Wednesday, August 27, 2008

Launch Date Moved

Due to weather moving through the area over the next few days we are going to postpone the launch until Sunday September 7, 2008.

Launch time will follow.

Friday, August 8, 2008

AGW Packet Engine setup

When we met the other night we tried to test all of the different components that we'll need to do our launch. One of the things we need to be able to do is receive the balloon's GPS transmission on a laptop to plot its location on a map. To do this we use a Radio Shack scanner to pickup the transmission and connect the scanner's audio output to the microphone input on the laptop. Next we use a program on the laptop called "AGE Packet Engine" to convert the audio input to digital APRS packets.

Now this was all working back in November when we were set to launch but for some reason it was no longer working. After about about 90 minutes of fighting this program I finally noticed a blurb in the instructions that said "If all else fails, delete the port*.ini files and the agwpe.ini file in the AGWPE directory". That did the trick!! :) The instructions for this program are at Now that this is working we can plot the balloon's location with another program called "AGW Tracker". AGWPE and AGW Tracker are both free and are available at Here are the settings that we ended up using for AGWPE:

New launch site

After months and months of watching Balloon Track send our balloon to the East out to sea we're now seeing balloon projections heading West! We've decided to move our launch site from Asheboro to Pittsboro since that is closer to home and we're no longer worried about landing in the Atlantic. We have some friends with a farm near Pittsboro which will give us a nice open area to launch the balloon and clear the trees.

It's all greek to me... using digipeaters

So we're back in the swing of things and we are struggling to figure out how to make the GPS transmit in a safe way over digipeaters so that people who cannot come along on launch day can track us. Ideally the Micro-Trak will send out the coordinates, our callsign, and enough repeater parameters to not blast the world with our traffic, but maybe cover part of NC. If that works, then people can use to track the balloon on launch day! We could not get this working on Wed night so I called up Britt, our friend and "real" ham enthusiast for help. It turns out that the APRS powerpoint we were reading is old and crusty and that the WIDE and RELAY parameters are no longer in use. Instead there is WIDE N-n. While I'm still trying to understand what it all means, the gist of it is that larger N and n #s mean you spam the whole world with your traffic (a bad thing). It looks like the recommended parameters for a balloon or "mobile" is WIDE1-1,WIDE2-1.

APRS "Fixing Digipeaters" is a good reference. We'll keep checking to make sure that this is right but if the tinytrack sw and the APRS websites agree that's probably right. Would be good to get a better understanding of it for my own sake though. (and other future ballooners).

Some examples of how to use FINDU's map-near.cgi. It displays position reports known to be near a given location, which may be specified as a lat/lon, callsign, or zipcode.