> Hang on, maybe I have it figured out. When the chase vehicle gets > beyond the horizon of the balloon (ie. more than 400 km away), you > need a digipeater hop to help you hear it!
=P > Our biggest issue is losing copy on the payload when it is near apogee > because our vertical antennas have a null overhead. The solution is to That's the main problem. The payload antenna also has a null off the bottom. Since I'm working with minimal ground crew (a 14-year old to work the phone and radios and a 10-year old to read out telemetry) I try to keep things as simple as possible. When we have things running smoothly enough to handle a second radio setup, I'll configure the payload for alternate frequency operation. We did learn some useful operational things today - like the fact that I can fill an 800-gram balloon from a Q size cylinder, which can be lugged short distances over rough terrain by one person. A K cylinder is *much* harder to handle if you need to move it away from the vehicle on soft ground, even with the dolly. I'd like to have some sort of radiosonde-style unreeling device to slowly extend the payload string to full length after it's a few hundred feet up. That'd make it easier to handle at launch. I'll have to do some research on how those things work. Scott
