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Showing posts from July, 2011

Geometry, Trigonometry, and Amateur Satellites

Back to Part III. I'm still playing around with building a satellite tracking application. I'm helping with a special event station to help raise awareness for the Friends of Science East's effort to restore Tesla's last lab, Wardenclyffe, in Shoreham, NY.

First, the good news, the satellite pass finder and viewer is up and running at!

Just drag the yellow thumbtack to your location and click the 'Passes' button and all the radio visible satellite passes for your location will be listed. By clicking on the map checkbox for any pass, you can display it on the globe. You can see how visible a pass will be from a city building by positioning yourself near the building and looking up for the pass. The app is still very beta, so please let me know if you see anything that could be better.

One of the big steps in getting the application to work was determining if a satellite would be visible over the horizon. To do this took…

Amateur Satellite Tracking Part III

Part I, Part II. I'm still playing around with building a satellite tracking application. I'm helping with a special event station to help raise awareness for the Friends of Science East's effort to restore Tesla's last lab, Wardenclyffe, in Shoreham, NY.

When reading through the Google Earth API documenation on linestrings, I noticed that they could be 'extruded'. This means that a plane is drawn down from the line to the ground. This seemed like an odd option at the time, but now I see the use for it. It turns out that it's difficult to tilt the view back far enough on Google Earth to see the satellite above from ground level. A wall that extends from the satellite to the ground though? Well, that's a different matter! (See the video below).

There are two next steps. One is to identify the horizon for a satellite. With this information, we can make a sort of automated siting scope to determine if a satellite is worth investigating further. Th…

Satellite Tracking: Initial Succeess

New Tracking AppN2YO site

As I mentioned yesterday, I'm playing around with building a satellite tracking application. I'm helping with a special event station to help raise awareness for the Friends of Science East's effort to restore Tesla's last lab, Wardenclyffe, in Shoreham, NY. After a few very minor issues, the first satellite is being tracked! First, the satellites in the AMSAT Keplerian data are named in a different fashion than they are on N2YO's site, (the site I'm using to verify my results). So, LO-19 in Amsats Keplerian data table:

1 20442U 90005G 11187.94329143 -.00000024 00000-0 64087-5 0 01550
2 20442 098.3466 141.1781 0012855 097.5464 262.7179 14.32152423120621

is designated as Oscar19 (LUSAT) on the N2Y0 site.

At first, I thought there just weren't actually any amateur satellites in the Amsat data, but soon realized the different naming after performing a 'Search By Satellite Name' on N2YO's site. I'll try to get …

Getting Started with Amateur Satellites and Satellite Mapping

Progress! See Part II.
I'm helping to plan an amateur radio special event on November 5th to raise awareness of the effort by The Friends of Science East to save Tesla's last lab, Wardenclyffe, in Shoreham, NY. One idea for the event is to operate from some of the buildings that Tesla occupied either as labs or as homes in Manhattan. I'm thinking an easy means of operation from there might be satellite. This brings up the interesting question of "which satellites are visible from which rooftops?" I've perused the net a bit and haven't found a program that will display amateur satellite orbits in relation to the NYC skyline, so I decided to plunk around and see if I could come up with my own. So far, I have a list of references I intend to start with and I know what technology I'm going to try to use.

Google Earth is now avaiable on web pages as a JavaScript plugin. I'll be using that as the programming framework. The docs for the portion of …

Hiam Percy Maxim's Dad in Mecanno Magazine

Prior to reading all about Hiram Percy Maxim on Dashtoons, I'd never heard of the original OM of ham radio. So, while perusing the December, 1927 issue of Meccano Magazine, I was surprised to find an article extolling the inventive brilliance of Sir Hiram Stevens Maxim, Hiram Percy's dad! In addition to highlighting Sir Maxim's childhood work ethic, the article points out that he was almost the inventor of Cordite except for one flawed sentence in his application that was filed fourteen days before the ultimately accepted application of Sir Dewar, (inventor of the Dewar flask), and Sir Abel. The article further details Maxim's invention of the machine gun, (an early model is shown below), and includes a quote from the Lord of Salisbury to the Prince of Wales:
"I have just been telling Mr. Maxim that he has prevented more men from dying of old age then any other person that ever lived!"

Help Index for Ham Radio Practice Exams at Copasetic Flows

You can now look up the available study material for the Copasetic Flows ham radio practice exams by subelement and group. The study material index can be found at:

Just click on the exam you're studying for using the tabs on the left-hand side of the screen. Then, you can select the subelement and group you're interested in using the buttons in the application window.

Subelement Progress Reports

Thanks to Dave, W4YDY, who remembered that the ham radio practice tests used to have a feature that created tests containing all the questions from a single test subelement.

For folks new to ham radio license tests, each of the three United States amateur license exam question pools, (technician, general, and extra), is organized into 10 subelements. Each of the subelements covers a particular subject area in amateur radio. For example, subelement 2 of the technician class exam covers 'Operating Procedures'.

Dave pointed out that his grandson used the subelement feature to practice the questions corresponding to a subelement as he was reviewing the same subelement in his study guide. When he took his exam he: "Only missed 3 questions and is now W4DWA."

The subelement focus feature and subelement progress charting has been added back to the U.S. ham radio practice exams at Now, in addition to tracking your practice test scor…

Subelement Study Focus Added to Practice Exams

Subelement specific practice tests have been added to the free ham radio practice exams at for the United States amateur exams. To study a specific subelement press the button, (look below the question area), that corresponds to that subelement. A new test will start specific to that subelement. The questions that appear in the exam will be only the questions for that subelement in numerical order. The exam header will have a message reminding you that you are studying for that subelement and not practicing a full exam.

As always with new features, if you see anything new or old that looks broken, please contact me at Have fun!

Dr. H.T. Barnes of Mecanno Magazine Fame

The September, 1929 issue of Mecanno Magazine briefly outlined Dr. H.T. Barnes efforts to destroy icebergs with thermite. Thermite is a mixture of aluminum powder and iron oxide, (rust), that burns at temperatures up to 5000 F, but does not normally explode. Dr. Barnes discovered that thermite embedded in ice would in fact explode. He patented the process as a method to destroy ice jams and icebergs. Decades later, the guys at Mythbusters would explore exploding thermite as urban myth, (see the video below), apprently unaware of Dr. Barnes' research. Here’s an excerpt from the Mecanno magazine article detailing Dr. Barnes' research:

"From ice jams to icebergs is a very natural step, and the inventor of the thermit method, Professor H.T. Barnes of Montreal, decided to try to blow up an iceberg by this means. For his first trial, he chose one that was nearly 100 ft. in height. Into a hole bored just above the waterline he placed 160 lb. of thermit and fired the mixtur…