[Boatanchors] TOWER ERECTION

[Marvin Match]

RAY FRIESS wrote:

"A while ago I was looking through some old QST, 73, and CQ mags. I was looking for tower tips and came across an article by a ham who stood his 30 footer on the ground against his house. He simply sat the tower on a thick sturdy wooden plank on the ground and then bracketed and guyed it to the house.  He had a tribander on it."

Be very careful about this one! A fellow in California (it was either Gordon West or one of his neighbors) installed an Aluma crank-up this way. When It came down, it ripped the eaves off of his house and took them with it.

I have a small Aluma tower that I'm installing this same way, however I just rebuilt my roof and I installed STEEL supports bolted through the rafters and going back into the roof about 2 1/2 feet, with steel spreaders between them just behind the facia. Then there is a 3" x 5" aluminum angle 4 feet long bolted onto the facia with 4 stainless bolts that go through the facia into nuts that I welded to the inside face of the the steel support bracing.

This is a very lightweight tower, only 6" on a side, but the vertical tubes are 1 1/2 inches, cross braces are 1 1/4, but I cannot find any information about it other than a label that says "ALUMA". Couldn't possibly be climbed. It will fold over at the roofline.

I have enough sections to go up as high as 48 feet, but might stop short of that and it will be guyed. All that will be on it is a rotor and a Hexbeam. About 3-4 square feet of windload. We seldom get much wind here. Occasionally 30 MPH, once every 5-10 years we see gusts to 45-50. The Hexbeam is symetrical.

So, is this dangerous? Probably. But I'm very confident about the bracing in the roof, and the roof was designed to accommodate the tower.

All this after I just posted that folks follow the manufacturers recommendations!

BTW, I have the ARRL book on towers . . . I didn't find much value in it.

I welcome any comments.

Marvin
KA7TPH