Today in Science History -
 The proper care and feeding of
vinyl records was - and still is - a big topic amongst audiophiles. As with
so many things, phonographs and platters have experienced a resurgence in popularity
in the couple decades as the world gets nuttier and people crave for a simpler,
saner time - imagined or otherwise. I remember back in the barracks at Robins AFB,
GA, where there was always at least one guy who would have a very extensive (pronounced
"expensive") stereo setup complete with an equipment rack, reel-to-reel tape player,
dual cassette tape deck, super-sensitive AM/FM receiver with a huge tuning knob
on the front, a turntable with a precisely balanced and weighted tone arm (with
a stylus that cost two month's pay for an enlisted man), a multi-hundred watt power
amplifier that never had the opportunity to put out more than a small percentage
of its capability due to barracks noise rules, a patch cable panel for routing signals,
and monster speakers...
 The term "ovonic" - a fairly unfamiliar word
these days - appeared in the May edition of Radio-Electronics, in an article
entitled, "All About Ovonics," just a few months after this news item ran in the
January issue (which I posted last month).
Ovonics is a portmanteau of "Ovshinsky" (from Stanford R. Ovshinsky, the inventor)
and "electronics." Read the "All About Ovonics" article for a deeper dive into the
subject. The big deal, which turned out to be not a big enough deal, was the use
of amorphous (strangely spelled "amphorous") glassy compounds as semiconductors
rather than the standard crystalline silicon structures. Maybe someday an enterprising
genius inventor type will give a rebirth to the concept...
 "It was a great idea for its time - a network
of NASA communications satellites high in geostationary orbit, providing nearly
continuous radio contact between controllers on the ground and some of the agency's
highest-profile missions: the space shuttles, the International Space Station, the
Hubble Space Telescope, and dozens of others. The satellites were called TDRS -
short for Tracking and Data Relay Satellite - and the first was launched in 1983
on the maiden voyage of the space shuttle Challenger. Twelve more would follow,
quietly providing a backbone for NASA's orbital operations. But they've gotten old,
they're expensive, and in the 40 years since they began, they've been outpaced by
commercial satellite networks. So what comes next? That's the $278M question - but,
importantly, it's not a multibillion-dollar question..."
 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...
 Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized RF and microwave filters
and filter-related products for military, commercial, aerospace and defense, and
industrial applications up to 40 GHz. Three new filter models have been introduced
- a cavity bandpass filter with a bandwidth of 15 MHz ±2 MHz, an insertion
loss of 3.5 dB; a ceramic duplexer with a Band 1 frequency of 824 to 835 MHz
and a Band 2 frequency of 869 to 880 MHz; and an LC highpass filter with
a pass band of 402 to 1500 MHz with an insertion loss of less than 1.0 dB.
Custom RF power directional coupler designs can be designed and produced when a
standard cannot be found, or the requirements are such that a custom approach is
necessary...
 Unlike today when resources of all types
seem to be endlessly available, during World War II countries needed to collect
and recycle much in the way of metal, rubber, cloth, and other basic materials for
re-purposing into products used in fighting the enemy. Media coverage of bottle,
metal, and tire drives showed children pulling Radio Flyer wagons loaded to overflowing
with such items gathered from trash piles and soliciting neighborhood residents
for anything that could be spared. Raw materials were not the only type of items
needed, however. "Use it up, Wear it out, Make it do, or Do without" was the slogan.
Finished goods like electronic components - vacuum tubes, transmissions cable, transmitters
and receivers, tuning capacitors, d'Arsonval meter movements, and other parts -
were sorely needed by manufacturers both for building new equipment and for servicing
damaged gear. After the war was won, the
War Assets Administration made good on the government's promise to reward citizens
for performing their patriotic duty. This four-page spread in a 1947 edition of
Radio News is an example of the effort to make surplus components available...
 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!
 Withwave manufactures an extensive line of
metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch,
board edge, panel mount), calibration kits (SOLT), a
fully automated
4-port vector network analyzer (VNA) calibrator, between- and in-series connector
adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes &
probe positioner. Special test fixtures for calibration and multicoax cable assemblies.
Frequency ranges from DC through 110 GHz. Please contact Withwave today to
see how they can help your project succeed.
 The
G−Line
(aka G−String) RF transmission system is a rather amazing invention contrived through
out-of-the-box thinking by its inventor, Dr. George Goubau (from whence the
"G" in the name derives). He determined that a sort of waveguide could be made with
a single conductor surrounded by insulation with a specific dielectric constant
that would cause the dielectric-air interface to reflect the wave in a manner similar
to atmospheric channels that facilitate long distance communications. The G-Line
is designed to efficiently transmit UHF television signals (470 - 806 MHz),
and like a waveguide exhibits a lower cutoff frequency (~300 MHz), thus acting
like a highpass filter. G−Line has its weak points, like that it must not come near
to obstacles that will affect the dielectric-air interface or the line will radiate
like an antenna. Also, over time the insulation cracks and/or absorbs moisture and
changes the impedance parameters, thus affecting the transmission characteristics...
 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.
 "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...
|
-
