Today in Science History -
 Here is an 10-question quiz on the basics
of
operational amplifiers (aka op amps, or opamps, compliments of Mr. John
Seginski, in the October 1969 issue of Popular Electronics magazine. The
first commercial opamp, the μA709, was introduced by Fairchild Semiconductor in
1963. Five years later they released the μA741, which was the most famous opamp
of the era; it is still widely used today. One of my electronics circuit courses
in college (c1987) used the 741 as the basis for analyzing integrated circuits,
and in particular, opamps. A couple companies offered vacuum tube operational amplifiers
which combined two or more tubes along with some integrated leaded biasing and compensating
components, and had a tube sock pinout on the bottom for plugging into a standard
socket. The GAP/R K2-W, produced by George A. Philbrick Researches, is an example.
It was commonly advertised in electronics magazines of the era. Today, just about
everyone having any involvement knows the basic equations for calculating opamp
gain for both inverting (Rfeedback/Rinput) and non-inverting (Rfeedback/Rgnd +1)
configurations...
 "Researchers developed an analysis
model using magnetic transport characteristics of molecules attached to the surface
of
MXene. The establishment of a property prediction and classification system
is expected to be utilized to produce uniform-quality MXene. Developed in 2011,
MXene is a two-dimensional nanomaterial with alternating metal and carbon layers,
which has high electrical conductivity and can be combined with various metal compounds,
making it a material that can be utilized in various industries such as semiconductors,
electronic devices, and sensors. To properly utilize MXene, it is important to know
the type and amount of molecules covered on the surface. If the molecules covered
on the surface are fluorine, the electrical conductivity decreases, and the efficiency
of electromagnetic wave shielding decreases. However, since MXene is only 1 nm thick,
it takes several days to analyze the molecule..."
 Locating images of automobile radios from
the 1930s through 1940s is a challenge. Sometimes one shows up on eBay, but those
that do are usually in un-reconditioned condition, and often with missing components.
Early car radios were composed of separate units holding the electronics, another
for the power supply, and another for mounting in or under the dashboard. The antenna
was often a rectangular loop run around the perimeter of the underside of the car
or truck. This schematic for the
American-Bosch 524A Automotive Radio appeared in a 1935 issue of Radio−Craft
magazine. I found a very nice website - Antique Autoradio Madness - which has a
large collection of schematics and photographs for automobile radio from all over
the world. It does not have the exact model reported on here, but there was a lot
of similarity between radios of the same vintage, so the information on this American
Bosch model 624A shown in the thumbnail image to the left is probably quite like
the model 524A...
 TotalTemp Technologies, a worldwide leading
provider of research laboratory and production temperature chambers and thermal
platform equipment, introduces their model
VmSD144−N Thermal Platform Vacuum Chamber. The efficient advantages of thermal
platforms are a natural for conductive heat transfer in high vacuum applications.
With all the new hardware going into space, where service calls are rare, thermal
vacuum testing is an important part of testing high altitude and satellite equipment.
Affordable and configurable for your application. Simultaneous high vacuum and thermal
testing without renting time at a test lab. Thermal platforms to fit your vacuum
chamber or fully turn-key systems. Platform shown inside bell jar is 6.5” x 7.5”,
other sizes and different bell jars available. Aerospace environmental testing in
a thermal vacuum chamber allows for the exposing and weeding out potential problems
due to extreme temperature and atmospheric pressure changes as experienced in space.
With equipment destined for space, the stakes are much higher with the cost of a
launch, chances of a failure could be catastrophic plus service calls in space have
historically been very costly. The game of basic thermal testing in space is a little
different than testing for land-based systems, mainly because the lack of heat transfer
by air. The intentional and unintentional transfer of heat by convection makes a
big difference from what could be common sense solution in an environment with air...
 Most people probably associate "elevator
music" with the
Muzak format. It became a registered trademark in 1954, although Muzak broadcasting
was around a couple decades before that. Muzak music has also played in doctors'
offices, restaurants, government public service facilities, buses, retail stores,
and even workplaces (to provide calm and cadence for workers). According to the
Wikipedia entry, the term "Muzak " was coined by its inventor, George Owen Squier
(Major General, ret.) as a play on the made-up term "Kodak;" i.e., "Muz" (music)
+ "ak." Over the years, a lot of scientific research went into Muzak's format including
genre of music, tempo, silence ("dead") time, volume, etc. Muzak has changed hands
many times, including to Westinghouse, until it finally declared bankruptcy in 2010.
If you type "muzak.com" into your browser now, you get redirected to moodmedia.com.
Rumors have it that rocker Ted Nugent tried to buy Muzak in 1986 just to shut it
down because it represented "all that is uncool about music..."
 Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 visits each
weekday. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the world.
With more than 17,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images.
Your Banner Ads are displayed on average 225,000 times per year! 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...
 Temwell is a manufacturer of 5G wireless communications filters
for aerospace, satellite communication, AIoT, 5G networking, IoV, drone, mining
transmission, IoT, medical, military, laboratory, transportation, energy, broadcasting
(CATV), and etc. An RF helical bandpass specialist since 1994, we have posted >5,000
completed spec sheets online for all kinds of RF filters including helical, cavity,
LC, and SMD. Standard highpass, lowpass, bandpass, and bandstop, as well as duplexer/diplexer,
multiplexer. Also RF combiners, splitters, power dividers, attenuators, circulators,
couplers, PA, LNA, and obsolete coil & inductor solutions.
 In a 1963 editorial in his Radio−Electronics
magazine, Hugo Gernsback dubbed electromagnetic wave frequencies above 300 GHz
as "radioptics."Today,
we refer to them as the sub-millimeter bands, or terahertz bands. The visual spectrum
runs from around 0.63 mm (red, 630 nm, 6300 Å) to 0.36 mm (blue,
360 nm, 3600 Å). Again, Mr. Gernsback shows himself to be a prolific
futurist and visionary. He was more than "all talk and no action," as he possessed
many patents for his inventions and produced some build-it-yourself electronics
kits. That was in addition to being a prolific writer and publisher of both fact
and fiction. At the time of this article, fiber optics was a fledgling technology
from a practical application standpoint. It was used in some critical communications
applications due to its security advantages (difficult to tap), but in the commercial
realm, those decorative multicolor fiber optic lamps were about it until laser semiconductors
hit the shelf. Today, optical fiber is quickly replacing metallic conductors everywhere,
most notable for Internet infrastructure...
 Now you can launch my classic "RF Workbench"
program directly into DOSBox!!! I believe I have figured out a way to launch RF
Workbench directly into a DOSBox emulator screen, without needing to first install
DOSBox, mount a hard drive, and then launch the program file. Instead, simply unzip
the "RFWB_DOSBox [unzip into Program Files (x86) folder].zip" file into your "Windows\Program
Files (x86)" folder. Then, double-click on the "RFWB−DOSBox−Launch shortcut link"
(.lnk) shown highlighted below left. Click one of the "RFWB 4.0" icons to download.
 There's not a much better way to finish
up a hard week at the office than reading a new episode of John T. Frye's "Mac's
Radio Service Shop." Mac McGregor and his trusty sidekick technician Barney
tackle nearly every issue associated with an electronics sales and service establishment
back in the heyday of radios and televisions. You might recognize the title of "Pride
and Prejudice" as being borrowed from Jane Austin's classic, which, to summarize,
deals with, well, pride and prejudice based on one's social status, and how it results
in lost opportunities. To be honest, I have not read the book but I did see the
movie version starring Keira Knightly. Anywho, you'll need to read the second half
of the story to get to the actual pride and prejudice part. As for the first part,
it might be difficult to imagine what all the fuss is over tape recorder usage (or
non-usage as is the case here), but remember that in 1955 it meant a case with vacuum
tubes and requisite heavy transformers...
 "MIT researchers analyzed and evaluated
low-cost, easily fabricated
supercapacitors that potentially offer high capacity plus structural strength.
The high-density energy stage has always been a challenge, whether accomplished
using electrochemistry and batteries, electric fields and supercapacitors, gravity-based
systems of various types, or any of the many other options. Now, a team of researchers
at MIT and the affiliated Wyss Institute for Biologically Inspired Engineering claims
to have devised a technical and cost-effective solution using relatively mundane
materials: concrete, carbon black, water, and potassium-chloride salts. Their approach
uses a cement-based material with an extremely high internal surface area due to
its dense, interconnected network of conductive material within its bulk volume.
The researchers achieved this by introducing carbon black - which is highly conductive
- into a concrete mixture along with cement powder and water, and letting it cure..."
 This is another installment of the
Hams in Combat series
that QST magazine ran during WWII. I enjoy waxing vicariously nostalgic
of a time before I was born, at time when there was still honor, courage, selflessness,
and pride of country. During World War II, it was an ingrained part of most citizens,
whether or not they happened to be serving in the military. Our modern day troops
still have it, but sadly fewer and fewer people see their own country as any place
special in the world. Sure, as General William Tecumseh Sherman famously said, "War
is hell," but then again so is witnessing the tearing apart of your country from
forces within - an "enemy at the gates," or a "fifth column," so to speak...
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...
 Werbel Microwave is a manufacturer of RF
directional and bidirectional couplers (6 dB to 30 dB) and RF power dividers
/ combiners (2− to 16−way) with select models operating up to 26.5 GHz and
100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are
designed and manufactured in our Whippany, NJ, location. Custom products and private
label service available. Please take a couple minutes to visit their website and
see how Werbel Microwave can help you today.
 This week's
crossword puzzle for September 24th sports an electronics theme. This being
the twenty−fourth day of the month, many of the words begin and/or end with and/or
contain the letter "X." Expect a few repeats, since words with and "X" in them are
harder to come by. 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, Hedy Lamarr, or the Tunguska event
in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort...
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, Baseball Caps, and more, all sporting my amazingly clever "RF Engineers - We Are the World's
Matchmakers" Smith chart design. These would make excellent gifts for husbands,
wives, kids, significant others, and for handing out at company events or as rewards
for excellent service. My graphic has been ripped off by other people and used on
their products, so please be sure to purchase only official RF Cafe gear. I only
make a couple bucks on each sale - the rest goes to Cafe Press. It's a great way
to help support RF Cafe. Thanks...
 Aegis Power Systems is a leading supplier
of AC-DC and
DC-DC power supplies for custom and special applications. Aegis has been designing
and building highly reliable custom power supplies since 1995. They offer a complete
line of switch mode power supplies and power converters for a variety of markets
including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft,
EV, telecom, and embedded computing applications. Design and manufacture of custom
power supply solutions to meet each customer's exacting specifications. Please visit
Aegis Power Systems today. Manufactured in the USA.
 Here is an
Electronic "A" Quiz for you to test your knowledge of terms, compliments of
Popular Electronics quizmeister Robert P. Balin. The number of spaces is equal
to the number of characters needed in addition to the leading "A" to spell the word.
About half of them are easily identified, but the others might take some head scratching
- particularly numbers one and four (hint: four has to do with vacuum tubes). Number
seven's illustration could be better, so don't feel bad if you don't get it (I didn't),
because it is a phenomenon only seen on cathode ray tube (CRT) displays, not on
LCDs. The word "amplifier" fits for number eight, but that is not the answer sought.
My score with only a couple minutes of consideration was a paltry 6:10.
 High altitude surveillance / data gathering
balloons are nothing compare to the number of
commercial Chinese drones occupying the skies of America. You might think the
data is only going to the user. "By now, most people have heard of the People's
Republic of China-based company Shenzhen DJI Sciences and Technologies. It isn't
hard to walk into any electronic store across the country and find DJI drones prominently
displayed. PRC drones dominate more than
90% of the United States' hobby drone market, 70% of the industrial drone market
and over 80% of the first responder market. DJI rightly receives
the lion's share of attention from Washington's national security watchers. In December
2020, DJI was added to the U.S. entities list over concerns about its platforms
being used for foreign espionage, and Congress continues to introduce legislation
targeting the company, albeit with mixed results. Now another Chinese drone manufacturer
is rising in the ranks: Autel Robotics. In 2021, Autel's U.S. market share was 15%.
Autel has become the drone of choice for several American law enforcement agencies.
The company even sells drones to U.S. federal agencies..."
 There is a frequency region between around
400 MHz and 1500 MHz where the self-resonant frequencies of discrete components
make filter design very difficult, and where the physical dimensions of transmission
lines and cavity filters are too large for practical implementation. One of the
most prominent ISM bands (900 MHz) falls squarely in the middle of the region.
Thanks to the wireless revolution, there are a plethora of SAW and dielectric filters
available for the 840 – 980 MHz band, but that is about it, and they are only
rated for relatively low powers (maybe +20 dBm). Helical filters fill that
gap nicely, and are a combination of all three formats. Like cavity filters, the
Q of the helical resonators
is very high if constructed properly. That is because at the frequencies of operation,
the skin thickness is getting very small and most of the current is flowing on the
surfaces. Plating the cavity walls and helix with a high conductivity material increases
the Q even more that bare of tinned copper...
 Sam Benzacar of Anatech Electronics, an
RF and microwave filter company, has published his September 2023 newsletter
that features his short op−ed entitled "Wi-Fi: More Than High-Speed Connectivity."
In it, Sam discusses the pervasive use of existing and planned WiFi networks for
use in monitoring and tracking applications. The IEEE has created a new standard,
IEEE 802.11bf, which "... Aims to Enable a New Application of WLAN Technology: WLAN
Sensing." "This standardization project aims to enhance the reliability and efficiency
of WLAN sensing and establish interoperability of wireless devices to enable a wide
range of new and useful applications. Measurements obtained with WLAN sensing can
be used to support new industrial and commercial applications in semiconductor manufacturing,
enterprise networking, and test and measurement equipment." As the bands become
more populated with users, stricter filtering will be needed, and that's where Anatech's
expertise comes in...
 The first time I saw a
microwave diode in this type of ceramic package was in the detector stages of
the S-band airport surveillance radar (ASR) and the X-band precision approach radar
(PAR) that made up the AN/MPN−14 radar system I worked on in the U.S. Air Force
back in the late 1970s / early 1980s. Both radars were primarily vacuum tube systems
with a few upgrades to solid state components in areas where suitable substitutes
for the original tubes were available. By the time this Bell Telephone Laboratories
advertisement appeared in a 1958 issue of Popular Electronics magazine,
no transistors had yet been invented for operation in the microwave realm, at least
not other than the "laboratory curiosity" type. It had only been a decade since
Drs. Brattain, Shockley, and Bardeen announced their invention of the first transistor.
As with so many leading edge technologies, this diode was developed under a Department
of Defense contract. Aside from being relatively expensive to produce, early versions
were available only to applications...
 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...
 Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
 Who hasn't, at one time or another, knowingly
or not, quoted or paraphrased one of
Yogi Berra's famous utterances? "It ain't over 'til it's over ," "Ninety percent
of the game is half mental ," "When you come to a fork in the road, take it," and
"It's déjà vu all over again ," are legend. They are affectionately known as "Yogi-isms."
The New York Yankees catcher, manager, and coach, Lawrence Peter "Yogi" Berra, was
born on May 12, 1925. Hanna−Barbera's famous pic-a-nic [sic] basket snatching Yogi
Bear first appeared in 1958 (eight years after this article was written). According
to legend, the ballplayer sued the bruin (not the Boston hockey team) for allegedly
misappropriation of his name. The similarity of not just the name, but the Barbera
part of the creator's name seemed too coincidental to be happenstance. Hanna−Barbera
claimed Yogi Bear was patterned after Art Carney's character, Ed Norton, on The
Honeymooners TV show. Yogi's life story is typical of a sports-loving guy of his
era; would that it had been my era, too...
 This article reporting ongoing research
for auto anti-collision systems and backup warning systems appeared in a 1972 issue
of Popular Electronics magazine has only come to practical fruition within
the last decade and a half. High-end cars were offering such equipment options in
the early 2000s, but it has only been commonplace since around 2010. 1972 components
were still pretty large and power hungry, and digital processing capacity and speed
was significantly less advanced as well. Bendix, one of the early developers of
anti-collision systems, estimated that the option on a new car might add about $200
to the price, which was a really ambitious estimate, even considering that is the
equivalent of $1,4511 in 2023 money per BLS Inflation Calculator. The total add-on
cost of both anti-collision and backup warning systems on today's automobiles probably
doesn't even hit that figure, and the performance is orders of magnitude better.
The price and sizes of transmitter signal generators and receiver sensors (antennas)
are amazingly low, as are all the other system components...
 The newest release of RF Cafe's spreadsheet
(Excel) based engineering and science calculator is now available -
Espresso
Engineering Workbook™. Among other additions, it now has an extensive coaxial
cable parameter calculator. Since 2002, the original Calculator Workbook
has been available as a free download. Continuing the tradition, RF Cafe
Espresso Engineering Workbook™ is also
provided at no cost, compliments of my generous sponsors.
The original calculators are included, but with a vastly expanded and improved user
interface. Error-trapped user input cells help prevent entry of invalid values.
An extensive use of Visual Basic for Applications (VBA) functions now do most of
the heavy lifting with calculations, and facilitates a wide user-selectable choice
of units for voltage, frequency, speed, temperature, power, wavelength, weight,
etc. In fact, a full page of units conversion calculators is included. A particularly
handy feature is the ability to specify the the number of significant digits to
display. Drop-down menus are provided for convenience. Now that a more expandable
basis has been created, I plan to add new calculators on a regular basis...
 "The U.S. Air Force has received its first
EC-37B Compass Call electronic warfare aircraft from contractors BAE Systems
and L3Harris Technolgies, industry officials announced Tuesday. BAE Systems said
in a release that the Air Force will next start combined developmental and operational
testing for this Compass Call, the first of 10 aircraft planned for the Air Force.
The new EC-37B fleet will replace Air Combat Command's decades-old EC-130 aircraft,
which the service is now retiring. BAE builds the electronic attack components of
the new Compass Call in Hudson, New Hampshire, and L3Harris integrates that mission-specific
hardware into a Gulfstream G550 business jet at its facility in Waco, Texas. The
Compass Call will conduct a variety of electronic warfare missions to jam enemy
signals, including communications, radar and navigation systems. BAE said this will
include suppressing enemy air defenses by blocking their ability to transmit..."
 While not a second-hand store junkie, I
do like to occasionally make the rounds of the local Salvation Army, Goodwill, and
other independent shops to see what kind of relics are donated. Since eBay, Etsy,
and their kind have gained immensely in popularity, it is getting harder to find
anything useful other than clothes and kitchen wares. A few months ago Goodwill
had a 1910s vintage
cabinet-style Edison disc phonograph (as opposed to wax cylinder) that was in
very good condition, complete with a handful of styli and a couple old records.
The original finish over smooth mahogany and burl veneers had only a few scratches
and could easily be polished to look practically new. The metal hardware could have
stood a fresh coat of black paint due to nearly a century of oxidation. Even the
original nomenclature plate looked factory-new, and a clearly legible paper plaque
of operating instructions was embedded beneath a layer of shellac. I expected an
asking price of at least $500, but was shocked to see only $125 on the price tag.
Surely, I thought, the employee who affixed the tag must not have realized the value
of such a treasure of American history. Out of curiosity, I put a fresh steel needle
in the tone arm and placed a vinyl album gotten from the music area in the store
on the platter and cranked 'er up. The sound was barely discernable, so that ruled
out any possibility of justifying the purchase...
 One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 220,000
per year (in six locations on each page, with >17,000 pages). That's pretty good
exposure for $300 per month. Some companies have expressed an interest in being
able to manage their advertising accounts themselves a la the Google AdSense program...
 Amplifier Solutions Corporation (ASC) is
a manufacturer of amplifiers for commercial & military markets. ASC designs
and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers
for low, medium and high power applications using Gallium Nitride (GaN), Gallium
Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs
operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film
designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility
in the town of Telford, PA. We offer excellent customer support and take pride in
the ability to quickly react to evolving system design requirements.
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