[TowerTalk] Stub mast strengthening

[GW4BLE]

Thanks guys, both off and on reflector for the replies.  What a great source of knowledgable people this is.

To answer the query, the 'thick wall' is 4.5mm, which in non-metric terms equates to 0.23 inches.  The rotator sits inside the tower, with thrust bearing approximately 2' higher, a TH11 will be immediately above the thrust bearing and spaced 9' higher  a 402-CD.


Steve
GW4BLE

Sent from my iPhone 4S

On 16 Apr 2013, at 19:44, Grant Saviers <grants2 at pacbell.net> wrote:

> Sleeving works, UST sells 20' x 2" x 1/8 wall steel masts with the lower 10' sleeved to 1/4".  With a 2.5" od (what is "thick wall" and what is the alloy and temper?) you potentially have a very strong mast.   What is the load?  Try one of the mast calculators before sleeving.  (ARRL, K7LXC)  or free by WD6P
> http://www.math.niu.edu/KARC/mast/
> 
> Grant KZ1W
> 
> 
> On 4/16/2013 8:31 AM, GW4BLE wrote:
>> I have a question concerning 'sleeving' (can't think of a better way to describe it) -  I have a 16' x 2.5" OD thick-wall aluminium tube that will be used as a stub mast, would inserting 6' x 2" OD thick-wall aluminium  tube into the bottom of the tube add to its' 'strength' in any way or would it just add unnecessary weight?
>> Sliding it in makes quite a snug fit, but not exactly 'tight'
>> 
>> Steve
>> GW4BLE
>> 
>> Sent from my iPhone 4S
>> 
>> 
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