Tim,
W9LT experimented with this (parasitic) design back in the 70's.
Whether or not he was working from his own idea, I don't know. I believe it
was published as I still remember the pictures with his home in the
background, but I can't recall which pub.
I played with one of these arrays at my QTH on 40 meters in the early 80's.
I finally ended up with a horizontal dipole at 60 ft, roughly the same
height as the top of the Lazy-V.
If you want this configuration to perform, you need to phase the elements in
a 4 sq configuration.
K9UWA is using a phased version on 80 meters and it consistently outperforms
much a higher dipole.
A search on the ARRL web site shows K7LR wrote something in 1966, but alas,
I don't have those resources.
Keywords: ANTENNA WIRE HF CONSTRUCTION HOMEBREW Leo, Bob, W7LR
Dec 1966 QST 34 V.H.F. Lazy-H Antenna, A
(Gimmicks and Gadgets) DeMaw, Doug, W1CER
Tim, can you share what design you finally settled on?
James Wolf, KR9U
> Hello Ron:
>
> You might want to take a look a my QST article about the Lazy
> "V" array that I used and was published in the early 90's. I
> installed the K8UR array and the full sloper K1THQ array
> prior to settling on the design that I worked on with WA3FET
> and K3LC (QST article). Both UR and THQ arrays had
> disappointing results at my QTH.
>
> Good Luck and 73!
> Tim K3LR
>
> Ron Feutz wrote:
>
> > Topbanders,
> >
> > I have long wanted to put a K8UR array (1/2 wave dipole
> 4-square with
> > center fed elements pulled back in at the bottom) or a
> similar array
> > using straight dipole slopers, on a 240' SSV commercial 2-way tower
> > that I own. The tower scales up nearly exactly from the 80 meter
> > array in ON4UN's book. I have a Comtek 4-sq controller
> that I intend
> > to use.
> >
> > ON4UN does not show baluns at the feed points; the Comtek
> manual does.
> > Are baluns necessary? I would prefer to not use them to
> lighten the
> > wind and weight load on the antenna/tower.
> >
> > The pattern shown in John's book for the K8UR array has a
> very broad
> > front lobe and a poor front-to-back, making the array a
> > less-than-ideal RX antenna. Is there anyone using one who
> could give
> > me advice on this? I lease only a small plot where the tower sits,
> > and don't know if I could get permission to put RX antennas nearby.
> >
> > The pattern for the array with straight sloping dipoles shows a
> > sharper front lobe and a much better F/B, but it has lots of high
> > angle radiation. It seems to be a trade off, but my gut
> tells me the
> > straight dipole sloper array would be a better RX antenna.
> >
> > Is there anyone out there who could model this for me? It would be
> > nice to know the right length for the dipoles at the start, as
> > cut-and-try would be a very cumbersome tuning method.
> >
> > 73,
> >
> > Ron - WA9IRV
> >
> > _______________________________________________
> > Topband mailing list
> > Topband@contesting.com
> > http://lists.contesting.com/mailman/listinfo/topband
>
> _______________________________________________
> Topband mailing list
> Topband@contesting.com
> http://lists.contesting.com/mailman/listinfo/> topband
>
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|