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Sender:
For blind ham radio operators <[log in to unmask]>
Date:
Sat, 20 Nov 2010 12:12:18 -0500
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[log in to unmask]
Message-ID:
<FD3E322590D748B989DA95E4B7296219@lras05>
Subject:
Re: nvis antenna
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From:
Lloyd Rasmussen <[log in to unmask]>
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I would probably try to get the ends up 30 feet also.  This would minimize
the vertical polarization component, but probably also reduce the
ground-wave propagation a little.  Depends also on whether this runs close
to your house, trees or other structures.  In any case, I wouldn't expect a
dramatic change, although I think that raising the ends would help you get
out a little better.

Lloyd Rasmussen, Kensington, Maryland
Home:  http://lras.home.sprynet.com
Work:  http://www.loc.gov/nls
 
> -----Original Message-----
> From: Junior Lolley [mailto:[log in to unmask]]
> Sent: Saturday, November 20, 2010 11:53 AM
> To: [log in to unmask]
> Subject: RE: nvis antenna
> 
> Lloyd, what height would you recommend on the ends?
> As I said the ends are about 10 feet off the ground.
> I can raise them up with not to much trouble.
> Thanks much.
> 
> 
> Junior Lolley KG4ITD Liberty County E. C.
> 
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]]
> On Behalf Of Lloyd Rasmussen
> Sent: Saturday, November 20, 2010 10:48 AM
> To: [log in to unmask]
> Subject: Re: nvis antenna
> 
> In my understanding of things, NVIS (Near Vertical Incidence Skywave) just
> means the use of low horizontal antennas on the low bands.  That's what
> most
> hams in most locations have always had on 75 meters.  Your antenna is
> probably in that classification already without any further change.  It
> might be a little more efficient, even at the high radiation angles you
> seek, if you could raise the ends, but you're probably almost there
> already.
> I heard you check into the Florida net on 3950 one night, and your signal
> was kinda weak up here compared to others on the net.
> 
> Lloyd Rasmussen, Kensington, Maryland
> Home:  http://lras.home.sprynet.com
> Work:  http://www.loc.gov/nls
> 
> > -----Original Message-----
> > From: For blind ham radio operators [mailto:BLIND-
> [log in to unmask]]
> > On Behalf Of Junior Lolley
> > Sent: Saturday, November 20, 2010 6:39 AM
> > To: [log in to unmask]
> > Subject: nvis antenna
> >
> > I have a 132 foot dipole I want to use for NVIS.
> > I have sandy soil here in Florida.
> > What is the best height off the ground to have each end?
> > It is 30 foot center on the tower.
> > I now have each end about 10 foot off the ground.
> > I am trying to mess around with NVIS a little bit.
> > if anyone can give me a little info it would help.
> > Thanks very much.
> >
> >
> >
> > Junior Lolley KG4ITD Liberty County E. C.

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