These items are an archive of past Topical Smorgasbord items that have appeared on the RF Cafe homepage. In keeping with the "cafe"
genre, these tidbits of information are truly a smorgasbord of topics. They all pertain to topics that are related to the general engineering
and science theme of RF Cafe. Note: There is also a huge collection of my 'Factoids' (aka 'Kirt's Cogitations') that might interest you as well.
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Have you ever started a relatively simple investigation
into a trivial matter, only to find yourself going down the metaphorical "rabbit
hole" even after finding the original answer? Such was the case for me when someone sent me an e-mail with a signature that
amateur radio call sign. The first three characters, KB3, matched mine and
that got me wondering on what date his call sign was granted compared to mine. Let us say for example* the writer's call sign was KB3PGM and mine is (actually) KB3UON.
I looked them up in the FCC's
ULS self-serve license ...
If, as the saying goes, "Misery loves company,"
then you will appreciate the following. Whilst perusing the December 2017 issue of NASA's
Motion Design supplement to their Tech Briefs publication, I ran across
the image to the right in an article titled, "Trends in Hydraulic Filtration"
(areas of interest are quite diverse here at RF Cafe).
After reading the caption stating that the holes were "fire holes," the first thing that
came to mind was
Sure enough, upon going back and reading more of the story (provided by Argo-Hytos),
I found ...
Another era, sadly, has come to an end. H. Ward
Silver (aka Ward Silver, NØAX) has announced the end of
his monthly column, "Hands-On
Radio," in QST magazine. The title of each column was enumerated as "Experiment
#nnn," followed by the subject. To wit, "Experiment #179 Maxwell's Equations - The Wave
Emerges" is Mr. Silver's final column, appearing in the December 2017 QST.
"Hands-On Radio" topics ranged in intensity from relatively simple discussion on calculating
power dissipation in resistors, capacitors, and inductors to more heady treatises on
subjects like electromagnetic fields within coaxial cable and waveguide to Maxwell's
equations. Mathematics, too ...
of my favorite old-time radio personalities, Paul Harvey, had a trademarked feature titled
The Rest of the Story. For those of you not familiar with the format, Mr. Harvey would
begin his story talking about particular life aspects of a person that, while remarkable,
usually had no connection with the person's eventual claim to fame. The listener's challenge
was to guess who the person was before it was revealed at the very end, followed by,
"... now you know --- the rest [emphasis] of the story." As far as I know the story of
FM radio inventor
Armstrong was never a subject, although it certainly met the criterion. I've already
let the figurative cat out of the bag, so you already know my subject ...
From May 9th through the 11th in the year of our
Lord 1958, the very first "Jamboree on the Air" (JOTA) was held by the Boy Scouts of America
(BSA). The American Radio Relay League (ARRL), in conjunction with the BSA, is promoting
this year's 60th anniversary event occurring from October 20-22. As you might imagine,
quite a lot has changed over 59 years in terms of equipment, but the basics in terms
of encouraging and assisting the next generation of licensed Hams remains as always the
primary goal of organizers. The Boy Scouts, of course, join in for the fun and learning
experience. Jamboree on the Air events, held in October, do not coincide with the National
Scout Jamboree, held in July ...
Nikola Tesla was born in 1856 in Smiljan, Austrian
Empire, and died in 1943 in New York City. His life is so amply documented far and wide
that regurgitating the information in books and blog posts would be a waste. Most of
what you find there is second-hand, having gone through the filter of an author's preferences.
I like to search for stories on various topics in their original publications; e.g.,
scanned newspaper and magazine archives. A hunt for early stories on Nikola Tesla turned
up many 19th century examples from the Newspapers.com website. It is interesting that
back in the day, men like Nikola and Edison were referred regularly to as "electricians."
The oldest article I found on Nikola Tesla appeared in the July 1, 1889 edition of
The Pittsburgh Dispatch, titled "The Electric Fiend" ...
It's finally here - the
North American Solar Eclipse of 2017! The amateur astronomy community has been anticipating
and preparing for the event for a couple years. Astronomy magazine dedicated
the entire August issue to providing detailed information on viewing suggestions along
the entire path. Traffic from the Pacific Coast of Oregon to the Atlantic Coast of South
Carolina will probably be a challenge as people vie for positions as close to the centerline
as possible. Those who manage optimal locations will see about 2 minutes and 40 seconds
of total darkness. Others within the 68-mile-wide path of totality will see from a fraction
of a second up to the full extent. According to a calculator on the Vox website, we will
only see a 76.2% eclipse, which will barely darken our skies ...
Hmmm.... let us see what made the front page of
the July 1, 1948 edition of Murray Hill, New Jersey's, The Madison Eagle newspaper: "Man
Found Dead, Wedged in Drain on Park Edge," "Lawyer Fined $50 on Zone Charge," and Sandra
Dean Stevenson had been born two weeks earlier. Oh, also included was "Invention
Replaces Vacuum Tube" and "Local Man Invents New Device in Electronics for Bell Lab;
Could Revolutionize Radio." Page 10 ran, "Bell Laboratory Releases Data on Newly Invented
Transistor." It is widely known that Drs. Brattain, Shockley, and Bardeen formerly announced
on December 23, 1947, within the walls of Bell Labs ...
We have all been treated to a seemingly endless
series of headlines portending rising ocean levels and the ensuing drowning of costal
cities due to
in the polar regions. This phenomenon ostensibly is brought on by the exponential increase
in carbon emissions from developing third-world countries as well as established first-world
countries in the post World War II era ... or was it post Vietnam, or maybe post
Gulf War? The reference keeps changing, but it definitely began occurring since at least
1990, right? There is a problem, though. In the early and mid 1970s climate scientists
began warning us of an approaching ...
For some inexplicable reason, it seems that of
the many articles I read dealing with antenna and feedline efficiencies, rarely is the
receive side of the equation addressed. Yes, transmit power is expensive and there
is a legitimate reason to reduce losses when converting power amplifier output to in-the-air
power, especially for DX operations. However, it doesn't do much good to launch the full
permissible 1,500 watts PEP and make a contact on the other side of the world if your
system cannot receive a reply because of the excessive line loss and/or mismatch loss
between your antenna and your receiver. Antennas and feedlines are reciprocal elements
so if ...
Friends, former employees, and fellow lovers of
all things electronic, we are gathered here today to remember and honor our lifelong
friend and enabler of our hobby and passion,
Radio Shack -
once a Tandy company, as we are familiar with it. Radio Shack has lingered in failing
health for a decade, all the time keeping a brave face on its dwindling number of stores.
Caretakers attempted a variety of infusions and transplants in an attempt to save the
American stalwart electronics retailer. Alas, a confluence of poor management ...
For Mother's Day this year, the kids and I got
Melanie a 23andMe DNA testing kit. She has spent a fair amount of time over the years
researching the family lineage which, in case you care, traces back primarily to Germany
and Switzerland. Along with some of the online ancestry websites, she searched the U.S.
Census database for immigration and early American household information (number of people,
ages, names, occupations, etc.) The entire
Census form consisted of a single page seeking basic information on whether you own
or rent, value of the home, live on a farm or not, color or race, ...
Long-time RF Cafe visitor and occasional contributor
Gary Steinhour, KF6U, recently sent me a note saying he had acquired a very used
amateur radio transmitter and was in the process of restoring it. Gary's first transmitter
as a freshly minted Ham over 50 years ago was a DX-60, so this was an effort to satisfy
a nostalgic emotional attachment. The project is complete now, and boy does it look nice!
Gary provides a brief account here ...
If you have ever seen the result of a lightning
strike on electronic equipment, then you know how devastating it can be - often total
destruction that includes molten metal. Woe be unto any human operator who happens to
be in contact with it at the time of the strike. Unprotected antennas are begging for
contact. Shortly after leaving a company where I worked on a Tx/Rx system for a phased
array weather radar I got word that the indoor equipment rack took a major hit because
the guy who maintained the site forgot to reconnect a
rod system cable after moving it during ...