[aprssig] balloon tracker

[Rochte, Robert]

>Energizer e^2 lithium AA.  Spec sheet says good to -40C

I've had bad luck with them on my last two flights...  I don't have any hard
data, but they really must drop off below about -20C.

>For this reason as well as size and weight, I need to do a DC-DC 
>converter and just drive the rig from two or three of these. 

That's my solution - a DC-DC converter, but powered by one of my LiSO2
batteries.  I wouldn't trust another flight to the consumer-grade lithium
batteries.

(I should say, I *would* use them for a daytime-only flight, but my solar
balloons are usually in the air for at least 2-3 hours after sundown...
During the day, just use the solar heating to keep your payload warm.)

-Robert, KC8UCH