 Friday the 23rd
Thursday the 22nd
Wednesday the 21st
Tuesday the 20th
Monday the 19th
Sunday the 18th
Friday the 16th
 Is this the future of engineering,
science, medicine, economics, and all other math-intensive fields? If it is,
we're in trouble. "A
Pathway to Equitable Math Instruction Dismantling Racism in Mathematics
Instruction" is being considered for incorporation into school curriculums
across the country. Its premise is that requiring students to arrive at the
correct answer is White supremacy (p1), and that any wrong answer is the fault
of the teacher, who needs to "Recognize mistakes as miscommunicated knowledge."
(p9) Get that? If a student screws up, it's not her fault. It is worth a few
minutes of your time to look through this. I guarantee you that China demands
correct answers of their math students. They are laughing at idiot school
systems in the U.S. We're doing their work for them in achieving global
technical dominance. The training manual was funded by the Bill and Melinda
Gates Foundation. Should we expect future releases of Windows to adopt the
anti-White supremacy, results are interpretive philosophy? A
BSoD is coming
to a computer near you. Apple will need to purge the racist objective measures
from their OS as well.
 This quiz is based
on the information presented in "Introduction
to Infrared and Electro-Optical Systems," by Ronald G. Driggers and Melvin
H. Friedman. All RF Cafe Quizzes make great fodder for employment interviews for
technicians or engineers - particularly those who are fresh out of school or are
relatively new to the work world. Come to think of it, they would make equally
excellent study material for the same persons who are going to be interviewed
for a job.
 Here is another exciting episode of the sleuthing
adventures starring Popular Electronics' tech savvy teenagers, Carl and
Jerry. The "Hardy Boys of electronics" are the creation of author John T. Frye,
who created short story adventures for many years - long enough to at one point
require a major modification in the boys' appearances to reflect more modern attire
and eyewear (Carl's "The Far Side"-style glasses had to go). This particular adventure
begins with Carl considering whether his ham radio hobby is more useful from the
standpoint of its technical aspects or of its social aspects. An unrelated electronics-themed
comic is included since it appeared on one of the story pages.
 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...
 Atenlab has been operating in Taiwan for
more than a decade, and has sold and installed hundreds chambers around the world.
Holistic, affordable Over-the-Air
(OTA) measurement systems perform comprehensive measurement and test in a controlled
environment. Compact Antenna Test Range (CATR) with one-touch operation supports
multiple systems - 2G, 3G, 4G, 5G - and major instrument brands. [M]ulti-probe OTA
measurement systems offer reduced time measurements over single-probe systems.
Thursday the 15th
 Windfreak Technologies announces the availability
of the new
SynthHD Mini RF Signal Generator. The SynthHD Mini is the smallest 10 MHz
to 15 GHz RF Signal Generator in the world - a mere 1.60 x 1.60 x 0.48 inches
(4.06 x 4.06 x 1.22 cm). Expect excellent performance despite the ultra-small
size and price of this device. Tune any frequency between 10 MHz and 15 GHz
in 0.01 Hz resolution. Adjust calibrated amplitude in 0.01 dB resolution
up to +20 dBm and across more than 30 dB of range. Perform FM, AM, Pulse,
Sweep, and List Modulations. See the Tabs below to download a full datasheet and
other documents. Windfreak Technologies has set the bar on microwave radio frequency
generators for quality, size, and price. As always, our products are designed and
manufactured in the USA! In Stock.
 "Sensors that can detect magnetic fields
have many potential applications, for instance, in the development of sophisticated
medical devices and transportation systems. Most approaches for
detecting 3D magnetic fields developed so far, however, require several sensors,
which makes them bulky and difficult to implement on a large-scale. With this in
mind, researchers at the Nanoscale Energy-Efficient Device and System (NEEDS) Lab
at Huazhong University of Science and Technology in China set out to develop a single
spin-orbit device that can individually detect 3D magnetic fields. The device they
designed, presented in a paper published in Nature Electronics and inspired by their
previous work, is based on a Ta/CoFeB/MgO (tantalum / cobalt-iron-boron / magnesium
oxide) heterostructure..."
 American
physicists Carl Anderson and Seth Neddermeyer were studying cosmic rays when they
discovered the muon in 1936. The
discovery of this particle was so surprising that Nobel laureate Isidor Isaac Rabi
exclaimed: "Who ordered that?" Dr. Rabi
was an American physicist who won the
Nobel Prize
in Physics in 1944 for his discovery of nuclear magnetic resonance and was a
pioneer in the development of the
cavity magnetron.
 So much time has passed since an average
home garage mechanic could service his car or truck with standard tools - combination
wrenches, screwdrivers, socket sets, timing light, and a multimeter - that asking
"remember when?" is passé. That era pretty much ended in the late 1980s as computerized
cars were becoming the industry norm. A good percentage of people nowadays have
never and will never service their own vehicles. In the mid 1940s, the electronics
world was lamenting a similar situation with diminishing ability to build and modify
electronic components like coils and stacked plate capacitors because of the increasingly
higher frequencies being used in communications (way up into the UHF band!). This
article introduces the
klystron tube, having been around for less than a decade at the time, as being
one of the culprits that was enabling the disturbing trend...
 I first saw this amazing photograph in the
April 2012 issue of Astronomy magazine. It is an
8-year-long image of the sun's path across the sky as recorded by by Fine Art
student Regina Valkenborgh from August 2012 through September 2020. She lined some
beer cans with photographic paper and punched a tiny hole in the can, mounted them
in locations around an observatory in the UK, then forgot about them. Most perished,
but this one survived and was found by a staffer. Ms. Valkenborgh now has the
honor of being responsible for the longest-ever photographic film time exposure.
Pinhole cameras have no lens, since light rays entering the container follow
a nearly singular path to the film surface. The smaller the hole, the sharper the
focus. Less light enters the camera, so a longer exposure time is required. Pointing
it at the sun provides an intense source of light, but it is still little enough
to not overwhelm the film over a period of 8 years.
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio 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...
 Triad RF Systems designs and manufactures
RF power amplifiers
and systems. Triad RF Systems comprises three partners
(hence 'Triad') with over 40 years of accumulated
knowledge of what is required to design, manufacture, market, sell and service RF/Microwave
amplifiers and amplifier systems. PA, LNA, bi-directional, and frequency translating
amplifiers are available, in formats including tower mount, benchtop, rack mount,
and chassis mount. "We view Triad more as a technology partner than a vendor for
our line-of-sight communications product line." Please check to see how they can
help your project.
|
 Communications links are so ubiquitous these
days that we pretty much take for granted the ability to connect to the Internet
and to other people. How many times have you been in public and heard someone have
a fit because she couldn't get a good enough signal to make a call? It requires
the person to get up and walk a few feet or maybe turn her chair in another direction
to get an extra bar on the iPhone. How inconvenient. Even when placing a call to
Hawaii or Alaska the expectation is that things just work. In 1963 when this
tropospheric scattering network was installed for linking Alaska to the lower
48 states, satellite communications was still in its infancy and coverage was nowhere
close to global. Even radio relay towers were relatively scarce across the landscape...
 Here is a little electronics hobbyist humor
in the form a comic series titled "Hobnobbing with Harbaugh," compliments of
Popular Electronics magazine. Dave Harbaugh drew many comics for technical
magazines. For the non-Ham, QSL is the Q-code for "'I confirm that I received your
transmission." You don't need to be an amateur radio operator to appreciate these
comic strips, though. Note that with it being 1963, the husband and wife are shown
sleeping in separate beds - just like in the TV shows of the era like The Dick Van
Dyke Show and I Love Lucy. BTW, the kid in the crib is spelling out -..(d) .-(a)
-..(d) -..(d) -.--(y).
 Electronic mail did not start out as we know
it today, whereby anyone with access to an Internet-connected device can compose
and send a typed message to a similarly equipped receiver. The first electronic
mail message was sent (and received) on November 1, 1960, between post offices in
Washington, D.C., and Chicago, Illinois. This article from Popular Electronics
magazine takes you on a step-by-step tour of how the
Speed Mail system worked, including its dedicated shortwave radio links between
participating cities. Great care was taken in an attempt to assure message confidentiality
by having the letter opened and scanned automatically inside a sealed machine on
the transmit end and then printed and placed in a sealed envelope on the receive
end. Knowing what we know now about government snooping...
RfCaFe
autodidacts
Electronics-Themed Comics June 1951 Radio-Electronics
 RF Cafe typically receives 8,000-15,000
website visits each weekday and about half that on weekends.
RF Cafe is a favorite of engineers, technicians, hobbyists, and students all
over the world. With more than 13,000 pages in the Google search index,
RF Cafe returns
in favorable positions on many types of key searches, both for text and images.
New content is added on a daily basis, which keeps the major search engines interested
enough to spider it multiple times each day. Items added on the homepage often can
be found in a Google search within a few hours of being posted. I also re-broadcast
homepage items on LinkedIn. If you need your company news to be seen, RF Cafe
is the place to be.
 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...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols 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). Symbols 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...
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio 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...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's Matchmakers"
Smith chart design or the "Engineer's Troubleshooting Flow Chart." My "Matchmaker's"
design has been ripped off by other people and used on their products, so please
be sure to purchase only official RF Cafe gear. My markup is only a paltry 50¢ per
item - Cafe Press gets the rest of your purchase price. These would make excellent
gifts for husbands, wives, kids, significant others, and for handing out at company
events or as rewards for excellent service. It's a great way to help support RF
Cafe. Thanks...
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...
|
 Is this cool or what? Of course I'll never
be able to afford one (maybe an R/C model someday, though). "Electric boats of all
shapes and sizes are beginning to make a splash in the maritime sector. It's estimated
that maritime greenhouse gas emissions account for around 2.5% of the global total,
marginally ahead of the 2% that aviation contributes. If shipping were a country,
it would be the sixth largest emitter of CO2 after China, the USA, India, Russia
and Japan. International shipping - much like long-haul flight - will not be electrified
any time soon, as the energy density of batteries simply cannot facilitate it. And
for an industry that's recently committed to halve its emissions by 2050..."
 "Technology continues to advance with solutions
that demand more and more performance in terms of energy efficiency and data processing.
Kuprion, Inc., has patented a
copper-filled via technology that addresses the heat problem at the board level.
In an interview with EE Times, Kuprion president & founder Alfred Zinn pointed
out that thermal management of PCBs is very important, as improving heat transfer
can increase mean time between failures (MTBF) while at the same time increase the
performance of heat-generating components. Zinn said Kuprion's Copper Filled Thermal
Vias technology is an easy and cost-effective method that, placed directly under
a component that needs to be cooled, opens a second heat dissipation duct doubling
the cooling rate..."
 "Researchers at the National Institute of
Standards and Technology (NIST) and collaborators have demonstrated an
atom-based sensor that can determine the direction of an incoming radio signal,
another key part for a potential atomic communications system that could be smaller
and work better in noisy environments than conventional technology. NIST researchers
previously demonstrated that the same atom-based sensors can receive commonly used
communications signals. The capability to measure a signal's angle of arrival helps
ensure the accuracy of radar and wireless communications, which need to sort out
real messages and images from random or deliberate interference..."
|
