|
 The
bridged-T filter is a quick-and-dirty construct used to notch out a specific
frequency that is interfering with a desirable frequency or band of frequencies.
It is a resonant LC (inductor-capacitor) circuit consisting of a single inductor
"bridging" a pair of series capacitors having a resistor to ground between them,
or, if preferred, a capacitor bridging one or two inductors. A convenient
nomogram (aka nomograph) is provided by the author in this 1964
Radio-Electronics magazine article for quickly selecting values, which was
a very popular design aid in the pre-calculator era. A slide rule could be used
to calculate a range of values when only a single variable was in play, but
juggling more than one variable (component value) was greatly aided by a
multivariable nomograph. Truth is nomographs can still...
 Television, in 1955, was still a relatively
new phenomenon to many - maybe even most - people. According to multiple sources,
the portion of American households with a TV set went from under 20% in 1950 to
nearly 90% ten years later in 1960. That was a meteoric rise, particularly considering
the expense of even a minimal TV. The technology was not even available commercially
when most people were born, so the rush to join in on the craze was akin to the
mass adoption of cellphones in the 1990s. "Carl &
Jerry" creator John Frye used his pair of electronics-savvy teenagers to help
make the "magic" behind recreating a moving picture on a CRT miles away from where
it was created. Water flowing through a garden hose has often been employed as an
analogy for current flowing through a wire to explain electricity to laymen and
beginning students of the craft. Here, it is not water flowing through the hose
but water leaving the hose and flowing through the air that serves to represent
an electron stream travelling from the electron gun to the phosphor-coated glass
front of a CRT. Frame rates, scan lines, deflection coils, and other relevant terms
are i
 "The
RF front-end (RFFE) industry, valued at $21 billion, is expanding beyond its
traditional focus on mobile and infrastructure to drive innovation in the automotive
sector. Each segment within the industry presents unique dynamics and growth opportunities.
After a difficult 2022, the smartphone market is showing signs of recovery, with
expected year-over-year growth of 4%, projected to reach 1.2 billion units by 2024.
The mobile RFFE market is predicted to hit US$18 billion by the end of 2024, though
it may face stagnation due to market saturation and pricing pressures. This
market is expected to expand, with the 2027 launch of RedCap..."
 I'm having a hard time writing this with
my eyes rolled back in my head. The last time I experienced this level of overwhelmedness
was probably the third or fourth week of my feedback and control class at UVM. Even
though
electricity and magnetism shares many complimentary and parallel concepts, for
some reason thinking in terms of magnetics when describing amplifiers, mixers, modulators,
etc., has always caused brain freeze. Maybe it has to do with an ingrained bias
due to my earliest dealings with circuits being from a technician background before
earning an engineering degree. The equations of electric fields and magnetic fields
are very similar so that helps lower...
 Temwell is a manufacturer of
5G wireless communications filters for aerospace, satellite communication, AIoT,
5G networking, IoV, drone, mining transmission, IoT, medical, military, laboratory,
transportation, energy, broadcasting (CATV), and etc. An RF helical bandpass specialist
since 1994, we have posted >5,000 completed spec sheets online for all kinds
of RF filters including helical, cavity, LC, and SMD. Standard highpass, lowpass,
bandpass, and bandstop, as well as duplexer/diplexer, multiplexer. Also RF combiners,
splitters, power dividers, attenuators, circulators, couplers, PA, LNA, and obsolete
coil & inductor solutions.
 Here we are with another set of three "What's
Your EQ?" circuit challenges, these from the February 1962 issue of Radio-Electronics
magazine. As usual, those challenges provided by Jack Darr are the purview of television
servicemen of the era. The photo shown of the problematic CRT display looks like
a chest x-ray or maybe hieroglyphics in the dark corner of a cave, but evidently
the artifacts are readily identifiable to an initiated few. The Forbidden Current
Path circuit answer is not what I thought it would be. I maintain that whether my
answer or the designer's answer is correct depends on the physical...
 "A new
world record
in wireless transmission, promising faster and more reliable wireless communications,
has been set by researchers from UCL. The team successfully sent data over the air
at a speed of 938 Gb/s over a record frequency range of 5–150 GHz. This speed
is up to 9,380 times faster than the best average 5G download speed in the UK, which
is currently 100 Mb/s or over. The total bandwidth of 145 GHz is more
than five times higher than the previous wireless transmission world record. Typically,
wireless networks transmit information using radio waves over a narrow range of
frequencies..."
 Sputnik refers to the first series of satellites
launched by the Soviet Union. The word "Sputnik" means "satellite" in Russian. The
launch of Sputnik 1 on October 4, 1957, marked a monumental moment in human history,
heralding the dawn of the Space Age and sparking a fierce technological competition
known as the Space Race between the United States and the Soviet Union. This satellite,
the world's first artificial one, orbited Earth at an altitude of roughly 215 to
939 kilometers and broadcast a radio signal that astonished the world, particularly
in the United States, where it spurred rapid advancements in aerospace and scientific
research. The successful launch of Sputnik was an achievement that was years in
the making, involving a combination of visionary planning, political motives, and
intensive engineering by some of the Soviet Union's top scientists.
Blog: Air Quality
Measurements with Particle Counters
 Transcat | Axiom Test Equipment, an electronic
test equipment rental and sales company has published a new blog post entitled "Provide
Essential Air Quality Measurements with These Particle Counters" that covers
how particle counters can provide essential measurement capabilities that can help
avoid contamination and support high manufacturing yields. These measurement tools
can detect and measure microscopic particles suspended in air that can contaminate
the most carefully planned manufacturing lines. Air particle counters can be designed
for various...
 In 1958, most people were not accustomed
to seeing the now-familiar maps plotting
sinusoidal
courses of satellites across the face of the earth. It had only been in October
of the previous year that any object other than the moon was in orbit around our
home planet - that was U.S.S.R.'s Sputnik. Just as people of all ages and all backgrounds
enthusiastically joined in the newfangled phenomenon of aeroplanes after the Wright
Brothers flew their fragile craft at Kitty Hawk, electronics communications and
scientists worldwide hopped aboard the satellite train. This article from a 1958
issue of Radio & TV News magazine provided insight into the construction
and flight characteristics...
 LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
 What were some of the
top issues of the radio and television industry half a century ago? In a lot
of respects, the same things that concern it today. A ready supply of service technicians
was a concern that was taken seriously by the Electronics Industry Association (EIA).
While there are not many local repair shops for electronics products nowadays, there
is still a huge demand to techs who are willing and able to do the hard work of
keeping the world's communication infrastructure operational - climbing towers,
repairing cell equipment. Now, as then, good pay, job security, benefits, and respect
for the job being done were at the top of...
 In a parallel to the traditional test setup
of signal generation and signal acquisition, RIGOL Technologies announced today
the latest additions to its portfolio of
performance measurement equipment with the introduction of the DG5000 Pro Series
Generators and DHO/MHO5000 Series Oscilloscopes. The DHO/MHO5000 Series bring next-level
performance to RIGOL's respected line of high-resolution oscilloscopes, while the
DG5000 Pro generators do the same for the company's capable Pro Series arbitrary
waveform generators...
 When selecting articles for posting here
on RF Cafe, I like to include ones that are directed toward newcomers to the field
of electronics as well as for seasoned veterans. This piece from a 1958 issue of
Radio & TV News magazine entitled "Basic Electronic Counting," is a
prime example in that it introduces the concept of binary numbers. We've all been
there at some point in our careers. A big difference between now and when this article
appeared is that in 1958, almost nobody was familiar to binary numbers, and fuggetabout
[sic] octal and hexadecimal. Only those relatively few people designing and working
with multimillion dollar, vacuum tube-based digital computers installed in universities,
megacorporations, and government research facilities had ever dealt with digital
numbers. The earliest example of powers of two I remember was back in junior high
school. It had to do with a
 "Every invention begins with a problem -
and the creative act of seeing a problem where others might just see unchangeable
reality. For one 5-year-old, the problem was simple: She liked to have her tummy
rubbed as she fell asleep. But her mom, exhausted from working two jobs, often fell
asleep herself while putting her daughter to bed. 'So [the girl] invented a teddy
bear that would rub her belly for her,' explains Stephanie Couch, executive director
of the Lemelson MIT Program. Its mission is to nurture the
next generation of inventors
and entrepreneurs. Anyone can learn to be an inventor, Couch says, given the right
resources and encouragement. 'Invention doesn't come from some innate genius, it's
not something that only really..."
 Mechanical filters of the type described
in this 1969 Electronics World magazine article are yet another example
of the genius of some people. They are actually a form of electromechanical device
in that the applied electrical signals are first converted into mechanical signals,
followed by resonant mechanical elements that discriminate according to frequency,
and finally a conversion back to an electrical signal is made. It is fundamentally
the same principal as a crystal, SAW, or BAW filter, albeit each with distinctly
different methods and topologies. Mr. Donovan Southworth, of Collins Radio, presents
the basics of mechanical filters in this brief write-up...
LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
 Attempts at making an
electronically printed facsimile (fax) of an original document at a location
distant from the source have been around for quite a while. As mentioned by
Radio-Electronics magazine editor Hugo Gernsback in this article, Samuel Morse
had a crude working device for printing messages on paper even before his eponymously
named code of dots and dashes became famous in 1837. A couple decades earlier, a
fellow named John Redman Coxe, of Philadelphia, Pennsylvania, devised a method of
electronically printing images and text on paper using a conductive solution and
a direct current pile (aka battery). Dr. Coxe, a physician, is not a well-known
figure in the electronics world, but in his day...
 "Researchers have discovered how the 'edge
of chaos' can help electronic chips overcome signal losses, making chips simpler
and more efficient. By using a metallic wire on a semi-stable material, this method
allows for long metal lines to act like superconductors and amplify signals, potentially
transforming chip design by eliminating the need for transistor amplifiers and reducing
power usage. A stubbed toe immediately sends pain signals to the brain through several
meters of axons, which are composed of highly resistive fleshy material. These axons
operate using a principle known as the 'edge of chaos,' or semi-stability, enabling
the swift and precise transmission of information..."
 The January 1969 issue of Electronics
World magazine published an extensive list of
Japanese company trade names and their addresses. Many of them went out of business
or were bought by other corporations long ago, as occurs in all countries. "Aiwa"
is listed twice, but that might have been a legitimate duplication due to separate
locations (BTW, I owned an Aiwa stereo at one time). My first "real" cassette tape
deck was made by TEAC (founded in 1953 as the Tokyo Electro Acoustic Company) and
my first "real" stereo receiver was made by Sansui. I remember the line in "Back
to the Future 3" where Doc Brown, having time-travelled from 1955, makes a
disparaging remark about a circuit in the DeLorean failing because of it being labeled
"Made in Japan." Marty counters...
• ARRL Defends
902-928 MHz Amateur Radio Band
• FCC's
Auto Safety Spectrum Rules
• $5M in U.S.
Chips Act Money to Metrology Projects
• U.S. State Department Approves
Surveillance Radar System Sale to Romania
•
5G Americas ITU IMT-2030 Vision for 6G White Paper
 John Redman Coxe was a prominent American
physician, scientist, and innovator born on September 20, 1773, in Philadelphia.
Coxe's intellect and curiosity drove him toward an illustrious career in both medicine
and early scientific exploration, which included experimentation in electrochemistry.
He graduated with a degree in medicine in 1794, setting the course for his lifelong
journey into medicine and early scientific innovation. Coxe broadened his approach
to medicine and science, inspiring him to explore the convergence of scientific
methods and practical applications. John Redman Coxe is most remembered not only
for his contributions to medicine but also for his interest in experimental physics,
particularly in the field of electrochemistry...
 TotalTemp Technologies has more than 40
years of combined experience providing thermal platforms.
Thermal Platforms are
available to provide temperatures between -100°C and +200°C for cryogenic cooling,
recirculating & circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
 When I saw this 1966 Radio-Electronics
magazine article entitled, "Vibration
and Shock - Nature's Wrecking Crew," for some reason the first thing I thought
of was "The Wrecking Crew," that anonymously played the music for a huge number
of popular singers - mostly those without prominent bands of their own during the
1960s and 1970s rock-and-roll era. ...but I digress. My introduction to the potential
deleterious effects of vibration on electronics was in the 1970s, with airborne
receivers and servos in my radio controlled model airplanes. Even though they were
transistorized, vibration from glow fuel engines could wreak havoc with potentiometers
in servos and solder joints everywhere, including battery packs. I remember seeing
the control surfaces jitter...
 You don't see jobs advertisements like this
anymore. Here is an ad that appeared in the the July 1944 edition of QST
(the American Radio Relay League's, ARRL's, monthly magazine), placed by Raytheon
Manufacturing Company (now just Raytheon Company), looking for
vacuum tube design, test, and processing engineers. Licensed amateur radio operators
were in high demand during the war years because of their knowledge and enthusiasm
for electronics and wireless communications. I hope you didn't come to this page
hoping to really find a tube designer job available. Of course, there are still
vacuum tubes being designed for TWTs and magnetrons, but those are few and far between...
 The "carborundum"
signal detector, an innovative device developed by engineer General H. H. C. Dunwoody
in the early 20th century, represents a significant advancement in radio technology,
particularly in the context of crystal detectors used for receiving radio signals.
This device utilized the unique properties of silicon carbide, also known as carborundum,
which was synthesized in the late 19th century by Edward Goodrich Acheson. The connection
between Dunwoody and the material lies in the application of carborundum as a semiconductor
in radio signal detection. The operational theory of the carborundum signal detector
is rooted in its ability to rectify alternating current (AC) signals. When radio
waves, which are essentially electromagnetic waves...
 "Researchers have created a cutting-edge
structure by placing a very thin layer of a special insulating material between
two magnetic layers. This new combination acts as a quantum anomalous Hall insulator,
significantly broadening its potential use in developing ultra-efficient electronics
and innovative solar technology. A Monash University-led research team has found
that a structure featuring an ultra-thin topological insulator, sandwiched between
two 2D ferromagnetic insulators, transforms into a large-bandgap quantum anomalous
Hall insulator. This heterostructure opens the door to ultra-low energy electronics
and even topological photovoltaics..."
|
 October 1954 arrived with the first-ever
issue of Popular Electronics. Editor Oliver Read wrote this introductory note describing
the magazine's grand plans for providing its audience with a sampling of as many
facets of electronics as possible, with projects for the do-it-yourself type (many
needed to be at the time), related hobbies like amateur radio and radio controlled
airplanes, military and commercial applications, short stories, tutorials, and an
endless supply of advertisements offering just about anything your budget could
afford. It turned out to be a pretty nice magazine, and many of the well-written
articles are still useful in today's world of nano-everything circuits - the fundamentals
haven't changed much: voltage still equals resistance times current ... Switzerland Electronics Market
 This is the electronics market prediction for
Switzerland, circa 1966. It was part of a comprehensive assessment by the editors
of Electronics magazine of the state of commercial, military, and
consumer electronics at the end of 1965. This statement was a bit unexpected:
"Although the Swiss are renowned for their precision work in watchmaking,
machine tools and instruments, their country is regarded as 'a bit backward' in
electronics." Not many major national production companies resided in
Switzerland; IBM and RCA had a large presence, though. Unless you can find a
news story on the state of the industry, detailed reports must be purchased from
research companies...
 Let us finish off the year 2021 with some
humor; goodness knows we need it after yet another 365 days of what has been awfully
close to a worldwide COVIDictatorship. "15 Days to Slow the Spread" back in early
spring of 2020 mutated like a coronavirus into unlimited variants of government
mandates restricting or destroying freedom of movement, freedom of association,
freedom of personal health choice, freedom of comfort, and numerous other freedoms.
These
electronics-related comics appeared in a couple 1949 issues of Radio-Electronics
magazine. Enjoy (if you still can). I do wonder why the octopus only does the work
of three servicemen...
 If there is or ever has been a solid state
device that required as much painstaking, precise, manual assembly required as some
of the magnificent vacuum tubes developed over the years, I don't know of it. This
500 kilowatt "super-power beam triode" featured in a 1950 issue of Radio &
Television News magazine is a good example. Think of the electrical, mechanical,
chemical, and manufacturing engineering that went into designing, building, and
testing such devices. Half a megawatt from a single tube is quite an accomplishment.
It required a 900 watt control grid signal for modulation. The article refers
to an electron-optical system, and I'm not sure what it meant unless it is the array
of 48 sharply focused electron beams...
 Werner von Braun and his team of rocket scientists
are credited with developing the first useful inertial stabilization platforms for
ballistic missiles. The infamous and formidable V2 rocket wreaked terror upon the
heads of Londoners during the latter days of World War II. It served to keep
the rocket in a fixed orientation during the boost phase of the flight, but did
not serve any active targeting function.
Inertial navigation systems, on the other hand, are used to provide both accurate
positional and attitude information for the pilot (if the platform has one) and
to steer the platform (vehicle) to a predetermined destination. Inertial navigation
systems are therefore much more complex. Early inertial navigation systems relied
on physical spinning gyroscopes mounted within a series of nearly frictionless gimbals
to maintain a fixed reference position in space. Contactless encoders about the
rotation axes of the gimbals sent positional information to a computer, which then
performed necessary calculations and sent formatted data to visual flight instruments...
 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...
 This story from a 1941 edition of National
Radio News reports on the FCC's having passed regulations to allow the
rollout of commercial television service as of July 1, 1941. These standards,
observes the Commission, "represent, with but few exceptions, the undivided engineering
opinion of the industry." They "satisfy the requirement for advancing television
to a high level of efficiency within presently known developments." Furthermore,
"Frequency modulation is required for the sound accompanying the pictures. Thus,
television is now benefited by the recent developments of frequency modulation."
It was an era of wonder and excitement in the world of wireless communications...
 The National Company, of Malden, Massachusetts,
which made this
cesium-based Atomichron in the mid-to-late 1950s, began life as a toy manufacturer.
It had an output frequency at the nominal resonance frequency of cesium - 9192.631830 MHz
- and was accurate to better than a second in 600 years. The unit was 7 feet tall
and weighed 500 pounds. Modern cesium standards are more stable and are portable.
As of January 2013, the NIST-F1 cesium fountain primary frequency standard is accurate
to within one second every 100 million years! That's a tad better than the Atomichron,
non?
 Here is an unusual twist in waveform recognition
presented by Radio-Electronics' and Popular Electronics' quizmaster,
Robert Balin. If you happen to be a former analog television repairman, then you
will probably recognize the answers based on your many years of diagnosing faulty
horizontal or vertical
sweep circuits. If not, then you might need to strain the "little gray cells"
a bit, as Agatha Christie's premier sleuth Hercule Poirot might say. The instructions
say to assume that if you choose the horizontal sweep sawtooth to be the errant
signal, then assume the vertical sweep sawtooth is correct, and vice versa. Right
off the bat, waveform 8 is unique enough to easily identify the sweep that would
produce it since only one has two repeating components. Most of the others can be
readily deduced, too, by mentally following the x and y points as the "correct"
sweep...
 We hear and read a lot in the news about
the electronic surveillance carried out by governments - on both foreign
entities and civilians. If you think this is a phenomenon that has only existed
since the age of cellphones and the Internet, you might be interested in this article
that appeared in a 1945 issue of the ARRL's QST magazine. Long before
the entire textual content of the Encyclopedia Britannica could be carried on a
USB stick in your pocket - and access virtually all the information in the world
on your iPhone, engineers were developing recording media to facilitate the
capturing and later analysis of over-the-air and wired communications. They
wanted both encrypted and unencrypted conversations. The National Archives has a
huge store of magnetic tapes, vinyl discs...
 The opening paragraph of this installment
of
Mac's Radio Service Shop includes a reference to someone named Dr. Kildare.
As the article appeared in a 1954 issue of Radio & Television News magazine,
you are excused for likely not being familiar with the good doctor. I remember Dr. Kildare
(a fictional character) as a Prime Time TV show that aired in the 1960s, but his
legacy goes back to the 1930s in movies and radio. Back to the story line, though.
Mac is wearing a newfangled type of headphone that must have looked like a stethoscope,
and that triggered Barney's comment. However, as is often the case, the subject
quickly changes to advertising techniques where Mac explains his philosophy of honesty
being the best policy. Along with such probity must be an effort to convince potential
customers that preventative maintenance is a sign of responsible ownership. Just
as you would take your car in for a relatively low cost annual checkup to hopefully
avoid a major bill later, TVs, radios...
 Listen to the RF
Cafe Podcast! A November edition of "Mac's
Radio Service Shop" is appropriate given today's date, especially since author
John T. Frye nearly always had the story's setting coincide with the month
in which it appeared in Radio & Television News magazine; the year
was 1951. The unspecified dateline is somewhere in the upper Midwest, most likely
Indiana. Mac's mention of converting a black-and-white television set to color by
installing a "color wheel" really betrays the era. The NTSC (National Television
System Committee) had not yet adopted an industry standard for color TV, and the
various manufacturers were selling a mix of mechanical, electro-mechanical and all-electronic
sets. In 1953, the NTSC settled on a 525-line interlaced scan (only 468 lines are
part of the visible scan). Knowing that a better color system would be available
soon due to massive public demand, Mac put his efforts into talking customers out
of a color conversion...
 Well, this might get some dander up amongst
the believers that Sir Robert Watson-Watt is "the
Father of Radar." In the December 1957 edition of Popular Electronics magazine,
Colonel William R. Blair was given that honored designation based on his work on
a pulse-echo method of direction finding in the 1920s. The Wikipedia entry for Col.
Blair refers to him more specifically as the "Father of American Radar." William
R. Blair was awarded U.S. patent #2,803,819, titled "Object Locating System," on
August 20, 1957 - a full 13 years after the patent application was submitted. Watson-Watt
was issued a patent in 1935 on a radio device for detecting and locating an aircraft.
His research was born out of an investigation into a "death ray" which had reportedly
been invented by the Germans.
 Here is the final installment in the "Basic
Digital Electronic Course" series that ran in three issues of Popular Electronics
magazine. The first two parts laid the groundwork with an introduction to binary,
octal, and hexadecimal arithmetic, Boolean logic, AND, OR and NOT gates, and some
truth tables. Armed with those fundamentals, the authors now dive into flip-flops,
encoders and decoders, debouncing circuits for switch inputs, integrated circuit
(IC) types, and interconnect methods to design and build a simple digital computer
with a 7-segment LED display. Don't expect too much from the computer since it was
only three years earlier, in 1971, that Intel introduced the world's first integrated
microprocessor - the 4-bit model 4004 central processing unit (CPU) ...
 As a follow-on to the "Planning Integrated
Signal Communications" story, this article is the next step in the U.S. Army Signal
Corps' implementation of
ubiquitous communications systems. Along with powerful transmitters and
super-sensitive receivers at command communications hubs are the many hand-held,
back-pack, and vehicular radios needed to complete strategic and tactical
operations across the face of the Earth. It wasn't just wireless systems that
Signal Corps engineers and technicians were responsible for, but also all the
wired equipment and interconnecting cabling. The possibility of software
configuration for network switches, radios, modems, telephones, antennas, and
ancillary components had never been thought of in 1950 (by very few, anyway).
Everything was set up with patch panels...
 This
electronics analogy quiz is a little easier than many of the others
published in Popular Electronics magazine because all of the electrical
and mechanical objects depicted here are very familiar. The concepts might seem
trivial to those of us who have been immersed in the science for decades, but I
for one can remember when first hearing these analogies how helpful they were.
Not only that, but I also recall during physics and mechanics courses in college
being amazed at the similarity of equations shared by electrical and mechanical
processes. Wikipedia has a huge page describing many of the most familiar
mechanical-electrical analogies...
 A lot of RF Cafe visitors might not be familiar
with some of the electronic devices presented in this
Electrochemistry Quiz by Popular Electronics' resident quizmaster, Robert
Balin (a big list of his other quizzes is at the bottom of the page). I offer my
assistance. A is a photocell, B is an early type of rectifier, C is a varistor, D is
a cathode ray tube (CRT), E is an electrolytic capacitor, F is a heated cathode in a
vacuum tube, G is a flashlight battery, H is an early receiver crystal detector, I is
a magnetic audio recording tape, and J is phonograph cartridge. I scored...
 This
Electronics Theme Crossword Puzzle for May 16th has many words and clues related
to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics,
and other technical 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. Enjoy!
 Many topics of the
electronics-themed comics which appeared in Radio-Craft were suggested by the
magazine's readers. Staff artists like Frank Beaven turned those suggestions into
cartoons. For a while there was a special feature called "Radio Term Illustrated"
where, as the name suggests, terms like "Signal Generator" and "High Potential"
are rendered in farcical form. These four comics, two of each type, appeared in
a May 1947 issue of Radio-Craft. I have to admit that even with my familiarity with
vintage electronics memes I do not get the Television "Organ" comic (yes, I understand
the organ grinder, but not how it applies to TV).
 Reading this article from a 1950 issue of
Radio & Television News magazine reminds me of a basic truth - at least
for receiving, it is usually possible to realize obtain useful operation with just
about
any reasonable length of straight wire for an antenna. Transmitting is a different
story since poor VSWR conditions on the antenna connection can damage or cause to
shut down the output stage of an RF power amplifier. Still, if your transmitter
can survive a high VSWR, then chances are you can send out a useful signal. You
won't be breaking any DX records or winning any contests, but you won't be dead
in the water. Surely anyone over 40 years old has jury-rigged an FM radio antenna
out of a length of straight (or bent) wire and/or fashioned a sheet of aluminum
foil around a set-top television antenna to pick up an acceptable signal. In many
cases where the 300 Ω twin-lead cable was improperly snaked along an aluminum
gutter or aluminum siding on a house on its way to the rooftop antenna or had a
long length of excess cable coiled... |
