[TowerTalk] Aluminum mast

[wb2dne@ix.netcom.com]

On 10/11/98 20:58:59 you wrote:
>
>
>I had an aluminum mast up for several years in a Rohn 25 "snorkle"
>type top section. Upon removal, I found that the aluminum was heavily
>scored where it rubbed against the steel. The use of an aluminum
>mast would seem to dictate the use of a thrust bearing to prevent
>eventual failure of the mast. I don't think that using a bushing in
>the snorkle would be advisable because of the reduction in the mast
>diameter that could be accomodated.
>
>73, Roger
>
>
Yes!, I've noticed the same here.  I use a 24 foot, 2"OD, 0.25" wall 6061 T6 aluminum 
mast for my VHF-UHF stack without a bearing or bushing at the top of the tower and a 
concerning amount of the aluminum is missing where the mast rubs on the top plate.  Of 
course a bearing/bushing would probably help prevent this problem but with the recent 
thread on aluminum vs. steel I gotta wonder if it would have occured with a steel mast.
73, 
Ed K3DNE



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