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Over the summer, member Divinity Rose coached a team of Junior Achievers as they worked to develop their technology based product and startup "Sensor Buddies."  The team was being paid as part of the Mayor's Summer Works program that employed 4200 youth over the summer. The team of three 17-year-old students from Central High School learned to solder and use many of our resources, including the wood shop, vinyl cutter, and laser cutter.

Their experiences at Lvl 1 facilitated growth, confidence building, and creative problem solving; it was so inspiring to see each of their individual strengths blossom. You can see their summary of the summer in the video below.

We look forward to seeing what they accomplish this year as senior in the business magnet program at Central High School with their teacher Dana Kelly. Thank you Mayor Fischer for facilitating such a great program.



As promised, here are some pics and a small video of my light show.

The controller for the lightshow is from  It is a 16 channel controller, but I blew out a couple of channels so they stay lit all the time.  Here is a pic.


The light controller is in the center and it feeds all the light plugs.  The sockets are just screwed onto a 2X8 board and is set into a rubbermaid tub.  This worked pretty well in the rain.  I cut slits in the side of the tub to run the wires.  No water got into the tub whatsoever.

I also built a FM transmitter to play the song to car radios.  I made a sign.


The transmitter I used was a ramsey FM 10C

It is a nice kit.  I would recommend it for this application.


 The software I used is Vixen.

Now I need to get more songs to play.

Another day, another repost from another project I'm working on. This time, from White Star Balloons, the world's lightest quad helix antenna.

After the scrub on the launch pad for flight attempt A, we went back to the books, to try and figure out what we could do to improve our odds the next time around. One of our biggest setbacks was the inability make an antenna suitable for our use: We needed an antenna tuned for 149 MHz, not needing a ground plane, weighing as little as possible.

After 4 tries, and some expensive test equipment, the end result was a Quadrifilar Helix antenna weighing only 80 grams!

Our ground test antenna was a 5/8ths wave whip antenna, which works well, but unfortunately needs a ground plane. Tests with both a quarter-wave dipole and a J-pole antenna were lackluster. Documentation from our satellite service provider implied that a quadrifilar helix antenna would provide the best coverage at all. While these antennas are pretty, their design and construction was voodoo magic at first.

Thanks to some design documentation here: and some help from the balloon community, we had some baselines for creating such an antenna. We still went through *quite* a few revisions.  We went through 3 revisions that didn't work, and one which works pretty darn well!

Here are the antennas which didn't work:

...continue reading "How to Build the World’s Lightest Quadrifilar Helix Antenna"


Just in time for the holidays! Build a small & simple, but very powerful USB charger for your iPod, iPhone, mp3 player, camera, cell phone, and just about any other gadget you can plug into a USB port to charge! Perfect holiday gift! Only $35 - cheap!

Sign up for the class here: