Topband: 3B9C Contacts

[Robert Brown]

Friends in Radio Land,

The antipodal enhancement of 3B9C's signals in NA is not likely 
as there are "large geographic variations in ionospheric structure" 
(Davies, 1989). 

More to the point is magneto-ionic ducting in the electron density
valley above the E-region, shown earlier by the ray-tracing/absorption 
analysis of the VK6HD-VP9AD QSO on p.63 of my book, "The Big Gun's 
Guide to Low-Band Propagation (2002).  Calculations using the PropLab 
Pro program show similar results, low-loss propagation in ducts, with
NA contacts given on the low-band reflector.

73,

Bob, NM7M