On a recent trip to Israel, Abigail (10) saw a very pretty, large, and expensive sand pendulum. In it, the pendulum was able to swing, while at the same time, the sand pan was able to rotate freely. We applied our motto “Why buy it if we can MAKE it!”.
Growing up in Ecuador, Maggi Sauce was always available at our table, and Maggi bouillon cubes were part of many of our cook’s recipes. On the odd Sunday that we didn’t have lunch out, my mom would prepare a Maggi soup (usually cream of mushroom or asparagus, being my father’s and my favorite), and there was always creamy onion dip prepared from an envelope of Maggi onion soup when we had guests. As such, Maggi soups do bring me fond memories, but I never thought someone would like them SO much as to go to a restaurant to eat freshly reconstituted soups and casseroles from a Maggi envelope… Continue reading
2 Weeks ago I visited one of our patients in Germany. The hospital was close to Leipzig, and I had a few hours to stroll through town. I went to the Museum in der Runde Ecke, which documents the power and banality of the former district headquarters of the East German State Security Service or “Stasi” in Leipzig, Germany. The exhibits are only labeled in German, but an excellent audioguide was available for 4 Euros. Continue reading
The high-gain antenna on my space communications array is based on a Fortec Star 120 cm dish. This is a high-quality, large dish designed for motorized FTA reception of analog, digital, and high-definition programs on Ku band satellites. I built a feed that combines a KU band horn for free-to-air (FTA) satellite reception with a helical feed for transmission and reception in the amateur L-band (23 cm, 1,296 MHz).
Being a peace-loving atheist, I am not interested in the religious and radicalized political junk that is most prominent over FTA. Instead, I use the Ku-band transmissions from geosynchronous FTA satellites as known-Az/El beacons to calibrate the aim of my array.
One of my current work-related projects required me to buy some gyroscopes for prototyping. I purchased some of the beautiful, motor-driven demonstration gyros made by Glenn Turner at www.gyroscope.com.
Also as part of the project, I came across the professional-grade (and professionally priced, starting at $1,600) gyroscopic camera stabilizers made by Kenyon Laboratories. These devices don’t seem to have changed much since Kenyon’s founder filed the following two patents in the 50’s: US2811042, US2570130. Continue reading
Last week I posted detailed construction information for my rubidium atomic clock frequency reference. Besides that unit, I also built a GPS-disciplined 10 MHz oscillator to serve as a secondary frequency reference, as well as a source of GPS NMEA data for my ham shack instruments that can use precise location and real-time-clock data (e.g. for satellite tracking). I just posted on www.diyPhysics.com details about this 10 MHz GPS-disciplined standard. Continue reading
I just posted on www.diyPhysics.com about my 10 MHz rubidium standard based on a surplus Efratom M-100. It is a free-standing 10 MHz +/-5×10-11 frequency standard for frequency counters, as well as a precise calibration source. I use it to keep precise track of frequency when working on Earth-Moon-Earth (EME) communications, where even tiny errors in tuning can make the difference between success and failure to receive weak echoes. Continue reading
SharkVision – A Sensing Suit for the Blind
Hannah Prutchi, 8th Grade, Science, VMS, October 2011
Blind people often use canes to avoid obstacles when walking. But, these are intrusive, can only detect obstacles where they are pointed, and could be dangerous to other people. I devised the “SharkVision Suit” to help blind people move around their environment more easily.
I developed this idea from the concept that sharks find their prey by sensing disturbances in an electrical field they form around their bodies. This suit simulates the shark’s ability to sense objects around its body, giving a blind person a new type of sense. Continue reading
I just posted at www.diyPhysics.com detailed instructions on the construction of a 250 kV DC high-voltage power supply. Although my hack for switching the polarity (referenced to ground) is simple, I am very surprised that I’ve never seen it elsewhere!