try getting the antenna say 5 feet above the top rail of the fence. the
metal top pipe rail will act as a paracytic element and may give you even
better results with an NVIS antenna.
as long as you can get a good 65, or better, 130 feet out of it.
73
Colin, V A6BKX
----- Original Message -----
From: "Gerry Leary" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, November 22, 2010 6:07 AM
Subject: Re: nvis antenna
> This is new information for me. I haven't been following this thread, but
> I
> might actually try it. My fence is a Metal chain link kind, but I could
> clamp plastic pipe on the support poles and hang the antenna from that.
> Do
> you think the fence will absorb the RF, and How far above the Fence do you
> think I should keep it? Gerry
> ----- Original Message -----
> From: "Junior Lolley" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Saturday, November 20, 2010 2:21 PM
> Subject: Re: nvis antenna
>
>
>> Colin, thanks much well it looks like I will have to lower the antenna a
>> little bit.
>>
>>
>> Junior Lolley KG4ITD Liberty County E. C.
>>
>> -----Original Message-----
>> From: For blind ham radio operators
>> [mailto:[log in to unmask]]
>> On Behalf Of colin McDonald
>> Sent: Saturday, November 20, 2010 4:05 PM
>> To: [log in to unmask]
>> Subject: Re: nvis antenna
>>
>> it'll depend on which bands you wish to work NVIS on.
>> Typically, 160 and 80/75M are the usable NVIS bands.
>> You want your main radiating wire down pretty low, say between 5 and 15
>> feet
>>
>> off the ground. It has to be in a horizontal configuration. Some guys
>> will
>>
>> put another wire along the ground as a paracytic element. A dipole at
>> 30FT
>> will have some NVIS properties, but not like something that is 8 or 10
>> feet
>> off the ground.
>> One of the best antennas I ever built was an 80M NVIS wire. essentially
>> just a piece of 14 gage copper wire strung in a large U shape around a
>> fence
>>
>> line. I made the wire about 68 feet long, connected the center conducter
>> of
>>
>> a coax to one end, and the ground of the coax to a cold water pipe that
>> went
>>
>> straight into the ground near the feed point. The antenna was no more
>> than
>> 5 feet off the ground. I cut about 6 inches at a time off the far end
>> from
>> the feed point until I obtained a 1 to 1 match at 3.750. The final
>> length
>> was probably around 65 feet. The U was approximately 20 feet per side,
>> with
>>
>> the longer leg being 25 feet long...the one that came back towards the
>> feed
>> point was the long side, that is, on the opposite side of the you...so
>> the
>> end of the antenna was actually about 5 feet back past the feet point,
>> but
>> 20 feet across the yard...this was a duplex back yard so there wasn't
>> much
>> room for an antenna. I just layed the wire on the top rail of the wooden
>> fence and used large staples to keep it from blowing off.
>> That antenna would consistently perform very well out to about 1200 miles
>> in
>>
>> any direction, and more often than not could talk and hear into ontario,
>> about 2500 miles to the east. It was a great NVIS antenna and the
>> signals
>> within that 1200 miles were almost always S9 and above...that is the
>> great
>> thing about NVIS antennas. they perform extremely well for what they are
>> designed to do.
>> Now, if that antenna had been up at 30FT, I don't think it would have
>> performed as well.
>> regards
>> Colin
>>
>> ----- Original Message -----
>> From: "Junior Lolley" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Saturday, November 20, 2010 4:39 AM
>> 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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