In this adventure from a 1962 issue of
Popular Electronics magazine, Carl and Jerry were once again called upon
by law enforcement to apply their combined
electronics expertise to help collar a perp. By this time, the boys were college
students in the electrical engineering program at Parvoo U. (fabled to be a tribute
to Perdue). A storied past in their high school days is well-documented in previous
"Carl & Jerry" technodramas. Mr. Frye was always careful to provide a balanced
mix of technical prowess and adventure into his stories. It is easy when reading
these kinds of stories in today's world to ask what is so special about the feat
pulled off here, but in fact access to materials and equipment...
"Researchers have uncovered a way to manipulate
DNA at the atomic level using electric field gradients to control nitrogen nuclear
spins. Their findings suggest that DNA could be used as both a storage and computation
mechanism in future quantum computing devices. A recent study by researchers from
Peking University highlights the potential of nuclear electric resonance to control
the nuclear spins of nitrogen atoms in
DNA using electric field gradients. This breakthrough suggests that DNA could
one day be manipulated for computational purposes..."
RF Cafe visitors are involved in many aspects
of what has come to be known as "green energy" through direct involvement in resource,
component, and end-product production, through ownership of those end products,
and through paying taxes to government which allocate subsidies for all phases of
the life cycle. For example, with government incentives, an EV like the Tesla Model
Y may cost the buyer $46k. However, without subsidies, the real cost would be closer
to $66k to $76k. The pursuit of green energy encompasses both notable achievements...
SatNow maintains a list of
upcoming satellite launches from the leading launch companies. These include
NASA, Space X, Rocket, ISRO, Blue Origin and many more. Learn more about each launch,
its launch date, location and launch vehicle used. We provide the latest news, interesting
white papers, technical articles and an innovative product search tool. The product
search tool is the first of its kind and helps engineers find products across various
categories in three areas: Satellite, Ground, Launch. SatNow also provides a huge
collection of online calculators for satellite communications. Examples are an anomalistic
period calculator, an antenna G/T ratio calculator, an antenna polarization...
Mixing a little fun with learning has always
been a good motivation for students. I have written in the past about a particular
electronic circuits professor I had that liked to play practical jokes during lessons
and exams. Including gag options on a multiple choice test is a great way to inject
a bit of tension-easing levity while at the same time eliminating one or more opportunities
to guess at a wrong answer (although no relief for the truly clueless). I sometimes
do that on the RF Cafe Quizzes that I generate. Radio-Craft printed a large
bunch of such quiz questions under the title "Radio WittiQuiz," where the questions and answers were provided
by readers...
• Wireless Broadband Alliance's
10 Predictions for Wi-Fi in 2025
• Fixed
Wireless Access is Preferred Next Internet Connection (I use it)
• FCC Upholds
Forfeiture Order Against Ham Operator
• European
Commission Updates AI Act
• 345%
News Radio Listening Surge for LA Wildfires
Combinational logic is a fundamental category
of digital circuit design in which the output depends solely on the present input
values, without any memory or feedback elements. Unlike sequential logic, which
retains state across clock cycles, combinational logic circuits process input signals
in real-time and produce immediate output. The relationship between input and output
in these circuits can be described using Boolean algebra and truth tables. The history
of combinational logic dates back to the early 20th century when Boolean algebra,
introduced by George Boole in the mid-19th century, was first applied to electrical
circuits. In the 1930s and 1940s, engineers like Claude Shannon and George Stibitz...
This first of a three-part series on
digital electronics run by Popular Electronics magazine
begins with introducing binary (base 2), octal (base 8), and decimal (base 10)
number systems, along with conversions between the types. Sure, this is probably
old-hat to most RF Cafe visitors, but there is always a new cadre of electronics
enthusiasts entering the field who appreciate the instruction. No matter how advanced
digital electronics gets, a fundamental understanding and fluency in binary arithmetic
is essential to success whether as a hobbyists or as a professional. If you cannot
move effortlessly between the various number formats...
"The Federal Communications Commission (FCC)
last week announced a Special Temporary Authority (STA) for AST SpaceMobile to enable
its operator partners - AT&T and Verizon - to test its Bluebird direct-to-device
(D2D)
satellite constellation over the United States. Meanwhile, in the United Kingdom,
Vodafone has used the nascent Bluebird constellation to enable a video call between
Margherita Della Valle, Vodafone Group chief executive in Newbury, England, and
Vodafone engineer Rowan Chesmer..."
The
San Andreas Fault has been in the news again lately, with hundreds of small
tremors being detected along its 750 mile extent. Given its proximity to many of
the world's most important and valuable high technology companies, government facilities,
and universities, a delve into some of the issues is relevant to RF Cafe visitors.
According to some sources, the probability of a major rupture along the San Andreas
Fault varies depending on the specific segment and the time frame considered. According
to the Third Uniform California Earthquake Rupture Forecast (UCERF3), developed
by the USGS and other institutions, there is an estimated 7% chance of a magnitude
8.0 or greater earthquake occurring...
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For anyone seeking a way to offload surplus or obsolete equipment, they offer a
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available fully calibrated. Please check out Transcat | Axiom Rental Equipment today
- and don't miss the blog articles!
Put on your thinking cap again and take
a shot at these trio of new circuit analysis problems that appeared in the "What's
Your EQ?" feature in the February 1964 issue of Radio-Electronics magazine.
These days, I'm guessing not too many people are familiar with the characteristics
of neon bulbs, and even way fewer with vacuum tube circuits. Neon bulbs were one
of the earlier forms of voltage references since once ignited, the voltage drop
across them is fairly constant, sort of like a gaseous Zener diode - except there
was zero current flow prior to ignition. Although I didn't know for sure, I figured
that even with its high input impedance...
It is doubtful that as many people today
build their own
stereo speaker enclosures as was the case back in the 1950s through about the
1970s. During those decades stereo equipment was a really big deal, as evidenced
by the large number of articles in technical and hobby magazines. I have posted
a couple dozen articles on the subject here on RF Cafe. Topics included equipment
reviews and feature comparisons, troubleshooting and alignment, modifications to
commercial units, build-it-yourself projects, optimized room layout and construction,
and even advice on how to best enjoy your stereo system. Lots of comics appeared
in the magazines as well poking fun at how a stereo enthusiast's family members
and neighbor might not appreciate the ear drum-busting power capability of your
system. There were also quizzes like this one on speaker enclosure baffle design ...
The long-running
patent litigation between ParkerVision and Qualcomm is in the news again. It
has been a significant case in the wireless technology industry, focusing on radio-frequency
(RF) receivers and signal down-conversion methods. Given the importance of RF technology
in Bluetooth, ZigBee, Wi-Fi, and even wireless charging, the outcome of this case
has broader implications for wireless communication markets. ParkerVision's patents
center on RF down-conversion technology, a key process in wireless communications.
RF down-conversion involves converting high-frequency signals into lower frequencies...
"Ofcom has given Amazon the go-ahead to
launch satellite broadband services in the UK and simultaneously announced it is
releasing more high-band spectrum that could be used by the satellite industry.
Meanwhile, the UK government is also getting in on the act, allocating funding to
a pair of projects in the satellite space. The UK telecoms regulator has granted
an earth station network licence to
Amazon's Kuiper. That essentially means that the company has the green light
to provide satellite connectivity services, including high-speed..."
This is a story with a lesson learned by
the author and thousands of others ever since electric power appliances and tools
first became available. Fortunately, his Ham buddy was not permanently harmed, but
even today with all the effort put into educating the public, people continue to
use ungrounded (2-wire type, or with the ground prong removed) extension cords in
conjunction with 3-wire power cords on tools and end up
electrocuting
themselves (or somebody else). I've told the story before about a friend of mine
from high school who shortly after graduation was making a piece of furniture in
a garage that had a damp dirt floor, and was electrocuted to death by the metal-framed
circular saw that had no ground connected. Nowadays we often have power provided
by a GFCI receptacle...
Crane Aerospace & Electronics' products
and services are organized into six integrated solutions: Cabin Systems, Electrical
Power Solutions, Fluid Management Solutions, Landing Systems, Microwave Solutions,
and Sensing Components & Systems. Our Microwave Solution designs and manufactures
high-performance
RF, IF and millimeter-wave components, subsystems and systems for commercial
aviation, defense, and space including linear & log amplifiers, fixed &
variable attenuators, circulators & isolators, power combiners & dividers,
couplers, mixers, switches & matrices, oscillators & synthesizers.
If you believe this 1953 advertisement in
Radio & Television News magazine, engineering at
Bell Telephone Laboratories invented the wire-wrapping process. A little additional
research shows that indeed it was a Bell Telephone engineering team led by Arthur
Keller who developed the method and a wire-wrap tool to do the job. Field technician
needed a fast, durable, and reliable electrical connection when making hundreds
or thousands of splices at relay stations and while up on telephone poles. The key
to making a good wire-wrap connection is sharp corners on the wrapping post so that
the corner pushes through any oxidation or contaminant on the bare wire. NASA and
the Department of Defense (DoD) have exacting workmanship standards to guarantee
a rugged, durable electrical connection...
"Coordinate your actions, unify your approach,
and collaborate to fulfill a shared objective. This 'pep talk' succinctly captures
how NASA's latest swarm-based breakthrough operates. Known as
Distributed Spacecraft Autonomy (DSA), it allows each satellite to make decisions
independently while uniting with fellow spacecraft to pursue collective goals, all
free from human oversight. Within NASA's DSA project, researchers achieved multiple
unprecedented feats when testing technologies for satellite swarms. Managed at NASA's
Ames Research Center in California's Silicon Valley, the project..."
This article reporting ongoing research
for
auto anti-collision systems and backup warning systems appeared
in a 1972 issue of Popular Electronics has only come to practical fruition
within the last decade and a half. High-end cars were offering such equipment
options in the early 2000s, but it has only been commonplace since around 2010.
1972 components were still pretty large and power hungry, and digital processing
capacity and speed was significantly less advanced as well. Bendix, one of the early
developers of anti-collision systems, estimated that the option on a new car might
add about $200 to the price, which was...
The debate over whether to
stop minting new pennies is rooted in economic efficiency, public convenience,
and the broader impact on commerce. President Trump's directive to the Treasury
Department to halt penny production is driven by the fact that each penny costs
nearly three cents to produce, leading to a financial loss for the U.S. government.
However, this decision raises concerns about potential shortages, changes in pricing
strategies, and consumer sentiment regarding the smallest unit of U.S. currency.
One major argument in favor of stopping penny production is the high cost...
Providing full solution service is our motto,
not just selling goods. RF &
Connector Technology has persistently pursued a management policy stressing
quality assurance system and technological advancement. From your very first contact,
you will be supported by competent RF specialists; all of them have several years
of field experience in this industry allowing them to suggest a fundamental solution
and troubleshooting approach. Coaxial RF connectors, cable assemblies, antennas,
terminations, attenuators, couplers, dividers, and more. Practically, we put priority
on process inspection at each step of workflow as well as during final inspection
in order to actualize "Zero Defects."
Here are four more
electronics-themed comics to help get your work week started on a happy note.
They all appeared in Radio-Electronics magazine in the 1960s. The page
107 comic conjures up a bit of a nostalgic memory in me, remembering earlier days
sitting at a workbench and troubleshooting a piece of electronics gear. I never
heated a coffee pot on a chassis, but definitely remember cases with vacuum tubes
operating inside that were hot enough to do so. Some of those buggers could melt
flesh. I've told the tale before how whilst in the USAF tuning up our air traffic
control radar system, I (and fellow techs) would open an access door on the front
(not intended to admit passage of a human hand) and blindly "walking" tuning wand-carrying
my fingers across the tops of piping hot tubes to get to a potentiometer...
"Join The Engineer, Dassault Systèmes, BAE
Systems, Monolith AI, AMRC and others experts from across industry on Tuesday Feb
25th for this online panel session exploring
what the rise of AI means for engineers. AI is currently dominating industry
discussion, is at the heart of industry's accelerating digital transformation and
is widely anticipated to be one of the most transformative trends in manufacturing
and engineering as more and more engineering and manufacturing organizations look
at how they can integrate AI capabilities within..."
The late 18th century was a period of intense
effort to standardize measurement systems in both France and the United States.
Thomas Jefferson and the French Academy of Sciences independently developed proposals
for a
rational system of weights and measures based on decimal principles. While Jefferson's
system was designed for national use, the French metric system aimed for universal
application. Despite their similarities, the two systems differed in fundamental
ways, particularly in their definition of base units...
Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Exodus' model
AMP20100 is an elegant, quiet, broadband class A/AB solid state amplifier (SSPA)
and excellent TWT replacement. Ideal for EMC/EMI testing applications including
automotive pulse/radar & commercial applications. Frequency ranges from 2.0
to 8.0 GHz, 200 W minimum, 250 W typical, 53 dB minimum gain,
and -20 dBc harmonics. Monitoring...
The
Gloster E.1/44, presented in this 1948 issue of Popular Science magazine,
was a British experimental jet fighter developed in the 1940s as a potential single-engine
counterpart to the twin-engine Gloster Meteor. Designed by the Gloster Aircraft
Company to meet Air Ministry Specification E.1/44, it was powered by a Rolls-Royce
Nene turbojet and featured a sleek, straight-wing design with a tricycle landing
gear. Initially conceived as a simpler and more economical jet fighter for the Royal
Air Force, the project faced numerous delays due to shifting priorities...
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.
In much the same way as the solution to
a word problem seems obvious when you look it up in the back of a textbook, Sylvania's
answer to manufacturing a
vacuum tube heater element that is more robust and less subject to vibration
failure is illustrated in this advertisement which appeared in a 1968 issue of
Radio-Electronics magazine. Eliminating the suspended element and wrapping
it securely on a supporting post facilitated an "instant on" requirement for up-and-coming
transistorized televisions and radios by reducing heat-up time to about a second.
The heater's symmetrical shape also assured even emission of electrons from the
cathode. Its captured winding around the support post also eliminated the annoying
failure mode where a broken-off heater...
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It is probably safe to say that most people, especially
today, believe that the United States was suddenly and unexpectedly thrust into involvement
in
World War II on December 7, 1941, when the Japanese navy launched a
surprise attack on Pearl Harbor. The fact is the U.S. was "unofficially" engaged
for over a year beforehand by "lending" both equipment and personnel to British,
Russian, Chinese, French, and other militaries as part of their effort to drive
back invading German, Italian, and Japanese Axis forces. World War II actually
began in the Fall of1939 with Hitler's invasion of Poland. Americans, being
safely separated from the front lines by the Seven Seas, knew little of and were
concerned little about the goings on "Over There." Once the call to arms was
sounded with the Pearl Harbor attack, the country quickly and enthusiastically
converted to full wartime mode. Manufacturing plants...
Hugo Gernsback is not necessarily a household
name in 2020, but in the early to middle 20th century, he was fairly well known
in both the hard science and science fiction realms. He was a prolific author of
books and magazines in both areas, applying his profound knowledge of technology
and his ability to foretell the futures of many aspects of communications, mechanics,
electronics, and marketing and societal behavior to the aforementioned. If you are
a regular RF Cafe visitor, you have seen very many articles written by Hugo Gernsback
reproduced. This particular work of prognostication appeared in a 1947 issue of
his Radio-Craft magazine. It presciently claimed that a post-war boom in
consumer buying after half a decade of sacrifice of creature comforts for the good
of the country and world would feed a significant adoption of
FM radio
over...
For twenty years now, I have been creating
weekly crossword puzzles for the education and enjoyment of the technically minded
visitor like you. This
Science Theme Crossword Puzzle for May 23rd 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!
I finally managed to get an early edition
of The
Wireless World magazine for a reasonable price on a eBay auction. Now I
will be able to post a few of those articles from the UK to compliment those from
some of the American magazines. This particular edition is from March 9th, 1932.
My next target is to get a few from the World War II era which although it began
on December 7, 1941 from America's perspective, it officially began on September
1, 1939 for Europe. Warning for the weak of heart - epochal words like "niggardly"
and "parsimonious" are used herein, and therefore adult supervision should be employed
if ignorance might cause an objection to at least one of the aforementioned...
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...
Part 1 of this 3-part article, titled
"Influence of the Antenna of the Choice of Wavelength for Best Communications,"
appeared in the February 1952 issue of QST magazine. Unfortunately, I do
not yet own that edition. However, I do have Part 3, which subsequently appeared
in the August 1952 edition. It will eventually get posted here. QST does
not have a publicly available archive, but if you happen to be an ARRL member, you
can access Part 1 after signing in. In this series, author Yardley Beers discusses
propagation
effects, modulation systems, and receiver techniques. A particularly interesting
topic included in this installment is that of using a form of pulse modulation in
FM broadcasting in order to exploit the 'capture effect' whereby a signal in the
presence of noise will tend to suppress the noise. I don't think modern stations
use that method, possibly because of incompatibility with stereo channels and data
added for digital readouts...
Robert Radford's (not to be confused with Robert
Redford) "Electromaze"
is a unique - and weird - sort of word puzzle that first appeared in the April 1966 issue
of Popular Electronics magazine. Some people were confused about the strategy,
believing that all the white spaces needed to be filled in. They do not. Just because
a letter might have an empty square adjacent to it does not imply that another letter
must fill it. You will probably want to print out the maze grid and find an old guy who
should still have a pencil stowed away somewhere you can borrow to use for filling in
the boxes...
America's first successful orbiting of a
satellite launch happened on February 1, 1958 with the launch of Explorer 1
atop a Juno 1 rocket. Our first attempted satellite launch was the Vanguard TV3,
on December 6, 1957, but it unfortunately succumbed to a failed booster rocket (it
rose only 4 feet off the launch pad). Russia had already launched its Sputnik 1
satellite on October 4, 1957, making it the very first manmade satellite to orbit
the earth - to the forever chagrin of U.S. scientists. Fortunately, advances occurred
rapidly for the U.S. space program after Explorer 1. In its first full decade
of existence, the
Goddard Space Flight Center, located in Greenbelt, Maryland, was responsible
for launching more than 100 different spacecraft...
It was a lot of work, but I finally finished
a version of the "RF &
Electronics Schematic & Block Diagram Symbols"" that works well with Microsoft
Office™ programs Word™, Excel™, and Power Point™. This is an equivalent of the extensive
set of amplifier, mixer, filter, switch, connector, waveguide, digital, analog,
antenna, and other commonly used symbols for system block diagrams and schematics
created for Visio™. Each of the 1,000+ symbols was exported individually from Visio
in the EMF file format, then imported into Word on a Drawing Canvas. The EMF format
allows an image to be scaled up or down without becoming pixelated, so all the shapes
can be resized in a document and still look good. The imported symbols can also
be UnGrouped into their original constituent parts for editing...
A good primer on the physics behind and
use of
thermistors was published in the November 1956 edition of Popular Electronics.
Thermistors are fundamentally substances that exhibit a large change in resistance
for a given change in temperature, called temperature coefficient of resistance
(TCR, or RT). Standard resistors would ideally maintain the exact same resistance
regardless of temperature, but in reality most resistor types increase in resistance
with an increase in temperature; i.e., a positive TCR. Most thermistors have a negative
TCR, which makes them useful for cancelling out resistor temperature sensitivity.
Thermistors are also used for temperature sensing and measurement, although thermocouples
generally do a much better job for that application...
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."
Frequency hopping spread spectrum, first
proposed and patented by Hollywood actress Hedy Lamarr, relies on both transmitters
and receivers to precisely tune in a pseudorandom manner to a band of discrete frequencies
in a time-synchronized manner with each other. The faster an encoded signal hops
between frequencies, the more difficult it is for an unintended listener to decode
the message. Same goes for the number of discrete frequencies used in the spread
spectrum scheme. Modern computer programs and fast-tuning receiver systems can gather
huge amounts of information spread across a broad bandwidth and re-assemble it into
intelligible data, and if an unlimited amount of time was available to do so, just
about any message can be decoded...
Radar speed guns have been the bane of drivers
- and the bounty of police department coffers - since the 1940s. The technology
that helped the Allied Forces win World War II was exploited immediately thereafter
by law enforcement in an effort to make the highways a safer place. Rather than
relying on a police officer's learned estimation of a car or truck's speed, a certified
radar unit was used by a trained operator. Prior to the advent of speed radar, a
common method for determining a motorist's speed was to measure the time taken to
travel between two points whose distance apart was known. The information was admissible
in court, but was more vulnerable to a crafty prosecutor's interrogation. Radar
removed that variable, although there probably have been cases where the accuracy
of the radar unit was challenged in terms of electronics performance, false signal
returns, adjustment for slant ranges, etc. The cover photo of this 1947 issues of
Radio-Craft magazine shows a constable...
Even though this CW (continuous wave, for
sending Morse code)
transmitter circuit was published in 1955 in Popular Electronics magazine,
it is still legal for today's Amateur radio operator. Portions of the 40-meter and
80-meter bands are still reserved exclusively for CW operation. As of 2021, the
40-meter band (7.025-7.125 MHz) and the 80-meter band (3.525-3.600 MHz)
are both reserved for CW for Hams holding either Novice (no longer issued) or Technician
licenses. Additionally, the 15-meter band (21.025-21.200 MHz) and the 2-meter
band (144.0-144.1 MHz) have CW-only areas. That is different than the frequencies
given in the article, so beware if you are tempted to throw one together for old
time's sake. The value for XTAL will need...
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...
Homepage
Archives for September 2022. Items on the RF Cafe homepage come and go at a pretty
fast rate. In order to facilitate fast page loading, I keep the size reasonable - under a megabyte (ebay, Amazon, NY Times, etc., are multiple
megabytes). New items are added at the top of the content area, and within a few
days they shift off the bottom. If you recall seeing something on the homepage
but now it is gone, fret not because many years I have maintained
Homepage Archives.
Homepage
Archives for August 2024. Items on the RF Cafe homepage come and go at a pretty
fast rate. In order to facilitate fast page loading, I keep the size reasonable - under a megabyte (ebay, Amazon, NY Times, etc., are multiple
megabytes). New items are added at the top of the content area, and within a few
days they shift off the bottom. If you recall seeing something on the homepage
but now it is gone, fret not because many years I have maintained
Homepage Archives.
This is a really nice
electronic schematic symbols chart that will come in handy for hobbyists who
work with vintage electronic equipment. Not only does it have component symbols
that a modern chart (this appeared in a 1942 issue of Radio-Craft magazine)
would not likely contain, but it has three-dimensional sketches of each device.
For example, vacuum tube symbols show the tube outline, its socket configuration,
and the pinout. If you get nostalgic for some of these old parts, some of them like
the knife blade switch and ceramic light socket can be bought a many hardware stores
or online. It's too bad the chart is not in color because it would make a nice picture
to frame for a decoration. If anyone with an artistic bent feels compelled to colorize
it and send it to me, I'll be glad to make it available to visitors...
The newest release of RF Cafe's spreadsheet
(Excel) based engineering and science calculator is now available -
Espresso Engineering Workbook™. Among other additions, it now has a Butterworth
Bandpass Calculator, and a Highpass Filter Calculator that does not just gain, but
also phase and group delay! Since 2002,
the original Calculator Workbook has been available as a free download.
Continuing the tradition, RF Cafe Espresso Engineering Workbook™ is
also provided at no cost,
compliments of my generous sponsors. The original calculators are included, but
with a vastly expanded and improved user interface. Error-trapped user input cells
help prevent entry of invalid values. An extensive use of Visual Basic for Applications
(VBA) functions now do most of the heavy lifting with calculations, and facilitates
a wide user-selectable choice of units for voltage, frequency, speed, temperature,
power, wavelength, weight, etc. In fact, a full page of units conversion calculators
is included. A particularly handy feature is the ability to specify the the number
of significant digits to display. Drop-down menus are provided for convenience...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils
available for RF, analog, and digital system and schematic drawings! Every stencil
symbol has been built to fit proportionally on the included A-, B-, and C-size drawing
page templates (or use your own page if preferred). Components are provided for
system block diagrams, conceptual drawings, schematics, test equipment, racks, and
more. Page templates are provided with a preset scale (changeable) for a good presentation
that can incorporate all provided symbols...
The
Cleveland Institute was one of many electronics training organizations that
exploited the rapidly growing electronics service industry in the last century.
Although this particular two-page spread appeared in a 1968 issue of Popular
Electronics magazine, the trend began back in the 1930s. Earlier electronics
hobby and professional electronics publications like Short Wave Craft and
Radio News were pitching the unlimited opportunities for anyone with the
smarts and motivation for technical subjects as employees and/or owning a business.
Even in the days when there were user-serviceable parts (primarily vacuum tubes
and fuses) inside many electronic products, few people were willing to risk causing
harm to themselves or their hard-earned radio and television sets. Even by 1968
when most of the electronics industry had shifted to solid state circuitry, the
vast majority of existing equipment still had tubes in them. The television set
my parents owned ... |