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 Transformers are the workhorses of power
distribution and signal processing, utilizing Faraday's law of induction to step
voltages up or down while maintaining high efficiency. By coupling magnetic fields
between primary and secondary windings through a shared core, they provide critical
electrical isolation and impedance transformation between circuit stages. From massive
grid-scale power units to tiny high-frequency RF baluns, transformers must manage
complex phenomena such as magnetizing current, eddy current losses, hysteresis,
and parasitic leakage inductance. This quiz explores the core physics behind transformer
operation, including the “turns ratio” relationship, the role of core...
 A column entitled "Radio-Electronics
Monthly Review" appeared in each issue of Radio-Craft magazine. As now, things
were moving quickly at the time. With WWWII recently ended, a lot of the new technology
developed to help beat back Nazism and Communism was being transferred to peacetime
uses. The May 1947 issue contained, amongst other items, info regarding how radio
servicemen were organizing efforts to get its ranks educated on FM sets as AM was
being replaced and/or supplemented with the new miracle noise-free broadcast systems.
It also reported that the IRS decided not to go forward with earlier plans to tax
television shows being displayed in public...
 Radio control (R/C) systems operating in
the 2.4 GHz ISM band, using one of or a combination of frequency hopping and
direct sequence spread spectrum scheme, have been in widespread use since the early
2000s. As with any new technology, there was a lot of reluctance to adoption of
the systems based on a few reports (valid or not) of performance issues - primarily
lack of control range where communications between the transmitter (Tx) and receiver
(Rx) with a pilot and aircraft was lost and a crash ensued. Tx power was already
at the FCC-mandated maximum, so manufacturers quickly improved receivers by adding
diversity with a second Rx antenna. The receiver...
 As reported in this 1967 Electronics
World magazine piece, lasers were still the things of science fiction to most
people. Real-world applications seemed to be far off in the future, but in fact,
work was underway setting the stage for today's blazingly fast communications
systems. The author here references attaining 5 THz optical transmission speeds
through fiber and through the air. At the time, a laboratory filled with bulky prototypes
chassis and optical tables were required to get those results. I can remember reading
articles in the 1970s when laser power output was measured in "Gillette power," referring to the beam's ability to burn through
a number of razor blades (a big deal...
 If my counting is correct, by 1952 only
33 of America's 48 states (Hawaii and Alaska weren't admitted until 1959),
and Washington, D.C., had
television broadcasting stations. That most of the early television
experimentation occurred on the east coast is apparent by looking at the number
of stations there compared to the west coast. You might think California would have
the largest amount of TV stations, but it only had 11 located in 3 cities. New York,
on the other hand, had 13 in 7 cities. Ohio had 12 stations in 5 cities, and Pennsylvania
had 7 stations in 5 cities, one of which was my town of Erie. Vermont, New Hampshire,
Mississippi, Wyoming, both Dakota, and Oregon were among...
 By now, engineers and scientists have managed
to replace most vacuum tubes with solid state devices - at least for consumer products.
The one place tubes remain are in microwave oven. Those klystron tubes operate in
the 2.4 GHz band and typically output ranging from about 500 W to 2 kW.
No doubt materials and methods have changed since the 1950s, but fundamentally klystrons
of today are the same as klystrons then. Between this article and Part 1 that
appeared in the April 1952 issue of Radio & Television News magazine,
authors Joseph Racker and Lawrence Perenic provide a very nice introduction on the
topic. According to the Wikipedia entry, the name "klystron"...
 The U.S. Army's Signal Corps was set
up to "exercise supervision over signal communications literally from the Pentagon
to the foxhole." Created in 1860 at the suggestion of a military doctor, the
Signal Corps originally used a system of flag waving for messaging
dubbed "wigwag" and graduated to overseeing the nationwide telegraph network six
years later. By 1870, members were tasked with establishing and operating a weather
forecasting service, so in 1907 when they created an aeronautical division it was
just in time for facilitating the nation's rapidly growing cadre of aircraft
pioneers by providing en route weather information. Having already mastered the
state...
 I have never seen study-at-home audio-visual
(AV) physics courses offered by Albert Einstein or AV courses on chemistry promoted
by Ernest Rutherford, but I can now say I have seen study-at-home AV courses offered
by electronics pioneer Lee de Forest. This full-page advertisement for the
de Forest's Training, Inc., company of Chicago, Illinois,
appeared in a 1945 edition of Radio-Craft magazine. The vaunted (at least
by the company) "Syncro-Graphic" training was an early attempt at the paperless
classroom. The student watched films reels of instruction rather than "frequent
flipping of pages to refer back or ahead to illustrations mentioned in text." It
would be another 50 years before...
 The history of electrical current is replete
with tragic incidences of maiming and death caused by ignorance and/or inattention
to known danger. Having been involved in both the electrical wiring and the electronics
fields since the 1970s, I am quite aware of the legion of hazards present when current
flows. My tool box contains screwdrivers and lineman's pliers with notches of
melted metal from inadvertent contact between differences of potential in circuit
breaker panels and electrical wall boxes. Once you experience the thrill of a sudden
blinding flash, unique buzzing sound, and smell of burning hot steel, you'll
never forget it. A lot of people have been
electrocuted, though, through no fault...
 Less than half a decade had passed when
Radio & Television News editor Oliver Reed wrote this piece extolling the
virtues of the transistor and how "it may well revolutionize the
entire electronics industry." If you have followed a lot of my postings from the
vintage electronics magazines here on RF Cafe, you are well aware that there
was a lot of resistance to and doubt about the future of semiconductors. Naysayers
had the same kind of reaction to the advent of the horseless carriage (automobile)
and locomotive, relativity and quantum mechanics, and even curative medicines. Point
contact transistors were still largely in use, but were costly compared to the relative
simplicity and low...
 Please take a few moments to visit the
everything RF website to see how they can assist you with
your project. everything RF is a product discovery platform for RF and microwave
products and services. There are currently 374402 products from more than 2667 companies
in the database, and engineers can search using a customized parametric search tool.
Also 5482 technical articles. Amplifiers, test equipment, power couplers and dividers,
coaxial connectors, waveguide, antennas, filters, mixers, power supplies, and everything
else. Please visit everything RF today.
 Inductance is a fundamental property of
any conductor, representing its ability to store energy in a magnetic field when
current flows through it. From the simple air-core loop to complex multi-layer transformers,
inductors are essential for filtering, impedance matching, energy storage, and signal
processing. Unlike capacitors, which resist changes in voltage, inductors resist
changes in current, governed by the classic relationship of electromotive force
being proportional to the rate of change of current. This quiz delves into the behavior
of inductors in both AC and DC circuits, the variables that define their magnitude
- such as core material permeability, number of turns, and geometry...
 Albert Einstein published his paper on
Special Relativity in 1905 and on General Relativity in 1916.
Since that time, many experiments have been performed worldwide by scientists intent
on both proving and disproving Mr. Einstein. Laser and nuclear based timepieces
have been improved for precision and calculations refined to aid in the task. This
1959 Popular Electronics magazine article reports on one of the first atomic
clock experiments used to test General Relativity. After more than 100 years, General
Relativity stands as originally presented. Even the rigors of quantum mechanics,
which Einstein did not embrace until much later in life, has not toppled its precepts...
 Even in this time of readily available computers
(including your smartphone) and printers, having a set of
rubber stamps for common electronics symbols would be pretty handy;
there are some Neanderthals among us who still use pencil and paper on occasion.
Simpler symbols like resistors and capacitors are easy enough to sketch by hand,
but something like a dual gate MOSFET with diode protection can take some time to
produce legibly. Common connector types like the DB signal/power series and some
RF kinds (BNC, SMA, etc.) would be useful, as would a set of oft-used logic gates
for the digital designers. The set shown here in a 1953 edition of Radio-Electronics...
 It has been many decades since I have seen
anything about a
Lecher Line, the last time in memory being in a college lab. It
might have been a physics lab, but most probably an EE lab. We used one to measure
wavelengths of signals from an RF generator. The apparatus looked sort of like the
one in the Wikipedia link, only just a little more modern (but not much more, being
typical school equipment). This new patents report from a 1947 issue of Radio-Craft
magazine has a waveguide version of a Lecher Line that supposedly was able to do
more precise measurements of very short wavelengths by providing for detecting the
internal wave over multiple wavelengths instead...
 A month before Bell Laboratories' announcement
of the transistor invention by Mssrs. Bardeen, Shockley and Brattain, Radio-Craft
magazine editor Hugo Gernsback published a piece extolling the virtues of a newly
developed
microtube, aka a "rice-grain" tube. As connected as Gernsback
was in the electronics industry, it is doubtful he knew of the impending game-changing
invention. Commercialization of the transistor took a few years to get to the point
where the devices could be manufactured cheaply and reliably enough to begin being
integrated (pun intended) into products, so vacuum tubes still reigned for another
decade or more. While the microtubes were designed into such...
 Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave
connectors, between-series adapters, RF components and filters for wireless
service providers including non-magnetic connectors for quantum computing and MRI
equipments etc. ISOTEC's product line includes low-PIM RF connectors components
such as power dividers and directional couplers. Off-the-shelf and customized products
up to 40 GHz and our low-PIM products can meet -160 dBc with 2 tones and
20 W test. Quick prototyping, advanced in-house testing and high-performance.
Designs that are cost effective practical and repeatable.
 This article explains the six most common
two-port network matrix descriptions used in circuit theory, RF/microwave engineering,
filter design, amplifier design, and transmission-line analysis: Z-parameters, Y-parameters,
h-parameters, ABCD-parameters, S-parameters, and scattering-transfer T-parameters.
Each representation describes the same linear two-port network, but each chooses
a different set of independent and dependent variables. Because of that choice,
some matrix types are natural for low-frequency circuit analysis, some for cascade
calculations, and some for high-frequency measurement where direct open- and short-circuit
tests become impractical. The most important...
 Each week, for the sake of all avid cruciverbalists
amongst us, I create a new
technology-themed crossword puzzle using only words 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,
see someone or something in the exclusion list who or that is directly related to
this puzzle's theme, such as Hedy Lamarr or the Bikini Atoll, respectively.
Enjoy!...
 There are lots of audiophiles in the RF
Cafe audience who might appreciate this article on the characteristics of human
hearing and ways in which stereo hi-fi equipment attempts to reproduce realistic
sound, as if from a live performance. A handy-dandy chart is provided that shows
the characteristics of various audible frequency ranges, and the
kinds of speakers best suited for reproducing the sound. It was
published in a 1955 issue of Popular Electronics magazine when stereo hi-fi
system building was a major pastime, but still should be applicable today. If you
do a search on RF Cafe, you will find many articles covering stereo hi-fi equipment...
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 The drone, aka Remotely Piloted Vehicle (RPV)
and
Unmanned Aerial System (UAS), has been mainstreamed in the last few years. Although
drones have been around since the end of World War I, in use for target practice
and eventually for reconnaissance, they have evolved from fairly crude platforms
that require intensive human interaction to fully autonomous systems that can be
programmed with a full mission profile then launched, modified for mission changes
en route and in situ if necessary, and finally retrieved and reused. GPS,
inertial guidance (gyroscopes), radar, lidar, and other complex sensors allow the
craft to monitor and correct its flight course and...
 This
Radio
Theme Crossword Puzzle for June 13 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...
 As usual, "getting" the message in some
of these vintage
electronics-themed comics requires at least a passing familiarity with the state
of technology and public mindset of the day. However, in most cases appreciating
the humor and/or irony is possible without it. This group of six comics appeared
in a 1953 issue of Radio-Electronics magazine. The first comic is a good example
of needing some insider information. Back when commercial television was broadcast
over the air from giant towers, multipath of the signal, particularly in urban areas,
often created a situation where the difference in arrival time of the signal at
the TV viewer's location caused more than...
 Each
year the Foundational Questions Institute (FQXi) holds an essay contest inviting
writers to submit missives addressing the question chosen by the FQXi board as being
particularly thought-provoking. In their words, "FQXi catalyzes, supports, and disseminates
research on questions at the foundations of physics and cosmology, particularly
new frontiers and innovative ideas integral to a deep understanding of reality,
but unlikely to be supported by conventional funding sources." The 2011 question
was "Is Reality
Digital or Analog?" (here is The Wayback Machine's capture of the original webpage).
Scientific American magazine, being one of three partners...
 Our president and other pontificating politicians
- particularly, it seems, those who hold college degrees in non-science realms -
have recently taken to referring to anyone who does not hold their points of view
as "Flat Earthers" and anti-science.
BTW, these are the same people who regularly chastise their opponents for name-calling
and uncivil discourse. So, if to them others are anti-science, then they obviously
deem themselves to be pro-science. Would you consider a person who laments the invention
of the ATM machine because it replaces bank tellers or a ticket kiosk at the airport
for robbing counter clerks pro- or anti-science? What about people who prefer...
 We have all seen news reports about the often
exorbitant
salaries
of government employees as compared to the earnings of folks in equivalent private
sector jobs. According to a March 2012 report by the Bureau of Labor Statistics,
the average total compensation for the average private industry worker was $28.57
per hour worked whereas for the federal government worker it was $40.90 per hour
- a 43% difference! When you look at the ranges of job titles and pay for government
workers as compared to equivalent private industry workers there seems to be no
logical correlation between which jobs pay more with the government versus private
industry. There...
 "The Congress shall have Power … To promote
the Progress of Science and useful Arts, by securing for limited Tımes to Authors
and Inventors the exclusive
Right
to their respective Writings and Discoveries." - United States Constitution,
Article I, Section 8. Therein lies the authority for legislation and prosecution
of rights for virtually every human creation within the jurisdiction of the country.
Each nation has it own version, and international agreements help assure universal
protection of a creator's rights of ownership; e.g., the "Convention for the Protection
of Literary and Artistic Works" (aka the "Berne Convention") of 1886 and the World
Intellectual Property...
 I have often said that some of the most capable
and enthusiastic engineers and technicians - and even managers - I have worked with
in my 30-something year electronics career have been amateur radio operators. They
are the rare few who are able to combine a hobby passion with a profession that
pays for the hobby... kind of like the airline pilot who flies model airplanes or
the druggie who works at a pharmacy. Oh, wait, scratch that last example. Here we
see a video from Chevrolet where two engineers, one of them a Ham, took up the challenge
to replace the
AM/FM whip
antenna originally planned for the 2011 Camaro convertible with a blended...
 Space Shuttle Endeavour (named after the
ship of British Lt. James Cook) lifts off for the last time tomorrow (April 29).
Atlantis flies next month, marking the end of the USA's manned space flight vehicle
program for the foreseeable future. Henceforth, we will be hitching rides on Chinese
and Russian craft that still land in the desert using parachutes. Here are some
stats on the Shuttle program. Number of shuttles: 5 - Challenger, Discovery, Atlantis,
Endeavour, Columbia; expected launches: 500; actual: 135; total flight time (as
of Jan 2011): 1289 days; shuttles lost: 2 (Challenger, Columbia); total passengers:
836; failure rate: 1:67.5; fuel consumption rate:...
 This
Engineering &
Science Theme crossword puzzle for October 31st 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...
 Applying the adjective "portable" to electronics
equipment in the vacuum tube era was often a stretch of the term. Usually, portable
radios were backpack ordeals with a separate battery carried by second person. They
can be seen in a lot of the old War War II movies. It was really not until
the advent of the "Handie-Talkie"
two-way radio sets that a truly hand-held, self-contained system was available.
This "Inside the Handi-Talke" article from a 19467 issue of Radio-Craft magazine
provides a very detailed look at the internal components and of the schematics.
"Walkie-Talkie" was another name often given to the Handi-Talkie, although some
might argue that there is a distinct...
 Here is a little levity from the "Hobnobbing
with Harbaugh" series of comics that appeared in Popular Electronics magazine. Unfortunately,
none of the "The
5 Most Wanted Household Inventions" have come to full fruition in the marketplace
yet, although the cellphone blockers can be found on the Internet in various unofficial
forms. Personal computers were a pipe dream in 1963, but nowadays we do have software
like TurboTax to take care of filing taxes, although you still can't simply dump
all your receipts into a bin and have it work. Flat-fixing robots might not be needed
in a few years as tubeless, airless tires hit the road. Alarm clock vaporizers are
not Star Trek...
 "Unprecedented
openings for non-engineers result from industry growth and shortage of skilled
men." Thus goes the subtitle for this 1957 Radio & TV News magazine
article pitching the promises of a career in electronics technology. It came at
a time that predated throw-away everything rather than attempting to repair stuff.
It was before the term "personal device" (aka "throw-away") had been coined. It
was before placards warning "No user serviceable parts inside" were routinely stuck
on practically every item purchasable in a department store. It was a time when
people took stuff apart to see how it works, and were actually able to figure it
out because...
 I have mentioned this before, but nearly
always the setting for John Frye's "Mac's Service Shop" technodrama stories coincide
with the time of year corresponding to the month in which it appeared (for the northern
hemisphere) - in this case the July 1952 issue of Radio & Television News
magazine. In addition to that, Barney's crack about Mac using his slide rule to
try calculating who the president would be is also time-appropriate since 1952,
being a Leap Year, was also an election year (Eisenhower beat Stevenson, BTW) ...but
I digress. Mac's actual preoccupation was with
open wire transmission lines. With the rise of UFH broadcasting on the horizon,
he...
 A controversy brews over the merits of breeding
plants that glow like a lightning bug. Proponents say
glowing
trees could eventually replace electric street lights, thereby reducing pollution
created by generating stations. Opponents say messing around with tree genes is
dangerous and should be disallowed since it could lead to unanticipated environmental
ramifications on both plant and animal species. The unique aspect of this effort
is that it is being pursued primarily by genetic hobbyists rather than corporations
- at least for now. There is bound to be a huge financial potential for such a copyrighted
line of plants. My opposition to the concept is primarily... |
