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Re: Dish depth question



Hi Phil.
Dish depth doesn't have anything to do with frequency, but everything to do 
with the feed you use.
What kind of feed antenna did you use?  If the dish is deeper you will want 
a less directive feed.  It is likely that your "old" feed was too 
directive, so didn't realize all the benefits of the size of the dish.
Likely the focal point (where the feed needs to be place) is different from 
where you put the feed...you don't mention recalculating the new focal 
length for this dish...did you?

At 18:53 2003-06-10, Phil wrote:
>Hello All,
>
>I got hold of another 1.8 metre dish a few days ago (it never rains but it
>pours). This dish is solid aluminium alloy and is quite a bit deeper, and
>heavier, than my other steel petal dish.
>
>I was initially quite excited about finding an aluminium dish to replace my
>rusted and slightly deformed steel dish. After a 300 km trip I was keen to
>test it and after building some support arms for the down-converter my
>excitement soon turned to disappointment.
>
>The focal point is very broad and the beacon was only just audible above the
>noise. The deeper dish is obviously not intended for satellite TV use and so
>I wonder what frequency it might have been built for? A lower frequency, I
>suspect.
>
>Another question, is the squint angle predicted by Predict accurate?  I
>thought that the squint angle was suppose to be closer to zero around about
>now.
>
>--
>Regards,
>Phil
>phil@spiderweb.com.au
>
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Scott Townley NX7U
Gilbert, AZ  DM43di
http://members.cox.net/nx7u

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