Today in Science History -
 "Researchers based in Russia report on molecular
beam epitaxy (MBE) of indium gallium arsenide (InGaAs)
quantum dots/wires (QDs/QWs) in aluminium gallium arsenide (AlGaAs) nanowires
(NWs) on silicon (Si) 'for the first time' [Rodion R. Reznik et al, Phys. Status
Solidi RRL, p2200056, 2022]. The research team at St. Petersburg State University,
Alferov University, Institute for Analytical Instrumentation RAS, Ioffe Physical
Technical Institute RAS, and National Research University Higher School of Economics,
have previously studied MBE synthesis of GaAs QDs inside AlGaAs nanowires on silicon.
The researchers comment that these hybrid nanostructures were effective sources
of single photons in a wavelength range of 750–800nm. Thus, they constitute 'promising
candidates for use in quantum cryptography and alkali metal..."
 Copper Mountain Technologies has a webinar
coming up in league with Eravant as part of our VNA 101 Bootcamp Webinar series
titled "Starter
mmWave Measurements." It begins on May 24, 2022, at 2 PM ET. This webinar will
demonstrate Eravant's VNA frequency extenders and their ability to perform full
two−port S−parameter measurements of millimeter−wave components. The example test
system will include Eravant's Proxi−FlangeTM waveguide adapters, as well as the
Wave−GlideTM positioning system. The VNA frequency extenders add full waveguide-band
frequency coverage to several industry-standard coaxial VNAs, including models available
from Copper Mountain Technologies. Proxi-Flange contactless waveguide flanges enable
fast and repeatable connections between VNA frequency extenders and the waveguide
components being tested. The Wave−Glide positioning system further streamlines component
testing by maintaining the alignment between VNA frequency extenders and the components
being tested while providing an easy and reliable method...
 While not many people are likely to build
this
R-C bridge circuit with vacuum tubes for use during design and troubleshooting,
this 1947 Radio News magazine article has a good basic description of operation
of any calibrated bridge circuit used to measure an unknown value. Interestingly,
a "magic eye" or "cat's eye" tube is used in lieu of a meter movement to give a
visual indication of an open, short, intermittence, poor power factor, and low "Q,"
as well as when the selected switch position correctly identifies the value of the
resistor or capacitor under test. Note that in that era μfd = μF and μμfd = pF...
 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 stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
 Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 267,269 products from more than 1397
companies across 314 categories in their database and enable engineers to search
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
 How RF circuits work have long been referred
to as "black magic," even sometimes by people who fully understand the theory behind
the craft. To me, the ways in which a transmission line - be it coaxial cable, microstrip,
or waveguide - can be manipulated and controlled with various combinations of lengths
and terminations is what most qualifies as "magic." Sure, I know the equations and
understand (mostly) what's happening with incident and reflected waves, etc., and
how the impedance and admittance circles of a Smith chart graphically trace out
what's happening, but you have to admit there's something mystical about it all.
Fortunately, Mr. John Marshall published this "Antenna
Matching with Line Segments" article in the September 1948 issue of QST magazine...
 Innovative Power Products (IPP) has over
35 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. Products listed on website
link to detailed mechanical drawings that contain electrical specifications as well
as performance data. Please take a couple minutes to visit their website and see
how IPP can help you today.
 As is frequently the case, John T. Frye's
intrepid teenage technophile experimenters,
Carl Anderson and Jerry Bishop, find themselves in an unplanned adventure. Often
times they end up applying their electronics knowledge to bail themselves out of
trouble, but this time the pair - and a friend - ended up helping the police catch
some bad guys (an oft-occurring theme). As you will see after reading "All's Fair
--," the device used would some day (today) be used by automobile manufacturers,
at the behest of law enforcement agencies, to enable remote control of somebody
else's vehicle with a "kill switch." This technodrama appeared in the September
1963 issue of Popular Electronics magazine...
 "The airbags in your car… the camera on your
video doorbell... the phone or other electronic device you're reading this on right
now. The everyday products that make modern life possible wouldn't be able to run
without key electrical components maintaining functionality and stability for years
at a time. And yet, these electrical components experience
complex thermal and mechanical loads during the daily course of their operation,
or, in the case of the airbag, during long-term passive cycles of environmental
heating and cooling while they wait unused within a car's interior. As producers
and consumers require ever more from electronic devices, those devices are becoming
more powerful, further increasing the thermal loads being subjected to vital components..."
 For a long time I have been scanning and
posting schematics & parts lists like this one featuring the
International Kadette Model 400 4-Tube Battery-Operated Superheterodyne radio
in graphical format. As with all the other vintage articles posted, it requires
running OCR on them to separate the textual content from the graphics. This particular
Radio Service Data Sheet came from the July 1936 issue of Radio-Craft magazine.
There are still many people who restore and service these vintage radios, and often
it can be difficult or impossible to find schematics and/or tuning information.
I will keep a running list of all data sheets to facilitate a search...
RF Cascade Workbook 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...
 PCB Directory is the largest directory of
Printed Circuit
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.
 Often, the photo on the covers of magazines
is related to a feature article within, but in the case of the March 1954 Radio-Electronics,
only a couple paragraphs are devoted to it. Although more commonplace back in the
day, mention of a
Lecher wire for measuring VSWR values of the antenna under test caused me to
look it up. The Wikipedia entry says, "Lecher line or Lecher wires is a pair of
parallel wires or rods that were used to measure the wavelength of radio waves,
mainly at VHF, UHF and microwave frequencies. They form a short length of balanced
transmission line (a resonant stub). When attached to a source of radio-frequency
power such as a radio transmitter, the radio waves form standing waves along their
length. By sliding a conductive bar that bridges the two wires along their length,
the length of the waves can be physically measured. Austrian physicist Ernst Lecher,
improving on techniques used by Oliver Lodge and Heinrich Hertz, developed...
 AC alternators replaced DC generators back
in the 1940s as demand for conditioned electrical power in vehicles rose beyond
that needed for ignition and lighting. Radios are the most notable additions, and
because amplitude modulation (AM) broadcasts were the dominant method of the day
for commercial stations, noiseless electrical supplies were required. Spark-induced
noise from ignition systems was bad enough since its frequency varied with engine
RPM, but the DC generator's commutator sparking noise - much of it right smack in
the audio frequency range - was just too much for the public to endure if widespread
acceptance of radio was to be realized. Remember that in the era, a radio was not
standard equipment in cars and trucks so customers needed to be convinced the extra
expense would be worth their hard-earned dollars. Use of a 3-phase alternator reduces
the component performance requirements for conversion to DC...
 "An on-chip circuit that can produce up to
six microwave photons simultaneously has been created by researchers in France
and Germany. Gerbold Ménard and Ambroise Peugeot at the University of Paris-Saclay
and colleagues built their device by connecting a Josephson junction to a microwave
resonator. While the team did not establish that the photons are entangled, previous
research suggests that the device could be a source of multiple entangled photons.
The ability to produce pairs of entangled photons is vital for many quantum technologies.
Most often, it involves a technique called parametric down-conversion, whereby a
single photon is split into two lower-energy photons after interacting with a nonlinear
optical medium. This technique could be used to produce higher numbers of entangled
photons, but such a system would be bulky and complex. Ménard, Peugeot and colleagues
have now shown that multiple photons can be produced..."
 In a continuing effort to provide archival
material for researchers and for anyone seeking information on a particular radio
restoration project, this Radio Service Data Sheet for the
Crosley "Chief" Model 132-1 radio from a 1933 edition of Radio-Craft is being
posted. An Internet search will show that there are many people engaging in such
activities. Restoring my Crosley Model 03BC console radio would have been more difficult
if not for others who have done similar work to assist the "community." I generally
despise the phrase "giving back" because it is usually uttered by people that really
owe nothing to anyone, but somehow feel obligated to do so or are conditioned to
automatically say such things. This is a case where I benefitted from somebody else's
work and there is an opportunity to return the favor...
 The candidate will be responsible for leading
and shaping antenna, radome, and antenna measurement system technology within the
Company. The selected
Antenna and Radome Design Senior Engineer candidate will also be expected to
lead diverse teams, provide technical oversight, delegate tasks, and work with the
Engineering organization to establish technology roadmaps, enable modernization,
and contribute to general innovation. In addition, the candidate will work with
government personnel and programs, and define and refine requirements to validate
hardware compliance. The candidate will be responsible for providing guidance, coaching,
mentoring, and training to other employees across the business within the candidate's
areas of expertise. Responsibilities to anticipate include: Development of antenna
or radome hardware and requirements, Working with interdisciplinary engineering
teams including thermal, structural, mechanical, systems, etc...
 The January 2016 issue of Scientific
American ran an article by Clara Moskowitz titled "Elegant Equations" that
presented a few prints from "The Concinnitas Project" which "...is a collection
of ten aquatints produced from the contributions of ten mathematicians and physicists
in response to the prompt to transcribe their 'most beautiful mathematical expression.'"
The renowned mathematicians and scientists who contributed to the project are Michael
Atiyah, Enrico Bombieri, Simon Donaldson, Freeman Dyson, Murray Gell-Mann, Richard
Karp, Peter Lax, David Mumford, Stephen Smale, and Steven Weinberg. My personal
favorite is "Ampère's Law," by Simon Donaldson, because it incorporates a simple
line drawing along with the familiar equations. It brings back memories of sitting
in electromagnetics class at the University of Vermont watching my seriously brilliant
professor...
 New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite of engineers,
technicians, hobbyists, and students all over the world. With more than 12,000 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.
 Empower RF Systems is a global leader in
power amplifier solutions. Empower RF Systems is an established and technologically
superior supplier of high power solid state RF & microwave amplifiers. Our offerings
include modules, intelligent rack-mount amplifiers, and multi-function RF Power
Amplifier solutions to 6 GHz in broadband and band specific designs. Output
power combinations range from tens of watts to multi-kilowatts. Unprecedented size,
weight and power reduction of our amplifiers is superior to anything in the market
at similar frequencies and power levels.
 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...
 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...
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