Buck wrote:

The TOA will help in any QSO. A low TOA will tend to open you up to
DX QRM such as on 40 meters, but an NVIS with near vertical TOA will
manage more regional communications than DX. You might not even be
bothered by the 500kw SW station in Germany. Of course, the station
you talk to will also have to deal with that station.

Knowing the TOA is as beneficial as knowing where the nuls are on your
beam.


That's a good and perfectly valid point. Knowing the TOA would be useful
in determining what range of distances you're most likely to encounter
QRM from.

Roy Lewallen, W7EL