rb433 + emp 8603

hi all my friends
i have rb 433 + mini pci 8603 ( have 2 konektor antena 2.4 ghz and 5 ghz )
i still Confused which one anten to set in winbox ( antena a or b antena ) if i use in 2,4 ghz



mini pci 8603 have external power supply , are must be use external power suply to get maximum power ( 28 dbm ) ?

http://www.interprojekt.com.pl/senao-emp8603-high-power-atheros-6thg-minipci-module-p-479.html

Thank
vivisiska
indonesia