http://www.qrp-labs.com/ultimate3/balloon.html
Farhan alerted me to this. This is clearly the coolest use so far of the Dynamic Duo (Arduino+Si5351).
It took me a moment to get my head around this. It is so fantastic. Let me break it down for you:
You take two party balloons. You build a little payload consisting of an Arduino Nano, an Si5351 board, a GPS module and a battery. You load the Nano with firmware that will take the GPS info and transmit it via WSPR and JT9. Then you release the whole thing and sit back to receive the telemetry packets that tell you where the thing is. Very cool. Very cool indeed.
THE Si5351 SERVES AS THE WHOLE TRANSMITTER. It connects to the antenna. (Steve Smith will, I'm sure, insists on a low pass filter, even here!)
Here is a similar project:
http://picospace.net/
And be sure to stop by the QRP Labs online store. Lots of good stuff there:
https://shop.qrp-labs.com/
I've been interested in balloons for a long time. A few years ago Billy, Maria and I released a party balloon over Northern Virginia with a note requesting that the finder send us an e-mail (It landed about 10 miles away, across the Potomac river, in Washington D.C.). Here is a picture of a paper-mache hot-air balloon that we built and flew near Lavallette, New Jersey (Ocean Beach Unit III) sometime around 1969. Many of the kids in the picture are my cousins:
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20