Today in Science History -
 These days it is probably rare that a person
would find the need to construct a custom
transformer for a power supply since just about anything you need can be found
on websites like eBay and Amazon. However, there are still many homebrew types out
there who enjoy the challenge (and maybe nostalgia) of creating a transformer for
a special need. For those folks, this article from a 1952 issue of Radio−Electronics
magazine will be a welcome bit of information. Author T.W. Dresser presents
the fundamental equations and design methodology needed for winding a transformer
on a laminated steel core frame. There are plenty of abandoned transformers which
can be stripped down and rebuilt as required. Even the newest electronic devices
- radios, TVs, Blu−ray players, kitchen appliances, etc. - have a transformer of
some sort...
 Transistors were still relatively new when
these cartoons were published in the September 1959 issue of Popular Electronics
magazine. Most people had never seen a transistor, much less handled one. Soldering
irons used for working on the point-to-point wiring used on vacuum tube gear could
also be used for soldering the old copper guttering and downspouts - at least the
ones that got hot enough and had enough thermal inertia to melt solder on sheet
steel chassis'. Does the guy in this General Transistor infomercial look a bit like
Dilbert - or maybe I should ask does Dilbert look a bit like this guy? BTW, are
you thinking what I'm thinking about the picture on the bottom left?
 "Most electromagnetic interferences (EMIs)
in the field are conducted emissions/immunities, radiated emissions/immunities,
electric fast transients (EFT), and electrostatic discharge (ESD). There are, however,
other types of EM-related disturbances, including
low-frequency magnetic fields, the subject of this article. The power-frequency
(50-60 Hz) magnetic field is a direct result of currents flowing in power networks.
When low-frequency currents flow in the entire power network, depending on the size
of the current-circulating loop, the impact on equipment/products in the environment
can be significant. A typical case is an equipment with a cathode ray tube (CRT)
screen. The display on a CRT screen would appear to wobble due to the presence of
a nearby low-frequency field1. Professional audio equipment such as electric guitars,
tape recorders, and loudspeakers are also sensitive to external magnetic fields..."
 As quoted in this 1954 Radio & Television
News magazine article about analog[ue] computers as compared to digital computers,
"Add two and two. Coming from an analogue computer, the answer would most likely
be, 3.999 or 4.001." While that is a true statement, there is one important feature
that an analog computer had over digital computers of the era: once initially set
up with a transfer function, outputs were nearly instantaneous as the input was
varied over a range of values, whereas a digital computer could take quite a bit
of time to crank through involved mathematical equations. Performing tasks such
as computing aircraft flight paths and other sequential operations was the analog
computer's forte. If you needed to calculate exact values for atomic research or
cryptographic code cracking, that was and still is the domain of digital computers...
 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...
 Anatech Electronics (AEI) manufactures and
supplies RF and microwave filters for military and commercial communication
systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters,
and RF products. Standard RF filter and cable assembly products are published in
our website database for ease of procurement. Custom RF filters designs are used
when a standard cannot be found, or the requirements dictate a custom approach for
your military and commercial communications needs. Sam Benzacar's monthly newsletters
address contemporary wireless subjects. Please visit Anatech today to see how they
can help your project succeed.
 Don't miss this chance to observe one of
the longest possible
lunar eclipses
tonight, Sunday, May 15th - a
super flower blood moon. The earth's umbral shadow first touches the edge at
10:27 pm EDT, then totality begins at 11:29 pm. The 85-minute-long total
eclipse is midway at 12:11 am, then leaves the umbral shadow at 12:53 am.
A lesser darkening of the moon happens on both sides of the eclipse while in
the earth's penumbral shadow, but it is not as stark. A second, nearly identical,
lunar eclipse will occur in November of this year, so if the weather does not cooperate
in allowing you to see this one, maybe you will get luckier in half a year. The
skies here in Greensboro, NC, are forecast to be clear tonight. I hope yours are,
too.
 This custom
s-Parameters themed Crossword Puzzle for May 15th, 2022, is brought to you by
RF Cafe. Clues for words relevant to the theme are marked with asterisks (*).
All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and
have only 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...
 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...
 Axiom Test Equipment allows you to
rent or
buy test equipment,
repair
test equipment, or sell or trade test equipment. They are committed to providing
superior customer service and high quality electronic test equipment. Axiom offers
customers several practical, efficient, and cost effective solutions for their projects'
TE needs and is committed to providing superior customer service and high quality
electronic test equipment. For anyone seeking a way to offload surplus or obsolete
equipment, they offer a trade-in program or they will buy the equipment from you.
Some vintage items are available fully calibrated. Please check out Axiom Test Equipment
today!
 Add-on devices like this "TV-IF
Signal Booster" began appearing in all sorts of magazines back in the early
1950s as television sets became more and more of a household fixture, and people
were beginning to assume the now well-establish couch potato domestic class. According
to this advertisement by Grayburne Corporation, "experience proves a 20% average
boost in overall signal is all that's needed to give satisfactory reception." Since
their signal booster plugs into the IF path, it is probably safe to assume the gain
refers to voltage and not power. A 20% gain in voltage is 10 * log (1.2) = 0.79 dB,
which is not much. Most likely the vast majority of TV installations would benefit
much more from fine tuning of the antenna and transmission cable system, but to
be fair, this devices targets indoor installations where the antenna is rabbit ears
that came installed on the set. In that case, relocating the television to another
place in the room and fiddling with the rabbit ears would also likely result in
as much or more of an improvement as the booster...
 "Hong Kong University of Science and Technology
(HKUST) reports on a
gallium nitride (GaN) non-volatile memory (NVM) with good speed, retention and
endurance at the same time. In silicon-based NVMs there tends to be a trade-off
in these characteristics, creating a manufacturing 'trilemma' due to the use of
Fowler-Nordheim tunneling across a tunnel oxide (TO) to change the memory state.
The researchers comment: 'This work shows that the mainstream GaN-on-Si platform
can also accommodate high-performance non-volatile memory devices in addition to
the power and radio frequency (RF) devices, to enable highly intelligent electronic
systems.' The device integrated a p-channel field-effect transistor (p-FET) with
p-i-n heterojunction diode. The p-FET consisted of aluminium oxide (Al2O3) gate
insulator on p-GaN..."
 This Radio Service Data Sheet for the
Kennedy Superheterodyne Short-Wave Converter (Model 54 "Globe Trotter") is an
example of the dozens of similar schematic and alignment instruction sheets that
have been posted on RF Cafe over the years. It appeared in a 1932 issue of Radio−Craft.
Obtaining technical information on most things, even readily available items, prior
to the Internet era was often very difficult - if not impossible. Service centers
had what was need provided by manufacturers and distributors, but if you wanted
to find a part number or service data on a refrigerator, radio, lawn mower, garage
door opener, etc., and did not have the original paperwork, you were usually out
of luck. Nowadays a Web search will quite often get you what you need thanks to
people (like me) who go to the trouble of making the information available. The
stuff doesn't just magically appear or get posted by benevolent governmental entities...
 At Raytheon Missiles & Defense, you
have the opportunity to try new things and make a bigger difference across a broader
end-to-end solution, a richer technology and product set, an expanded range of disciplines,
a growing global footprint and a more diverse team of colleagues and customers.
Raytheon now has an opportunity for an experienced
Senior Electrical Engineer: TWT & HPA Design who is seeking to utilize their
strong academic background and experience in High Power/High Voltage Transmitters.
This position requires an experienced senior technical and business leader with
a proven track record of invention, capture, and successful execution in High Power
Microwave (HPM) and Pulsed Power technologies. Responsibilities include design and
hands-on testing of high voltage/high power RF components plus providing technical
support to production activities across multiple programs. Team leadership skills
including cost and schedule management plus proposal writing and presentation experience
are desired...
 "It is anybody's guess as to what modulation
system the amateur of 1975 will be using." That forward-looking line appeared in
this 1947 QST magazine infomercial by the
National
Company. The writers probably had no real idea how different electronics would
be 25 years in the future, especially since John Bardeen et al would not invent
the transistor until two more months (December 1947) after the publication of this
issue. In their traditional style, this full-page advertisement was heavy on text
and light on images. The company invested in customer education with the hope being
a well-informed and appreciative hobbyist would reward them with patronage...
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...
 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.
 There is a physical limit to how small of
a distance may separate two distinct objects (line, dots, etc.), generally agreed
to be about half a wavelength of the color being observed, and be seen with perfect
human eye. Applying that rule of thumb to blue light with a wavelength of approximately
4000 Å (400 nm) yields a distance of 200 nm. Accordingly, there is
no amount of magnification possible which will allow a healthy human eye to resolve
objects closer together than that. Even with perfect optics, magnifications of greater
than about 1500x are not able to render greater detail. To resolve smaller distance
requires shorter wavelengths, but we cannot see them directly and need a device
to transform the detected image into a visible image. That is what an
electron microscope does to enable molecule sized particle to be "seen." The
SARS-CoV-2 particle has been measured by electron microscopy and found to range
between 50 to 140 nm, so it cannot be viewed directly with an optical microscope.
Cigarette smoke is about 400 nm in diameter...
 "This paper describes the fabrication of
digital logic circuits comprising resistors and diodes made from
protein complexes
and wired together using printed liquid metal electrodes. These resistors and diodes
exhibit temperature-independent charge-transport over a distance of approximately
10 nm and require no encapsulation or special handling. The function of the protein
complexes is determined entirely by self-assembly. When induced to self-assembly
into anisotropic monolayers, the collective action of the aligned dipole moments
increases the electrical conductivity of the ensemble in one direction and decreases
it in the other. When induced to self-assemble into isotropic monolayers, the dipole
moments are randomized and the electrical conductivity is approximately equal in
both directions. We demonstrate the robustness and utility of these all-protein
logic circuits by constructing pulse modulators based on AND and OR logic gates
that function nearly identically to simulated circuits. These results show that
digital circuits..."
 Astronomers consider all elements heavier
than helium to be metals. That definition obviously does not jive with the standard
chemical definition of a metal as an element that readily conducts electricity,
but a concept called "metallicity"
argues that from a star (and therefore the universe) formation perspective, extremely
high temperatures and pressures in first generation stars (like our sun) preclude
the identification of distinct elements other than hydrogen and helium. Heavier
elements, such as lithium (#3 on the periodic chart and a major component in LiIon
batteries, is classified as a metal in chemistry) are overwhelmingly created after
a massive enough hydrogen star collapses and begins fusing H and He into heavier
elements. The relative abundance of hydrogen in the universe is deemed to be about
92%, and helium is 7.1%, so together they comprise about 99% of all elements. Universally,
oxygen is at 0.1%, carbon is 0.06%, nitrogen is 0.015%, silicon is 0.006%, and iron
is 0.004%. By comparison, the Earth's elemental composition is 48.8% oxygen, 14.3%
iron, 13.8% silicon, 0.2% hydrogen...
 At Raytheon Missiles & Defense, you
have the opportunity to try new things and make a bigger difference across a broader
end-to-end solution, a richer technology and product set, an expanded range of disciplines,
a growing global footprint and a more diverse team of colleagues and customers.
Raytheon Missiles and Defense is seeking an engineering professional to work with
a variety of programs as a contributor to detailed design, simulation, product development,
and initial product testing. The RF Products Department is currently searching for
Electrical Engineers who have experience designing RF and Microwave hardware &
CCA design, including transmitters, receivers, and exciters. This role includes
design and test activities that span preliminary design to integration. Products
we develop support radar and datalink applications on a variety of tactical missile
programs. Critical to this role will be designing for challenging mechanical constraints
and extreme environments...
 News reports are full of features about
the wave of radio controlled (R/C) "drones" terrorizing citizens with their often
inexperienced pilots navigating their camera-laden craft to peer into bedroom windows,
obtain "birds-eye" views of sporting events, and to be a general pain in the posterior
to people trying to enjoy their right to privacy and safety (except, of course,
unless it is the Government choosing to violate them). Incredible advances in radio,
navigation, and sensor systems has facilitated a wide variety of very affordable
multirotor (the correct term, not "drone") aircraft that can literally fly themselves.
For under $500 you can buy a
GPS-guided
multirotor that can be programmed to fly to one or more waypoints and return
to the launch location, with range and flight duration limited only by battery capacity.
Gimbaled, remotely steerable cameras can snap photos or record video and either
store it onboard for later retrieval or wirelessly transmit the images back to the
operator. Platform stabilization is provided by ultra-miniature, ultra-lightweight
orientation and rate gyros...
 This quiz is based on the information presented
in Battlespace Technologies: Network-Enabled
Information Dominance, by Richard S. Deakin. Published by Artech House. Note:
Some of these books are available as prizes in the monthly RF Cafe Giveaway. This
book has some of the best photos of modern war-fighting technology that I have seen.
"The era of mechanized warfare is rapidly giving way to the battle for information
superiority enabled by electronic technologies that provide data for detailed analysis
of enemy forces and capabilities. this book discusses how to use sensor technologies,
including radar and electronic warfare systems, to disseminate information to key
decision makers in timely and relevant manner..."
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