications in the C-band, 4.0-8.0 GHz frequency
band. Providing superb pulse fidelity and up to 100 μsec pulse widths. Duty
cycles to 6% with a minimum 63 dB gain. Available monitoring parameters for
Forward/Reflected power in watts & dBm, VSWR, voltage, current, temperature
sensing for outstanding reliability and ruggedness in a compact...
 By the time most of us who even remember
cathode ray tubes (CRTs) were first introduced to them, the technology and manufacturing
processes had been pretty much perfected - especially for the standard 525-line
(or 625-line outside the U.S.) resolution type. The National Television System Committee
(NTSC) published a standard for black and white (B&W) television in 1941 and
then for color in 1953. This "Picture Tubes" article in a 1955 issue of Popular
Electronics provides a look inside a CRT manufacturing plant at General Electric.
For some reason the photos in the magazine were very poor quality (maybe for secrecy).
If you want one of the best explanations I have ever seen on how a TV picture scan
is implemented, check out this video entitled
What is 525-Line Analog Video? If you don't understand raster scanning after
watching it, you never will. You might be surprised to learn that there were not
actually 525 lines of picture information...
 The March 1962 "News Briefs" feature in
Radio-Electronics magazine was chock full of interesting developments.
Space flight was a big deal in the day, not that it isn't today, but the difference
is everything about it was new then. Fundamental technology was in the process of
being developed, and then continual improvements would be made during the ensuing
decades until we get to where we are today with a permanent presence of men in orbit,
interplanetary science probes, space-borne telescopes, Earth environment sensors,
and space weapons, and thousands of active
communications satellites. The sky is awash with manmade objects. In other news,
satellite TV was quickly gaining in capability (including live transmissions and,
gasp, "Living Color" per NBC)...
 The distinction between
direct conversion, heterodyne, and superheterodyne receivers represents a significant
evolution in radio technology. Each type of receiver plays a crucial role in the
development of modern communications, and their invention marks important milestones
in the history of radio engineering. To understand these differences, we will explore
the invention history, technical descriptions, and practical implementations of
each type, including their inventors, patents, and notable applications. A direct
conversion receiver (also known as a "zero-IF receiver") represents the simplest
type of radio architecture. It was first conceptualized in the early 20th century
as a way to simplify radio designs by eliminating the intermediate frequency (IF)
stage...
 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..."
|
 While
acoustical tiles are not exactly the stuff of RF engineering, their properties
and their effects on sound waves are analogous to RF absorbers and their effects
on electromagnetic waves. Reflections that cause multipath reception of signals
that contain the same information but are out of phase and unequal in amplitude
to the primary (direct) path seldom combine to enhance the overall signal-to-noise
ratio, so placing absorbent material in the surrounding environment is necessary
to improve signal quality. This article from a 1959 issue of Popular Electronics
goes through the process of outfitting an area with acoustical tiles and gives some
empirical test data from before and after...
 1965 was near the beginning of the transition
from vacuum tubes (plasma state) to semiconductors (solid state). If you are not
familiar with tube circuits, when deciding what type of
mathematical operation is being performed by each circuit, mentally
replace the tube with a FET or a BJT. The tube plate becomes the transistor drain
or collector, the cathode is the source or emitter, and the control grid is the
gate or base, respectively. Don't worry about biasing. Circuits A, D, and I should
prove to be the easiest. Circuit F is pretty obvious if you look at the input and
output waveforms...
 Here is a simple JavaScript routine that
converts between frequency and wavelength in the electromagnetic field realm. Wavelength
and frequency are related by the following formula: c = λ * ν * √εr ; where c =
speed of light, λ = wavelength, ν = frequency, and εr = relative permittivity. Here
are some familiar objects and their equivalent wavelength-related frequencies in
air...
 If you read the physics and geographic news
of the day, most likely you have seen articles on the rapidly increasing
migration rate of the geomagnetic "north pole" over the past few decades. Magnetic
north has never exactly lined up with geometric north (as borne out in geological
samples of rocks), and neither has it ever been uniformly distributed across the
globe. Ancient explorers on terra firma and at sea knew that a magnetic compass
needle did not align with the same stars, moon, or sun position for every location,
after accounting for difference in longitude. That is because the earth's magnetic
field is very nonuniform in strength and does not follow straight lines from pole
to pole as they more generally do from outer space. A correction factor must be
applied to any magnetic north indication based ...
 Once a major manufacturer of both primary
(one-time use) and secondary (rechargeable) batteries, the National Carbon Company
changed names many times through acquisitions and mergers until its current incarnation
as GrafTech International. National Carbon Co. appeared frequently in electronics
magazines during the World War II era for their innovations in portable power
supplies. They are credited for developing the world's first "D" size dry cell battery.
This advertisement in a 1958 issue of Popular Electronics heralded the company's
introduction of what was essentially what we call a
hydrogen fuel cell ...
 One sure giveaway to the age of a picture
is the presence of a wheat penny, a buffalo nickel, or a Mercury dime. This 1957
advertisement in Radio & Television News magazine for
Channel Master antennas has all three. It shows a walking Liberty half dollar
as well. Quarters haven't changed much over the years, with George Washington's
head on the obverse side since 1932. The wheat penny design ended in 1959 when the
Lincoln Memorial was put on the reverse side in its place. Thomas Jefferson's head
has been on the nickel since 1938. Theodore Roosevelt's head was ensconced on the
obverse of the dime in 1946. John F. Kennedy was placed on the half dollar obverse
in 1964. This ad is about antennas, not coins, though. For a lot, if not most, of
RF Cafe visitors, there has always been cable and satellite television. For some,
TV has always been available on their smartphones...
 This Science Theme crossword puzzle for
January 24th 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!
 According to this 1976 issue of QST
magazine, in 1974 the FCC received 42,000 complaints of
radio frequency
interference (RFI). 38,000 of them (90%) involved interference to home-entertainment
devices such as stereos and TV sets. 34,000 (89%) of were found to be due to design
deficiencies in the home-electronic devices themselves. Since that time, and especially
since Wi-Fi and cellphones, the potential for RFI has increased significantly. Fortunately,
thanks to much more stringent compliance testing, the likelihood of interference
from a commercially produced device has been reduced, but the sheer volume of stuff
spewing some level of RF energy has raised the overall noise floor in heavily populated
regions around the world. Concurrently - and also fortunately - technology advances
in filtering, oscillator frequency stability, shielding, and modulation schemes...
 Being an old-school old guy (turn 62 this
year), I still work the daily
crossword puzzle in the daily newspaper - surely you've heard of it, that
antiquated print media form of which I am the only house on my street which has
it delivered daily. Old habits die hard, as the saying goes. Working the Sudoku
puzzles is also a pencil and paper exercise only because of my method of figuring
out the numbers. My older sister is a whiz at them, and she does them on her iPhone.
But I digress. In addition to the weekly RF Cafe Engineering and Science crossword
puzzles I create each week, I also like to post crosswords that appeared in the
vintage electronics magazines. This one appeared in a 1974 issue of Popular
Electronics...
 During World War II, the government
created a specification for military-grade cable and assigned the designation
RG-#/U, where "RG" stands for Radio Guide and the "U" stands for Utility. The
"dash number" was sequentially issued and has no bearing on the characteristics
of the cable. Founded in 1902 in St. Louis, Missouri, by Joseph Belden, the eponymously
named company has been and continues today designing and manufacturing coaxial cable.
Most of the RG-x/U coaxial cable types displayed in this 1951 Radio & Television
News magazine advertisement are still being used today, in particular the very familiar
RG-58/U (50 Ω), RG-59/U (75 Ω), RG-8/U (50 Ω), and RG-11/U (75 Ω)...
 This is cool. I saw a U.S. Air Force recruitment
advertisement in a 1960 edition of Popular Electronics pitching careers as radar
operators (air traffic control) and technicians (maintenance). The picture has the
dual-display
glide path and elevation sweeps from the MPN/13/14 radar system that I worked
on in the late 1970s - early 1980s. A photo I took circa 1980 of our unit based
at Robins AFB, Georgia, is shown below. The precision approach radar (PAR) operated
at x-band (10 GHz) with an operational range of 10 nautical miles. The azimuth
and elevation antennas were mechanically swept with motors that changed the geometry
of a waveguide having dipole stubs along its length. The entire PAR system ...
 60 years ago, when this article was originally
published in Popular Electronics magazine, most computers were constructed
either of gears or of vacuum tubes. The Univac in the photo below was a breakthrough
for having been
built entirely of transistors. Even with its "compact" size compared to is successor
the ENIAC, the total computational power and programmability was orders of magnitude
less than that of my handheld calculator, whose size is largely dictated not by
the volume of the electronic circuits, but by the size of the display and the need
for input keys larges enough to press reliably. Doesn't the photo of Pascal's calculator
of 1642 look like it could be a modern 19" rack-mount chassis, complete with handles?
 Have you heard of an electronic musical instrument
called a Theremin? You can still buy from Moog today the same sort of Theremin that
was described in this
Carl & Jerry episode from a 1961 issue of Popular Electronics magazine.
Ever the early adopters of breaking technology, the teenagers exploit the motion-sensitive
feature of the Theremin in hopes of improving Carl's basketball game. As usual the
boys, in mock dialog, describe the Theremin's operational theory for the benefit
of readers not familiar with the musical instrument. They do not, however, mention
that the device is named after its Russian inventor, Léon Theremin, who patented
the device in 1928. Read on to discover how a Theremin strapped to Jerry's back
was used to help Carl be a better free-thrower...
 Mrs. Helen McKee knew exactly what she was
signing up for when she agreed to marry Mr. McKee. After all, she met and got familiar
with the guy over the air during some rag chewing sessions. This story is a humorous
(and true) account of what life can be like for the
spouses of enthusiastic Ham radio operators. We all hope for
such an understanding 'significant other.' Melanie has certainly endured and
supported a lot of my pastime endeavors over the past 32 years. It's a short
read, so take a break and put a smile on your face...
 Listen to the RF
Cafe Podcast. It is a rare thing when I take exception (i.e., disagree) with
anything Mac McGregor has to say, but on the
subject of soldering I must object. In this 1956 installment of Mac's Service
Shop, Mac and Barney are discussing the plusses and minuses of making a solder joint
mechanically sound prior to applying solder. Barney mentions an article he read
where the author asserts that the only way to make a quality solder joint is to
wrap component leads and wire ends around posts, lugs, eyes, etc. and then flowing
the solder. Both Mac and Barney argue that a perfectly sound solder joint can be
made simply by laying the lead or wire in place and applying solder. From a servicing
perspective that sounds good, because - as I can attest to from much experience...
 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 ...
 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...
 Reactance charts were a dime a dozen (free,
actually) and appeared as regular features in electronics magazines in the days
before smartphone apps provided ready access to reactance versus frequency calculations.
This one was in the May 1959 issue of Electronics World. Calculators are
nice and indispensible in design work, but sometimes having "the big picture" of
how various values of inductance and capacitance "react" with changes in applied
frequency is often useful - especially if you are a newcomer to electronics. To
paraphrase a popular saying, "A
reactance chart is worth a thousand calculators."
 Here in the February 1947 issue of Radio-Craft
magazine is part three of a six-part series on
Antenna Principles. The first two parts concentrated on dipole antennas and
feeders, and multi-element long-line and rhombic antennas. Part three is on directional
arrays and radiation fields. In addition to a bit of theory, real-world examples
are given of various directional antenna configurations along with field strength
graphs. Without powerful computers to calculate and plot out predicted radiation
patterns, a large combination of experience and in-situ measurements was required.
A huge amount of time was spent for even relatively simple arrays. Finitely detailed
topographical and structural models are now available which, along with very precise
electromagnetic field calculation algorithms allows efficient and accurate planning...
 Good luck trying to find a good
ham radio related comic in any magazine today. I am convinced
that publisher boards either discourage or outright prohibit comics these day for
fear of hurting some overly sensitive person's feelings and inviting lawsuits, or
worse yet social media flaming frenzies. Fortunately, I am not afraid and am glad
to make these vintage comics available. You and I, being reasonable people, cannot
possibly find anything insulting or denigrating in any of these five comics, but
somebody could. BTW, for the non-ham, a "pink ticket" from the FCC is a notice of
violation, which could be anything from neglecting to announce your call sign every
ten minutes to having a faulty transmitter that is spewing noise outside your band...
 September 6th's custom
Antennas
themed crossword puzzle contains only only words from my custom-created lexicon
related to engineering, science, mathematics, chemistry, physics, astronomy, etc.
(1,000s of them). Clues with an asterisk (*) are specifically antenna-related. 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.
 "Praetersonic" - now that's a word you don't
run up against very often. It is a combination of praeter* (beyond) and sonic (related
to sounds), or what more familiarly is called ultrasonic. If fact, praetersonics
was the early term given to
surface acoustic wave (SAW) piezoelectric devices. Amazingly,
even as far back as the early 1970s, SAW filters were being fabricated that
worked in the 40 MHz realm. This Popular Electronics article does a really nice
job of introducing the basics of SAW and BAW (bulk acoustic wave) technology at
the time it was coming into the mainstream. Lots of hurdles still needed to be
overcome, like high insertion loss, difficult to control impedances and internal
signal reflections, etc. As with many new technologies, pundits cast hopeful
prediction...
 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 Lamar or the Bikini Atoll...
 RF Cafe visitor Brad B. just provided
the following
Watkins-Johnson Tech Notes for the collection: v5-3, v5-4, v5-5, v5-6, v6-2,
v6-3, v6-4, v6-5, v6-6, v8-1, v8-4, v9-1, v9-2, v9-3, v9-4, v9-5, v10-2, v10-5,
v10-6. They run the gamut from Solid State Limiting Amplifiers and Antenna Polarizations
to Digital Signal Processing for Multichannel Receiving Systems. Many old-timers
consider the W-J Tech Notes to be some of the best sources of circuit and systems
design guides ever written, especially for military, defense, and aerospace applications.
 Woo-hoo, I have finally achieved Ham radio
license Nirvana! Reporting this on World Amateur Radio Day seems appropriate. On
Saturday, April 15, 2017, I passed my
Amateur Extra exam in the presence of three VEs at the Wattsburg
Wireless Association meeting room in Erie, PA. Nearly 7 years have transpired since
I took the Technician test in the same room in 2010. My General license test was
taken at the Forsyth Amateur Radio Club meeting room in Winston Salem, NC, in, 2015.
Until the FCC updates my record in the online Universal Licensing System (ULS),
my call sign will be KB3UON/AE. Motivation for pursuing the Ham radio license goal
was ...
 These NEETS training modules created by the
U.S. Navy appear to have originally come out in 1990s and has been modernized a
few times since then, so the information is fairly up to date. You will still find
a lot of descriptions of vacuum tubes, but that is because even in 1998 the military
still had a lot of legacy equipment that needed to be maintained. This particular
module provides the student with an introduction to and history of
semiconductor physics. The chapter runs a total of 62 pages so
there's a lot of content...
 Anytime I see an airplane in a photograph,
my interest is immediately piqued to learn the story behind it - sort of like with
the "MPATI - Its Problems & Solutions" feature in the May 1963 edition of
Electronics World magazine. This "Aerial
'Private Eye' Traces TV Signals" story also involves airplanes and television
broadcasting, albeit in a completely different way. A couple enterprising broadcast
engineers created a company called Tele-Beam Industries, in Napa, California, that
measured and mapped TV signal strength in the region surrounding transmission towers
to provide the stations with information useful in marketing and radiation characteristic
planning. Signal strength measurements were made from some starting altitude down
to within 100 feet of the ground, in 100 foot increments, and was repeated in increments
of 10° of azimuth...
 Last week I posted Part 2 of this "Know
Your Electronic Chemicals" series which appeared in two 1960 issues of Electronics
World. Fortunately, I was able to obtain the previous edition with Part 1 (the
vintage magazines I buy typically sell for $2-$3 apiece on eBay). Many, if not most,
of the chemicals presented in the articles are not used anymore, but similar types are.
Interestingly but typically, almost no emphasis is placed on the use of protective clothing,
goggles, gloves, gas masks, etc. A lot of people were harmed unnecessarily due to not
taking basic precautions, but it just was not part of normal operating procedure. To
be honest, even though I know better, other than...
 Admittedly, I did not do any follow-up research
on this, but there is reason to believe that prior to this Radio News magazine
article, there was not a general agreement on what formula to use for thermal noise
in an electrical system. Here is a statement made by author S.J. Mallory, "At
first, however, there was no general agreement concerning the magnitude of this
basic Johnson noise power level. Some engineers used the quantity KTB, others used
2KTB and still others used 4KTB." We of course all use KTB nowadays for thermal
noise power - aka
Johnson noise. It's a good read on the subject of sources that determine the
noise floor of a system. There's also this kind of Johnson noise...
 NASA (and its predecessor NACA), and private
and public operators have been monitoring solar events in the optical realm for
many decades while attempting to correlate terrestrial phenomena with it. Auroral
light displays in the extreme polar regions have long been known to be caused by
solar flare and
coronal
mass ejections (CME). With the advent of radio, the electrical nature of the
upper atmosphere became evident when static (AM) and long range propagation affected
long range communications. Extreme CME activity eventually was associated with behavior
of the electrical power grid; indeed, massive blackouts and brownouts are to blame
for many. Last but not least came concern for sun-sourced electrons regarding satellites.
More than one 'bird' has been smoked by the sun's ejecta. In 1967 when this article
appeared in QST magazine, scientists were still in the early stages of
measuring and understanding the effects of solar activity on the sun. The Geophysical
Year... |
