The paper investigates the magnetic flux density levels under and around a single tower
transmission line. The single tower is a tower carrying transmission circuits with negligible mutual
effect from any other circuits. Three cases for a single tower carrying a single circuit are
considered. The first is a conventional delta which exhibits the highest level patterns. The second is
a compact inverted delta which exhibits the optimal level patterns. The third is a compact delta
which falls in between. A single tower carrying a conventional double 3- phase circuit is compared
with a 6-phase converted circuit having the same configuration. These two cases are compared with
a compact design 6-phase single tower transmission line. The 6-phase compact circuit exhibits the
optimal performance. The conventional converted 6-phase circuit exhibits the highest density level
patterns. The conventional double three phase circuit falls in between.