Fwd: Re: [amsat-bb] S-Band Antenna Comparisons, etc.

["Edward R. Cole" <al7eb@xxxxxxxxxxxxx>]

>From: K5OE@aol.com
>My comments about the sharpness of the pattern though, are quite serious:  
>half the gain of this large antenna is lost if accurate tracking is not 
>maintained within a few degrees.  I've never aimed a dish like this at a 
>satellite before and I was surprised by how sensitive the pointing is--this 
>is not like waving your Arrow Antenna at AO-27!
>73,
>Jerry, K5OE

Wait till you try tracking at 10 GHz with >35 dBi gain!!!  That is a beam
width of ~3-4 degrees!

I'm not sure that ordinary antenna rotators will be accurate or have fine
enough movement for microwave operation.  My 2m eme array has 19 dBi gain
and the Ham-III rotator is controlled with a HB speed control to slow down
movement.  Otherwise I can get only +/- 5 degree positioning!  Elevation is
easy since I am using a satellite actuator-motor.

Ed

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