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Size of dish /vs/ Ed K9EK

Please give more info on your posting regarding the size of the dish /vs/
the operating freq.  I always viewed a parabolic as a reflecting surface
funnel which, using the old angle of incisidance = angle of refraction,
provided gain because of it's ability to direct more incoming wave fronts at
the focal point, which does not change with frequency. Thus, a 6 foot dish
had much more gain than a 60 cm does. Gain for a given size dish was reduced
as the frequency decreased, however the size merely provided the size of the
funnel. The dish is not a resonate element in the antenna, merely a
mechanical reflector of varying size. Thus, a 60 cm dish which works well at
2Ghz will also work well (but with less gain) at 1Ghz.
Where am I off base?
Thanks for your help on this.
Gunther Meisse

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