[aprssig] Tracker3 9600 baud balloon tracker beta offer

[Robert Bruninga]

> it finally froze after sunset.  A fast-rising balloon in daylight
> would probably be fine, but I'd still recommend more than
> the 1/2 inch foam that we used for insulation.

For daytime flights, insulation is not needed at all.  I've never
understood this concentration on foam especially -white-foam when the
balloon payload is in -bright-sun the entire flight.  Just put the payload
in a clear plastic coke or water bottle.  Provides flotation as well as
solar heating.

Our first one back in 1990 something had 3 layers of concentric clear
plastic bottles and it overheated.  Have flown a few small ones since, but
still need to do a well instrumtend flight to find out if one-layer is
sufficient.  My present plan is a clear very light weight plastic water
bottle and the payload (painted black) wrapped with one layer of bubble
wrap inside the bottle.

This also satisfies the ballistic cushion requirement also.

Bob, WB4APR