Have you considered using a 'ceiling mount' 11b/g antenna upside down? that should have the radiation pattern you need. It may also help to put it on a 'ground plane' - i.e. mount it in the center of a metal sheet. Though for the range you're looking for, it shouldn't be necessary (unless there's a lot of steel furniture in the office space?).
As David said, there's usually only one transceiver (ignoring MIMO hardware) and the two antennas are never 'lit' at the same time. I'm guessing that you'd be better off with one good antenna than your current arrangement. Paul (not an RF guy, but know a few :) Ralph Becker-Szendy wrote: > I know this is not a Soekris-specific question, but I couldn't find a > good answer on the net, because very few people build their own 802.11 > access points - with Soekris owners being a notable exception. > > I'm using my Soekris 5501 as an 802.11b/g access point, using a MSI > MP54G2 card (Ralink RT2561 chip set). It has dual antenna connections > for diversity. It is installed in a basement directly underneath the > office space (all wood/drywall construction), which is 2 stories high > above the basement, and about 25 feet radius. For lack of knowledge, > I use two different rubber ducky antennas on it, a 7 dB gain > single-element antenna pointed straight up (to make a wider > doughnut-shaped field to go 25 feet out), and a smaller 2 db antenna > at right angles to it to fill the hole in the doughnut (for users who > are directly above the bigger antenna). The antennas are only a few > inches apart, and mounted directly on the 5501 box (I used a blank PCI > slot cover with holes drilled in it to get all the extra wires out). > > I have been experiencing lots of receive errors on it, and reception > seems very position sensitive, so started playing with the antennas. > And at some point it occured to me that I have NO idea what it means > to have two diversity antennas. Are they electrically separate, and > the AP has two separate transmitters/receivers? How does it select > which packet goes where? Or if they are just connected to each other > electrically, wouldn't having two antennas in close proxomity cause > terrible interference effects? > > As a more general question: For an AP to serve a 25' diameter by 15' > high area is very easy, even with a simply antenna. Maybe I should > just use a single antenna, and simplify the system. In that case, > should the second connection left disconnected, or should I install a > resistive terminator on it? > > Pointers at some knowledge on antenna setup for 802.11 access points > would be appreciated. > > -- > Ralph Becker-Szendy [EMAIL PROTECTED] (408)395-1435 > 735 Sunset Ridge Road; Los Gatos, CA 95033 > _______________________________________________ > Soekris-tech mailing list > [email protected] > http://lists.soekris.com/mailman/listinfo/soekris-tech > _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
