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:
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."
having been the person who first switched on the signal for a commercial TV station in 1949, and then
be the one to shut if off again 60 years later! On June 12, 2009, 99-year-old WAGA engineer
Paul Cram did just that in a ceremony marking the FCC-mandated
switchover from analog to digital broadcasting.
Paul mentions how back in the day, a B&W TV with a 7" screen cost $1,000. BTW,
does the comment made by the reporter right after the signal goes dead strike you as odd?
It will take a little more than simply downloading an app from the Internet for your iPhone to pull this off. Researchers at Freie University of Berlin developed the application seen controlling a specially equipped car. I hope there was an emergency kill switch incorporated to remove any possibility that it could run into that cool old airplane on the other side of the hangar. ...the Rest of the story.
Remember when laser power was measured in units of "Gillette power (GP)," when rare earth minerals like ruby were the known medium for lasing? 1 GP was the laser power needed to cut through a Gillette razor blade. That was in a lab environment. We've come a long way, baby. This video shows the C-130-mounted Advanced Tactical Laser targeting a 1-ft square area on a truck hood. It burns through the hood and the engine... from a moving platform. Wicked.
The IEEE has produced a few videos in a series called Thank an Engineer. This one is titled "Thank an Engineer: Notebook PC." Although some of the scenes are a little hokey, I can remember loading a CRT and CPU tower onto a cart to wheel it over to the meeting room as part of a presentation. By the time I left the corporate world to go independent in the spring of 2007, it had gotten to the point where everyone at meetings had a wirelessly connected notebook. They answered e-mail, wrote reports, ran simulations, surfed, and occasionally listened to the speaker.
In 1971, Joe Hafele and Richard Keating conducted an experiment to test the General Theory of Relativity's prediction of time dilation, aka The Twin Clock Paradox. They synchronized two atomic clocks with a standard and took one on a flight in a Boeing 747 while leaving the other behind. Einstein's equations predicted a loss of about 40 ns in the W-E direction, and a gain of about 275 ns for E-W. Measured results were within the calculated uncertainty. Here, Dr. DonZi explains away the "paradox" part of the Twin Clock Paradox.
Google's Project to the 10100 (that number is a googol, by the way), is "a call for ideas to change the world by helping as many people as possible." Google has committed $10M to implementation of winning ideas, which include the following topics: community, opportunity, energy, environment, health. education, shelter, & everything else. Call me a skeptic, but I consider all the money, equipment, and labor volunteered by people of their own free will and then fume over governments telling me it is never enough. There is a lot of money being made by legislators pandering to activists.
It is time for the Christmas video assortment. Here
is an eclectic mix of Trans-Siberian Orchestra, Bing
/ David Bowie singing a duet, and a new
where Jack Bauer (24) interrogates Santa Claus.
from RF Cafe!
Many companies are creating videos to pitch their products. This short clip from DowKey Microwave demonstrates how to use their line of switches, filters, power dividers, etc., to easily assemble switch matrices ranging from simple to quite complex. What I would like to see is videos showing production processes like how a lumped element filter is assembled and tuned, how coaxial connectors are machined, how to automate testing of amplifiers, etc. Most of those tasks do not qualify as trade secrets, so broadcasting them is not competitive a risk. It could be a great public relations tool.
Ski season is nearly here again in the northern hemisphere. It will be a few years before you are sharing the slopes with robots, but work is underway at the Jozef Stefan Institute in Slovenia. This little dude uses GPS receiver and USB camera feeds into a microprocessor to navigate the slalom course set before it. Bojan Nemec first presented this at the IEEE/RSJ International Conference on Intelligent Robots and Systems.
Beginning in humble Tibet (even though it was produced in the U.S.) and zooming out to the very edge of the known universe (13.7 billion light years), this video claims to contain an accurate 3D mapping of every cataloged object, including gas clouds. A couple years ago there was a similar animation that began at the microscopic scale and zoomed out to the cosmic level, but it was not based on a real mapping.
Here is another example of a video produced by an RF component manufacturer to pitch its products. Using engineer characters that are sort of a cross between a Weeble and a South Park deviant, Giga-tronics created a storyline about reliability and flexibility in their selection of signal generation and measurement equipment. Again I suggest videos demonstrating component production processes like assembly, measurement, and tuning.
Cal Poly claims in this video to be the only university with an anechoic chamber for testing antennas. The Electrical Engineering department developed this facility as part of their 'Learn by Doing' philosophy that gives students an opportunity to get hands-on exposure to test set-ups and making measurements, as well as an ability to check theoretical predictions against measured results. Having such experience will be a nice resume enhancement.