I think if you check the ARRL Antenna Handbook..you will find
something on 4 wire lines. As I recall..the impedance is around 200
ohms..(nominal) as compared with 400 to 600 ohm z of parallel
lines..so ..I guess..the impedance is lowered by a factor when using
4 lines (in a square)...Im going by memory..so dont take this as solid
facts.