Re: [amsat-bb] AO-40 beacon question

["Mark L. Hammond" <mlhammond@xxxxxxxxxxx>]

At 11:37 AM 3/02/03 -0600, you wrote:
>on 3/2/03 10:41 AM, Lars Mortensen at labmo@post3.tele.dk wrote:
>
> > I fully agree with Mark reg. the article written by Colin Hurst
> > (VK5HI),... it's a VERY fine piece of work, and I recommend reading it.
> > Based on that article, I once made the below ESTIMATED radiation pattern
> > for the 5 turn S2 helix on AO-40 (and I un
>
>I guess I wasn't quite clear enough with my question.  Let me rephrase it:
>
>Is there any time in the orbit that the beamwidth of the S2 antenna is
>narrower than the beamwidth required to cover the earth visible to the
>satellite at that point in the orbit?  Does that make sense?

Sort of :)


I guess there's "functional beamwidth", if you will--which to me sounds 
like squint.  Basically, how much of the antenna's lobes are pointed toward 
earth.

I think I see your question now.  This may be oversimplified, but is this 
your question?--if the bird has 0 deg squint, does it really fill the 
entire "circle of coverage" projected on a tracking program?  Or does it 
only cover "part" of it...

I guess I was answering what appeared to be the issue:  "why can't I hear 
the bird?"   I just updated ALON/ALAT with current values based on Stacey's 
recent email (and new M block too!), and it changed my squint angles by >5 
deg.  Perhaps the bird had you in the S2 null, and therefore you weren't 
getting much signal from it?

73,

Mark


Mark L. Hammond  [N8MH]


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