[TowerTalk] 16om vertical and the number of radials

[Paul Christensen]

>"Do like the (LF/MF) broadcasters (or at least what they used to do) ...measure field strength at several few points when the antenna/radial system is new, then measure at the same points every year or two."

The Potomac Instruments FIM-41 is capable of directly-read field strength measurements and has a spec'd measurement range up to 5 MHz.  Would like to have one myself.

Measured field strength graphs typically show that beyond 60 radials (and arguably 30 radials), performance decelerates to diminishing returns.  The benefit of the 120-radial broadcast standard is: (1) system stability, especially when driving directional arrays and (2) mitigation of a slowly decaying and eroding radial system over time.       

Paul, W9AC