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 This is a great
electronics-themed comic from a February 1972 issue of Popular
Electronics. It encompasses the essence of the stereotypical salesman ruse,
especially in that era when people were sure that electronics repair services were
out to rip them off by selling unneeded services and replacement parts. Aspiring
TV technicians who couldn't grasp the technology moved on to working as mechanics
in a garage, poking tiny holes in brake lines to scare owners into paying for complete
braking system rebuilds. I usually like to post multiple comics on each page, but
at the moment only this one is available...
 "Scientists have achieved a major breakthrough
by creating the world's first next-generation
betavoltaic cell. This advanced power source was made by directly connecting
a radioactive isotope electrode to a perovskite absorber layer, a cutting-edge material
known for its efficiency. Betavoltaic cells generate electricity by capturing beta
particles emitted during the natural radioactive decay. In theory, they can operate
for decades without maintenance. Beta particles also present excellent biological
safety advantages, as they cannot penetrate human skin. The newly developed technology
offers a stable, long-term power supply without the need for recharging, making
it a promising next-generation..."
 Until solid state electronics had supplanted
the majority of vacuum tube type televisions and radios,
portable tube testers were essential equipment to successful,
efficient troubleshooting and repair in businesses and people's homes. Yep, believe
it or not the stories told about doctors and electronics repairmen visiting homes
are not just fables. I remember as recently as the 1960s having our family doctor
make house calls when I or one of my fours sisters got sick. Both doctors and TV
servicemen ceased the practice at about the same time - probably the result of a
Brotherhood of Electronics Technicians and General Practitioners collective bargaining
agreement ;-) Many column inches of editorials, articles, comics, and letters to
the editor were devoted to the trials and tribulations of in-home servicemen and
the experiences...
 Finally, a concise,
1,000-word essay (a picture's worth a thousand words, right?) that illustrates
how a capacitor can block direct current (DC), but pass alternating current
(AC), has been published! Even the uninitiated layman can now understand a
principle that has stumped even electrical engineering students for two
centuries. What used to require a familiarity with Faraday's and Ampere's laws,
electric field and charge theory, and a mastery of calculus to fully comprehend,
is now within the grasp of the common man. It is no longer necessary to use the
water system equivalent (e.g., pressure=voltage, flow=current,
diameter=resistance) of a rubber diaphragm inside a pipe to get through to
fledgling electric circuit students. This ingenious drawing appeared on an
online news site (no attribution).
 As with your school and college days where
once there was no longer any reason to memorize physical constants, conversion formulas,
and names of people, places, and things, much of the noggin's gray matter was repurposed
to remember topics of more immediate need. You can always look up what you have
forgotten. While studying for your Ham radio or FCC license, being able to be able
to quickly convert between wavelength and frequency is essential. Recalling on demand
frequency-wavelength pairs is a real time saver on a timed exam.
Even being able to perform the conversion on a calculator during the test takes
up valuable time that could be better used on other tasks. This handy-dandy chart
for converting...
 Quadrature modulation and demodulation is
as commonplace and unremarkable today as were Space Shuttle launches before NASA
cancelled the program in 2011 (eliminating America's ability to send astronauts
into space). However, before integrated circuit implementation was available, it
was a relatively rarely employed scheme. Yes, there were many applications using
analog quadrature systems, but use with digital communications requires closely
matched (amplitude and phase) pairs of mixers and power splitters / combiners, along
with close tracking over time and temperature. The "magic" of quadrature systems
is...
 Phosphorous: From Latin phosphorus "light-bringing,"
from Greek Phosphoros "morning star," literally "torchbearer," from phos "light,"
contraction of phaos "light, daylight" + phoros "bearer," from pherein "to carry."
Long before mankind had developed methods of bombarding phosphorous compounds with
electron beams to make them glow, 17th-century scientist Hennig Brand observed the
characteristic light emitting property of phosphorous when exposed to oxygen. No
doubt the Ancients noticed the naturally occurring glow of bioluminescent plants
and animals, and maybe even luminescent glow caused by the breaking open of phosphorous-containing
rocks. Radioactive decay in the vicinity of phosphorescent materials can also cause
a...
• 5 Trends Set to
Redefine Global Telecoms
• RAN
Sales Grow in U.S., Decline Globally
• U.S. Restricts
EDA
Software Sales to China
• FCC To
Close Robocaller Network Loophole
• NI Highlights Role of
AI in SDR Solutions for SIGINT
 Allegory is not an often seen style of prose
in the electronics writing world, and typically is not meant to be humorous; however,
there have been a few instances of it in the vintage electronics magazines I read.
One of the most famous examples of allegory is a story by Paul Bunyan titled "Pilgrim's
Progress." "She Wore a Red Germanium," by Leta Foster Ide, is a more contemporary
form of allegory that RF Cafe visitors will appreciate. Mike R. Fonic (microphonic)
is the lead character in the story who complains to his doctor, "I'm off my feed.
Got no capacity. Fact is, I'm in a breakdown." Mike's wife's Aunt Enna (antenna)
is no help, evidently. Come to think of it, the author's name, Leta Foster Ide...
 Since I am currently planning a loudspeaker
configuration to replace the original speaker in my 1941 Crosley 03CB floor model
AM / shortwave radio set, this article made for a good refresh on
audio frequency crossover networks. A very nice set of design
charts is provided. Of course today there is no need to design and build your own
since commercial units are very good and cost less than what I could build myself.
Many moons ago while serving in the USAF at Robins AFB, Georgia, I did actually
build my own crossover circuit for use in custom speaker cabinets I built in the
base woodshop. The speaker that came in the Crosley has a 12" cone, which is still
in good condition, but it uses an electromagnetic voice coil rather than a permanent
magnet like modern speakers use...
 Hidden away on page 134 of a 1959 issue
of Electronics World, at the end of a Mac's Service Shop-like
electronics shop docudrama (Another Day in the Shop) is this handy tip
on how to fabricate a make-shift
thermal wire stripper from a soldering gun or a soldering iron. The
beauty of thermal strippers over mechanical strippers is that they do not nick the
underlying metal wire. Heated elements melt the insulation and then a blunt edge
is used to slide the insulation off the end of the wire. Another advantage is that
you can strip a wide range of wire gauges and insulation types without needing to
adjust the jaws or change to a different hole location - although a proper temperature
setting is required to avoid a gloppy, stringy mess...
 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 filter models have been added
to the product line in July, including a 1200-3000 MHz highpass filter, a 118-137
MHz user-tunable VHF filter, and a 1215.6-1239.6 MHz / 1563.42-1587.42 MHz
GPS L1/L2 cavity duplexer filter. Custom RF power filter and directional couplers
designs can be designed and produced with required connector...
 You've heard of the World's Fairs, the most
familiar probably being the 1933 Chicago World's Fair where the theme was "A Century
of Progress." World's Fairs have been held in various cities worldwide since the
late 1790s. In 1929, the World's Fair was held in the United Kingdom, but the "Radio World's Fair," which began its annual run in 1924
(click on stamps thumbnail), was held in New York
City. Surprisingly little exists on the Internet about the events. It was more of
a trade show to introduce new products than it was a fair, as can be seen from the
photos. Radios with decorative wooden cabinets were becoming popular as the number
of commercial broadcast stations was growing rapidly. Remote control in the day
meant a handheld unit with a cable attached to the main system. Crosley introduced
its first gendered radio model - the Monotrad...
 Sprague Electric engineer Benedict Rosen,
discusses how the characteristics of a circuit in need of protection against RF
interference needs to be considered when selecting filter components. He points
out that attempting to hang a shunt
feedthrough capacitor on the input and/or output of a low impedance
(e.g., 50 Ω) RF circuit could make the situation worse, depending on whether
the circuit is strongly capacitive or inductive in its out-of-band region. Sprague
was a major manufacturer of all sorts of capacitors qualified for use in military
and aerospace systems, so they put a lot of effort into characterizing device parameters
over a wide range of voltage, current, power, temperature, mechanical, and frequency
environments...
 Monostable multivibrator, one-shot multivibrator,
monocycle multivibrator - it's a matter of semantics, although
the circuit designer doesn't necessarily think so. The distinction, evidently, is
that this monocycle multivibrator uses a positive-going pulse as a trigger and the
output in its rest (stable) state is a digital "0" (low). A mere 2 mA of current
flows since all the unijunction transistors (UJTs) are turned off. A UJT, to refresh
your memory, is not used as a linear amplifier because of its regenerative, negative
resistance operating region that causes it to effectively lock into a fully on or
fully off conduction state until an external stimulus causes...
 "Forecasts are mostly just guessing plus
math" -
Dilbert, 12/1/2017. It was part of a dialog with the Pointy-Haired
Boss who compelled Dilbert to prepare a financial report for him...
 Windfreak Technologies designs, manufactures,
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Since the conception of WFT, we have introduced products that have been purchased
by a wide range of customers, from hobbyists to education facilities to government
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 The manned space program has unarguably
provided mankind with many new and innovative tools, medicines, electronics, materials,
physics, materials, appliances, and mathematics. Known officially as "spinoffs,"
products include items like the portable heart defibrillator unit, the portable
vacuum cleaner, freeze-drying food processors, powdered lubricants, memory foam,
quartz clocks and battery-powered tools. Many
NASA inventions have not found an application in your basement
or garage, however, because their purpose is too specialized. Take, for instance,
the ZeRT, or Zero Reaction Tool. It is basically a torque wrench that is operated
by one hand by squeezing. As the name implies, the ZeRT removes the consequence
of Newton's third law motion...
 I was first introduced to the concept of
receiver noise figure at the start of my engineering career in
1989 at General Electric AESD in Utica, NY. During my four years in the U.S. Air
Force working on airport surveillance and precision approach radars, I do not recall
having ever heard the term noise figure or noise temperature. We did signal to noise
and signal sensitivity measurements as part of the normal maintenance, but the terms
never arose. Ditto for my courses at the UVM. We never did cascade parameter calculations
for noise figure, intercept points, compression points, etc. That is primarily the
realm of practicing...
 A team at the University of Bristol developed
SLCFETs, a breakthrough transistor structure that leverages a latch effect in
GaN materials to enhance speed and power, advancing the future of 6G. Self-driving
cars that eliminate traffic jams, receiving a healthcare diagnosis instantly without
leaving your home, or feeling the touch of loved ones across the continent may sound
like science fiction. However, new research led by the University of Bristol and
published in the journal Nature Electronics could bring these possibilities closer
to reality, thanks to a groundbreaking breakthrough in semiconductor technology...
 Being the birthday of Dr. Robert W.
Wilson, there is no better occasion to post this article about the "sugar-scoop" antenna used by the two Bell Telephone Labs engineers
(the other being Dr. Arno A. Penzias) who serendipitously discovered the cosmic
microwave background radiation (CMBR) believed to be a signature of "The Big Bang."
The pair were investigating an unexplained hiss in the background of the very low
noise receiver attached to the antenna. That microwave energy was constant and came
from all areas of the sky, regardless of where the antenna was pointed. They eventually
deduced that the signature was consistent with...
 ConductRF is continually innovating and
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and phased matched VNA applications as well as standard & precision RF connectors.
Over 1,000 solutions for low PIM in-building to choose from in the iBwave component
library. They also provide custom coax solutions for applications where some standard
just won't do. A partnership with Newark assures fast, reliable access. Please visit
ConductRF today to see
how they can help your project!
 To some extent, I agree with the readers
of Radio-Craft magazine who wrote to editor Hugo Gernsback complaining
about the lack of opportunity available to radio servicemen returning from the battlefield
at the end of World War II. As noted in this editorial entitled, "Radio
Industry Unfair?," many are people who sold or took leave from their established
electronics service and/or stores in answer to their country's call to go abroad
to fight for the free world. However, Radio-Craft was, throughout 1945,
filled with advertisements by electronics manufacturers promising jobs and opportunities
and anticipated demand for representation by service shops and sales outlets. Evidently,
it did not turn out to be so, at least to the degree predicted. Gernsback does have
a good point, though, that if the letters submitted to him are an indication of
the quality...
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 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...
 The items reported in the September 1967
issue of Electronics World magazine represent the beginning stages of many
technologies that are still in used today. The monolithic ferrite memory was a major
producibility improvement in what was formally hand-wired toroidal matrices of cores.
They were the first step in integrated memory (although we don't use magnets anymore
in ICs (just on hard drives). The Electronically Controlled Robot looks like something
from a modern Japanese university - without the skin, hair, and eyeballs. Note that
as today, supplying power is one of the biggest hurdles in making a human-looking
robot (umbilical required). The Solid State Camera "Tube" is one of the very first
solid state camera imaging chips. It had a whopping 2,500 pixels. The Computer-Directed
Drawing Machine converted a 2-dimensional drawing into a 3-dimensional perspective.
Shipboard Satellite Communications was at the time one of the first uses of satellites
for global communications, it being a big deal because...
 With today being the 78th anniversary (June 6,
1944) of the
D-Day
invasion of Normandy (aka Operation Overlord) and other beachheads on the coast
of France, I thought posting this advertisement from the July 1944 edition of
QST magazine would be apropos. This issue of the magazine probably arrived
in ARRL member's mailboxes within a couple weeks of the miraculously successful
invasion of Omaha Beach, Utah Beach, Gold Beach, Juno Beach, and Sword Beach. When
you consider that in those days - and also not so long ago for that matter - the
lead time for going to the printing presses was measured in months, the fact that
this ad made the final cut for the next month's issue (July) is noteworthy. Accordingly,
I duly make note. Back in the 1980s, there was a big push for commercial-off-the-shelf
(COTS) equipment to be used in military equipment in order to save money. It was
the era of $600 hammers and $7000 coffee makers manufactured by defense contractors.
The Project On Government Oversight (POGO) was created to address concerns. Anyway,
donations of equipment and components from private citizens...
 The
World Administrative Radio Conference (WARC) is associated with the
International Telecommunications Union (ITU). It is hard to pin down exactly
when the organization's name official became the WARC since it is no longer a
separate entity, and good luck locating a definitive history on the WARC proper.
The closest I could come to determining a time when it was first referred to as
the World Administrative Radio Conference was from this list of all radio
conferences on the ITU website. The Geneva 1967 WARC is it. Previous events did
not include the word "World" in them, from what I could find. Please let me know
if you have another authoritative source...
 Bliley Electric Company is one of the relatively
few companies that advertised regularly in electronics magazines during the World
War II era that is still in business today - at least under the same name (Bliley
Technologies now, but still the same base name). While the company is no longer
located in the Union Station Building anymore, it does still live in Erie, Pennsylvania,
only a mile or so from where I Melanie and I last lived there (2021). They still
make crystals today, albeit with different materials and different methods. In fact,
there is a short Bliley company history video on their website, and also this video
from a local TV station showing of the internal workings at Bliley...
 A few years back, I bought the issues of
The Saturday Evening Post which contained the very first published comics from Peanuts
creator Charles Schulz. As with just about everything else, they were available
on eBay for a few bucks apiece (although prices have really gone up since the beginning
of the year). Most of the issues also had articles and advertisements - and even
comics - that make appropriate fodder for both RF Cafe and my hobby website,
Airplanes and Rockets. Here are a few of the tech-related comics I found. The first
one might seem to be a bit distasteful to the survivors of the RMS Titanic
disaster and/or their relatives, given that only 36 years had passed. The next one
is about architectural engineer - ahem, and the Hazel comic applies for obvious
reasons...
 Liquid crystals have been with us for so
long now that it is hard to imagine a time when they were considered a scientific
laboratory entity. Before being controlled by electric fields for use in alpha-numeric
displays, the thermal properties of
liquid crystals of the cholesteric type found applications in temperature and
power measurements. Since the colors scattered by cholesteric liquid crystals under
incandescent light are unique to a given temperature, measurement of temperature
is possible to an accuracy of better than 0.1 °C. Bendix manufactured a liquid
crystal microwave power density meter. Nematic liquid crystals are the type found
in displays (twisted nematic LCD's) and are controlled by an electric field which
causes light to be transmitted or blocked at varying levels. In 1973 when this article
appeared in Popular Electronics magazine, Seiko...
 Fractals
have been a mathematical curiosity since first being popularized by Benoit Mandelbrot
(who coined the term) in the 1960s. Perhaps, and in retrospect no coincidence, was
the popularity of the cloaking concept featured in the 1960s phenomenon called Star
Trek. I say coincidence because who would have guessed that some of the leading
research in invisibility cloaking would involve barriers derived from fractal forms?
Have aliens been guiding the technology? If so, maybe they're working at
Fractal Antenna Systems,
because in mid December the company issued a press release detailing work being
done on a cloaking system that works in the microwave band (as opposed to visible
light) - chosen for convenience...
 Color television was a big hit with homeowners
and was adopted fairly rapidly in the 1960s even considering the relatively high
cost and low number of network color broadcasts in the beginning years. The enthusiasm
underwent a severe reduction when word got out that large doses of
x-rays were streaming out of the front of the CRT for sets that did not take
precautions to prevent it (which was the majority of sets initially). The major
cause was extremely high voltages applied between the electron gun and
phosphorescent raster grid - in the neighborhood of 35 kV or more - when the
high voltage regulator circuit malfunctioned. Note that even when everything was
working properly, a small amount of x-ray radiation was emitted. The x-ray
problem...
 Even in this current age of ubiquitous computers
and cellphones (also computers), there is still ample reason to consider using
nomographs for presenting data and providing a hand calculation or conversion
resource. In days prior, nomographs were an indispensible tool for both design and
troubleshooting circuits. A huge number of nomographs can be found here on RF Cafe
as they appeared in vintage magazine articles. This 1946 issue of Radio-Craft presents
the first of a two-part tutorial on creating nomographs for any purpose, and uses
current, voltage, and resistance as an example. Their utility is not limited to
electrical and electronic topics, as many have been created for plumbing, hydraulics,
mechanics, chemistry, finance, aerodynamics, pneumatics, lighting, acoustics, and
I've even seen one...
 Bell Telephone Laboratories used to run some pretty
interesting advertisements in magazines back in the 1940s through 1960s that touted the
many communications innovations coming from their scientists and engineers. They built
what was indisputably the worlds best, most reliable telephone network. It, along with
the Interstate Highway System, is credited for a large part of what fueled America's
growth so significantly after World War II. This ad from a 1949 issue of Radio &
Television News magazine tells how repairmen used a specially designed
sensor to trace out faulty phone lines by listening for a test signal sent out
by the central office. What caught my attention about this ad was the uncanny
resemblance the man in the photo has to Melanie's father - especially with the
ball cap and glasses...
 As legend goes, the use of microwaves for
preparing food was pursued after a serendipitous discovery by Raytheon engineer
Percy Spencer whereby he noticed the chocolate bar in his pocket had melted while
he was working near a radar transmitter magnetron. Being a newly discovered phenomenon
in 1945, Mr. Spencer was probably not aware that his own body parts were being likewise
cooked, but he did recognize the commercial potential of an oven that used microwaves
to cook food. It only took Raytheon (Amana) to have the first
Radarange available for sale to professional kitchens. This article
was printed a full decade after the discovery and even then the size and power consumption
was too great for grandma's countertop ...
 You probably read a while back of the San
Francisco's Bay Area Rapid Transit (BART - good acronym, as in Simpson) shutting
down cellphone service in order to thwart a rumored attempt to organize a flash
mob attack. 1st Amendment groups have sued BART over the action. Also in the news
has been the government's plan for being able to
shut down the
Internet in the event of a national emergency (defined as whatever they need
it to mean). We already know that Big Brother has the capability to universally
control both wired and wireless phone service. OnStar-equipped vehicles have been
shut down remotely by law enforcement. It all seems very Orwellian, but it began
before the publication of "1984" (in 1949). Did George just dream up the book's
theme of total government control and a lemming populace, or did it come from astute
observations of past behavior that was projected into the future? On December 8,
1941, the day after the Japanese attack on Pearl Harbor, the FCC issued a "Notice
to All Amateur Licensees" that began thusly: "All amateur licensees are hereby notified
that the Commission has ordered the immediate suspension of all amateur radio operation
in the continental United States...
 Anyone out there old enough to remember when
you were a kid and managed to be able to stay up late enough, maybe on a Saturday
night, to be able to watch the television station sign off the air at night? Here
in the U.S., the custom was to announce the end of the programming day, play the
National Anthem, and then put up the station logo while broadcasting a single tone.
The
tone and test patterns were actually used by TV technicians for calibrating
instruments for use in servicing sets. In 1951 when this TV Station List appeared
in Radio-Electronics magazine, black and white (B&W) was still the
standard, so these images are what you would have seen then. I'm not quite that
old (born in 1958), but I do recognize the stations we could receive at my parent's
home in Mayo, Maryland. Being located between Washington, D.C., and Baltimore, a
pretty good selection of both VHF and UHF...
 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 (which also include hexadecimal and Gray code),
then continuing to Boolean algebra... |
