Oh wow this is a great one. Can't find the link online but some of the older, Vietnam era field manuals concerning radio-wave propagation and the NVIS effect a

Oh wow this is a great one. Can't find the link online but some of the older, Vietnam era field manuals concerning radio-wave propagation and the NVIS effect are pretty amazing. Not as usefully today in the age of SATCOM, but a great skill nonetheless.