Normal
this is correct, and the reason why diversity technology does exist. I don't want to discuss about Lamda 1/4 or 1/2 or 1 this depends on the antena type and so. BUT we discuss the minimum space at that point. If you place the antennas far away then one has allways a higher level and you do not have a diversity setup anymore, if then the drop out because of reflection summing occours ...you have a drop out. Place the antennas near to each other about 20-40cm and tilt one about 45 degrees is a perfect starting rule!