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Old September 6th 04, 09:26 AM
Ian White, G3SEK
 
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Roy Lewallen wrote:
Dale Parfitt wrote:
I wasn't talking about skip either- the majority of V/U weak signal
work is
extended ground wave via perhaps enhanced tropo.


Ground wave? Really? I admit I'm not a propagation expert, so I'd
appreciate an explanation from someone who is. Is there really enough
ground wave propagation at VHF/UHF to be useful for any purpose, even
short range communication?

No, it isn't ground wave at all. It's just a loose way of saying "normal
short-range VHF/UHF propagation" which is a complex combination of
line-of-sight, diffraction and scattering.

At medium ranges - which can be several hundred miles between
well-equipped stations - atmospheric refraction and scattering are the
main mechanisms. When weather systems lead to an "opening", signal
strengths and workable ranges are enhanced by much stronger refraction
and ducting.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek