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 ...
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This collection of video and a few audio files represents files that have been featured on the RF Cafe homepage. Every week or so a new file is added that should be of interest to RF Cafe visitors.
Please send me an e-mail if you have a good subject. Note: "Videos for Engineers" formerly went by the name "Cool Videos."
The American Radio Relay
League (ARRL) runs an annual home video contest through their QST magazine. Members vote on the submissions
and then QST staff announce first, second, and third place winners in the amateur production category.
There is also a single winner for a professional production.
2012 QST Video Contest. For some reason,
the FLV video file format used by the QST page does not always load properly in Internet Explorer, so
you might need to use Firefox or Chrome. The FLV player is a lousy choice because it does not even allow
you to back up or advance the video; it will only play from beginning to end - surprisingly low-tech
for the ARRL guys. First place in the Amateur category went to Erin King, AK4JG, for her work in the
successful launching of a helium balloon that lifted a wireless video camera to an altitude of 91,000
feet. It used an amateur radio transmitter to report GPS position data that allowed the launch team
consisting of members of the Columbus Georgia Amateur Radio Club to retrieve the payload after it parachuted
down into a pine tree miles from the launch point. The Automatic Packet Reporting System (APRS) was
employed for tracking. A search on balloon-borne video flights turns up a lot of results from all over
When I saw the headline this weekend about students dropping a piano from a dormitory roof, I figured it was yet another installment of the annual Piano Drop orchestrated by the Massachusetts Institute of Technology (MIT) engineering class; it was. The Piano Drop is held on the same day as the last day that a class can be dropped. In 1972, notorious trickster Charlie Bruno decided it would be a good idea to take a piano to the roof of the Baker House dorm ("Year after year, Baker is the top choice in the housing lottery") and, with great fanfare by assembled students below, send it to its undignified musical death. According to witnesses, though, rather than go out with a cacophony of nonharmonic percussional tones and semitones, the ceremony ended with a single, short-lived loud thud. Still, for guys, just watching something fall from great heights and crash to the ground is worth the trouble. Don't doubt me. This year's event marks two important benchmarks, one of which helped boost the story to the national level. 2012 is the 40th anniversary of the piano drop tradition, and, the reason for increased coverage, it is the first time that dropped classes can be expunged from a student's records. As a side note, in honor of Charlie's efforts, a new unit of measure was named after him: the Bruno. One Bruno is "A unit of volume equal to the size...
When a worker assembling cellphones in a plant in China hurls him/herself out of a window, it makes headlines. Like the human cost of extracting the minerals that go into making cellphone components, people yawn and write it off as the cost of progress. Among the many other dimensions of that cost is one that, until recently, received little attention - cell tower worker falls. According to a joint investigation by Frontline and ProPublica that was aired in May 2012, there is a well-established record of ill-equipped and ill-trained climbers who fall victim to low budget operations... and, to be honest, their own stupidity.
Cell tower climbers experience 10x more on-the-job deaths as the average construction worker. That might seem logical and even expected given that you normally think of a construction worker as the guy banging nails in that new housing development down the road. However, many construction projects are multi-story commercial and industrial buildings with heavy equipment and mammoth components being installed in often precarious situations. We have seen the vertigo-inducing photos of guys nonchalantly walking across steel beams suspended hundreds or even thousands of feet in the air. The difference with the cell tower crews is apparently lack of supervision, accountability, and most importantly, lack of self discipline...
I ran across this full-length video of the documentary titled, "Nikola Tesla - Master of Lightning," which was aired by PBS in 2000. It is the most extensive visual resource of information on Tesla that I have seen. Most people, if they have ever even heard of Nikola Tesla, associate him with gigantic high voltage generators making his hair stand on end, but his contributions to the world of electricity go far beyond that. Aside from the lightning machines, he also developed almost single-handedly the basic concept of alternating current (AC) power generation, distribution, and motors. The battle, both personally and corporately, with Thomas Edison and his proposed direct current (DC) system is epic and tragic. Documentaries like this one tend to flourish the tale a bit with exaggerations that build sympathy for the featured good guy du jour, so keep that in mind when viewing. A similar documentary on Edison likely conflicts a bit when relating who tried to hose whom in the AC-DC battle. One of the most interesting aspects of the long-running contest - "The War of the Currents" - Tesla had with Edison was how down and dirty the fight got. If you think mud slinging in business and politics is something new, wait until you see how public demonstrations were conducted to "prove" how dangerous one form of voltage was compared to the other. Actual footage is presented where Edison's camp electrocuted an elephant...
This is a hilarious spoof that
Saturday Night Live came up with
for addressing the well-known issues with the new iPhone 5. Christina Applegate plays the host
to a panel of tech industry gurus and a "trap" panel of Chinese iPhone 5 factory workers. "Tech
Talk" faux representatives from real-life entities CNET, Wired Magazine, and Gizmodo gripe about the
funky maps, "purple haze" from the camera, and how easily scratched the case is (these are the top 3
complaints by users). After smarmily registering their complaints, the hostess then presents employees
from the iPhone 5 factory (Foxconn is never mentioned by name) who proceed to sarcastically address
each topic with responses demonstrating how petty the whining is compared to their life's woes in China
under Communist rule. I won't give any more away; you'll have to watch it to get the full effect of
Australian photographer Chris Tangey caught this rarely seen "fire devil" on video. Just as a water spout is formed when a tornado touches down on a body of water and sucks water up into itself and a dust devil sucks up dust from the desert surface, this tornado landed on a brush fire and sucked the flame up into a 100-foot high towering inferno. Hence the name fire devil. I wonder why water spouts aren't called water devils?
Only recently has the importance of the role played by of the town of Chatham (pronounced "kat'-um"), Massachusetts, in the success of World War II been recognized to the degree it deserves. Thanks to the effort of Chatham Marconi Maritime Center's Ed Fouhy, the extent of strategic radio operations performed there is made available both online and, to a much greater degree, to visitors at the physical location. The entire campus was totally renovated in the 2009-2010 timeframe Foughy and his team produced a video that crams the story of years of intense activities and accomplishments into a seven-minute video. About a third of it can be viewed below, but if you want to see its entirety, you will need to visit the Center.
A separate video, also shown here, is an interview with Mr. Foughy by the Cape Cod Chronicle where he talks about the research and some of the surprising discoveries that went along with his project. The U.S. Navy used the site primarily to intercept and monitor German U-boat activities in the Atlantic Ocean. In the early days of WWII, U-boats wreaked havoc on both military and merchant ships crossing the northern Atlantic. They operated with near impunity because of the genius of German commanders and submarine crews. They maneuvered stealthily underwater and surfaced during the night in order to exchange mission intelligence and to receive...
5/21/2012As you might expect, the BlendTec blender guy couldn't resist an opportunity to see how Apple's new iPhone 5 would fare when put up against his company's Total Blender. But wait, this time the "Will It Blend" contest isn't limited to just the Total Blender and a single challenger. Adding to the excitement is a third contender - the Samsung Galaxy S3. The question before Tom the blender guy is which phone will succumb to the ravages of the blender's mighty cutters the soonest? I was not surprised at the outcome when considering, present company excluded of course, the typical Apple product user versus the rest of us. Let's just say Siri lost her soothing voice early in the game. I hope that last comment didn't spoil the suspense.
"Today we made science fiction science fact." "We hit every target we wanted to. We prosecuted every one." So says a very happy Keith Coleman, Boeing's program manager for the CHAMP project. Counter-electronics High-powered Microwave Advanced Missile Project is the culmination of decades of work to develop a non-lethal weapon that defeats targets without collateral damage, sort of like a neutron bomb for electronics. From the Boeing website, "On Oct. 16th at 10:32 a.m. MST a Boeing Phantom Works team along with members from the U.S. Air Force Research Laboratory (AFRL) Directed Energy Directorate team, and Raytheon Ktech, suppliers of the High Power Microwave source, huddled in a conference room at Hill Air Force Base and watched the history making test...
New video documentaries about Nikola Tesla pop up on the Internet fairly often. I, for one, welcome the flood of information being made available on all the pioneers of electrical and electronic inventions. For that matter, the media on pioneers of all forms of invention in the physical word are a welcome resource be it on mechanics, chemistry, energy production, space exploration, physics, transportation, or related topics. A lot of the material has been in archives waiting to be digitized. Prior to that, these films were shown in classrooms, museums, seminars, etc., where only a few people were able to see them. Some bumbling, fat-fingered projector operator would eventually tear or burn them, relegating the reels to the trash bins of history, thereby removing the opportunity for others to witness the contents.
If you take the time to watch the videos, some interesting information can be learned that has not been generally known. For instance, were you aware that Mr. Tesla's intelligence was obvious because he had very long thumbs? Apes, it was argued, being distant evolutionary relatives, were not as intelligent as humans and had short thumbs. Ergo, the longer the thumbs, the more intelligence a person possessed. I kid you not.
A narrator who looks like a dieting Santa Claus takes us through a series of experiments and demonstrations thought up by Tesla during his discoveries, and then takes us through equally ingenuous ways...