I can't speak to switchable bi-directional arrays but I can speak to my 900ft terminated beverage (450 Ohm resistor to a ground rod with 2 - 1 / 4 wave radials per band). It has 20db plus front to back ratio on 40 - 160M. The gain is sometime not much more than half an S unit to one S unit vs my bi-directional 600 ft beverage (un-terminated), but the front to back comparison is literally shocking sometimes.
Ed N1UR _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
