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Tech Smorgasbord Archives - 35

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.

| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 |

Is Your Domain Being Blocked by a Country?

How to Test Whether Your Domain Is Being Blocked by a Country, Kirt's Cogitation #275 - RF CafeRecently, a company based in China contacted me about advertising on RF Cafe. After doing a lot of up-front work for them creating advertising materials, the representative informed me that he cannot access the RFCafe.com domain from his location. It is really difficult to conduct business when the customer cannot review your work, so at least for now, I am going to pass on the opportunity. The obvious question that arises from the experience is whether RFCafe.com is being blocked by China, and how do I find out? Fortunately, a few options exist with websites that will perform the check for you by pinging your URL from servers within multiple countries. Some, such as GreatFirewallOfChina.org, tests from inside China using servers in Beijing ...

7/8/2016

Under a Telephone Pole, by Carl Sandburg

Under a Telephone Pole, by Carl Sandburg - RF Cafe"There is no new thing under the sun." "Everything old is new again." Many such idioms exist regarding how often things tend to run in cycles; it's just that often times people who think they are witnessing a new phenomenon are not aware of the previous occurrences. I have written of examples where 'old timers' lament the attitudes of a fledgling work force when writings show the previous generation of 'old timers' who worked with the current 'old timers' in their youth expressed the same type concern. Experienced Ham operators think newbies cannot carry on the tradition of wireless because they are not required to learn Morse code anymore to earn a license. An article titled "OMG! We've Been Here B4," appeared in the March 2016 issue of Smithsonian magazine ... 

6/22/2016

Anyone Else Remember Calling WE6-1212 and TI4-1212?

Anyone Remember Calling WE6-1212 and TI4-1212? - RF CafeLong before there was a World Wide Web for getting the latest weather report and the local time for setting your clocks, there were phone numbers that were set up with recordings of the sought after information. As a kid in the 1960s and 1970s, I called the weather forecast number, WE6-1212 ('WE' for weather), multiple times daily during the winter in hopes of hearing a forecast for snow, and during the summer in hopes of favorable conditions for flying model airplanes and launching Estes rockets. An obsession with time and watches and clocks had me calling the time phone number, TI4-1212 ('TI' for time), so often that my father used to refer to the lady on the recording that updated ...

6/16/2016

Able Signal Amplified Digital Outdoor HDTV Antenna Installation

Able Signal Amplified Digital Outdoor HDTV Antenna - RF CafeSince I do not have time to watch television on a regular basis, paying for a cable or satellite subscription cannot be justified. My plan was to install a traditional FM/VHF/UHF television antenna on the roof along with a rotator. Some pretty models are still available from Channel Master, RCA, and a few others. TV broadcast stations in the Erie area are all within 10 miles or so, so signal strength would not be an issue. I listen to both AM and FM radio most of the day, so being able to get an FM signal boost from a steerable antenna would be a nice bonus since occasionally reorienting the FM dipole was needed to get a clear signal. The entire outfit would cost less than a year's ...

6/8/2016

Makerspaces & Maker Faires

Makerspaces & Maker Faires - RF CafeDIY (do-it-yourself) is the relatively new term adopted to describe any activity engaged in by laymen and even professionals plying their trades after hours. Subjects range from hanging a kitchen cabinet or planting a tree, to a total engine rebuild or building a robot. Reasonable quality and capability tools for performing around-the-house chores are fairly cheap and available for purchase or rent for projects most people undertaking such challenges. Cordless saws and drills, stud finders, airless paint sprayers, and electronic readout levels can be had for under ...

6/7/2017

Challenges in Early Automotive Radio Design

Challenges in Early Automotive Radio Design - RF CafeEarly automobiles presented significant challenges to mobile radio designers due to a combination of a fledgling understanding of electrical and electronic circuits and quickly evolving automotive materials and configurations. A 1935 issue of Radio-Craft magazine presented eight automotive radio designs that represented break-through techniques for dealing with some of those innovations. All of the technical issues involved here have been pretty much solved in modern radios. Ignition interference is nearly invisible to FM and satellite reception, although audio frequency circuits can still pick up noise is not properly filtered ...

6/1/2016

The Periodic Table of Substitute Performance

The Periodic Table of Substitute Performance - RF CafeIn a Scientific American article titled "Elemental Urgency," Jennifer Hackett reported on a paper published in 2013 by Yale University's Thomas Graedel et al regarding the availability (or unavailability) of the raw elements - and suitable substitutes - used extensively in modern manufacturing. Unlike half a century ago when most products were made from relatively common and easily obtainable elements like lead, iron, tin, nickel, aluminum, carbon, zinc, silicon, and even silver and gold, many more elements are now regularly included in mass manufacturing processes. Rhenium (Re), used in high strength, temperature alloys ...

5/31/2016

The Concinnitas Project

The Concinnitas Project - RF CafeThe January 2016 issue of Scientific American ran an article by Clara Moskowitz titled "Elegant Equations" that presented a few prints from "The Concinnitas Project" which "...is a collection of ten aquatints produced from the contributions of ten mathematicians and physicists in response to the prompt to transcribe their 'most beautiful mathematical expression.'" My personal favorite is "Ampère's Law," by Simon Donaldson, because it incorporates a simple line drawing along with the familiar equations. It brings back memories of sitting in electromagnetics class at the University of Vermont watching my seriously brilliant professor (no kidding), Dr. Kenneth Golden, draw ...

5/16/2016

You've Heard of a Copyright, But How About a Copyleft?

You've Heard of a Copyright, But How About a Copyleft? - RF CafeNo, this is not a liberal vs. conservative thing, although you might be tempted to think so when considering the terms of each. A copyright, as you know, is legal protection against unauthorized usage or obvious modification of original works, something a right-winger would like because it represents a right to private property. A copyleft, on the other hand, is a left-winger's dream because it permits free distribution of original works with the only restriction being that it and/or derivative works also be declared copyleft material. That explains why evil capitalist companies like IBM copyright and patent everything it creates, and why liberal-dominated companies like ...

5/10/2016

Tesseract Antique Instruments

Tesseract Antique Instruments - RF Cafe SmorgasbordMy introduction to a tesseract was during an episode of Carl Sagan's "Cosmos" series in the 1980s, where he was demonstrating how beings in of dimension N would perceive items of dimension N+1. The tesseract, Sagan explained, is a 3-dimensional projection of 4-dimension hypercube. Watch the embedded video for more information. The Tesseract website, which has nothing to do with a hypercube as far as I can tell, deals in some very cool antique scientific instruments. I learned of it from an article in Astronomy magazine where an editor recommended it when researching the potential value of a collectible telescope. Run by Drs. David and Yola Coffeen, Tesseract has a huge inventory of items ...

4/28/2016

The "Fair Use" Doctrine and the U.S. Copyright Office

The "Fair Use" Doctrine and the U.S. Copyright Office - RF Cafe"The Congress shall have Power … To promote the Progress of Science and useful Arts, by securing for limited Tımes to Authors and Inventors the exclusive Right to their respective Writings and Discoveries." - United States Constitution, Article I, Section 8. Therein lies the authority for legislation and prosecution of rights for virtually every human creation within the jurisdiction of the country. Each nation has it own version, and international agreements help assure universal protection of a creator's rights of ownership; e.g., the "Convention for the Protection of Literary and Artistic Works" of 1886 and the World Intellectual Property Organization. America has the U.S. Copyright Office. Those of us involved in presenting information and referring to legally protected ...

4/27/2016

Google Interview Questions

Google Interview Questions - RF CafeQuestions asked by interviewers at Google are objects of much ballyhoo. Depending on the job being sought, questions range from relatively simple and objective to massively esoteric and subjective. Perform a search on "Google Interview Questions" and you will find a host of websites that collect experiences from recent interviewees. Some people curse Google for their insanely difficult questions, but what is fundamentally a form of profiling and discrimination is what provides Google with exactly the employees they need to be at the leading edge of all sorts of technology - networking, software, hardware, publishing, website design, social media, global politics, search optimization, etc. As you can see, many questions require the interviewee to state assumptions and conditions prior to asserting a solution. For instance, "Estimate the number of tennis balls that can fit into a plane" has no single answer because while the size of a tennis ball ...

4/1/2016

RF Cafe Now Has Google's 'Mobile-Friendly' Blessing

RF Cafe Now Has Google's 'Mobile-Friendly' Blessing - RF CafeMany format changes to RF Cafe have occurred since its inception in 1999, primarily to optimize the layout and content for presentation to my targeted audience - engineers, technicians, hobbyists, managers, and salesmen who make a living and/or pastime of electronics. This latest format change, however, comes in response to Google deciding to penalize website search ranking for any page or pages that do not pass its Mobile-Friendly Test. With 2/3 of the world's search business, they set the rules. If a page is not deemed Mobile-Friendly, it will likely be demoted to a lower spot on the search result page compared to if it was compliant. In some cases a website that would ...

February 15, 2016

Glowing Trees a Problem for Astronomers

A Dream of Trees Aglow at Night - RF CafeA controversy brews over the merits of breeding plants that glow like a lightning bug. Proponents say glowing trees could eventually replace electric street lights, thereby reducing pollution created by generating stations. Opponents say messing around with tree genes is dangerous and should be disallowed since it could lead to unanticipated environmental ramifications on both plant and animal species. The unique aspect of this effort is that it is being pursued primarily by genetic hobbyists rather than corporations - at least for now. There is bound to be a huge financial potential for such a copyrighted line of plants. My opposition to the concept is primarily a concern for light pollution projected skyward. Astronomers have a difficult enough time with ever-encroaching sources of ambient light, but a planet overrun by cross-bred and mutated glowing plants (and possibly animals), especially if they are capable of emitting levels high enough to replace street lights, would effectively blind billions of dollars of investments in telescopes... 

5/8/2013

Google's White Spaces Spectrum Database

Google's Spectrum Database - RF Cafe SmorgasbordThere are not many technical realms where Google engineers have not either entered or created. Wireless connectivity is key to their continued dominance in the information domain, so they understandably have a vested interest in the "white space" spectrum debate. White space comprises portions of the electromagnetic spectrum where bands are either unlicensed or where licensed bands are or will be up for grabs. An example of the former is the 2.4 GHz Wi-Fi band, and an example of the latter is some parts of the broadcast television band that is being vacated in areas. Google is working with the FCC to build a real-time database of what they term "dynamic spectrum" in order to provide useful information to both users and providers. A separate database is available for fixed and mobile spectrum. Enter your location of interest and the map zooms into that region. For instance, in my town of Erie, Pennsylvania, there are 21 channels available as of January...

5/17/2013

Ham Etiquette (or lack thereof)

Ham Etiquette (or lack thereof) - RF CafeOften in the letters to the editor section of ARRL's QST magazine there are lamentations about an overwhelming lack of technical knowledge and/or proper etiquette and manners amongst fellow Hams. One contributor commented, "Today, it's hard to distinguish a radio amateur from a CB operator." DX operation (long distance) seems to be the most affected aspect, although the problem is fairly widespread. Most writers blame the problem on the ease with which a license may be obtained these days. Ever since a requirement to demonstrate proficiency in Morse code was removed, ostensibly, the quality of operators has plummeted (my license was earned in the sans code test era). That may be so, but I propose the problem is much deeper - it is societal. Every generation whines...

5/21/2013

The Electrician's Trade Demystified! - A Review by Moi

The Electrician's Trade Demystified - RF CafeThe Electrician's Trade Demystified!, by David Herres, is, per the cover's claim, "Everything an aspiring electrician NEEDS to KNOW." That is a pretty bold claim for a book of 250 pages when considering how wide AND deep the field of electrical tradesmanship really is. However, because of the way in which David approaches the subject, I am convinced that within reasonable constraints of expectations, the book does an excellent job at informing an aspiring electrician with everything he needs to know. How can I corroborate the assertion, you might ask? Simple. There is no attempt to cover every chapter word by word or to impart a comprehensive knowledge of every topic to the reader. Instead, all chapters are addressed in terms of what kind of material is contained, how it is arranged, what material should be memorized by every electrician, and how the table of contents and

4/23/2015

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