[TowerTalk] Mast material question

[Stan Stockton]

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

Sent from my iPhone

> On May 28, 2024, at 3:07 PM, john simmons <jasimmons at pinewooddata.com> wrote:
> 
> Mark,
> 
> DXEngineering has a mast load calculator (offline as of this moment). Although I'm not answering your question directly, many here will have a good 'seat of the pants' feeling if you tell us what antennas and what heights you are planning for.
> 
> 73
> -de "Curly" John NI0K
> QRZ.com<https://www.qrz.com/db/ni0k>
> Hamshack Hotline<https://hamshackhotline.com/> call me: 6100000271
> 
> On 5/28/2024 8:39 AM, Mpridesti via TowerTalk wrote:
> 
> Looking to purchase a mast that was quoted as:
> 
> CRT 2 inch OD x 0.25 wall by 20 ft DOM
> 
> Not galvanized as yet.
> 
> Will this be near equivalent to Chromoly?
> 
> A modest antenna load is planned- wind surface area.
> 
> Regards,
> 
> Mark, K1RX
> 
> 
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