On Fri, 28 Jul 2006 21:20:43 GMT, "Ralph Mowery"
wrote:


wrote in message
roups.com...
Sirs:

I am a programmer and electrician, but not a radio person! I am
sending an experimental balloon to over 100,000 ft. I have purchased
two 900MHz RF Aerocomm ConnexLink Radios. The radios have a power of
1000 m.a., which states it will transmit and receive up to 20 miles
line of sight. I do realize that this is probably under ideal
circumstances and will not likely be the case when I actually deploy.
I would be interested in purchasing some antennas which would somehow
increase the range. What sort of characteristics make up a good
antenna for what I want to do? It is possible that someone could find
me one that would work with my project? Also, anything you might
contribute concerning radio transmission would be very much
appreciated.
Money is no object for this experiment, so any ideas you have are very
much welcome.

Just about any antenna will work . I would look into a 1/4 wave antenna
mounted upside down so it is pointed down for the balloon. I hope you ment

So that would have its pattern null pointed down at the earth?

Not to imply that the balloon would necessarily be directly above the
observer(s), but if and when it was at the zenith, it would be
relatively hard to hear.

The OP hasn't told us the elevation angles of the locations of the
balloon in flight, how fast it is likely to spin, data rate or
equivalent (eg is this intended to send images back?), etc... they are
all relevant to commenting on suitability of the 1000mA??? radio, and
the type of antennas for the balloon and ground station(s).

Owen

For an amateur balloon project, see
http://members.optusnet.com.au/~phil...oonlaunch1.htm
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