Today in Science History -
Here are three more
electronics-themed comics for you, these from a 1949 issue of Radio−Electronics
magazine. The first one is probably still a concern for parents today, although
the dilemma would probably be with the kid fiddling with the remote control rather
than with the buttons on the TV set. The second might require you to be old enough
to remember when both doctors and electronics servicemen made house calls. The third
comics is my favorite due to its cleverness at portraying what was a common occurrence
with boys wanting to watch a baseball game but not having the money for entrance
to the ballpark. Spanky and the gang of The Little Rascals used to pull that stunt
a lot. I took the liberty of colorizing the comics...
Every week while sitting in the studio where
Melanie takes her violin lessons, I usually read technical and hobby magazines,
but at the time I was been studying the ARRL General Class License Manual in preparation
for taking the written exam in a couple months. One time a lady saw the book title
and remarked, "I
didn't know ham radio people were still around." Wow. It would be tempting to
blame her for being ignorant, or to blame the ARRL for not adequately getting the
word out, but the reality is that for the most part the mass media does not consider
Ham radio's contribution to be significant enough to cover in news stories. Amateur
radio operators perform a mighty public service in times of trouble, but they do
it so efficiently and effectively, without actively seeking credit, that their efforts
are lost in the noise. Ham radio operators have been on the front lines of national
and civil defense since World War II and even a bit before (see links below).
So important have been the contributions of Ham operators that the FCC has consistently
protected the very valuable spectrum reserved for amateur radio...
"Most every electronic circuit will pose
the threat of EMI radiation on other circuitry, with drones and UAVs being particularly
susceptible. There’s one simple but important solution: implement EMI shielding.
drones and unmanned aerial vehicles (UAVs) rely heavily on seamless communication
from ground systems. Cell-phone towers, buildings and large metal structures, high-voltage
power lines, and a high concentration of Wi-Fi networks in an area can cause serious
electromagnetic interference (EMI) in drone performance. EMI effects on drone operations
are unpredictable. They can severely disrupt a drone’s navigation system by shifting
the drone's compass out of alignment. When flying close to large structures, EMI
can degrade the quality of GPS reception..."
Keith Barkley published an article in the
June 2001 issue of RF Design magazine entitled, "Two-Tone
IMD Measurement Techniques." Seven rules to ensure the best characterization
of non-linear RF components. He writes: "Two-tone testing for intermodulation distortion
(IMD) has a long and venerable history. Since the dawn of RF engineering, it has
been used to characterize the non-linearity of RF components, both active and passive
Measurement methods, pitfalls and tidbits of information have been gathered over
the years by myriad sources, here and elsewhere. A few simple rules can help in
setting up a test system that can accurately measure two-tone IMD for RF power transistors.
For this discussion, f1 and f2 will denote the two signals' input into the device
and Δf will be the frequency separation between them..."
Here is a very useful article on the benefits
and technical challenges of
stacking antennas; it appeared in a 1958 issue of Radio−Electronics magazine.
It avoids rigorous mathematical analysis and instead presents recommended guidelines
and includes some very nice measured antenna patterns (no computer-generated predictions
in 1958) of the various configurations. The authors discuss radiation pattern changes
based on horizontal versus vertical stacking, and a combination of both. Plotting
all the vertical and horizontal radiation patterns would have take a lot of time
with a slide rule back in the day. This is the first of a series written by engineers
at the Scala Radio Company...
RF Cascade Workbook 2018 is the next phase in the evolution
of RF Cafe's long-running series, RF Cascade Workbook. Chances are you
have never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system
cascade parameter and frequency planner that includes filters and mixers for a mere
$45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch
and the format is entirely customizable. It is significantly easier and faster than
using a multi-thousand dollar simulator when a high level system analysis is all
that is needed. An intro video takes you through the main features...
KR Electronics designs and manufactures
high quality filters for both the commercial and military markets. KR Electronics'
line of filters
includes lowpass, highpass, bandpass, bandstop and individually synthesized filters
for special applications - both commercial and military. State of the art computer
synthesis, analysis and test methods are used to meet the most challenging specifications.
All common connector types and package form factors are available. Please visit
their website today to see how they might be of assistance. Products are designed
and manufactured in the USA.
Radio-Craft magazine ran a regular
feature entitled "Radio-Electronics
Monthly Review," which reported on industry news and events. The death of diode
electron tube inventor Sir Ambrose Fleming appeared as a major item. He lived to
the ripe old age of 95½ - an amazing feat at a time when the average lifespan of
a male born in 1949 was less than 40 years. Regardless of the year born, your life
expectancy increases as you get older both due to better available lifestyles, nutrition,
and medicine, and because you continually cross benchmarks of genetic and environmental
factors that take out others born in the same era. Another interesting item was
the call for more ubiquitous deployment of 2-way radios (walkie-talkies) in rural
areas to compensate for a relative lack of telephone service...
"An international research team, with the
participation of the Institute of Molecular Science (ICMol) of the University of
Valencia, has achieved spin-electric control in
molecular nanomagnets. This fact offers great advantages when preparing quantum
devices based on magnetic molecules. The work has been published in the journal
Nature Physics. For some time, science has been looking for viability in the development
of devices based on quantum bits (qubits), basic units of a quantum computer. In
magnetic materials, a possible qubit is provided by the spin-quantum property of
elementary particles such as the electron. In this context, the electrical control
of spin offers important advantages for the development of quantum computing and,
in general, quantum technologies. An international research team with the participation
of ICMol has taken a step forward in this field by achieving..."
Skyworks is pleased to introduce SKY68031-11,
the world's smallest,
multi-band RF front-end (RFFE) module for licensed, low-power, wide-area network
(LTE-M/NB-IoT) applications including asset tracking, health and fitness wearables,
smart metering and industrial monitoring. This module integrates the entire RF front
end necessary for a cellular IoT radio operating in low-band (5, 8, 12, 13, 14,
17, 18, 19, 20, 26, 28, 85) and mid-band (1, 2, 3, 4, 25, 39, 66, 70) frequencies.
The FEM monolithically integrates a broadband power amplifier, transmit harmonic
filters, antenna switch and MIPI RFFE controller, all in a compact 3x3 mm package...
Wharfdale is a brand well known to stereo
hobbyists and professionals for more than half a century - particularly in Europe.
Wharfdale Wireless Works was founded by British entrepreneur Gilbert Briggs in 1933,
and still sells speakers under the name "Wharfdale." As a pioneer in high fidelity
sound reproduction, Mr. Briggs was highly sought as an author by electronics and
audio media. In May 1957, he wrote this article for Radio & TV News
magazine. Studies of the audio response of the human ear and the physics of the
space where speakers and listeners would be were undertaken as the electronics age
progressed in the post-war years and consumers began seeking more than simply noise
emanating from a loudspeaker...
Is it my imagination, or do the
SMA connectors at the arrows appear to be not fully seated? Per the article: "Proponents
of quantum technology believe its will change the world. Others remain skeptical,
as they do of technologies like fusion energy. Speaking at a quantum developers'
forum, IBM Distinguished Engineer Jan-Rainer Lahmann retraced the history of quantum
computing, reviewing IBM's hardware and development roadmaps and describing the
ingredients of 'Raspberry
Pi Quantum.' The history of quantum computing goes back four decades to a conference
where the Nobel laureate Richard Feynman introduced the idea of simulating quantum
mechanical systems on a traditional computer. At the time, this required a significant
computational resources. Even with Moore's Law scaling, it was clear to Feynman
and many others..."
RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees
and/or managers of hiring companies are welcome to submit opportunities for posting
at no charge. 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors...
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.
On the May 13, 2005 episode of The Tonight
Show, Jay Leno held a Morse code vs. SMS speed contest between two Ham Radio operators
using Morse code and two Millennials using their smartphones for texting (SMS).
At least one member of the audience thought texting would win. Watch the video to
see if she was right. Mr. Chip Margelli (K7JA) did the sending. He declares, "Let
me assure you that we never saw that message before I flipped the blue card over.
Each message, in rehearsal, was different. The character count was the same as the
one during dress rehearsal, though, to account for the time slot. And they put the
card on the table "upside down" creative to how I flipped it, as you can see on
the video." Mr. Ken Miller (K6CTW) did the receiving...
In 1966, Paul Rockwell wrote a 4-part series
for the ARRL's QST magazine on station design for long distance communications
(DX) that covered antenna selection and siting (Part I), economics and construction
(Part II), Station Configuration and Receiver Topics (Part III), and Propagation
Quirks and Operating Tips (Part IV). This the the forth and final installment. One
of the handy-dandy items shown is a
which had a template of the familiar day-night analemma-based curve superimposed
on the projection map of the earth. It was quite a deal in its day, and believe
it or not, the company is still in business offering software-based Map-Clocks and
restoring models all the way back to when they first came out in 1965 (only a year
before it appeared here)...
atomically thin sheets of molybdenum
disulfide both move and block heat. Packing transistors close together raises the
problem of heat frying the devices. Now scientists have developed an artificial
material that is one of the best ever at conducting heat in one direction while
keeping that heat insulated from its surroundings in other directions. The research
might one day help microchips grow more powerful without breaking from overheating.
As electronics continue to miniaturize, greater amounts of heat are getting produced
in a given space, which makes heat control a key challenge in electronic design..."
Do you know what a soroban is? I have to
admit ignorance prior to reading this 1963 "Carl and Jerry" adventure in Popular
Electronics. As with many of these stories, real equipment, people, and companies
were referenced; this time it was the Pastoriza Personal Analog Computer, a modular
electronics system for calculating differential equations. The cost was around $300
(~$2,700 in c2021 money per BLS Inflation Calculator). Analog Devices bought the
company from James Pastoriza in 1969. What does the Pastoriza computer have to do
with the story, you might ask? Nothing, really; it was mentioned in a discussion
Carl and Jerry had when accepting a calculating speed challenge from obnoxious dormitory
mate, Bruce. Jerry would add a series of numbers on his soroban while Bruce would
add them with a pencil and paper. The winner got bragging rights...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Stencils available for RF, analog, and digital system and schematic drawings!
Every object has been built to fit proportionally on the provided A-, B- and C-size
drawing page templates (or can use your own). Stencils are provided for equipment
racks and test equipment, system block diagrams, conceptual drawings, and schematics.
Unlike previous versions, these are NOT Stencils, but instead are all contained
on tabbed pages within a single Visio document. That puts everything in front of
you in its full glory. Just copy and paste what you need on your drawing. The file
format is XML so everything plays nicely with Visio 2013 and later...
TotalTemp Technologies has more than 40 years
of combined experience providing thermal platforms.
are available to provide temperatures between −100°C and +200°C for cryogenic cooling,
recirculating circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
Science Theme Crossword Puzzle for October 24 has many words and clues related
to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics,
and other technical subjects. The letter "P" figures Prominently in this crossword.
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
Innovative Power Products (IPP) has over
30 years of experience designing & manufacturing RF & microwave passive
components. Their high power, broadband
couplers, combiners, resistors, baluns, terminations
and attenuators are fabricated using the latest materials and design tools available,
resulting in unrivaled product performance. Applications in military, medical, industrial
and commercial markets are serviced around the world. Please take a couple minutes
to visit their website and see how IPP can help you today.
A year after the two atom bombs were dropped
to end World War II, the newly formed Atomic Energy Commission conducted detailed
detonation tests at the Bikini Atoll, in the South Pacific. Most people more than
40 years old are very familiar with the images of the giant mushroom cloud that
formed over the site. This "Radio in
the Atom Tests" article from the July 1946 issue of Radio−Craft magazine
reports on plans being made to measure and record sound pressure, nuclear radiation,
radio and radar signatures, temperature, light spectrum and intensity, and other
parameters. The information would be used for improved bomb making, nuclear power
generation, medical imaging and treatment, and general research on nuclear fission
and fusion (a fission implosion is to initiate a fusion reaction)...
"Researchers from King Abdullah University
of Science & Technology have proposed a solution to address the widespread public
concern about electromagnetic fields (EMF) exposure from mobile networks. Masters'
student Zhengying Lou, postdoctoral student Ahmed Elzanaty and distinguished professor
Mohamed-Slim Alouini of KAUST proposed that mobile
tethered drones might offer a speedy and environmentally friendly alternative
for receiving terrestrial base stations while alleviating public concerns about
exposure to EMF. Ahmed Elzanaty stated that it is mainly a problem of perception,
but this concern has led to attempts to destroy signaling towers, especially those
associated with the 5G network. He does point out, however, that recent experiments
on animals link some adverse health impacts with long-term exposure to EMF..."
The Civil Aeronautics Administration (CAA),
born in 1940 and now known as the Federal Aviation Administration (FAA, since 1958),
was established originally to regulate the burgeoning commercial airline and cargo
transport air traffic as well as the private aviation activity. According to an
FAA document, on April 3, 1947, CAA controllers began in-service evaluations of
ground approach control (GCA) radar system at Washington National and Chicago
Municipal airports. It was commissioned for official use by the CAA on January 7,
1952, at Washington National Airport. This story from a 1957 edition of Radio &
Television News magazine reports on the system upgrade to long-range radars that
would permit, eventually, continuous coverage across the entire USA...
PCB Directory is the largest directory of
Board (PCB) Manufacturers, Assembly houses, and Design Services on the Internet.
We have listed the leading printed circuit board manufacturers around the world
and made them searchable by their capabilities - Number of laminates used, Board
thicknesses supported, Number of layers supported, Types of substrates (FR-4, Rogers,
flexible, rigid), Geographical location (U.S., China), kinds of services (manufacturing,
fabrication, assembly, prototype), and more. Fast turn-around on quotations for
PCB fabrication and assembly.
Commercially available radio receivers for
the home had only been around for a couple decades when this advertisement from
Crosley appeared in a 1932 issue of Radio-Craft magazine. I keep looking
in old electronics magazines for an ad featuring my 1941 Crosley model 03CB console
radio, but thus far with no luck. There is a chance, although I have not seen any
direct evidence of it, that the 03CB chassis was sold as a special upgrade to the
less ornate 02CA model. What makes it special is that it was probably one of the
last new radios sold prior to the shift of material usage to military equipment
in World War II...