[amsat-bb] Re: 10' Dish available

Robert Bruninga bruninga at usna.edu
Mon Oct 16 20:49:41 PDT 2006

> How does one build a feed to properly illuminate a pizza
> reflector?  Or is this a matter of 1/4 of a 10' dish being
still so 
> over-kill that you only use the fat end, and under-illuminate

Well, presumably one will be using this on S-Band either for
802.11 or other 2400 MHz purpose so one has to build his own
feed anyway.  Probably a dipole over a splashplate.  That is
typically a good feed for a typical .4 F/D dish?  If that is so,
then when it is used to illuminate just 1/4th of the dish area,
then there is spillover and a few dB are lost.  Maybe a good
feed for the 1/4 quadrant dish might be a dipole over a
splashplate with a director?

Someone who is good on feeds might suggest the right answer
here...  But in any case, one is not trying to illuminate the
tastey end tip of the pizza slice, but generally the center of
the crusty end...

De WB4APR, Bob

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