[TowerTalk] 40m BEAM BOOM

[WA3GIN]

Hi folks,

This year we got the garden done early and I'm having time to work on the 3 ele 40m beam project.

Today I assembled a boom that is about 47ft long. The boom material is .250" wall 3" OD.  

The plan calls for a 41ft boom with the equal spaced elements spaced 21ft from the driven elelment.

The question is how far from the mast should the truss cable be iconnected to the boom; half way between the mast and element, about 10ft; from the mast to the element 21ft?

The elemlents are 2" OD irrigation tubing the first 20ft either side of the boom, then 1.250" OD swagged down to .250" (old 204BA 20 m elements with homebrew donuts to couple to the 2"OD tubing. The element will be guyed at the donut coupling point. or 20ft down the element.

I was planning to have the beam mount just above the thrust bearing with about 10ft of mast extending beyond the boom. I presume the higher up the mast the guy point is installed the better.

Thoughts are welcome and very much appreciated.  Feel free to answer direct.

73,
dave
wa3gin