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Today in Science History -
 It's Friday and
therefore time for a
pop quiz (does that line give you a fearsome flashback to your school days?).
Whenever I have one available, I like to post quizzes from vintage electronics
magazines, like this one on diode circuit functions. Many of them have vacuum tubes,
but this one has the solid state symbols so the under-40 folks won't be
uncomfortable. Your job is to look at the diode circuits and match them with the
names of the functions. A couple of them will probably cause some head scratching,
but you should do well. Don't jump to a quick conclusion with circuit "E" without
noticing the two signal generators ...
 "Graphene Flagship researchers have shown for
the first time gate tunable third harmonic generation in graphene. This research, led
by Graphene Flagship Partner University of Cambridge, in Collaboration with Politecnico
di Milano and IIT-Istituto Italiano di Tecnologia in Genova and published in Nature Nanotechnology,
could enable on-chip broadband optical switches for data transport in optical systems.
Optical harmonic generation is the creation of new frequencies (colours) when high intensity
light interacts with a nonlinear material. Third Harmonic Generation (THG) can create
light ..."
  Istvan Novak has a
clever low budget, close-enough type fixture for quickly measuring the impedance (and
determine the self-resonant frequency) of capacitors up through a few tens of MHz.
Mr. Novak's application is bypass
capacitor characterization. "Bypass capacitors are used in large
numbers in power distribution networks. Most vendors today supply
not only typical characteristics, but also various simulation models. Nevertheless,
doing our own characterization of these components is still useful and often
necessary. In this short article, I'll show you how to create simple home-made
fixtures for these measurements. For bypass capacitors, measuring impedance over a
reasonably wide frequency range ..."
 Restoring and/or upgrading vintage radio receivers
is still a very popular pastime for hobbyists, and for that matter for some professional
servicemen who preform maintenance on established equipment installations. Three of the
most significant changes that can be made to older receivers to
improve sensitivity are to clean up the power supply DC output, replace noisy components
like vacuum tubes and leaky capacitors, and tune / modify / replace RF and IF filters.
This article discusses a method of replacing a stock LC filter with a high selectivity
mechanical filter. The nice thing about an analog receiver is that narrowband, steep-skirt
filters can be substituted without concern for group delay at the band edges that can
(and will) wreak havoc on digital signals ...
 Saelig Company has introduced the
Circuit Design SLR-434M Smart Modem - a compact, easy to use narrow-band embedded
radio modem operating in the 434 MHz ISM band. It incorporates LoRa® technology to achieve
extremely long range for low bit-rate data with low power. The SLR-434M's excellent receiving
sensitivity allows communication into areas once considered difficult for RF to penetrate,
and making it possible to transmit 1800 feet or more. The SLR-434M is also switchable
to accommodate ...
 "A new discovery may dramatically improve heat
transport in insulators and enable new strategies for heat management in future electronics
devices. The discovery was made by researchers at the Department of Energy's Oak Ridge
National Laboratory who made the first observations of waves of atomic rearrangements,
known as phasons, propagating supersonically through a vibrating crystal lattice. The
discovery gives a different way to control the flow of heat. It provides a shortcut through
the material ..."
 "A new
beamforming chip promises to shrink the size and weight of aircraft
antennas by eliminating the need for mechanical steering linkages. The chip could serve
in radar for defense aircraft and for in-flight broadband on commercial jets. Analog
Devices, maker of the new chip, also foresees it being used in air traffic control, surveillance,
weather monitoring, and even 5G communications. ADI engineers say the key is the product’s
inherent ability to cut size and weight. “By going to an electronically steered antenna
design, we are able to reduce the size of the antenna element itself and eliminate the
mechanical arm and motor ..."
 RF component manufacturer
Pasternack Enterprises has
a useful article in the May issue of Microwave Journal titled, "5G Update: Standards Emerge, Accelerating 5G Deployment." I am still
a bit fuzzy on what exactly 5G entails, other than it must be better than 4G since it's
a whole number higher. This helps a little. "Though the expected features and use cases
for 5G are diverse and extensive, the start of the 5G rollout will likely address only
a few of the featured use cases: enhanced mobile broadband (eMBB), ultra-reliable low
latency communications (URLLC) and massive Internet of Things (mIoT) or massive machine-type
communications (mMTC) ..."
 Sugar Grove, West Virginia, is within the U.S.
National Radio Quiet Zone (NRQZ), which also encompasses the Green Bank, WV area.
It was established by the FCC in 1958 to protect hypersensitive, cryogenically cooled
radio astronomy receivers from manmade terrestrial signal sources. As you can imagine,
there are not many places remaining in human-inhabited regions of earth that are not
massively invaded by radio frequency energy. If you visit the area today, you had better
not have your cellphone, computer, or other RF-producing device turned on or you can
be subject to a hefty fine. Roving signal detecting trucks monitor the region for offenders.
This 1961 report on advances in electronics also features the world's first computerized
bank check ...
 Gowanda Components Group is pleased to announce that its offerings
of RF and microwave passive magnetic components are expanding in connection with the
acquisition of HiSonic in Olathe, Kansas. "HiSonic's designs, technologies and customers
complement those within our Magnetics Division," said GCG CEO Don McElheny. "The synergy
in our capabilities and applications will enable us to offer a broader range of innovative
inductor and transformer solutions to design engineers in commercial, medical, microwave,
military, space and other markets around the world ..."
 "Only a few decades ago, finding a particular
channel on the radio or television meant dialing a knob by hand, making small tweaks
and adjustments to hone in on the right signal. Of course, we now take such fine tuning
for granted, simply pressing a button to achieve the same effect. This convenience is
enabled by radio frequency synthesis, the generation of accurate signal frequencies from
a single reference oscillator. The need for better radar in World War II drove the
development of radio frequency control, and its miniaturization in subsequent decades ..."
 With a fair helping of chagrin, I admit to being
a "10-4 Good Buddy" type of Ham radio operator. That moniker is applied liberally by
pre-1991 (February 14, to be exact) amateur radio licensees to post-1991 licensees because
that was the year in which the FCC no longer required aspiring Hams to pass a
Morse
code proficiency test for an entry level license. It was a sort of Valentine's Day
gift. In 2003, the ITU announced the rescinding of its code requirement and allowed countries
to set their own standards. By 2007, General and Amateur Extra exams no longer required
code tests. I earned my Technician license in 2010 ...
 Written by Terry Edwards, "Technologies for RF Systems" is a comprehensive resource provides
an introduction to the main concepts, technologies, and components in microwave and RF
engineering. This book presents details about how to design various amplifiers, circuits,
and chips for communication systems. It offers insight into selecting appropriate ADC
and DAC technology. Several worked examples are found throughout the book. This book
provides a summary of 21st century RF systems and electronics and discusses the challenges
of frequency bands and wavelengths, software-defined radio (SDR) and cognitive radio.
RF semiconductors are covered ...
 "A new
magnetic lattice material developed by researchers at the University
of Missouri could be used to increase the battery life of electronic devices by more
than a hundred times, it is claimed. Singh's team developed a two-dimensional, nanostructured
material created by depositing a magnetic alloy, or permalloy, on the honeycomb structured
template of a silicon surface. The new material conducts unidirectional current, or currents
that only flow one way. The material also has significantly less dissipative power compared
to a semiconducting diode, which ..."
 A lot of nostalgia gets waxed here on RF Cafe,
to which frequent visitors can readily attest. Old timers (if you're not one now, you
some day will be) often like to see remembrances of days of yore, the halcyon days of
past hobbies, family, long naps, school (yuk), vacations, and other pleasurable times.
Hopefully, you already have or will soon have a few of your own. This 3-page
Lafayette Radio Electronics spread from a 1965 issue of Popular Electronics
magazine is typical of what what avid electronics hobbyists would have read and drooled
over with so many great items in the offering. If you were like me, the cost of most
of the things I wanted were well outside my budgetary reach. Prices for electronics gizmos
were quite high ...
 everything RF has created the largest database
of searchable RFID products.
We have compiled complete catalogs from the leading RFID manufacturers across 6 categories
and make the products searchable by specification: RFID antennas, RFID reader ICs, RFID
reader modules, RFID readers, RFID tag ICs, and RFID tags. everythingRF has also created
parametric search tools in each category and are now adding more products and companies
to the system ...
 "There are still some places the Internet of Things
fears to tread. Researchers at the University of Arkansas and the KTH Royal Institute
of Technology, in Sweden, are building a radio for those places. This month, in IEEE
Electron Device Letters, they describe a mixer, a key component of any wireless
system, that works just fine from room temperature all the way up to
500 ºC. It's the first mixer IC capable of handling such extremes.
Of several projects 'one of the more sexy is trying to put a rover or some sort of instrument
on Venus that will last for more than two hours ..."
 A news story with a title about a boat and reverse
current is more likely to be referring to water flow in a river or stream than about
electrical current in a conductor. Having grown up in a neighborhood next to a tributary
of the Chesapeake Bay, I spent quite a bit of time around boats, both large and small.
Salt water is particularly destructive to metal hulls due to
cathodic corrosion, exacerbated by the salt water's conductivity. While working as
an electrician in the 1970s, I installed electrical supplies for a few dockside cathodic
protection systems that probably functioned like the one described in this 1965 issue
of Popular Electronics magazine. The principle is fairly simple whereby anodes
are placed in the water around the hull and a counter-current is induced ...
 It'll come as no surprise to any savvy buyer,
and certainly not to any design engineer, that each new generation of electronic products
packs more performance into a smaller package than the product it replaced. No matter
whether it's a remote industrial sensor node or the next smart wearable device, space
is becoming an increasingly scarce resource. Aimed at IoT and personal electronics applications,
the TLV9061 consumes only 0.64 sq.mm and is the
world's smallest op amp. Something's gotta give. In this case, many
things. Fitting the increased capability into a smaller volume requires the designer
to make improvements in multiple ...
 Cesium-137, iodine-131, carbon-14, plutonium-239,
strontium-90, uranium-235, and the list goes on. These and other
radioisotopes associated with nuclear material are the result of explosions, medical
treatments, laboratory experiments, or in some cases naturally occurring deposits. Regardless
of the source, most people, including me, cringe at the thought of being exposed to the
insidious effects of the cell-altering energy they possess. Ionizing radiation is the
dangerous type of radiation due to its ability to dislodge electrons from atoms, and
in the process forming cancerous cell mutations or killing the cells altogether. Researchers
in the early days of radiation discovery experienced sometimes gruesome maladies as a
result of the handling isotopes. Some knowingly subjected themselves to harmful doses ...
 Saelig has introduced the
STD-302Z 434 MHz Narrow Band Multi-Channel Transceiver - a half-duplex
UHF radio module that is suitable for industrial remote control and telemetry applications
operating in the 434 MHz ISM band. The STD-302Z is designed with SAW filter and
narrow-band filtering techniques to provide reliable data communication in industrial
situations where interference rejection and practical distance range operation are required.
Offering 10 mW of RF power from its PLL-synthesized transmitter with programmable
RF channels, the STD-302Z's double superheterodyne receiver sensitivity is specified
down to -119 dBm ...
 QuinStar Technology designs and manufactures
mm-wave products for communication, scientific, and test applications along with providing
microelectronic assembly, rapid prototyping, and mass customization. Amplifiers, Oscillators,
Switches, Attenuators, Circulators, Isolators, Filters, Waveguide, Antennas, Phase Shifters,
Transceivers, Mixers, Detectors. QuinStar specializes in cryogenic
amplifiers, circulators, and isolators. Please visit QuinStar today to see how they can
help your project ...
 "The future of electronic devices lies partly within
the 'internet of things' - the network of devices, vehicles and appliances embedded within
electronics to enable connectivity and data exchange. University of Illinois engineers
are helping realize this future by minimizing the size of one notoriously large element
of integrated circuits used for wireless communication - the transformer. Three-dimensional
rolled-up radio frequency transformers take 10 to 100 times less space, perform
better when the power transfer ratio increases and have a simpler fabrication process
than their 2-D progenitors, according to a paper detailing their design ..."
 Lou Frenzel has posted a good article titled, "Electronics Still Thrives as a Hobby" on the Electronic Design
website. While attending his local Maker Faire in Austin, Texas, he discovered some statistics
on the cross-section of electronic hobbyists as gathered by the Jameco Electronics supply
company, who sponsored the event. He expressed surprise at the average age of participants,
but it actually comports well with that of many - if not most - hands-on (not including
game controller and smartphone button pushing) types of hobbies these days ...
 If you look just beneath the RF Cafe page title,
you will see the Morse code dits and
dahs that represent this website's name. Click on it and you will be taken to the Morse
Code information page, and therein is an audio player that will sound out the code for
you. The music file was originally created in MIDI format in order to keep it as small
as possible. At the time, all the web browsers supported MIDI files. Times have changed
and now most browsers will not support them. I finally got around to converting the file
to MP3 format, so now the embedded player will provide the intended code transmission ...
Author:
Kirt
Blattenberger
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