Today in Science History -
 Having never been a sports aficionado, I
have not spent much money or time at baseball, football, or soccer fields, hockey
rinks, bowling alleys, curling sheets, or basketball courts. When an air show comes
to town, however, I'm there. I'll stand in line for 45 minutes to tour the inside
of a DC-3, B-25, B-17, PBY-5, or just about anything that will admit me. What is
particularly enjoyable is being able to inspect the
radio equipment racks and bays. The sight and smell (I consider it an aroma)
of the old UHF and VHF sets, recording equipment, power supplies, generators, synchros,
and the associated wiring and connectors is something I never tire of experiencing.
I always imagine the men who operated and maintained everything doing their assigned
duties to keep those wonderful machines flying. Maybe you know of what I write.
This article provides a nice overview of the state of the art for airborne electronics
in the post WWII era.Dig the Zenith console radio...
 "Researchers at Princeton University have
built the world's smallest
mechanically interlocked biological structure, a deceptively simple two-ring
chain made from tiny strands of amino acids called peptides. In a paper published
August 23 in Nature Chemistry, the team detailed a library of such structures made
in their lab - two interlocked rings, a ring on a dumbbell, a daisy chain and an
interlocked double lasso - each around one billionth of a meter in size. The study
also demonstrates that some of these structures can toggle between at least two
shapes, laying the groundwork for a biomolecular switch. 'We've been able to build
a bunch of structures that no one's been able to build before,' said A. James Link,
professor of chemical and biological engineering, the study's principal investigator...."
 Copper Mountain Technologies is pleased to
announce that
Online Help manuals are now available for S2VNA and PXIe software by selecting
the Online Help buttons. These online manuals are easy to navigate and have been
designed to deliver an enhanced user experience. Online Help manuals for additional
software versions are in development. The existing operating manuals and documentation
for all other versions of software are available for download. If you prefer to
use a PDF manual for S2VNA or PXIe models, it is also available to download by clicking
the "Download Documentation" button...
 James Kilton Clapp in 1948 first published
details on an oscillator that used positive feedback obtained from an LC (capacitive &
inductive) voltage divider to initiate and sustain oscillations. Thus was born the
now familiar Clapp oscillator. It had an advantage over both the Colpitts and Hartley
oscillators because the feedback, not being dependent on a simple capacitive or
inductive voltage division, respectively, made it more reliable as a variable frequency
oscillator (VFO). This article does a nice job of explaining the operation of the
Clapp oscillator. Just as the Colpitts and Hartley oscillators handily provide an
easy mnemonic for being based on voltage dividers of capacitance with the Colpitts
oscillator and inductance (Henries) with the Hartley oscillator, the Clapp oscillator...
 New Scheme rotates
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RF Cafe is a favorite of engineers,
technicians, hobbyists, and students all over the world. With more than 16,000 pages
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types of key searches, both for text and images. New content is added on a daily
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If you need your company news to be seen, RF Cafe is the place to be.
 Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components
and filters for wireless service providers including non-magnetic connectors for
quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM
RF connectors components such as power dividers and directional couplers. Off-the-shelf
and customized products up to 40 GHz and our low-PIM products can meet -160 dBc
with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and
high-performance. Designs that are cost effective practical and repeatable.
 This
Electronic Oscillator Theme crossword puzzle for September 19th, 2021, contains
only words and clues related to engineering, mathematics, chemistry, physics, and
other technical words. 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., Hedy Lamarr or the
Bikini Atoll). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
 Even in this current age of ubiquitous computers
and cellphones (also computers), there is still ample reason to consider using
nomographs for presenting data and providing a hand calculation or conversion
resource. In days prior, nomographs were an indispensible tool for both design and
troubleshooting circuits. A huge number of nomographs can be found here on RF Cafe
as they appeared in vintage magazine articles. This 1946 issue of Radio-Craft presents
the first of a two-part tutorial on creating nomographs for any purpose, and uses
current, voltage, and resistance as an example. Their utility is not limited to
electrical and electronic topics, as many have been created for plumbing, hydraulics,
mechanics, chemistry, finance, aerodynamics, pneumatics, lighting, acoustics, and
I've even seen one...
 Is it just me or does this seem like a moot
/ obvious arguement? "For anyone looking for an end-of-the-summer mind bender, this
might be one to consider.
Where does the terahertz (THz) spectrum range start? The subject came up during
a symposium last year, and it was covered here. Some researchers figure it starts
at 100 GHz. Others say it's 300 GHz. Suffice it to say, the debate is alive and
well - depending on who you talk to. Why should we care? For one, it helps to know
what’s what when it comes to spectrum, the idea being there's a finite amount in
the lower bands. Some day, somebody will come knocking for even more spectrum, and
these very high frequency ranges will come in handy when there's nowhere else to
go. For another, it's part of the grand plan for 6G, and even though it's early
days in a lot of ways for 5G..."
 Navy electrical equipment is designed and
installed with every possible provision for the safety of the men who use it and
service it. But this does not completely
prevent injury to you and your shipmates or damage to equipment. Safety also
depends on the Electrician's training. To insure safety while standing watch or
working on a circuit, he must always work safely and observe safety precautions.
Men have been burned, electrocuted, or maimed for life because they became careless
in their work or failed to observe safety precautions. You were selected to be an
Electrician's Mate because of your intelligence, so use your brain to prevent accidents.
Injury and damage can be avoided by staying alert, exercising intelligence...
 Teledyne Relays today announced availability
of a significantly expanded line of
50+ GHz coax switches, adding transfer switching, terminated, and normally-open
models to its product line-up. These join the CCR-50U SPDT DC-53 GHz failsafe/ latching
relay and CCR-39 SPnT DC-52 GHz latching coax relays that already enjoy wide acceptance.
In addition to excellent RF performance, the family offers the widest operational
temperature range (-55 to +85 °C), lowest weight and amongst the longest life (up
to 5 million actuator cycles) of any 50 GHz switches available today...
 In this August 1963 adventure from Popular
Electronics magazine, teenage techno-investigators Carl Anderson and Jerry Bishop
use their home-brew sonar device to help the local sheriff nab a couple bank robbers.
The "Hydro Probe" mentioned in the article was a real product manufactured by the
Raymond Development Company of Watertown, Massachusetts (no longer in business).
By this time the duo were students pursuing electrical engineering degrees at Parvoo
University (a play on Perdue University, located in the boys' home state of Indiana).
Enjoy.
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 16,000 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.
 TotalTemp Technologies has more than 40 years
of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between −100°C and +200°C for cryogenic cooling,
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and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
 Remember the early 1990s Teen Talk Barbie
where one of her phrases, "Math
class is tough!," caused a big kerfuffle because it ostensibly stereotyped girls
as being afraid of math? Maybe if Talking GI Joe (this 1967 version is the
one I had as a kid) also uttered a math phobia statement all would have been fine.
The truth is that a large portion of both girls and boys (and men and women) of
all ages break out in a cold sweat whenever the subject of math arises in print
or in a conversation. The ARRL goes to great lengths to help ease the math anxiety
of radio operators who are studying for a license exam. In this multi-part 1946
Radio−Craft magazine article, the authors attempt to assuage some of the
reluctance of readers to apply mathematics to their electronics hobby endeavors...
 "Seeking a route to high-performance power
semiconductors, scientists in Japan have bonded
gallium nitride to a diamond substrate – the latter an insulator whose thermal
conductivity is many times that of copper or silver. 'The researchers succeed in
the direct bonding of diamond and GaN at room temperature, and demonstrate that
the bond can withstand heat treatments of 1,000°C, making it ideal for the high
temperature fabrication process of GaN-based devices,' according to Osaka City University,
home of the project. Unsurprisingly, attempts have already been made create a GaN-on-diamond,
using some form of transition or adhesion layer..."
 Canadian website visitor Richard F.
sent me this photo of his "Log
Polar Plane" acetate stencil, circa 1958. As a collector of vintage of science
/ technical paraphernalia, he ran across this as part of one of his acquisitions.
"Computing Aids" is printed on it. I had never heard of the log polar plane, but
according to the Wikipedia entry, "In mathematics, log-polar coordinates (or logarithmic
polar coordinates) is a coordinate system in two dimensions, where a point is identified
by two numbers, one for the logarithm of the distance to a certain point, and one
for an angle. Log-polar coordinates are closely connected to polar coordinates,
which are usually used to describe domains in the plane with some sort of rotational
symmetry. In areas like harmonic and complex analysis, the log-polar coordinates
are more canonical than polar coordinates." The David Young, on the University of
Edinburgh website, explains, "Log-polar sampling is a spatially-variant image representation..."
 It was a little difficult to make out the
shape within the
crossword puzzle grid from this December 1960 issue of Popular Electronics
magazine, so I got out my blue Crayon and filled in the hashed squares. It appears
to be a transistor schematic symbol. Unlike the weekly RF Cafe crossword puzzles,
not all of the clues and words are specifically related to science and engineering,
but a large percentage of them are. Admittedly, I have the advantage of a software
program to help place the words within the grid. Margaret LeFevre did not. Doing
it by hand is a lot more work. I can't imagine how the people who created the
New York Times' Sunday-size puzzles were able to do it without computer
assistance!
 Television and radio facsimile machine electronics
technology was credited for aiding in the development of a new type of
scanning electron microscope (SEM) that could image the surface of opaque object
to a resolution of 100 angstroms (Å). The television contribution part of the technology
was precisely controlling a raster path for the electron beam. The facsimile part
was the knowledge of how to assemble a printed image from streaming data. It is
interesting to note that in order for an object to be imaged via SEM, its surface
must be electrically conductive. Accordingly, non-metallic objects like bugs, plants,
plastic, wood, etc., must receive a coating of metal by a process such as sputtering.
Doing so can leave a few atoms thick later without losing too much resolution due
to softening of features...
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