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Sunday the 21st
 This custom RF Cafe
electronics-themed crossword puzzle for January 21st contains only clues and
terms associated with engineering, science, physical, astronomy, mathematics, chemistry,
etc., which I have built up over more than two decades. Being the 21st day, words
containing the letter "U" are marked with an asterisk (*). Many new words and company
names have been added that had not even been added to the world's technical lexicon
when I started in the year 2002. 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. You might,
however, encounter the name of a movie star like Hedy Lamarr or a geographical location
like Tunguska, Russia, for reasons which, if you don't already know, might surprise
you. The technically inclined cruciverbalists amongst us will appreciate the
effort. A full list of all RF Cafe crosswords is at the page bottom. Enjoy!
 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 280,000
per year (in eight 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...
Friday the 19th
 This 1954 Popular Science magazine
piece on "The
ABC's of Color Television" is useful, but it is strange that a labeled picture
of the composite video signal is not provided to go along with the definitions of
the various parts of it (front porch, back porch, red/green/blue video, color killer
for black & white signals, I, Q and Y signals, etc. ). Nor is there a labeled
picture of any of the components of a color TV (CRT, deflection coils, horizontal
and vertical sync controls, hue and brightness controls, etc.). Of course in 1954
not many people had ever even seen a color television set, much less make adjustments
on one. It wasn't until around 1965 that most Prime Time shows were broadcast in
color. The first commercial color television broadcast occurred in 1954 during the
Tournament of Roses Parade. Price was a major deterrent since a typical cost in
equivalent 2024 money was around $5,000...
 The FCC just wants part of the action for
itself. - "The argument goes that since new cars make it increasingly easy for passengers
and drivers to access hands-free communication tools, find-your-car services, and
other technological bells and whistles, these services have been used to 'stalk,
harass, and intimidate survivors of intimate partner violence.' Letters were
sent to nine car manufacturers, citing a recent report in the NYT (paywall) titled
'Your car is tracking you. Abusive partners may be, too.' The letter reads: '...the
report recounts in detail how a woman was tracked by a former partner through connected
services associated with the car she was using. In another example, a man used his
remote access to the car to harass his wife by activating the car's lights and horns
a night and running the car's heat on hot days. The report finds that car makers
have been reluctant or unwilling to assist victims of this abuse or restrict abusive
partner access to the car's connectivity and data..."
 When I first started working as an electrician
apprentice in the summer of 1974 as part of my high school vocational program,
ground fault interrupter (GFI) receptacles and circuit breakers were not mandated
by the National Electric Code (NEC). It was only a little more than a decade earlier
that UC Berkeley professor Charles Dalziel invented the GFI circuit while researching
the effects of electrical current on humans (electrocution). By the late 1970s,
shortly before I enlisted in the USAF to begin my electronics career, GFI (now referred
to as GFCI) protection was required for areas near water like in bathrooms and outside.
Nowadays the NEC calls for GFIs in bathrooms, kitchens, garages, outdoors, and any
place where wet or damp conditions might exist. In Arc Fault Circuit Interrupters
(AFCI) have been required on may types of circuits since 1999. AFCIs detect the
presence of arcing and open the circuit if present. Early AFCI devices were notoriously
overly sensitive and often tripped on imperfect but safe vacuum cleaners, kitchen
blenders, and hair dryers. Proposed 2017 NEC requirements for GFCI and AFCI circuit
applications have been greatly expanded - undoubtedly due partly to the successful
lobbying efforts of device manufacturers. The cost for new homes will increase accordingly.
Melanie's sister and her husband had a big new house built a couple years ago and
while we were visiting, they complained about a new humidifier that was not working
anymore...
 Crane Aerospace & Electronics' products
and services are organized into six integrated solutions: Cabin Systems, Electrical
Power Solutions, Fluid Management Solutions, Landing Systems, Microwave Solutions,
and Sensing Components & Systems. Our Microwave Solution designs and manufactures
high-performance
RF, IF and millimeter-wave components, subsystems and systems for commercial
aviation, defense, and space including linear & log amplifiers, fixed &
variable attenuators, circulators & isolators, power combiners & dividers,
couplers, mixers, switches & matrices, oscillators & synthesizers.
 Mr. Lothar Stern, of Motorola Semi, published
a 3-part series on
transistor theory in Popular Electronics magazine in 1973. This is
part 2. Part 1 introduced the basics of the bipolar transistor, and this
follow-on article starts addressing transistor circuit configurations - common emitter,
common gate, common collector, Darlington, differential - as well as presenting
gain equations and delving a bit into the physical construction of the semiconductor
elements. Part 3 describes the newest processes in use at the time and what
was available for low power and high power RF applications...
 The National Institute of Health's (NIH)
National Toxicology Program (NTP) announced it has
cancelled its Radio Frequency Radiation (RFR) study because, and I quote, "The
research was technically challenging and more resource-intensive than expected.
No additional RFR studies are planned." The challenging part was trying to establish
a high confidence correlation between mouse and rat testing and human body testing,
since without direct equivalent empirical testing on humans, only educated guesses
could be made. Short of Axis countries' type of testing on humans during World War II,
the methods and levels of radiation could not be used on people. No mention is made
of what, if any, other test programs were/are in process or planning. Interestingly,
the report states, "However, the studies question the long-held assumption that
RFR is of no concern as long as the energy level is low and does not significantly
heat the tissues," and that, "NTP studies of RFR used in 2G and 3G cellphones do
not apply to 4G or 5G technologies." The good thing is now that money can go toward
caring for the millions of new illegal immigrants entering the country since 2021.
 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...
Thursday the 18th
 A lot of people think the modern day solar
energy craze is a relatively new phenomenon, but old guys like me remember back
in the early 1970s, during the Arab Oil Embargo, when we were promised that massive
arrays of
photovoltaic (PV) cells would save the world from its dependence on foreign
oil suppliers. At the time, the massive oil reserves below the ground here in the
USA, and in easily accessed offshore regions, were not known. PV cell manufacturers
(small by today's standards) were popping up around the country. I remember one
in particular, Solarex Corporation, which served as a sort of poster child for solar
power, went toes-up due to underperformance in conversion efficiency and excessive
costs. Tragically, we were told by "experts" that between wind, solar, hydro, and
nuclear, that electricity would be practically free, and many homes and businesses
had electric heating installed in the form of baseboard electric heaters. Now, with
closing nuclear plants after the 3-Mile Island incident and the current government
shutting down gas and oil mining and pushing expensive "renewable" energy sources,
people are getting winter electricity bills over $400/month. This 1954 Popular
Science magazine article reports on some of the very earliest attempts at solar
cell manufacturing...
 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
filters have been announced for mid-January 2024: a 750 MHz LC bandpass
filter with a bandwidth of 50 MHz, a 70 MHz LC bandpass filter with a 10 MHz
bandwidth, and a 3400 MHz highpass filter with an insertion loss of 1.5 dB.
Custom RF power filter and directional couplers designs can be designed and produced
with required connector types when a standard cannot be found, or the requirements
are such that a custom approach is necessary...
 Even with all of today's prefabricated components,
gizmos, and tools - at incredibly cheap prices - there are still many people who
prefer to make their own non-standard parts and even tooling when tinkering on a
project. Many hobby magazines have monthly columns dedicated to hints, tips, shortcuts,
ideas, etc. to solve, remedy, conquer, etc., the many kinks, problems, challenges,
twists, hitches, snags, etc. of the task at hand. The aforementioned words can be
found in the titles of those columns. Short Wave Craft magazine ran a feature titled
"$5.00
for Best Short Wave Kink" that rewarded readers for submitting nifty ideas.
Contemporary magazines and websites still offer cash rewards, typically in the $25-$50
range. In today's money that $5 is equivalent to around $112...
 "In a scientific breakthrough that could
reshape our understanding of how light interacts with matter, researchers from the
Attoscience and Ultrafast
Optics group at the Institute of Photonic Sciences (ICFO) in Barcelona, Spain
have discovered a new phase of matter, aptly named a 'light-matter hybrid.' The
findings, published inNature Communications, not only reveal a previously unseen
state of material, but also open doors to potential applications in photovoltaics,
high-power electronics, and beyond. In the hybrid, the material's properties are
altered according to the strength of pulses light, in one case dropping resistance
to near zero. At the heart of this technique is attosecond x-ray absorption spectroscopy,
which allowed the ICFO research team to study how electrons behave on timescales
as short as a billionth of a billionth of a second (an attosecond) when exposed
to powerful infrared radiation. This was achieved through a classic pump-probe technique,
where an infrared laser pulse excites electrons into high energy states, and an
x-ray beam subsequently probes the energy distribution..."
 There are many designs for
multiple-wavelength antennas available. Some use resonant "traps" and specific
length sections of lines to change the effective RF length according to specific
frequency bands, and others employ complex phasing of multiple antennas to a single-point
feed. Doing so allows operation across bands that do not necessarily fall within
or close enough to harmonic ratios, while still presenting decent VSWR to the transceiver
for acceptable performance. Still, nothing beats a single, finely tuned antenna
for each band of operation, or for that matter an antenna whose length is trimmed
to operate at peak efficiency even within sub-bands. It is possible to "match" just
about any antenna impedance to a transmission line and transceiver, there will always
be loses in efficiency and thus loss in power due to resistive losses in matching
networks and transmission lines (where reflected power is dissipated). This arrangement
of a continuously variable length wire antenna is one answer to the problem. It
takes a bit of mechanical aptitude and a willingness to adjust the length with each
frequency change, but after the initial calibration you simply adjust it to marked
points. Designing a fully automatic electromechanical version is well within the
skill set of many Hams...
 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...
Wednesday the 17th
 If you believe this 1953 advertisement in
Popular Science magazine, engineering at Bell Telephone Laboratories invented
the
wire-wrapping process. A little additional research shows that indeed it was
a Bell Telephone engineering team led by Arthur Keller who developed the method
and a wire-wrap tool to do the job. Field technician needed a fast, durable, and
reliable electrical connection when making hundreds or thousands of splices at relay
stations and while up on telephone poles. The key to making a good wire-wrap connection
is sharp corners on the wrapping post so that the corner pushes through any oxidation
or contaminant on the bare wire. NASA and the Department of Defense (DoD) have exacting
workmanship standards to guarantee a rugged, durable electrical connection with
low resistance, and imperviousness to contamination. In fact, properly formed wire-wrap
connections are considered to be gas-tight. This same ad ran in a blitz in the October
1953 issues of Radio & Television News, Radio-Electronics
and Popular Science...
 Here are a couple new vintage
electronics-themed comics for your enjoyment as you wind your way through the
work week. They appeared in a 1944 issue of Radio-Craft magazine. My favorite
is the one with the lady in the vacuum cleaner repair shop. Look at her request!
Her husband must have put her up to it. The other comic is pretty good, too. Having
lived toward the end of the vacuum tube era, my appreciation of the equipment is
more for the nostalgic quality than memories of having to wait for the tubes to
warm up and re-tuning the radio and TV set at intervals while listening and/or watching.
You might want to e-mail this page link to your friends. A big list of all the posted
tech-themed comics is at the bottom of this page...
 "New developments
on a nearly century-old concept for a
'self-eating' rocket engine capable of flight beyond the Earth's atmosphere
could help the UK take a bigger bite of the space industry. University of Glasgow
engineers have built and fired the first unsupported 'autophage' rocket engine which
consumes parts of its own body for fuel. The design of the autophage engine - the
name comes from the Latin word for 'self-eating' - has several potential advantages
over conventional rocket designs. The engine works by using waste heat from combustion
to sequentially melt its own plastic fuselage as it fires. The molten plastic is
fed into the engine's combustion chamber as additional fuel to burn alongside its
regular liquid propellants. This means that an autophage vehicle would require less
propellant in onboard tanks, and the mass freed up could be allocated to payload
instead. The consumption of the fuselage could also help avoid adding to the problem
of space debris - discarded waste that orbits the Earth and could hamper future
missions. Overall, the greater efficiency could help autophage rockets take a greater
payload into space compared to a conventional rocket..."
 These 8 new schematics from a 1936 issue
of Radio-Craft magazine for vintage
tube-type car radios brings the total to 210 posted on RF Cafe. Included are
Motorola "Golden Voice" Model, RCA Victor Model H-6, Simplex Model TA, Automatic
"Magic Eye" Model A1, Arvin Model 28, Philco Model 818, Fada Model 266 Motoset,
Bosch Models 736, 737, 738. The Motorla "golden Voice" model features a "magic eliminode"
circuit which not only filters out automobile engine noise, but balances the noise
out of the antenna lead, so that suppressorless operation is possible on almost
all cars. A glance at the schematic shows that all that magic is performed by a
built-in L-C filter network for the power supply, and an antenna tuning circuit.
In those days, installation of a radio in a car usually required the skills of an
electronics technician in order to match the antenna and fine-tune the receiver
according to its environment...
 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!
Tuesday the 16th
 I thought beginning sentences with the word
"So" was a relatively recent (and annoying) thing, but the author of this 1948
Popular Science magazine article on
cosmic rays (which are actually particles) uses it at least six times. For some
reason those kinds of grammatical peculiarities stand out to me when reading or
listening. Other than that, Mr. Mann does a nice job presenting the basics
of cosmic rays, which were a fairly newly discovered phenomenon in the day. You
can tell by the large number of named PhD's researchers who were delving into the
physics of cosmic rays that it was a hot topic, probably highlighted in importance
because of the discovery that cosmic rays were (are) constantly bombarding every
plant, animal, and mineral on Earth. Surprisingly, no mention is made of the role
Einstein's special relativity theory plays with measurements made on the muons created
by cosmic rays. The Muon Paradox is explained by time dilation. Concern over whether
these highly energetic particles could cause cancerous mutation in living tissue
was a great motivator. Fortunately, our atmosphere protects us from the majority
of effects produced by cosmic rays. Astronauts...
 Artificial Intelligence (AI) has become a
very controversial subject in the last few years, especially since the debut of
the ChatGPT engine. "GPT" means it Generates new content using a Pre-trained database
of data and Transforms it into user-requested output used on "deep learning" models.
I have posted a few articles on AI topics. A couple RF Cafe visitors have chimed
in with opinions on AI and whether it is more good than evil, or vise versa. One
guy in particular, an ubersmart engineer living north of the border, contributed
the following, which I post with permission (less identification). This was his
reaction to my posting of the "ChatGPT Thinks I Discovered and Own Everything" piece...
I have never been inclined to try ChatGPT, because I believe that I would get more
pleasure from creating something myself than from coaxing ChatGPT into creating
something I like...
 RoHS (Reduction of Hazardous Substances),
Pb-Free (lead-free), and other green programs were not a significant concern in
the electronics industry when this article was published in the early 1970s. Instead,
research and development efforts concentrated on understanding and improving the
chemical and mechanical aspects of soldered electrical connections. Having "grown
up" in the electronics industry during that era, most of my
solder and soldering knowledge and practices still tend toward Sn-Pb (tin-lead)
alloys for most applications, whether for soldering electronic components to a PCB
or terminal post, soldering copper water pipes, or soldering music wire landing
gear assemblies for model airplanes. Along with the rather sudden move to lead-free
solder came reliability problems including "tin whiskers" and fragile interfaces,
a requirement to re-design many component types to endure the higher processing
temperatures required for leadless solder, and figuring out how to excuse the extra
energy used and Earth-warming temperatures required to accommodate...
 "Physicists at the National University of
Singapore have innovated a concept to induce and directly quantify spin splitting
in two-dimensional materials. By using this concept, they have experimentally achieved
large tunability and a high degree of
spin-polarisation in graphene. This research achievement can potentially advance
the field of two-dimensional (2D) spintronics, with applications for low-power electronics.
Joule heating poses a significant challenge in modern electronics, especially in
devices such as personal computers and smartphones. This is an effect that occurs
when the flow of electrical current passing through a material produces thermal
energy, subsequently raising the material's temperature. One potential solution
involves the use of spin, instead of charge, in logic circuits. These circuits can,
in principle, offer low-power consumption and ultrafast speed, owing to the reduction
or elimination of Joule heating..."
 Here are a few interesting photos from the
annals of radio communications' 1935-era history that include airborne, land mobile,
and fixed operator stations from around the world. They were published in a 1935
issue of Short Wave Craft magazine.
Japanese amateur radio operator Seichiro Handa is shown sitting in his "shack"
donning headphones and a Morse code key. The author mentions that judging by his
high quality radio equipment, Mr. Handa's finances seemed to be unaffected
by the Great Depression that hit the United States and other Western countries beginning
with the stock market crash in October of 1929...
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...
Monday the 15th
 Popular Science magazine, as did
Mechanix Illustrated and Popular Mechanics, included a wide variety
of science and mechanics topics in every issue - as the titles imply. Sometimes
brief news reports were used, and other time entire multi-page articles were written.
In a case of the former, this collection of items appeared in the June 1947 issue.
Digital computers were replacing analog computers due to their more flexible programming
ability and lower inaccuracies. Data storage was easily handled with magnetic tape,
but the speed of read/write operations was usually a bottleneck in the process.
Radio Corporation of America (RCA) developed what they called the
Selectron vacuum tube, which used phosphorous dots to store a charge representing
a digital "0" or "1." Operation was somewhat akin to dynamic random access memory
(DRAM) that required periodic refreshing of the storage cell value before it fades
to obscurity. Before the Selectron could make it to prime time, magnetic core memories
were invented. Also in the report was a method the Dutch used for hiding radios
in books during World War II...
 We
had a strong storm run through the area last week, knocking out power for almost
24 hours. Linemen were on the job during the worst of the deluge. When we lived
up north, they were out in blizzards repairing downed power lines due to winds,
fallen trees and branches, and busted poles. In 2013, Congress declared April 18th
as National
Lineman Appreciation Day. Typical neighborhood overhead or buried lines are
around 7.2 kV, and lines running out of substations can be 35 kV or more.
Would you want to touch that, even with a ten-foot pole, while rain is pouring down
or snow is falling? Me neither. Winter and spring are the seasons of power outages
in the north, and summer and fall in the south. I'll give a shout out to the linemen
now rather than on April 18th, while I'm appreciating typing this on a desktop computer
in a warm house with lights, refrigerator, water heater, and everything else working.
 World War II ended on September 2,
1945 following the surrenders of Japan and Germany. Almost immediately after WWII
ended, the
electronics market was flooded with vacuum tubes, resistors, inductors, antennas,
transmission lines, meters, batteries, transformers, speakers, incandescent and
neon bulbs, hookup wire, and even entire radios and test equipment. It was a good
time for electronics manufacturers, hobbyists, and repair shops. In fact the U.S.
government made a special effort to compensate the public for sacrifices made during
the war. It didn't last long, however. The Korean War broke out on June 25, 1950,
and ran through July 27, 1953. This episode of Mac's Radio Service Shop hints at
the déjà vu of Mac's war years and the recurrence of leaner days settling in again.
 "The wafers of silicon that ultimately become
the chips in your smartphone consist of a single crystal. But that crystal has many
faces, and it matters which of those faces is at the surface, where transistors
are made. According to research presented last month at the 2023 IEEE International
Electron Device Meeting (IEDM), the industry might not be using the best
crystal orientation for
upcoming devices. By changing the crystal orientation, a team at IBM Research achieved
as much as a doubling of the speed of positive charge through transistors, though
it came at the cost of a slight slowdown for negative charge. Crystals can be reduced
to a unit structure that's infinitely repeatable. For silicon, it's a cube that
looks like it's got a diamond stuck inside it. There are silicon atoms at each corner
of the cube as well as at the center of each face, and four more atoms within the
cube's interior. Today's transistors, FinFETs mostly, are built on silicon whereby
the top of that cube is the surface of the wafer. Experts call that crystal orientation
'001.' Silicon wafers with the 001 orientation are used in many advanced logic technologies,
including in IBM's 2-nanometer chip..."
 A lot of people from the era of rooftop
television antennas were/are familiar with the name Channel Master. Many of their
antennas included integrated FM radio elements. Very few were likely aware that
Channel Master also made radios. I don't think they ever made televisions. The fact
is, companies like Channel Master did not design and manufacture their own radios
and televisions; instead, they paid to have custom versions of existing products
branded with their names. Sears, Roebuck's Silvertone line, Montgomery Ward's Airline
products, Western Auto's Truetone line, and others are examples. This
Channel Master Model 6515 "Super Fringe" transistor radio was made by Sanyo.
1960, when this ad appeared in Electronics World magazine, was the transition
period between vacuum tubes and transistors. It was not uncommon to find two or
more identical radios bearing different company logos. Channel Master Model 6515
"Super Fringe" radios can be found in eBay for around $30...
 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 280,000 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. If you need your company news to be seen, RF Cafe is the
place to be...
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