RF Cafe Software
About RF Cafe
1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.
My Hobby Website:
Try Using SEARCH
to Find What You Need.
There are 1,000s of Pages Indexed on RF Cafe !
These images have been chosen for their uniqueness. Subject matter ranges from historic events, to really cool phenomena in science and engineering, to relevant place, to ingenious contraptions, to interesting products (which now has its own dedicated Featured Product category).
Cool Pic Archive Pages
you follow news stories on science and innovation, the topic of "smart fabric" (aka smart textiles, smart clothing)
shows up fairly often. Evidently the technology is fairly slow to be integrated into commercial products because
most of what you will find during a search is either for women's novelty clothing or for military applications.
That tells me the price must still be too great for a Wal-Mart version to be produced. There are notable exceptions
like this method of printing shapes on fabric that are only visible to digital cameras because of the sensor's ability
to capture colors beyond the range of human vision - clever. I am surprised to never have seen this show up in the
news where someone used the tech to get a T-shirt with a banned message past event screeners (political, advocacy,
Not all government is a waste. To the contrary, many scientific and medical research and standards setting functions are essential to industry and national well-being. NIST, NASA, and NOAA are among my favorites. Shown here is a watt balance contraption that NIST is proposing in an effort to redefine SI (International System of Units) units based on fundamental physical properties rather than relying on mutable standards like the existing meter rod. The 130-year-old platinum-iridium cylinder maintained at the International Bureau of Weights and Measures in France has been losing mass, which really is a cause for concern since no one knows where it went. Because of national pride issues, etc., replacing the rod will require involvement from my most detested function of government - politicians.
Chip art is passé. What was once the avant-garde art form of IC designers daring enough to include images of Dilbert, Garfield, or a surfboard on the surface of the die, is now a pauper's task. If you want to be a player in the 20-teens tiny art world, you need access to 3-D nanoscribing tools. Crude polygonal outlines requiring imagination to decipher the creator's intentions are the realm of the former. Nonomachinists do realistic forms with curved surfaces, as required. Check out the Eiffel Tower, the Brandenburg Gate, and Statue of Liberty (mirror image per Kevin A.'s e-mail) as modeled by Nanoscribe GmBH. They produce compact and easy-to-operate table-top laser lithography systems, that can produce 3-D nanostructures.
much would you pay for a hard-bound volume of the first 12 issues of The Wireless World, printed in 1913? According
to the guy who listed this family heirloom on eBay, about $120k USD should cover it. Per the listing, W H Smith &
Sons printed its 778 pages for The Marconi Press. "The National Archives in the UK have searched their records and
have no copies. The British library have searched their archives and have found 2 copies in the UK within institutional
archives. WorldCat archives have no record of this book. Bonhams the Auctioneers have no record of this volume going
through auction." Only four pictures, which appear to have been made with a low-end phone, are posted. "This journal
was presented in Newfoundland to my great grandfather Alfred William Salmon... If it sells it sells , if not I'm
happy to place in my own family archive. Better hurry.
Maybe it comes from having crossed the half-century Rubicon, but with increasing frequency I find myself seeking out vintage magazines to learn how the world used to be. I am a realist who has no misconceptions about how idyllic things used to be and that today is utter debauchery, but it is apparent from a lot of the publications that we surely have changed significantly in the last 50+ years - better in some ways, worse in others. A couple weeks ago I purchased a lot of WWII era QST magazines off of eBay. As I have been doing for a while on my Airplanes and Rockets website, I am going to begin scanning and posting vintage electronics magazine advertisements and articles. A lot of the information is timeless in its application, especially since vacuum tubes are still in widespread use in the Amateur Radio <more>
Advertisements from the old magazines often help detail important parts of our history. This is particularly true for the World War II era. America's great foundation manufacturing companies participated in, and were rightly proud of the united war effort in which they and their patriotic employees engaged. We were under dire threat from Axis powers that sought to dominate the free world. Stalwarts like General Electric, Westinghouse, Ford, General Motors, Goodrich, Boeing, et al, routinely ran advertisements telling stories of their contributions to the war effort. Here is one example from the September 1945 edition of Popular Mechanics, where Bell Telephone Laboratories ran an ad titled, "The Bird with the 16-Mile Tail." A C-47 Dakota was used to lay down communications cable in otherwise isolated areas.
engineering and physics professor Dr. Stevens F. Johnson is not teaching students at
Bemidji State U. the fundamentals of universal mechanical
truths, he entertains himself by enduring the sting of a tattooist's needle. You might recall my first discovering
Dr. Johnson's science-related tattoos a couple years
ago when researching examples of such art form on the Web. His collection has grown considerably - and impressively
- since then. Says our featured human canvas, "After years of needling [get it, "needling"
- KRB] from my musician wife... I finally took up the challenge in Jan 2009 and began wasting large amounts
of time designing my own science, engineering, and mathematics tattoos." I am partial to the Hertzsprung-Russell
diagram tattoo, being an amateur astronomer myself. The one shown above is for vector calculus. A tip to Dr. Johnson's
students: For the next exam, ink some of the required equations on you arms and legs, then claim they are tattoos
(wear a tank top and shorts that day).
Prior to the invention of radar (RAdio Detection And Ranging), other means were needed to detect approaching aircraft during times of war. Human spotters were often posted in open fields, tall building rooftops, shorelines, and hills in order to provide a measure of warning against approaching enemy aircraft (acoustic defense). Effectiveness was dependent on many parameters like quality of eyesight, hearing and alertness of the observers, atmosphere transparency (visibility), light level, aircraft size, configuration, color and noise level, etc. Even under ideal conditions detected aircraft would be no more than a few minutes away from the observer, so that did not leave a lot of time to prepare a response. Observer networks were set up as far in advance of key targets as possible through a radio relay network, but it left a lot to be desired. <more>
Designing and planning über sophisticated science projects often involves more than just supercomputers and Ph.Ds with pulsating veins in their foreheads. In the case of the KATRIN spectrometer (Karlsruhe Tritium Neutrino Experiment), created to measure the mass of neutrinos, the assistance of truckers, boat captains, and law enforcement was required. Built just 250 miles from its final resting place in Karlsruhe, Germany, there was no direct land route that could accommodate its hugeness. KATRIN was put on a boat on the Danube River and floated past Vienna, Budapest and Belgrade, into the Black Sea, through the Aegean and the Mediterranean, around Spain, through the English Channel, to Rotterdam and into the Rhine, then south to the river port of Leopoldshafen, Germany. There it was offloaded onto a truck and squeaked through town to its destination. It took two months and 5,600 miles to go 250 miles as the crow flies. This picture is separate from the article and can be seen here.
wife's μP controlled embroidery machine has nothing over this winding machine that weaves superconducting niobium-titanium
wire into multiple-strand cable. The commercial grade alloy was discovered by engineers at
Westinghouse's Pittsburgh labs in 1962. That was 51 years after Dutch physicist
discovered superconductivity while measuring the electrical conductivity of solid mercury when cooled to within
a few degrees of absolute zero. To date, the cost of keeping cables cool enough to retain its superconductivity
under high currents has relegated use to particle accelerators and MRI machines. NbTi becomes superconductive at
9.2 K, which requires a lot of support equipment to maintain. What is needed is a "high temperature" superconductor
that operates above 30 K (-243 °C, -405 °F), not exactly warm by normal standards.
The holy grail of superconductivity is an alloy that operates above 77 K, which is the boiling point of nitrogen.
The breakthrough could be announced later today, or decades from now.
This might still be the world's largest model of a FET built from carbon nanotubes. Way back in 2006, San Francisco's Exploratorium opened a nerd's avant-garde exhibit called Nanoscape that featured giant scale models of carbon nanotube structures. Shown here is a 3-D field effect transistor (FET) as it might be constructed from nanotubes. Five short years later, the science of carbon nanotube fabrication has advanced at an amazing rate. There is almost a fanaticism in the research realm for making new discoveries about the nature of graphene (the "stuff" of nanotubes) or finding new applications for it. Graphene is the new silicon.
In intern at Facebook has cemented his future there. Paul Butler used geographic data and 500 million social connectivity links of Facebook members to create an amazing map (see hi-res version). After much trial and error that involved statistical manipulation and clever rendering algorithms, a picture emerged that forms continental outlines and worldwide interconnects. No superpositioning of actual land mass boundaries are used - they emerged entirely from the connection lines. Glaringly absent are most of Russia and a good portion of China. Cuba is also missing. Pardon me for noticing, but it seems that the more Communist and totalitarian an area is, the darker it appears on the map - a fitting metaphor for the darkness of human oppression. Oh, oceans and deserts are also dark on the map except for where enlightened by the crossing of communications with free people. Oops, there I go with another metaphor.