On Wed, 02 Apr 2008 15:37:48 GMT, DTC <me@nothingtoseehere.zzx> wrote:

>If your airplane tilts in
>just the slightest, you'll loose the signal.

Nope. A 2dBi donut pattern isn't the same as a hemispherical pattern,
but close enough. When we were tinkering with model airplane video,
the best antenna was a 3cm coaxial antenna (1/4 wave driven element,
1/4 wave coax sleeve) made out of a piece of RG-175, dangling roughly
downward. The only times when the signal disappeared were when the
plane flew overhead and when the body blocked the signal (i.e.
inverted flying). The null was rather sharp and the image returned
quickly. It's not as bad as it would seem. Some of the other model
airplane pilots were using patch antenna, which had less drag, and
were only useful in level flight.

What was really cool was flying the plane with the camera in the
cockpit and watching through video goggles. 640x480 for each eye:
<http://www.vuzix.com/iwear/products_vr920.html>
Nice for watching 3D TV when not flying. Say goodby to about $350 for
those.

Incidentally, almost all the ground based video receivers had some
manner of directional antenna attached. Ours was overkill with a
24dBi dish (because I had one handy). Others were using everything
from cantennas to big panels. There were a few high gain omnis, but
they didn't work too well.

>All you can really do is
>try it out and see how far it works.

Yep. I kinda prefer calculations first, but a sanity check is always
a good idea.

Thought 2.4GHz was kinda crowded? Futaba 2.4GHz radio control.
<http://2.4gigahertz.com/>
The wireless video and these should interfere nicely.

Ugh. Back to working on my taxes...


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558