David I'm inclined to agree with the other Gs . . . you could do this MUCH
more cheaply yourself (maybe a tenth of the cost) . . . and probably make a
stronger and more efficient antenna.
21ft thick-walled alloy scaffold aren't that expensive, yet are extremely
strong . . . and if you see a scaffold van parked, ask the driver how much
he could let you have a couple for (I think you'd be surprised!)
Clamp 2 together, and add another 21ft normal thickness pole on top
(obtainable from any TV aerial company).
Then increase the length with a horizontal wire section, to get it resonant.
Personally, I wouldn't even use the poles as the radiator . . . easier to
just run a thick wire from the top to a couple of feet out from the bottom .
. . if you want to increase efficiency use 6 wires in a cage.
And if you do that, you could use a fibreglass top section - old Windsurfing
masts are cheap as chips on eBay and VERY strong ! (I still Windsurf, so
have several of these)
73 Roger G3YRO
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