On4un writes that many stations find elevated radials to be a few db below
ground radials. I believe this is ground dependent.
At my new QTH, initially I set up inv U about 80 ft high with 4 125 ft
elevated tuned radials about 10 feet high. Perfect SWR curve without any
matching but the signal was not great
Later I loaded 100ft tower with 32 radials while still having the first
antenna. I expected about 2 db difference but it was 8 db. As determined by
RBN. Similar SWR curve.
The FCP paper suggests that short elevated radials are better than the long
one. At my other QTH i used 7 tuned 70 ft radials, and it worked fine.
I suggest that you experiment with shorter and longer radials and use RBN
for comparisons to see what works at your QTH. Shorter radials need a
transformer as baluns overheat.
Ignacy NO9E
On Mon, Jan 10, 2022, 02:31 Grant Saviers <grants2@pacbell.net> wrote:
> Agree with N6RK.
>
> My T has 8x 125 elevated radials (b4 N6LF work) but is in trees, with
> the significant losses and is hard to maintain, climbers are unobtanium
> currently.
>
> I am working on a self supporting 160 vertical for a clearing, top hat
> loaded a with mid loading coil. With 3 elevated 125ft radials it is
> within a fraction of db of more. Also, the land constraints has them at
> 290, 30, and 110 degrees which skews the pattern 1db towards EU, which
> is a plus from WWA.
>
> Grant KZ1W
>
> On 1/9/2022 08:22, Richard (Rick) Karlquist wrote:
> >
> > On 1/9/2022 4:51 AM, CUTTER DAVID via Topband wrote:
> >> Hi Rob
> >>
> >> I see copper prices have doubled in the last year.
> >>
> >> My intention is to compare and contrast the cost and performance of
> >> short verticals over a large field of ground radials v the very modest
> >> amount of wire required for the FCP. In Guy's article
> >>
> >
> > This is a false dichotomy between FCP and a broadcast station ground
> > screen. The best use of wire is to have a small number of elevated
> > tuned radials with proper RF choking. As shown by N6LF, you can do well
> > with just 8 radials, about 100 feet long each. On 160 meters, they
> > should be 20 feet high for optimum performance. BTW, cheap aluminum
> > electric fence wire works perfectly for elevated radials Also consider
> > N6BT's single spiral radial configuration as an alternative to FCP.
> >
> > Rick N6RK
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
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