[FARC] NVIS Info Links

[Bob Moroney]

(This is a re-send of the reflector email that went out after the March 
meeting, in case you missed it.)

All,

Here are three links pertaining to the NVIS-related stuff that we 
discussed at the FARC meeting last night.

The first link is to a page that provides a very good tutorial on NVIS 
(Near Vertical Incidence Scatter) propagation phenomena and techniques, 
as well as still more NVIS links to investigate.

http://www.athensarc.org/nvis.asp

The next link is to an Acrobat document showing how to build an NVIS 
antenna based on the military standard version, the AS-2259.  It also 
includes info on winding the coils that improve the antenna's electrical 
performance.  We'll be making some of these coils (for 80M at least) at 
the April FARC meeting.

http://www.k3cal.org/nvis_antenna.pdf

The last link is to a site that tracks, on an hourly basis, the 
worldwide ionospheric conditions that support (or limit) NVIS 
propagation.  The chart on this site graphically shows why 40M is of 
little NVIS use at this time, at least at our latitude.

http://hflink.com/propagation/

73, Bob K9CMR