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ted · 08-19-2002

I am not sure how much the connector and cable losses are for the 5 dBi antenna, but I am sure they are basically dependent on the antenna design, but the cabling itself. Therefore for any other antenna (inclusive that 8dBi one) with same/similar cable and connectors the losses should be comparable. I do not know why the mag mount should add to the losses, the 5 dBi from FAB antenna has a tiny ground reference plane above the magnet.

Now about antennas. Where the gain comes from? An antenna has no amplifiers or other active elements, so there is no "real" gain, except on cost of directivity. 8 dBi antenna has a narrower beam than that 5 dBi. Both are "omnidirectional" - but the radiation pattern is a more or less flat "donate". For higher gain it is simply flatter.

Result: For access points close to the horizont plane of the antenna you get 3 dBi more for the higher gain antenna, but for an access point ABOVE the horisontal level of the antenna the gain for 8dBi antenna falls more rapidly. Therefore, with that higher gain antenna you may actually get smaller signal strength from a building you pass at close (and where the access point is elevated above street level), whereas a signal from far away (on same level than the antenna) in an open space should be a little stronger.

My bet is therefore that the 5dBi antenna is a bit more useful for wardriving in cities, and it is also more car friendly to install.

08-19-2002	#2 (permalink)
ted Stumbling on Join Date: Aug 2002 Location: Houston,TX Posts: 47	I am not sure how much the connector and cable losses are for the 5 dBi antenna, but I am sure they are basically dependent on the antenna design, but the cabling itself. Therefore for any other antenna (inclusive that 8dBi one) with same/similar cable and connectors the losses should be comparable. I do not know why the mag mount should add to the losses, the 5 dBi from FAB antenna has a tiny ground reference plane above the magnet. Now about antennas. Where the gain comes from? An antenna has no amplifiers or other active elements, so there is no "real" gain, except on cost of directivity. 8 dBi antenna has a narrower beam than that 5 dBi. Both are "omnidirectional" - but the radiation pattern is a more or less flat "donate". For higher gain it is simply flatter. Result: For access points close to the horizont plane of the antenna you get 3 dBi more for the higher gain antenna, but for an access point ABOVE the horisontal level of the antenna the gain for 8dBi antenna falls more rapidly. Therefore, with that higher gain antenna you may actually get smaller signal strength from a building you pass at close (and where the access point is elevated above street level), whereas a signal from far away (on same level than the antenna) in an open space should be a little stronger. My bet is therefore that the 5dBi antenna is a bit more useful for wardriving in cities, and it is also more car friendly to install. Last edited by ted : 08-19-2002 at 03:26 PM.