What frequency is this for?
Joe WB9SBD
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 10/29/2011 1:43 PM, Bob Bruninga wrote:
Bob, You might want to consider a Helical antenna
for your mobile station. It would have less wind
drag and easier to rotate.
Actually, I'm beginning to think we will build our own dish. I have a 5' solid
metal dish. I think we will just use it as a form and lay in some copper strips
evry 4 inches or so in one dimension, then overlay say, #12 copper wire every
1" in the other direction, and then solder each crossover point.
The result will be a linear polarized 4' dish with very low aerodynamic
crossection. A little structure behind it and is it should handle 70 MPH
easily.
I think 1/4" wide copper strap is used for winding some big motors, and should
be easy to find. Using the flat strap for the supports gives a nice soldering cross
point.
We need the 4' dish to close the link when the balloon is 20 miles up. I dont
think we can get that with a helix. My guess is the dish will give us about 24
dBi vertically polarized with a beamwidth of about 10 degrees?
Bob, WB4APR
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