Hi Markus,    No idea why your specialist would say that.  It's wrong.  Your original question (diversity for b/g only on an AP650) is very straightforward.  With only 2 antenna connections that are capable of transmitting there's no diversity benefit for 11a/g rates to have anything more than 2 antennas.    Of course if you want the receive sensitivity benefits of a MIMO receiver, then 3 are better than 2.  But that has nothing what-so-ever to do with diversity.    CSH

Diversity would require two antennas.  As the AP650 is a 2x3 design you'd want to use the transmit antennas for a diversity solution.  The antenna connections have RX and TX information stamped physically on the unit next to the connector.    CSH

Chris, I got another answer form our specialist saying that with our MIMO AP´s you need to have 3 antennas in order to get diversity. Would like to know what is the truth here? -markus-