[TowerTalk] Mast material question

[john at kk9a.com]

I used aluminum masts at my P40A station.  I had stacked monobanders on
them. The mast was Ø2 1/2" with a heavy wall and it never had any corrosion
issues, unlike the Rohn 55g tower.

John KK9A 


Stan K5GO wrote:

Here is seat of pants.  You can put a rather large antenna on a piece of
water pipe if the antenna is mounted about 3 inches above the top of the
tower. Imagine the force it would take to permanently bend a piece  of 1.5”
schedule 40  water pipe 3 inches from where it was secured.

Nobody talks about aluminum but I have 15 feet of 2” OD, 3/8” wall 6061-T6
that was installed 50 years ago with a 2 element Mosley 40 at the bottom a 4
element Cushcraft 20 in the middle and a little Hygain DB1015 at the top.
It was changed a few years ago to something different.  It had seen some
tremendous winds but never a problem in 50 years. 

It would be interesting for someone like K6OK to tell us an example of how
many SF you could have at 3 inches, 7.5 feet and 15 feet with that aluminum
mast and survive about 90 mph over which is when those elements would
probably have been stripped off.

Stan, K5GO