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Oh, and one other consideration-- your 802.11 most likely , (for the want
of a better word) is "Omnidirectional" which is a lousey way to illuminate a dish!! A dish is much happier when it is illuminated with a beamwidth of say 60 degrees (for the sake of arguement), any other power outside that beamwidth isn't even hitting the dish (wasted energy, further decreaseing the gain )! Translation: if even a horn ,or a small yagi, ect. would make a much more effecient feed than a point source (radiating in ALL directions) You are starting with little gain, and overlapping (wasteing power) that is 2 strikes against you for directional gain!! Jim NN7K I Sent: Actually, (gain wise), as, from memory, double the SIZE, (or conversely), Double the Frequency, you gain 6 dB! lets see: these for 18 GHz, , lose 6 dB, for 9 GHz, Another 6, to 4.5 GIG, and another 6 to 2.25 GIG ! total, 18 dB loss! Now, as to the dish, IF the round one, what was stated about getting the feed centered is true, HOWEVER, if you have the ELEPTCIAL dish, these are made to view 2 SATELITES! and, even Directv is useing them!! Reason?? Has to do with "OTHER" services, like internet connects, and LOCAL TV feeds!! In esscence, the dish is aimed between 2 sattelites, allowing it to "see both sattelites at the same time. This allows aprox 2-3 HUNDERD more (local ) channels to be direct broadcast to your home (ABCBSNBCPBS) !! These are NOT very effecient antennas at 2.4 GHz, but, if you place your 802.11 feed, where the original feedpoint was for 18 GHz, most likely will be at the most effecient point. Also, buried in the RECIEVERS for satelite Recievers, they have aiming instructions for these dishs, by zip code, and you will note the different pointing instructions for them, both round and eliptical!! Hope this helps, Jim NN7K |
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