ASCII Art has been
around nearly as long as digital computers have been in existence. It was the
only type of "graphics" available to most users before other than text displays
were commonplace. Universities, corporations, and government research facilities
had crude forms of graphical displays, but it was not until the 16-color,
640x200-pixel CGA (Color Graphics Adapter) monitors began shipping with IBM PCs
that most people had access to "real" graphics. To compensate, some pretty
clever souls came up with what has become known as "ASCII Art." ASCII (American
Standard Code for Information Interchange), for those of you too young to
remember when that was part of common computer parlance, is the basic set of
numbers, letters, and special characters that all computers are capable of
rendering based on unique codes assigned to them. For instance, ASCII character
48D (30H) is the number "0," 65D (41H) is upper case "A,"...
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..."
If you have not yet discovered the Engineering
and Technology History Wiki (ETHW) website, now would be a good time to surf on
over and take a look at the vast resources there - particularly the "Oral-History"
series of in-person interviews of our field's top scientists and engineers. Among
them are Dr. Harold Beverage, Dr. Ulrich L. Rohde (N1UL), Harold S.
Black, Harold A. Wheeler, Dr. Irwin Jacobs and Dr. Andrew Viterbi,
and of particular significance to me,
Dr. David B. Leeson (W6NL), founder of California Microwave and Ham
radio contesting champion. Many of the oral interviews were conducted in the pre-Internet
era and some of the people are no longer with us. A few days ago, I had the honor
of being contacted Dr. Leeson as part of his search for information he wants
for some work he is doing. His name is familiar to amateur radio contesters who
participate in DX (long distance) events...
Last week Melanie and I drove down to Greensboro,
North Carolina, to attend our daughter's wedding. The weather was typically hot
there, but not out of the norm. All went well at the small ceremony. Both bride
and groom showed up, as did the minister and necessary witnesses. After the blessed
event was over, we headed back northward to our humble abode in Erie, Pennsylvania.
Our route upon exiting NC is I81 for a few miles in Virginia, then north onto I77,
up to Rt. 19, then I79 all the way home up and down mountains for a few hundred
miles. Our 2011 Jeep Patriot has never had any mechanical issues, but then it only
has 81k miles on it and is kept in the garage. That day, though, the transmission
overheating idiot light illuminated while on I81 - not a particularly hilly stretch.
The outside temperature there was about 80 °F. I had noticed a slightly higher
pitch sound from it while going uphill, but didn't think anything of it until the
light came on. (On−Trak Automotive
Let me begin by stating that in general,
I am not an "anti-vaxxer." Since my days in the USAF, I have chosen to get an annual
flu shot, my kids received all the required / recommended vaccinations during their
school years. I've even had the second-generation shingles shots. No problemo. All
those vaccines were subject to the full scientific regimen of development and testing
prior to being administered to the general public. The current crop of
COVID−19 vaccines, however, are a major exception - especially the mRNA varieties.
None have been thoroughly vetted with the traditional multi-year studies which include
a very wide cross-section of voluntary participants. Furthermore, none have been
approved by normal guidelines - these are emergency approvals. Statistical studies
were performed which attempted to correlate cause and effect. If necessary, necessary
modifications to the formulation were made and then trials began anew. Once the
medical and science community had enough data...
A few times in the past I have mentioned
the U.S. Army's long-running comic-book-style of training material for vehicle maintenance.
It began in 1940 under the title of The Army Motors and ran through the
end of World War II. In June 1951, at the beginning of the Korean War, the
publication was re-introduced as
PS Magazine - The Preventative Maintenance Monthly, where the "PS" part
stands for "Post Script," a la the "p.s." you might put at the end of a written
letter. In this case the "p.s." is a post script to the regular Army vehicle maintenance
manuals. I recently happened to run across the RadioNerds.com's extensive section
on PS Magazine, and it is a treasure trove of downloadable PDF versions of the magazines.
As you can see from the cover illustrations and the contents, its appeal was primarily
to the predominantly male vehicle maintenance force...
Engineers are entirely comfortable with numbers
multiplied by very large powers of 10; that is, with many trailing (or leading if
a decimal) zeros after the significant figures. A terahertz is 1 x 1012,
or 1 followed by twelve zeros, or
A picosecond is 1 x 10-12, or eleven zeros between the decimal point
and the one, or 0.000000000001. The mass of the sun is approximately 1.9885×1030 kg,
or 1,988,500,000,000,000,000,000,000,000,000 kg. The mass of an electron is
approximately 9.10938×10−31 kg, or 0.000000000000000000000000000000910938 kg.
We don't even break a sweat when punching those kinds of numbers into a calculator.
We're used to it. When most laypeople these days hear politicians nonchalantly toss
around figures in the trillions of dollars regarding a country's deficit or planned
new spending packages, or the net worth of Amazon's Jeff Bezos, Tesla's Elon Musk,
and Donald Trump, they have no concept of how big the numbers are...
RF Cave visitor and contributor Joseph Birsa
(N3TTE), sent me a note about yet another edition of a special purpose catalog published
by Sears - the
Sears 1940 Amateur Radio, Test Equipment, Sound System Catalog. A little research
revealed that it was actually an extended version of the 1940 Sears, Roebuck and
Co. Superior Amateur Equipment and Radio Service Supplies - 64 versus 48 pages,
respectively. Even the standard edition Sears, Roebuck Fall 1941 Catalog contained
a large section dedicated to radios and equipment. The cover on the shorter catalog
makes me think of The Radio Boys series of books, where a cadre of four early 20th
century teenagers experienced adventures centered around build and operating wireless
equipment. Hallicrafters, National Company, Meissner, and Hammarlund receivers and
transmitters were offered for sale. Bliley and Silvertone...
When doing some research for creating a new
quiz on inventors
and their inventions, I decided to look for people according to their countries.
I almost always do image searches since doing so does a good job of filtering out
pages that merely mention the topic of interest. My first Google search was "american
inventors." I expected to see the familiar faces of Thomas Edison, Henry Ford, George
Westinghouse, Marie Curie, Alexander Graham Bell, George Washington Carver, Edwin
Armstrong, Hedy Lamarr, Benjamin Franklin, Robert Goddard, Albert Einstein, the
Wright Brothers, Samuel Morse, William Shockley, etc. Those are the names that first
come to my mind, and admittedly the list is dominated by White men. Imagine my surprise
when the Google search results belied my perception. Take a look at the first few
pages of results to see what I mean. Next, I moved on to an image search for "canadian
As our traditions are besieged by malcontents
determined to denigrate, impugn, and ultimately erase memories of holidays and events
that have meant so much to families and friends, I feel compelled to resist the
movement by documenting parts of the past that will cause us to wax nostalgic over
our cherished traditions. Intimidation and violence is part of the strategic calculus;
we have seen it in spades in 2020, and 2021 promises to be even worse. The Cancel
Culture might eventually win out with the complicity of government agents both elected
and unelected, but I'm not going down without a fight. Here is a collection of twentieth
century, December issue
QST magazine covers with Christmas themes that will no doubt be
familiar to many of you. Finding them was more difficult...
December 24, 2020
RF Cafe visitor Michael Maassel, an electrical
engineering professor in North Dakota State University's Electrical and Computer
Engineering Department, requested that I post these few questions to help him effectively
prepare students taking senior-level (aka "Capstone") design courses for a real-world
experience after graduation. Says the good professor, "The biggest headache I have
is getting the students to
document their work, both in hardware and in software. Currently,
I am requiring that the students use a quad line notebook. This has not been very
successful." How do you handle documentation in your every-day work?
For many years Melanie and I have been collecting
and reading The Radio Boys series of thirteen books, which were written in
the 1920s by Allen Chapman. It was a time in history when the miracle of radio communications
was capturing - even enrapturing - the public with its seemingly miraculous ability
to convey messages across town and around the world without the need for wires,
hence "wireless." The stories center around four teenage buddies, namely Bob Layton,
Joe Atwood, Herb Fennington, and Jimmy Plummer (aka Doughnuts") who, with the assistance
of a local pastor, Dr. Dale, took an avid interest in radio and built from scratch
a successful crystal radio. Their enthusiasm compounds upon itself as adventures
and experiences using wireless foster interest in building better receivers and
then building transmitters for sending Morse code and audio ("phone"). In order
to appeal to his intended audience - primarily young boys - villains, good guys,
hapless bystanders, government agents, local law enforcement, family, and even the
occasional damsel in distress...
About a decade ago, photos began appearing
on news websites showing Chinese citizens walking around
wearing face masks in order to filter out the massive air pollution
pouring from city factories and coal-fired electric power generation plants. Articles
were written advising on the best types of face masks to use while visiting or working
in China. The only topic about China competing for shock factor at the time was
the rash of suicides at Foxconn as the poor soulless, hopeless workers who build
our inexpensive electronics products jumped from upper factory windows and roofs.
Since around March of this year, nearly every location in the United States and
around the world is looking like China did for the entire last decade. A worldwide
pandemic was declared because of a deadly virus which originated from the Wuhan
area of China...
Have I mentioned that my YL, Melanie, decided
she would earn her Amateur radio Technician license? After living in a household
with a bilingual husband (English and Electronics) for nearly 38 years and having
become fairly proficient at ETL (electronics as a third language*), Melanie decided
to earn her Technician license. She has never delved into the technical aspects
of electricity / electronics, but has, along with hearing me speak of it (too) often
and having proof-read my writings and scanned and OCR'ed more than a thousand articles
from vintage electronics magazines, her gray cells are permeated with the vocabulary,
lingo, jargon, vernacular, slang, and argot of the realm. Being an expert test taker,
she will undoubtedly pass the written test with flying colors. With much self-restraint,
I have avoided offering my sage advice and knowledge during her studies of the ARRL's
Ham Radio License Manual. The current edition is the 4th, being valid from
2018 through 2022. Melanie has asked for a little clarification on SWR, decibels
and couple other minor topics, but otherwise has progressed...
The world was introduced publically in 2007
to the concept of a 3-dimensional Smith chart by Chris Zelley. In article published
in IEEE Microwave Magazine entitled, "A Spherical Representation of the Smith Chart,"
the radically new concept was illustrated on the surface of a ping pong ball using
a felt-tipped pen (thumbnail at left). Inspired by the sight, Andrei A. Muller and
a small team of developers in 2013 created a version of the
3D Smith Chart in software using the Java language that allows
it to execute on any platform. In 2017, an expanded functionality commercial version
of 3D Smith Chart was released at a very modest price. A number of articles have
been published on the topic extolling the unique ability of a 3-dimensional complex
impedance volume to expose...
The other day a song entitled "Western Union"
played on my local over-the-air oldies radio station. It was released by the group
The Five Americans in 1967. I've heard it many times before, but it finally occurred
to me that the use of Morse code-like symbols in the refrain made it a perfect candidate
for a spot here on RF Cafe. The full lyrics of "Western Union" can be found at the
bottom of the page, but notice the "Dah-Dit-Dah-Dit-Dah" repeats in the refrain.
Even though I'm a licensed (as of 2010) Ham, my shameful (according to some veterans)
status as a post-Morse-code era did not require demonstration of code proficiency.
As such, my lack of a Morse code deciphering ability required that I rely on an
online translator for considering what the code might be. Depending on how you separate
the dits and dahs, the string of characters can be interpreted as TETET (- . - .
-), TAA (- .- .-), KA (-.- .-), NK (-. -.-), CT (-.-. -) or other combinations,
none of which seem to mean anything in particular...
A couple years ago a house two streets away
had an estate sale after the elderly gentleman who owned it passed on. There was
a lot of old amateur radio gear for sale, and most of it had been bought early
in the morning, right after the beginning of the sale according to the man's daughter
who was on-hand. The newspaper notice mentioned the Ham equipment. In the back yard
was a nice 40-foot crank-up tower that was a bit weather-worn, but otherwise appeared
to be in good condition. She said that was the first item sold. I didn't ask how
much she got for it. The house was to be sold, and they were glad to have the tower
gone before listing it on the market. I have wondered in the past when seeing a
"For Sale" sign in the lawn of a house with one or more radio towers in the yard
how much they would impact the sale price. Some Hams would plan to take...
Lincoln Vocational Technical Center. One
day in late spring of 1973 I found myself walking around the gymnasium of Annapolis
Junior High School (AJHS) trying to decide which courses I would prefer upon beginning
tenth grade the following fall. It was one of the final days of ninth grade, which
had been by far my least happy year in school. Living in Mayo, Maryland, I and my
fellow neighborhood ninth graders should have attended Southern Senior High School
(SSHS) in Harwood, Maryland, where our predecessors had gone for ninth grade, but
overcrowding caused the Anne Arundel School Board wizards to decide that for at
least that year, we would remain at AJHS for another term. Historically, kids from
my area went to AJHS only for seventh and eighth grades and then switched to SSHS.
Annapolis, being the capital city of Maryland, was significantly more urban than
the rural areas which SSHS type people were accustomed to. The clientele was much
more aggressive in the big city. Sure, we had our "red neck greaser" rowdies in
the southern part of the county, but at least their parents would whip them if they
got caught getting into trouble. The north county parents, we believed at the time...
If you are annoyed by
pop-ups and extraneous framework elements and/or SEO (search engine
optimization) tracking code accompanying application notes, white papers, and images,
and videos, many times you can get rid of them by editing the URL displayed in your
browser address bar. Compare the displays in this set of screen captures based on
the original URL provided in an e-mail (top) to the one where all the extraneous
terms have been removed from the URL (bottom). Note that the yellow highlighted
components have been eliminated. Often, I remove that stuff from hyperlink URLs
before sending my visitors to websites. Companies don't particularly like me doing
that, but doing so helps maintain your privacy. URLs in e-mails are particularly
likely to contain appended code that contains one or more "&utm_" parts. UTM
is the Urchin Tracking Module introduced by Google Analytics' predecessor Urchin
and are now supported by Google Analytics. They typically ....
Miscellaneous Earlier Smorgasbords and Factoids: