Topband: details about the WFAN skywave plot (Correction)

[Richard Fry]

CORRECTION:  See FCC §73.190 at the link below, not FCC §73.189 (sorry).

FCC methodology and formulae used to determine the skywave signals
of AM broadcast stations:

http://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol4/pdf/CFR-2012-title47-vol4-sec73-190.pdf