Paul Burridge wrote:
On Fri, 19 Dec 2003 16:57:48 GMT, Allan Butler
wrote:

Allan Butler wrote:

OK here is what is going on as far as I know now.

The 3.5 MHz transmitter is to study sea wave propagation at that frequency
over sal****er at a defined altitude.

Well then you're stuck with 80 meters. But I'd guess 5W output would
be plenty for your purposes. However, I'd be very interested in the
type of antenna you eventually settle on for this unusual purpose.
Nothing really springs to mind as being particularly suitable...

Zeppelin Antenna comes to mind. It was invented for this purpose.
If you can do with a wire antenna hanging off the baloon about 60m
down is another story.

Kind regards, Eike