|
 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..."
|
 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...
 I always learn something new with each episode
of "Mac's
Radio Service Shop," but not necessarily related to electronics. Such is the
case in this 1950 issue of Radio & Television News magazine where after Mac
gives Barney a quick lesson in how to determine a transformer's winding turns ratio
when needing to create an impedance match circuit. He then, while discussing whether
'free' repair estimates are truly free or of any real value at all, he uses the
phrase 'a horse on you.' Maybe it is because I don't frequent bars that I had never
heard that, but after a little research I now know it refers to a bar dice game
called 'Horse.' 'A horse on you' is when you lose the final round of a 2-out-of-3
challenge. 'A horse apiece' is when you and your opponent...
 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...
 Do you know how engineering whipping boy
Dilbert came to be called
by that name? Per Scott Adams, while working at Pacific Bell he ran an informal
name-the-comic-strip-engineer contest from his cubicle. A guy named Mike Goodwin
suggested Dilbert. "I ended the contest immediately and declared Mike the winner,"
says Adams. It sounded perfect. Years after the comic strip had become syndicated,
Mike commented that he believes the name idea might have come from seeing his father's
old WWII aviator comics with "Dilbert the Pilot." DtP was a screw-up, invented by
Navy artist Robert Osborn, whose purpose in life was to illustrate the wrong way
of doing things so that real pilots wouldn't make the same mistakes. The name was
funny then, as it is funny now. BTW, Dilbert is a variant of Delbert meaning nobly
famous. During the War, "dilbert" became a synonym for "blunder" for Navy pilots.
The Navy even produced an aviator safety film titled, "Don't Kill Your Friends,"
featuring Dilbert the Pilot...
 If only eBay had been around at the end of World
War II, this surplus equipment would have dominated the electronics and electromechanical
gizmo categories. Electronics magazines of the post-WWII era were filled for years with
advertisements like this one from
G & G Radio Supply Company in a 1953 issue of Radio & Television
News. That B-29 bomb sight, like the one used on the Enola Gay, could be purchased
brand new for a scant $295, which even in equivalent 2018 dollars of $2,758 (per the
BLS), is a steal. This is not the famous Norden bombsight, but it's still a
sweet collector's item, which is available on eBay today if you would like to
own one. Already have a B-29 bombsight? How about a complete IFF (Identification
Friend or Foe) secondary radar system? For a mere $350...
 Triacs are not a component often used in RF
and microwave circuit design, but being conversant in its operation could make you
popular at nerd parties. A triac is basically the equivalent of two SCRs connected
back-to-back, allowing it to conduct on both the positive and negative half-cycles
of an AC connection. Both devices are most commonly used in switching applications.
The unique feature of an SCR and triac is that once the gate voltage is sufficiently
high to begin conduction between the anode and cathode, it can be removed and conduction
will continue until the anode-cathode voltage is removed ...
 The Duoscope, as presented in a 1954 issue
of Radio-News magazine, was a pretty neat concept - sort of like a picture-in-picture
(PiP) scheme for television, only in a way much better. Whereas PiP provides only
a partial screen for each television program,
Du Mont's "Duoscopic" viewer somehow received two independent
signals and combined them on the screen in such a manner that there was both a horizontally
polarized for one show and a vertically polarized image for the other. The viewer
selected which picture to watch by wearing the appropriately polarized glasses or
by watching through a floor-mounted transparent, polarized screen. The superimposed
image on the CRT looked a lot like a virtually indiscernible 3-D picture as seen
without colored glasses. Similarly, the audio for each program was selectable using
a remote (wired) switch box. Headphones were used to provide private listening.
The Duoscope turned out to be just another "outside the box" concept that never
played out in the consumer world...
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...
 The opening line of this
Transistor Terminology Puzzle states it is the tenth anniversary of the invention
of the transistor, but that is because the crossword appeared in a 1958 issue of
Radio & TV News magazine. It was just before Christmas of 1947 that
Drs. John Bardeen, Walter H. Brattain and William Shockley announced their
discovery from Bell Laboratories. Note that 1947 is eleven years earlier, not
ten. However, the theme of this crossword seems to reference the bipolar
junction transistor (BJT), which was developed in 1948 - hence the 10th
anniversary claim. The first transistor was a point contact type. Print out the
page and have a go at it...
 As mentioned often here on RF Cafe,
especially with an ever-increasing amount of devices and appliances with "no user
serviceable parts inside," the demand for electronics technicians is as great today
as it was decades ago. Associated equipment is significantly different now and a
lot more of it consists of swap-out modules and assemblies rather than performing
repairs in the field. However, there still exists a significant amount of
legacy electronics everywhere, and it all needs to be maintained
until upgrades are installed. There...
 Interestingly, when I searched for the
Hallicrafters TG-10-F Radio Keyer, the first thing that came up was an eBay
offering for a Gray Manufacturing Army Signal Corps "Keyer TG-10-F" Morse Code Practice
Machine. Evidently more than one manufacturer was contracted to make the model.
It looks like a tape record / playback machine, but it feeds a reel of paper strips
with dots and dashes followed by straight lines forming letters and words. An optical
reader encodes the audio signal for code practice students - up to 300 at a time
using the built-in amplifier. Morse code was a primary mode of communication during
World War II because the transmit and receive equipment was simple and reliable,
and could perform acceptable in the presence of noise and weak signals. It also
had the advantage of some level of privacy since most people could not understand
code, especially when sent at high data rates (WPM). There does not seem to be a
feed speed adjustment on the control panel... (see
update on Technical Manual)
 Here is another exciting episode of the sleuthing
adventures starring Popular Electronics' tech savvy teenagers, Carl and
Jerry. The "Hardy Boys of electronics" are the creation of author John T. Frye,
who created short story adventures for many years - long enough to at one point
require a major modification in the boys' appearances to reflect more modern attire
and eyewear (Carl's "The Far Side"-style glasses had to go). This particular adventure
begins with Carl considering whether his ham radio hobby is more useful from the
standpoint of its technical aspects or of its social aspects. An unrelated electronics-themed
comic is included since it appeared on one of the story pages.
 You always need to pay careful attention
to "breakthrough" type articles when they appear in April issues, since many magazines
have a tradition of burying an "April Fools' Day" item without notice. This April
1932 issue of QST magazine seems to be legitimate. The term "lycopodium
pattern" aroused my suspicion, but it turns out to refer to a pattern of vibration
that resembles the needle orientation of certain pines and cedars. As radio frequencies
continued to increase during the early years of "wireless" development, the use
of quartz crystals as a stable reference source ran into a physical limitation because
as crystal slices reached a certain thinness, overtone and subharmonics appeared
that caused problems in circuits. A new mineral called tourmaline saved the day.
With an elasticity much greater than quartz, tourmaline is able to vibrate at higher
fundamental frequencies for a given thickness...
 Do a WWW search for
filter equations and you will find thousands of pages, including
a few here on RF Cafe. However, if you want an example of how to implement the transfer
functions in a spreadsheet or software, examples of actual code are elusive (other
than maybe a Matlab or MathCAD worksheet). As one who has incorporated equations
for Butterworth, Chebyshev Type 1, Chebyshev Type 2, and other filter
functions in many spreadsheets and software over the past few decades, I figured
it might be useful to post snippets of my code so that someone else can copy and
paste it directly into other work. BTW, I do not consider myself to be a filter
expert by any means and there is no ground-breaking knowledge here; it's just hopefully
easier to find. Writing a macro to use in a spreadsheet is the preferred...
 For many years I have been scanning and posting
"Radio Service Data Sheets" like this one featuring the International
Kadette Model 1019 A.C. Superhet Radio in graphical format, and also include
some textual content to serve as search engine keyword targets. There are still
many people who restore and service these vintage radios, and often it can be difficult
or impossible to find schematics and/or tuning information. As shown in the thumbnail
image, you can still find many of these old radios in condition ranging from disaster
to fully restored. I will keep a running list of all data sheets to facilitate a
search...
 Lots of old-time sci-fi movies and TV shows liked
to display
Lissajous patterns on oscilloscopes when an authentic high tech look was
needed in a scene. Every engineer, technician, and physicist in the world - me
included - roll his or her eyes at the sight of such a lame attempt to impress
the public. Of course the truth is the first time I saw a Lissajous pattern
gyrating on an o-scope screen, I was mesmerized. The need to crank on the signal
generator knobs and take control of the electroluminescent object d'art was
overwhelming. Now, in the same manner that watching the first couple Space
Shuttle launches was a thrill not to be missed and then became just another
launch, so, too, is watching a live Lissajous pattern on a scope - it's just
another Lissajous. Except, well, that's not quite so - at least for me. I always
eagerly viewed Shuttle launches...
 I have no idea why this "LSI Gives Semiconductors
a 'Trip'" quiz from Popular Electronics magazine is titled what it is.
LSI stands for "Large Scale Integration" and is generally applied to integrated
circuits, not discrete components. The quiz's creator has come up with 17 questions,
only the first of which has anything to do with LSI circuits. The other 16 are on
topics like capacitor plate spacing, magnetorestrictive material, and coaxial cable.
I realize that LSI attempts to minimize the number of external components necessary
by absorbing them into the IC, but I'm just not sure what that has to do with whether
a submarine can communicate via SHF while submerged.
 Transistors always have been and always will
be prone to damage or destruction if operated at temperatures higher than their
designed ranges. Modern foundry processes have made it possible for greater heat
tolerances for a given transistor size, but care must be taken during circuit design
to assure that the devices will under normal ambient conditions not exceed their
intended temperature range. Often a
heatsink is required in order to use a transistor at its full rated temperature,
and sometimes extensive measures are needed to keep the heatsink within an acceptable
maximum temperature. Take a look inside your computer for an example of how far
heatsink technology has come. The liquid-cooled (desktop) and heat pipe-cooled (laptop)
schemes are amazingly efficient and capable of dissipating heat from the CPU package,
which would otherwise fry in milliseconds without it...
 Author Edward Tilton discusses here the tradeoff
between
bandwidth and sensitivity in receivers, given that broadband noise power follows
bandwidth in a 10 log BW fashion. Pulling in the most distant stations requires
very low noise in able to get the SNR as high as possible, which requires the minimum
bandwidth possible. Prior to highly stable local oscillators, operating successfully
in a narrow bandwidth for voice (phone), and particularly for CW (Morse code), dictated
the use of a fixed frequency crystal to keep from having to constantly re-tune the
station. Nowadays, of course, what used to be considered a metrology grade oscillator
can be bought for tens of dollars...
 Robert Taylor, along with inventing the concept
of "super-modulation," also coined the new communications term "Intelligence
Transmission Efficiency." It refers in part to the ratio of power in the intended
sideband relative to power in the at least partially suppressed other sideband and
carrier. Admittedly, I have not read this material enough to fully comprehend the
concept of super-modulation, but at least based on the Fig. 1 waveform, there
seems to be an element that adds a DC bias to the detected signal due to a nonsymmetrical
(about 0 Vdc) transmitter modulation by pumping more power into the positive peaks.
I'm happy to be corrected by any knowledgeable reader. For that matter, if you have
experience with super-modulation and care to share it with RF Cafe visitors, I'll
be glad to post your comments...
 Earth-Moon-Earth (EME) communications have
been used by amateur radio operators for a few decades now, made possible by more
capable transmitters and receivers as well as digital encoding which facilitates
operation closer to the noise floor. EME is regarded largely as a novelty branch
of Ham radio since relatively few people are set up to exploit it. In 1946, the
U.S. Army Signal Corps created "Project Diana," named for the Roman moon goddess
Diana, as an experimental exercise to bounce radar signals off the Moon and receive
the reflected signals. It was the first attempt at radar astronomy and was the first
time a terrestrial radio signal was bounced off another celestial body. Once artificial
satellites were orbiting in the late 1950's, Hams and other entities were encouraged
to detect and track orbits and signal transmission properties - including frequency
and power - to aid government engineers and scientists in determining stability
(electrical and mechanical), speed, rotation, altitude, path, atmospheric and cosmological
noise sources, and other parameters...
 Have you heard about this? I hadn't. If you
think the only goal in Afghanistan is to stamp out the Taliban, think again. An
article in the October 2011 issue of Scientific American details the extensive
mineral surveys that have been carried out there in the last year or so. Afghanistan
is home to what may be the largest cache of
rare earth elements
in the world, with a potential to replace China as the largest extractor (~90%)
of those atoms that lie in the lanthanide and actinide regions of the periodic table
- the two rows that are typically pulled out of the chart. China, you may have heard,
is severely restricting the export of rare earths - wanting to keep it for themselves
- thereby triggering a near panic. Prices are rising so alarmingly that reopening
mines in the U.S. has once again become profitable in spite of the crippling regulations
that years ago closed down operations here (huge loss of jobs and tax revenue) and
forced us to become reliant on offshore supplies...
 Call me obsessive, but the switch to and
from DST has bugged me not so much for its existence, but for butthead politicians
that won't keep their hands off of it. A few years ago I wrote a piece titled, "A Graphical
Look at Daylight Saving(s) Time," to deal with it, and then again last year
with, "Daylight Saving(s) Time vs. Standard Time." Research the history
of DST and you will see how often Congress has changed the days - always for good
reasons, don't you know. In 1958, the year of my birth, DST began on April 27th
 (vs. March 10th this year), and ended on September
28th (November 3rd this year) - See 1958 Old Farmer's Almanac pages. What else can
I say on the matter?
 The
Josephson effect was predicted in 1962 by British physicist Brian David Josephson.
It postulated the possibility of a resistance-less path for electrical current across
an extremely thin insulator sandwiched between two superconductors. Dr. Juri Matisoo,
of IBM, is credited with building the first Josephson junction switch in 1967, demonstrating
sub-nanosecond switching times. Back in the day, superconducting materials, like graphene,
were resources available only to well-funded research establishments like major corporations,
universities, and government facilities. Now, anyone with an interest can order both...
 With the extreme volatility of today's stock
market, I thought this might be a good time to re-post an article I wrote back in
2012 entitled "Arbitrage
via Microwaves." The ±200 point daily swings of a mere 8 years ago seem
paltry compared to ±1,000 of late. The original page on the IEEE Spectrum magazine
website is dead now, so I had to change the hyperlink to an archived page on
The Wayback Machine - a great resource for
you to remember if you ever need to retrieve a webpage that has been disappeared
[sic]. My piece begins: "If you have wondered why the world's stock markets behave
the way they do, why the DJIA falls 150 points on one day on news of Greece leaving
the euro, then gaining 200 points the next day on news of a bailout, then back down
a day later on more news of the bailout, your confusion is understandable. It seems
that there might be nobody who actually can predict the market's contortions...
 Once upon a time, all non-passive electronic
products and test equipment used vacuum tubes. Since tube diodes need a voltage
bias, even something as simple as a rectifier circuit was "active." Even though
modern day
transistorized equipment has largely overcome most of the disadvantages of solid
state versus vacuum tube, in the early days of silicon and germanium transistors
and diodes issues like voltage and power handling and input impedance was a limiting
factor to some applications. Until the advent of rugged and reliable field-effect
transistor (FET) transistors, if you needed a very high input impedance for an oscilloscope
or multimeter, a vacuum tube circuit was a necessity. A high impedance test instrument
input is required with high impedance device under test (DUT) in order to avoid
loading down ...
 This story from a 1963 edition of Popular
Electronics proves that my ongoing effort to point out that the sometimes harmless,
sometimes harmful
tensions between engineers and technicians is not a recent development. I have
told of my own witnessing of engineer vs. technician pi**ing contests stretching
back into the early 1980s during my first job as an electronics technician at Westinghouse
Electric. Rather than joining the fray, I appreciated the abilities of engineers
to provide, typically but with some exceptions, a good combination of academic and
real-world experience. Being a technician myself at the time, I also recognized
a tech's typically much closer association with hands-on experiences building, operating,
and troubleshooting electronic equipment. I was going to college at night working
on earning my BSEE, so I was determined to benefit from the strong points of both
groups. Having taken both technician level and engineering level classes in subjects
like circuit system analysis, I knew of the much higher level...
 In this episode of
Carl & Jerry, the teens ponder a question posed by Jerry's mother upon looking
down their hillside home: "[L]ook at all those TV antennas down there. Hardly two
of them are alike; yet they're all intended to receive the same stations. How come
there are so many different kinds?" That was all the pair needed to set them off
in an investigation to determine the answer. Being avid electronics and RF hobbyists
and experimenters, they discuss the principles of how antennas work, various types
of transmission lines, impedance matching, antenna types, bandwidth, and other topics
relevant to the challenge. As with most Carl & Jerry stories, the intent is
to educate the reader. As a bonus, I posted two of the electronics-related comic
panels that were in this edition of Popular Electronics...
 ...because
it is important to remember what is actually in it - not just what the Public Schools
teach about it::: "In CONGRESS, July 4, 1776. The unanimous
Declaration
of the thirteen united States of America, When in the Course of human events,
it becomes necessary for one people to dissolve the political bands which have connected
them with another, and to assume among the powers of the earth, the separate and
equal station to which the Laws of Nature and of Nature's God entitle them, a decent
respect to the opinions of mankind requires that they should declare the causes
which impel them to the separation. We hold these truths to be self-evident, that
all men are created equal, that they are endowed by their Creator with certain unalienable
Rights, that among these are Life, Liberty and the pursuit of Happiness..." |
