[BC] Conductivity vs Skywave

[PeterH5322@aol.com]

>A good, sectionalized MW radiator (e.g., a Franklin type) can have a bit 
>over 2 dB more gain in the horizontal plane than a conventional 180inf 
>series- 
>or shunt-fed radiator with the same ground system and tx site.  That 
>additional gain will improve field strength, dB for dB, at all locations 
>served by the ground wave -- no matter what the conductivities and terrain 
>profiles may be.

Minimum conforming for Class A - 362.10 mV/m/kW at 1 km, achievable with 
about 170-175 degrees.

195 degrees, the average over all U.S. ND-U Class As, gives about 400 
mV/m/kW at 1 km.

A Franklin gives about 510 mV/m/kW at 1 km.

As the horizontal field increases with height, the vertical field 
decreases. Then the vertical field begins to increase again at 180 
degrees.

The law of diminishing returns rears its ugly head at over 205 degrees.

Hence, 195 or 200 degrees is ideal for a Class A.

There is one ND-U Class A with a 207 degree non-sectional, and one DA-2 
Class A with a 225 degree non-sectional.