Well... "forgeddaboutit" it is :)
Looks like I gonna stick to a loaded vertical with quarter mile of radials.
On Thu, Apr 19, 2012 at 9:26 PM, David Gilbert <xdavid@cis-broadband.com>wrote:
> OK ... I see now that it is supposed to be parasitically directive.
> Your original post said that the three loops would be in the shape of a
> pyramid, which I took to mean that they would be arrayed symmetrically
> around the mast in order to put their broadsides in three bilateral
> directions. No way you will be able to put up such a structure without
> guying the mast, though, and hoisting up three loops past the guys
> sounds highly impractical to me.
>
> The various comments you've received regarding PVC and ABS still hold,
> of course.
>
> 73,
> Dave AB7E
>
>
>
> On 4/19/2012 2:18 PM, Alex Malyava wrote:
> > The design I have in mind is here -
> > http://dl2kq.de/mmana/lib/Loops/Switch/3el-slope_delta80.png
> > It is 22 (or 24?) meter high non-conductive mast. Spacing between tops of
> > the loops is about 6...7 feet.
> > Horizontal parts of the loops are 10' above the ground... It has to be
> > vertically polarized, of course...
> >
> > It looks so nice and promising so I started to think about it... If it
> does
> > not work out due to technical difficulties - I would stick to 18m high
> > SpiderBeam mast, top load it, lay down a bunch of radials and do low
> power
> > single band from some NJ/PA campground.
> >
> >
> > On Thu, Apr 19, 2012 at 5:10 PM, David Gilbert<xdavid@cis-broadband.com
> >wrote:
> >
> >>
> >> Both PVC and ABS are totally unusable for such a tall mast. Neither
> >> one is stiff enough in those lengths, and if you tried to guy them in
> >> enough places to keep them up you wouldn't have room for any wires.
> >> Picture trying to support a vertical wire by guying it and you would
> >> come close to the same thing.
> >>
> >> I have to ask, though ... what's the appeal of having three delta
> >> loops? It's not going to do any good to phase them if they are all
> >> close enough to be suspended from the same support. If you feed them
> >> with horizontal polarization they are going to perform very badly on
> >> 80m, and if you feed them with vertical polarization they won't work any
> >> better than a single omnidirectional vertical. And with a single
> >> vertical you can top load it (make a portion of the upper guys
> >> conductive to act as a top hat) and wouldn't need anything close to 80
> >> feet in height.
> >>
> >> So what's with the delta loops? If you think the delta loops are going
> >> to be lower noise I think you'd be surprised, and in any case you'd be
> >> better off transmitting on the vertical and using a small loop to
> receive.
> >>
> >> 73,
> >> Dave AB7E
> >>
> >>
> >>
> >> On 4/19/2012 12:56 PM, Alex Malyava wrote:
> >>> Hi,
> >>> I want to build an antenna for a Field Day or any other occasion, like
> >>> going far away from my noisy house and enjoying low bands.
> >>> The antenna I have in mind is 3 element delta loops for 80m band.
> >>> Yes - 80 meters delta loops. Yes - three of them in a for of a pyramid.
> >>> To hold all of that I need non-conductive mast about 80 feet high.
> >>>
> >>> What materials I better use?
> >>> My original intent was to try 3" or 4" PVC/ABS pipes aka white and
> black
> >>> plastic pipes used in plumbing.
> >>> I can glue-in some inserts to connect pipes of the same diameter and
> put
> >> a
> >>> few levels of guy ropes.
> >>> This noodle suppose to hold 750' of copper wire...
> >>> Am I crazy and that thing gonna break? Should I telescope it like
> >> starting
> >>> with 6" at the bottom and and go all the way to 2" at the very top?
> >>>
> >>> Speaking of insulated: I thought I can use aluminum telescoped tubes,
> but
> >>> how do I electrically break whole mast apart in a couple of places to
> be
> >>> almost non-conductive?
> >>> Another option is to use 4' military sections, but I am not sure how 20
> >> of
> >>> them gonna behave.
> >>>
> >>> Alex K2BB
> >>> _______________________________________________
> >>>
> >>>
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