I had some business meetings in England this week, and on my way back to Birmingham Airport I stopped in Stratford-Upon-Avon to see the houses where Shakespeare was born and died. Warwick Castle was also along the way, so I stopped briefly to take a few pictures before sunset. Continue reading
Category Archives: David
Abigail’s Whimsical Sand Pendulum
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!”.
Maggi “Cook Studio” in Leipzig: Delicious Home-Cooked Meals from Ready-Made Packages – A Culinary Oxymoron?
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
A Lesson in State Paranoia: The Stasi Museum in Leipzig, Germany
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
d.i.y. Combined L-Band (23 cm) Helical Feed and Ku 0.4 dB LNBF for 120 cm Dish
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.
d.i.y. Gyroscopic Camera Stabilizer that Really Works!
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
New Radiation-Detection-Related Posts at www.diyPhysics.com
I just published three scintillation-probe related posts at www.diyPhysics.com.
First is on the construction of a very simple low-pass filter to interface commercial PMT amplifiers/scintillation processors to the PRA (“Pulse Recorder and Analyser”) software MCA: Continue reading
Posted to diyPhysics.com: d.i.y. GPS-Disciplined 10 MHz Standard + UTC Clock
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
Posted to www.diyPhysics.com:d.i.y. 250 kV High Voltage DC Power Supply with Neat Trick for Switching Polarity
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!
CNC Conversion of Sherline 2000 Driven by Mach3
In my dayjob as an implantable-device engineer, I often need to prototype small parts. So, after the successful modification of my home X2 mini mill to CNC, I decided to do the same to the Sherline precision micro mill that I have at work. Continue reading