 Wednesday the 21st
 As of the year 2020 there was an estimated
7.8 billion people in the world. Most of them, thanks to the technology invented
and provided by capitalist societies, have some form of Internet access. A large
fraction of them have paid nothing for it (while hating those who provided it) -
I'm just sayin'. Out of those 7.8B people, surely a handful have already or will
in the future search the World Wide Web (WWW) in pursuit of information on vintage
test equipment, either as fodder for some publication, for reference in obtaining
particular models or for service data. In the interest of those folks, I go to the
trouble of scanning and posting content like this test equipment advertisement by
Superior Instruments (aka SICO)...
 Copper Mountain Technologies will be presenting
a webinar entitled "Introduction
to Antenna Aperture," hosted by none other than Robert Zavrel (W7SX), author
of "Antenna Physics: An Introduction." It begins at 2:00 pm EST on Tuesday,
April 27th. Robert is an accomplished RF Engineering Executive with 30 years of
applicable experience and a verifiable consistent record delivering technical innovation,
streamlined operations, increased productivity, and exceptional leadership and mentoring.
The concept of antenna aperture is perhaps the most important antenna specification
that is largely ignored by amateur texts. Many commonly published equations for
radio engineers and amateurs alike rely upon antenna equations that employ aperture
but never explain the fundamentals, they simply give the equations and leave it
at that. The purpose of this brief overview is to explain the concept and relate
it to why we should care. Virtually all advanced texts on antenna theory explain
aperture in detail since their goal is to provide deep understanding of the subject
This is an attempt to provide an empirical fundamental understanding...
 Amateur radio operators, as with hobbyist
participants in many other realms, historically have contributed significantly to
the efforts of their professional counterparts. I have written of it often. This
particular instance is where signal measurements in the Ham bands during a
total eclipse of the sun (August 31, 1932 in this case) were used to assist
scientists debating the merits of rival theories relating to origin of ionization
in the Kennelly-Heaviside Layers of the E and F regions, both of which were proposed
in 1902 (yes, the Heaviside of step function fame). Long distance (DX) communications
are dependent upon such ionization to reflect radio signals that would otherwise
pass through the atmosphere and into space. The test at hand would settle the argument
since the one should fail if ionization was unaffected during totality.
 Nokomis, a high technology research and development
company, is seeking a
PCB Layout
Designer to design complex, multilayer PCBs with high density BGAs using Mentor
PADS. This position will be responsible for completing a variety of tasks in a cost-effective
and time-efficient manner. The ideal candidate will have experience in the layout
of a mixture of different types of technology boards, thru hole, SMT, and mixed
with possibly blind and buried vias. The boards will have a wide range from very
simple one-layer, single sided placement, to multi-layer double sided placement.
Technology ranges from analog to high-speed digital layouts. This is a contract
position...
 Centric RF is a company offering from stock
various RF and
Microwave coaxial components, including attenuators, adapters, cable assemblies,
terminations, power dividers, and more. We believe in offering high performance
parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power
levels from 0.5-500 watts are available off the shelf. Order today, ship today!
Centric RF is currently looking for vendors to partner with them. Please visit Centric
RF today.
Tuesday the 20th
 It takes a while - and money - to accumulate
issues of the vintage electronics magazines for posting articles here on RF Cafe.
Often I can find groups for sale that comprise a full calendar year, but often they
are groups of random months and years. That makes getting a complete series of articles
like this one on "How
an Electronic Brain Works" difficult. A lot of times installments appear every
other month, so when a series has more than ten articles, it can run well over a
year. For instance Part I of "How an Electronic Brain Works" appeared in the
September 1950 issue of Radio-Electronics. The final chapter, Part XIII,
appeared in October 1951. Throughout the series, authors Edmund C. Berkeley and
Robert A. Jensen describe the workings of "Simon," their compact electronic computer
- some even call it the first "desktop computer." Here is an article (with photos)
about "Simon" in the November 1950 Scientific American magazine...
 ConductRF offers RF Engineers a large selection
of
Hi Flex cable for vector network analyzers (VNAs). We have standards
for applications at 18-40 GHz, 50 GHz & 70 GHz. Our torque resistant
connector heads and phase stable constructions ensure great performance for many
tests to come. Other key features include: 2.92 mm, 2.4 mm & 1.85 mm
connector options, low VSWR & insertion loss, low phase change with flexing,
options available swept right angle connectors. ConductRF VNA series provides customers
with reliable ruggedized solutions for Lab and Production Vector Network Analyzer
testing. With options for 18 GHz, 26.5 GHz, 40 GHz, 50 GHz, &
70 GHz, these cables offer cost leading alternatives to original OEM VNA cable
solutions...
 "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..."
 As with so many things we take for granted
today, the U.S. Army Signal Corps' nationwide announcement on January 25th, 1946,
that the first
earth-to-moon-to-earth (EME, aka moonbounce) contact had been made by radar
was a big deal. Hams make EMEs on a regular basis, although it still is not a simple
accomplishment and takes some special equipment. The term "selsyn" used in the article
is a portmanteau of "self-synchronous," and refers to a device for precisely positioning
something like an antenna. Magazine editor Hugo Gernsback included some kudos from
contemporary notables like Audion inventor Lee DeForest and Radio Corporation of
America (RCA) president David Sarnoff for having predicted the method and results
in a 1927 article entitled "Can We Radio the Planets? See "Moon-Radio Predicted
in 1927" at the bottom of the page.
 Pasternak has an interesting article on
the Microwave Product Digest website entitled, "CubeSats:
An Emerging Market for the Microwave Industry." In framing the story with the
history of satellite communications, the author hearkens back to 1945 when Arthur
C. Clarke ("2001: Space Odyssey") described in Wireless World magazine
a way that communications could be achieved via Earth-orbiting "Extra-Terrestrial
Relays." Pasternak begins, "Spacecraft in low, mid, and high orbits provide
a diverse array of services from TV and radio broadcast to terrestrial and maritime
communications, remote sensing, and navigation and timing. Not surprisingly, the
satellite industry has been a steady consumer of RF and microwave components for
more than five decades, and the pace is likely to increase. The driver of this good
fortune is the 'smallsat' that makes it possible for even companies and governments
without enormous financial resources to create space-based services..."
 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...
 NextPCB is one of the most experienced PCB
manufacturers in China, has specialized in the PCB and assembly industry for over
15 years. NextPCB provides the most innovative printed circuit boards and assembly
technologies in the highest quality standards, turnaround time as fast as 24 hours,
the lowest manufacturer direct prices, and the most dedicated customer service in
the industry. Turnkey service without a broker including components sourcing, PCB
prototyping, manufacturing, assembly, quality testing, and final shipment. Certified
by IATF16949, ISO9001, ISO14001, UL, CQC, RoHS and REACH.
Monday the 19th
 "Monday, NASA's
Ingenuity Mars Helicopter became the first aircraft in history to make a powered,
controlled flight on another planet. The Ingenuity team at the agency's Jet
Propulsion Laboratory in Southern California confirmed the flight succeeded after
receiving data from the helicopter via NASA's Perseverance Mars rover at 6:46 a.m.
EDT. 'Ingenuity is the latest in a long and storied tradition of NASA projects achieving
a space exploration goal once thought impossible,' said acting NASA Administrator
Steve Jurczyk. 'The X-15 was a pathfinder for the space shuttle. Mars Pathfinder
and its Sojourner rover did the same for three generations of Mars rovers. We don’t
know exactly where Ingenuity will lead us, but today's results indicate the sky
– at least on Mars – may not be the limit'..."
 Until the last couple decades, people of
the world recognized and called out evil by name when it reared its ugly head. Except
for subversive imbedded agents, media outlets - radio, television, print, speeches,
etc. - openly and vigorously condemned and attacked the enemy of its country's traditional
way of life. The theme ran deep and wide in news reports and in magazine features.
This advertisement for Air Adventures magazine which appeared in early 1940s
Radio News magazine is an example. In the place of politically correct
speech that doesn't dare to offend an entity which openly and maniacally seeks to
kill you we had the vast majority of media promoting nationalism and patriotism
in order to defeat the enemy. As with just about everything, eBay is a good source
of these vintage Air Adventures magazines. This particular publication only
ran for three editions. However, there were plenty of other titles that featured
stories of heroic adventures against the Nazi scum ;-) Flying Aces magazine...
 "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..."
 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...
 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...
 Copper Mountain Technologies develops innovative
and robust RF test and measurement solutions for engineers all over the world. Copper
Mountain's extensive line of unique form factor
Vector
Network Analyzers include an RF measurement module and a software application
which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware
via USB interface. The result is a lower cost, faster, more effective test process
that fits into the modern workspace in lab, production, field and secure testing
environments.
Sunday the 18th
 This
Science & Math Crossword Puzzle for April 18th 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. Enjoy!
 Radio-controlled flying drones are commonplace
today - so much so that the FAA has enacted legislation to strictly limit who can
fly them, where they can be flown, how big they can be, what type of payloads can
be carried, how far from the pilot they can be flown, etc. - the typical kind of
overreaching and overregulating that governments promulgate (especially in the last
few years). Sport model airplane flying has suffered loss of freedoms because of
it by getting lumped in with multirotor drones. The military, of course, has been
using radio-controlled drones for decades, as highlighted in this 1945 Radio-Craft
magazine article. Author Louis Bruchiss extolls the advantages of being able to
guide an ordinance payload after being released from an aircraft of after being
launched from the ground. Even vehicles like the German V-2 rocket with its gyroscopically
stabilized guidance...
Friday the 16th
 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..."
 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.
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