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 The market for
high-performance RF, microwave, analog, and digital circuit simulation software
is
dominated by a small number of vendors whose products are effectively
mandated for official project proposals and regulatory deliverables. These
vendors most familiar to all of us in the field maintain their premium pricing
not solely through superior technical merit, but through a systematic practice
of regulatory and procurement capture. By influencing standards bodies,
government procurement specifications, and academic curricula, these incumbents
ensure their tools become the only legally or practically acceptable options for
signed-off engineering work. The pattern is consistent: a smaller company...
 Here are a couple more
electronics-themed comics from vintage Radio-Craft magazines. Artist
Frank Beaven, who created a huge number of comics and advertisements (e.g., Eveready
batteries, Zippo lighters) for technical and other types of publications (Saturday
Evening Post, New Yorker, Esquire), did both of them. Beaven
must have a fan base since many examples of his drawings are offered for sale on
eBay. Most of his comics credit reader suggestions as the basis for the subject.
I have to admit to not really "getting" the gag in the top comic. Maybe Sinatra's
voice strained the frequency response of simple tabletop radios of the day. The
bottom comic is one of a series entitled ...
 This custom
Communications Engineering crossword puzzle contains some words particular to
radio, radar, analog and digital circuits, components, and other tech-themed words
and clues. Each week for two decades I have created a new technology-themed crossword
puzzle using only words (1,000s of them) from my custom-created lexicon related
to engineering, science, mathematics, chemistry, physics, astronomy, etc. You will
never find among the words names of politicians, mountain ranges, exotic foods or
plants, movie stars, or anything of the sort. You might, however, find someone or
something in the otherwise excluded list directly related to this puzzle's technology
theme, such as Hedy...
 The "Monthly Review" column appearing in
Radio-Craft magazine was an assorted collection of news tidbits about
electronics and communications industry happenings, similar to
contemporary magazines. Looking back to 1947, the world was hopeful about the future
as World War II was finally over and even the loser countries were focusing
on how their societies would be shaped by technology and lessons learned in the
preceding seven to ten years (depending on when a country entered the war). Two
items here are particularly interesting because they refer to ongoing research into
large screen televisions and video phones (aka "televisers"). Large screens at the
time meant either...
 One of the Notable Tech Quotes which has
appeared on RF Cafe is, "The nice thing about standards is that you have so many
to choose from," by computer scientist Andrew Tanenbaum. In the middle of the last
century, a change in the fundamental understanding of current flow precipitated
what has become a very large opportunity for people to misunderstand descriptions
of
current direction caused by a difference in voltage potential
(voltage) - depending on the era a particular description was written. Beginning
with Benjamin Franklin, electron current flow was assumed to be from positive to
negative, ostensibly but incorrectly, because a positive thing must contain an excess...
 "Fortune reports that Elon Musk's SpaceX
and Tesla are constructing Terafab, a chip manufacturing complex that Musk says
will become the largest and most valuable building on Earth. 'Terafab
Texas will be the largest and most valuable building on Earth by far. And it
will be stunningly beautiful,' Musk wrote on X. The New Century Global Center in
Chengdu, China, currently holds the record for the world's largest building at about
18.9 million square feet. Terafab's planned 100 million square feet would exceed
that by more than five times. Texas Gov. Greg Abbott (R) said in a press release
that 'the first phase of the Terafab project represents a capital investment of
more than $16.8 billion and will create 3,000 new jobs...
 Computer analysis in 1976 was a job performed
on a corporate, university, or government mainframe. Radio Shack's TRS-80 came
out in 1977, but it did not have the capacity to calculate and plot antenna gain
charts like the one in this QST article. Yes, an ambitious programmer could
write the code necessary to perform the double integrals presented in the article,
but to do all the figuring needed to create all the graphs in Figure 4, the job
would just about be finishing up today - and that's not too much of an exaggeration.
For some reason the authors never mention what computer was used or where it was
based. When I saw the title of "Loops vs.
Dipole," I expected the loop to be...
 Even with having been granted more than
400 patents in his lifetime, and being a major player in the realms of energy, data
storage, and semiconductor research and manufacturing, you - as well as most people
- have probably never heard the name
Stanford Ovshinsky. He was somewhat of a celebrity in the 1960s
and 1970s when working hard to promote his concept of "glassy semiconductors," -
aka Ovonic devices. Ovonics are amorphous materials that are used for making switches
for digital logic and memory devices. Either the Ovshinsky process did not pan out
for high volume commercial production or some other technology displaced the what
it was hoped to dominate...
 If I told you that Lester William Polsfuss
is widely credited with being a major player in the pioneering of electric guitars
due to his solid-body (no acoustic resonance chamber) designs, you might wonder
where I came up with that claim. However, if you know that Mr. Polsfuss is the surname
of Les Paul, then you would quickly agree. As if being a popular musician and, along
with wife Mary Ford, selling millions of records wasn't enough, Les Paul was
also an experimenter and inventor in the electronic music realm. This article entitled
"Les Paul: Technician and Musician" appeared in a 1958 article
in Radio-Electronics magazine, and was at the time a contemporary look
inside his...
 Sam Benzacar, of Anatech Electronics, an
RF and microwave filter company, has published his August 2026 newsletter that,
along with timely news items, features his short op-ed titled "Filtering
for Quantum: A Problem No One's Talking About." Sam aptly points out that as
quantum computers scale in size, specialized laboratory-built components become
both expensive and a schedule liability for development efforts. When a handful
of qubits was considered breakthrough-amazing, building all the parts in-house made
sense since processes and materials were being invented in the process of doing
so. However, at the point when thousands of filters, amplifiers, and other types
of components routinely manufactured...
 Georg Simon Ohm's discovery of the relationship
between voltage, current, and resistance revolutionized our understanding of electrical
circuits. Ohm's Law provided a simple, yet powerful mathematical tool that has become
essential to both theoretical physics and practical engineering. Although it was
initially met with skepticism, Ohm's perseverance and commitment to his scientific
work ultimately transformed the way we interact with electricity, influencing technologies
that define the modern world. His legacy lives on not only in the equation that
bears his name but also in the unit of electrical resistance - the ohm - that honors
his contributions to science...
 When you think about it, the speed at which
a human being is able to accurately copy
Morse code is limited by the same kinds of processes that limit
the speed at which binary data can be sent between electronic transceivers (modems).
Noise introduced into the signal at both the transmitting and receiving ends or
in the transmission path connecting the two, degrades the ability of the receiver
(electronic and human) to discern between a "1" and a "0." It can take the form
of electrical or audio interference and distortion. Phase noise in the electronic
realm is sort of the equivalent of an irregular sending human hand that cannot maintain
equal dwell times for dits and dahs, thus making the recognition...
 Why Phase Stability Matters During RF/Microwave
Testing. When engineers evaluate RF test cables, specifications such as insertion
loss, VSWR, shielding effectiveness, and connector type typically receive the most
attention. Yet for many Vector Network Analyzer (VNA) applications, one characteristic
can have a greater impact on measurement accuracy than all of these combined: phase
stability. Phase stability refers to a cable assembly's ability to maintain a consistent
electrical phase relationship when subjected to movement, flexing, temperature changes,
or repeated...
 Magnetic amplifiers (aka "mag amps") use
a property of saturated core inductors (saturable reactors) to obtain signal amplification
via a transformer-type plus diode-assisted voltage multiplication.
Magnetic amplifiers were preferred over vacuum tube amplifiers
in some circuits because they do not require a high bias voltage, are generally
smaller in size, are quite robust and are practically immune to microphonics. Their
biggest limitation is bandwidth. The high number of turns in the core provides a
lot of interwinding capacitance so the self-resonant frequency is in the low megahertz
range. Additionally, the need for the magnetic amplifier reactor to operate in a
saturated condition further...
 Anritsu has been a global provider of innovative
communications test and measurement solutions for more than 120 years. Anritsu manufactures
a full line of innovative components and accessories for
RF and Microwave Test and Measurement
Equipment including attenuators & terminations; coaxial cables, connectors &
adapters; o-scopes; power meters & sensors; signal generators; antenna, signal,
spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth &
WLAN testers; PIM testers; amplifiers; power dividers; antennas. "We've Got You
Covered."
 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...
 This Bell Telephone Laboratories (aka Bell
Labs) advertisement appearing on the inside back cover of the 1958 issue of
Radio & TV News magazine celebrated the 10th anniversary of their
announcement of the world's first
point contact transfer resistance (transresistance) semiconductor
device - aka the transistor. John Bardeen, William Shockley and Walter Brattain
recorded the monumental event in a lab notebook on December 23, 1947 - a nice Christmas
present for the world! The trio's invention was not like the robust bipolar
transistors used today, or even ten years later in 1958. Rather than employing point-contact
"cat's whisker" metallic probes for making the emitter and collector...
 For many years, I have been scanning and
posting schematics & parts lists like this one that appeared in radio and electronics
magazines in the middle of the last century. Most use vacuum tubes. This
General Electric Model 280 Farm Radio "Radio Data Sheet" was in
the May 1947 issue of Radio-Craft magazine. The Radio Museum website has
more information on the GE Model 280 Farm Radio. Farm radios were designed to work
on storage batteries since until the Rural Electrification Act of 1936 was put into
effect, most rural properties had no commercial AC electric power service. 11 years
later, work was in progress to light up the entire country, but many locations had
to wait while resources...
 Here are a couple new-old
tech-themed comics from vintage Popular Electronics magazines.
Both have a Ham radio theme, so maybe you need to have been there to appreciate
the scenario... or maybe not. It is possible that the presence of clothes pins on
twin lead or ladder line could de-tune the line, and could crush the internal dielectric
of a coaxial line. There is no metal on boxer shorts, but maybe the clothes pins
are the type with a metal spring. For the other comic, you just need to know what
••• --- ••• is to get it. Enjoy...
 Question: If a fuse is rated at 3 amps,
at what value of current should it "blow?" Answer: Not at 3 amps. As this
Littelfuse company advertisement from a 1954 issue of Radio & Television
News magazine informs us, fuse ratings do not indicate the current value at
which a fuse opens to protect a circuits, but rather the maximum current level at
which it will NOT blow (open circuit). The same goes for circuit breakers. Various
types of fuses are available to handle certain types of applications. For instance,
a highly capacitive load will according to the well-known equation iC(t) = C * dv/dt
could draw a very large amount of initial (inrush) current if there is not enough
series resistance to limit it to prevent...
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Loading history...
The RF Cafe Homepage
Archive is a comprehensive collection of every item appearing daily on this
website since 2008 - and many from earlier years. Many thousands of pages of unique
content have been added since then.
 Electrolytic capacitors have long been the
components that provide the highest capacitance density factor, that is, they have
the highest capacitance value for a given volume of space occupied. Anyone familiar
with electrolytic capacitors is aware of the polarization indicated on the package
(a marking or unique physical feature), indicating that there is required direction
for hookup; in fact, a backwards connection can lead to an explosive failure. Yes,
I know there are now unpolarized electrolytic capacitors available. While physical
construction of electrolytic capacitors have evolved over the decades since this
article was published in a 1930 issue of Radio...
 I was very surprised to find an example of
a rather significant flexible printed circuit substrate in this "Printed
Circuits Are Here to Stay," article appearing in a 1959 issue of Radio-Electronics
magazine. That era was when much debate, particularly amongst service people, was
occurring regarding whether printed circuits would be a welcome replacement for
the previous point-to-point wiring method of connecting components and cables. Proponents
appreciated the neatness and compactness, while opponents didn't like the lack of
robustness and intolerance to heating and pulling off mounted components. What was
even more interesting was the mention of a...
 If you think the controversy over whether
drivers being distracted by telecommunications devices is something new, consider
this article from a 1935 issue of Radio-Craft magazine. Mobile radio was
a relatively new possibility at the time, as was the horseless carriage into which
installation was a cause for concern by insurance companies and government regulators.
Just as nowadays we worry about and sometimes fining drivers who use a smartphone
for texting while driving, the state of Connecticut in 1935 went so far as to propose
imposing a fine of $50 ($1087 in 2026 money) for installing a radio set or any "other
device which...
 "What's the big deal about a night vision
scope for your rifle?," you might ask, since I can buy an
infrared scope for my rifle on Amazon for under $500. The answer is that no,
it is not a big deal now, but in the 1940s while it was being developed and deployed
for the military, it was Top Secret. Just as radar is a yawn in any discussion of
leading edge technology today, it was vital to keeping the free world free. It wasn't
until after World War II had ended that infrared scopes found their way into
unclassified articles, but even then the cost was way more than any non-governmental
entity could afford. The Night Owl Optics NightShot Digital Night Vision Riflescope
from...
 This data sheet with schematic and aligning
procedures for the
Garod model 6AU-1 tabletop radio appeared in the November 1946 issue of
Radio-Craft magazine. It was AM only (shortwave and FM were not in use yet),
and operated off of batteries (DC) or the AC line. It was one of the earlier radio
to use a Bakelite-like phenol formaldehyde resin material for the cabinet rather
than the more traditional wood. Molded plastic was not yet a thing in high volume
commercial production. The brown (or bright red) and gold motif was considered avant-garde
(aka Art Deco) compared to the more conservative solid and wood laminate finishes.
There was also a version with...
 Carl and Jerry were early adopters of the
near field communications (NFC) craze that is going full-swing today. As they often
do, the harmlessly mischievous teenage duo used their combined grasp of modern electronics
to pull off gags on unsuspecting friends ... and sometime adversaries. In this episode,
a near-field transmitter and receiver pair is designed to help Carl bedazzle a scientist
who was attempting to disprove the ability to use "Extrasensory Perception" (ESP)
- the title of this 1956 Popular Electronics magazine technodrama - to determining
what another person was thinking about. In this case it was detecting which playing
card was being...
 In a Scientific American article
titled "Elemental
Urgency," Jennifer Hackett reported on a paper published in 2013 by Yale University's
Thomas Graedel et al regarding the availability (or unavailability) of the raw elements
- and suitable substitutes - used extensively in modern manufacturing. Unlike half
a century ago when most products were made from relatively common and easily obtainable
elements like lead, iron, tin, nickel, aluminum, carbon, zinc, silicon, and even
silver and gold, many more elements are now regularly included in mass manufacturing
processes. Rhenium (Re), used in high strength, temperature alloys to applications
like jet engine turbine blades and...
 Here is your custom made
Filter-themed crossword puzzle for April 3rd, 2022. Clues for words relevant
to the theme are marked with an asterisk (*). All RF Cafe crossword puzzles are
custom made by me, Kirt Blattenberger, and have only 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...
 Humor in 1933 was evidently very different
than it is today. This is part of what was in the April edition of the ARRL's QST
magazine from that year. Unlike the unannounced "April
Fools" features that may or may not appear in a given year's April issue nowadays
(the April 2022 issue of QST has a gag article on page 40 - the page 38
article is actually real), much ado was made over the gags back in the day. You
might have noticed the humor in some of the older electronics-themed comics also
sometimes invokes the "what am I missing?" response. Shown below on the left is
the gag table of contents page and on the right is the "real" table of contents.
I get the...
 "Necessity is the mother of invention,"
is a common saying that proves itself to be particularly true in times of war. World
War II launched scientists and engineers belonging to both the Axis and the
Allied powers into inventive frenzies in their efforts to hasten an end to hostilities;
of course each side also wanted to be the victor. We all know how the story ended.
Although some countries were not immediately able to capitalize on their countrymen's
technical advances, within about a decade normalized relations had been established
between former foes, and the exchange of products, services and scientific information
proceeded. Some discoveries were...
 Contra-polar (negative) energy is a concept
that has been investigated by many researchers beginning in the mid 19th century,
when the nature of energy was beginning to be understood from a truly scientific
perspective. Entire theories of universe and matter-antimatter creation have been
published, reviewed and refined. This article from the April 1955 edition (note
the month) of Popular Electronics reports on then-current applications of contra-polar
energy. At the time, most such work was performed in secret government laboratories
and at test ranges that were closed to the public and results banned from publication,
but since that time freedom-of-information...
 In 1942 and throughout the War Years,
Life magazine (and many others) ran many articles promoting industries,
services, organizations, and individuals who contributed toward our ultimate victory.
Of course no one knew for certain that we would prevail in the end, but if it hadn't
turned out that way, it wouldn't have been for lack of effort and sacrifice. Part
of the objective was to inform the populace about how the country was pooling its
resources - physical, labor, and mental - to defeat the Axis Powers that sought
to takeover the world. This particular issue of Life focused on the
chemical industry, with the raw materials and processes used to produce
needed...
 Depending on which news story you believe,
both
AM
and FM (and television for that matter) over-the-air broadcasting is dying out
at an increasingly rapid rate. Between recordable podcasts, wired Internet connections,
and the growing ubiquity of Wi-Fi connectivity, a large majority of people in the
civilized world are getting their broadcasts via the Web. If you "follow the money"
in broadcast advertising, the lion's share of dollars have shifted to online venues,
simultaneously draining revenue from local stations. When this story was written
in 1946, OTA radio was king for real-time and free reception of information - particularly
in a mobile environment...
 The Varian brothers, Russell and Sigurd,
are widely credited for invention of the klystron around 1937. Credit for further
developments in the
klystron - from its technology to origin of the name - is a bit fuzzy based
on many articles I have seen. According to a 1944 Radio News magazine article,
Sperry Gyroscope Company developed the tube into commercial viability and was assigned
the trademark name "klystron" based on their creation of the field of "klystronics."
However, the Wikipedia entry for Stanford professor Hermann Fränkel claims the name
"klystron" was suggested by him. This full-page Bell Telephone Labs promotion in
a 1956 issue of Radio-Electronics..
 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... |
