[G4] Airport Auxiliary Antenna

[DaleH]

I'm thinking about getting an auxiliary antenna for an Airport 
Extreme base station, probably the Dr. Bott ExtendAIR Omni.

My question concerns whether adding such an antenna cuts off the 
built-in antenna operation of the Airport?

I have my Base station mounted on one side of a brick wall and would 
like to mount the antenna on the other side of the brick wall to 
improve performance in the next office area without losing what I 
have thus far.

Also, can anyone who currently uses one of these give me an idea of 
how long the power cord and antenna extension cords are?

Thanks!
DaleH