Today we practice directional finding with the beacons we made. My daughter did a great job soldering the beacon and it work perfect. We went outside with some yagi antennas to find the hidden beacons. It was really cool and we learned a lot. Tomorrow is our launch day. Things are on track for that.  

Last Wednesday I helped coordinate a launch with the University of Idaho's Upward Bound program. It was a very successful launch and recovery. We topped out at 78,500 ft, got good stills and video, good pressure and temperature data, and recovery took less than a hour. I used some new sensors for pressure and temperature and they work perfect. The sensors are MSR 145s. http://www.msr.ch/en/product/datalogger.php They are very easy to set up, have a mass of 25 gm, and have an operating range down to -20 C. Perfect for our work. 
The landing site was 1/2 mile off the road and the module was 150 ft from the last gps packet we had received. One of the easiest recoveries. We did not use the mircohunt on this flight because I have not tested it with the microtracks at a distance yet. I've run a test of them all operating together at short range. Before I fly them together though I want to see if there is any interference at a distance. 

The students really had a good time and enjoyed the whole process. They had many good experimental ideas. Marshmallows, CD, Milkyway bar, light bulbs, pedometer, and a credit card with a magnetic strip. 

I emailed Bob and asked him if it was ok to encase the transmitter in silicon to weatherize it. He said no problem so the transmitter is weatherized now and works great. I think I am going to attach it and the antennae to a parachute cord. I can sew the antennae up and down the cord with the transmitter located in the middle. This should keep the dipoles separated well and upon landing keep them off the ground. 
I'm also going to build a 555 timer in order to delay the DF transmitter power up. I want the signal to initiate upon landing in order to minimize interference with the aprs tracking signals. 

I have since ordered and received the DF transmitter. It works perfectly sending out my call sign in CW every minute. I still need to tune my antennae. I have not had any luck with the armature radio club yet. Next week I have a launch with the university. I will be facilitating a launch with the upward bound program.

After looking through lots of web sites on foxhunting transmitters I think I finally found one that will work for our purposes. It's made by Doppler DF Instruments and broadcast at 146.565 MHz. This can be picked up by my 2 m HT and both of the scanners we use for tracking. This would allow us to have 3 directional receivers and antennas in the field in order to minimize retrieval times.