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."
It has been a while since EMP (electromagnetic
pulse) has been in the news. With Iran and soon Venezuela having nuclear capability, there is a renewed emphasis on investigating
the issue. An organization named EMPACT produced
this video highlighting research on survivability of products and systems subject to an EMP. One demo
is of a car being disabled by an EMP generator frying its computer. Too bad a lot of the cars that might
survive a real EMP event have been destroyed in the government's Cash for Clunkers program.
Applied Wave Research launched their AWR.TV service earlier in the year, and just announced the addition of a broad array of content related to electromagnetics (see "Applications" channel under "Electromagnetic"). Other enhancements to AWR.TV include applications tracks for MMICs, printed circuit boards, and signal integrity, along with the option to download all material as iPod and iPhone-compatible podcasts. Even if you do not do EM modeling, the videos are a great learning tool.
If you are fortunate enough to be in the great circle path from the Gulf of Khambhat to Biratnagar to Beijing, you have the opportunity to witness the longest total solar eclipse of the 21st century. It begins tonight at 8:24 pm EDT (Wednesday morning in China). A full 6 minutes and 39 seconds of totality is predicted. The Shadow & Substance website has some really cool animations. Griffith Observatory will be showing a live webcast.
7/21/2009Trevor Baylis, inventor of the wind-up radio (Clockwork Radio, now marketed by Freeplay), is advocating for making patent theft a criminal offense rather than just statutory. His argument is that if offenders faced the threat of jail time rather than just a fine, it might serve as more of a deterrent. Patent lawyers say the long, drawn-out nature of the prosecution makes doing so unlikely. Note in the video that Mr. Baylis is using his lathe w/o proper eye protection.
This computer simulation of water flow past a ship's hull is one of nine that made Wired's "Best Science Visualization Videos of 2009." No EM simulations are included, but I can overlook that lapse of judgment after viewing the amazing capabilities of what was chosen. Dynamic supernova explosions, earthquake propagation, human body modeling, and other physical events require equation derivation and software coding skills that are utterly unimaginable by most mortal beings.
Printed flexible circuits have been around for a while, but the process has been hampered by high temperatures needed to sinter the deposited copper ink. Substrate materials like paper and low grade plastic can be impossible to use with standard techniques. This new method developed by PulseForge uses a system that pulses μs-long wideband spectral blasts that evaporate the copper ink volatile carriers and leave the conductor behind, firmly adhered to the unscathed substrate.
You find electronics in the most unexpected places. Here, Freddie "Boom-Boom" Washington
is standing in front of a blackboard in Buchannan HS's radio broadcast studio that has a basic AM transmitter
schematic drawn on it - triodes and all. It is from the Welcome Back Kotter episode titled,
"Sweatwork." A while back
I posted an episode where the Sweathogs employed
ESD principles in shock
therapy to help Juan stop smoking.
A controversially graphic PSA video has been produced in the UK that addresses the growing problem of texting while driving. Even in the modern realm of senses desensitized to acts of intense violence, this video manages to invoke a shocked reaction. My sister's daughter was killed last year in a texting while driving incident late at night, where she ran off the road in a moment of inattention - phone records cooberated the suspected cause. The car was unrecognizable. Her father delivered a eulogy at the funeral that included an admonition against using a cellphone while driving.
Gyroscopes have always fascinated me. Even after taking engineer physics classes and learning the principles, I still find it amazing that the momentum of a spinning, stationary object will resist an attitudinal perturbance. This video demonstrates the ability of a gyro to hold up a relatively heavy mass, and the resulting precession. It is the same phenomenon that causes the Earth's 26k-year cycle of the precession of the equinoxes.
8/4/2009 Results are in from the 2009 Rube Goldberg Machine Contest at Purdue University. The task: Replace an incandescent light bulb with a more energy-efficient bulb. This year's winners harkened from a liberal arts college rather than from an engineering college - how shameful! For those not familiar with Rube Goldberg, he was an engineer-turned-cartoonist who drew crazy contraptions to perform mundane chores. The rendition style is recognizable as what was used in U.S. patents up through the mid 20th century.
Guitar Hero has gained a following that its inventors never imagined. Every time I go into Best Buy there is a line of kids waiting for a chance to show everyone how good they are. Boxes of the product are stacked high on the floor. The connection speed between my fingers and my brain is measured in seconds, whereas Guitar Hero requires milliseconds, so I do not bother embarrassing myself. This video shows a robotic player that fingers the guitar by actuating solenoids after visually reading the colors off the display as they rush by. NI software drives the system.
First we had the humorous Will it Blend™ type of product abuse test, now we have guys at Popular Mechanics dropping phones phones in toilets to see how well they withstand "normal" abuse. In this instance, they test commercial cellphones designed to comply with MIL-STD-810F for ruggedness. Of course, in the real world the willingness to retrieve the phone is a trade-off which contrasts the value of the phone with the contents of the loo - yuk!