[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Eggbeaters ?



Dave:

If you look at the amount of time a LEO satellite will spend in the half 
power beam width of an antenna with take off angle 15 degrees,  you 
realize you are hitting a very large proportion of the passes.  When the 
satellites go overhead,  they whiz by and on top of that,  you get a 
1/s^2  (where s is the slant range to the satellite) help when it goes 
over head.  We could do some mean and variance calculations but 
hopefully you get the idea.

Bob
N4HY


Dave Hartzell wrote:

> Thanks all for the input....
>
> Just one question, why is 15-degrees (or so) the magic number here  
> for Yagis?   I have an Arrow, and if I mount that at 15 degrees, what  
> happens when the spacecraft is overhead?  Maybe the beam-width of the  
> Arrow is wide enough...
>
> Dave
>
> On Dec 3, 2005, at 6:07 PM, Edward R. Cole wrote:
>
>>
>> Instead I would go with a small yagi or the corner reflector  pointed 
>> up at
>> 15-degrees (or so) and rotatable in azimuth.  If using linear  
>> polarity it
>> probably matters little if you chose Vertical or Horizontal so pick  
>> what is
>> easy to construct.
>
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>


-- 
Laziness is the number one inspiration for ingenuity.  Guilty as charged!
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home