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.
On 4/19/2012 12:56 PM, Alex Malyava wrote:
> 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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