[TowerTalk] Tower Challenged

[Roger (K8RI)]

Gene Smar wrote:
> Jeff:
>
>      I agree with Tom - don't use the chimney to mount any appreciable-sized antenna.  The chimney may look sturdy but mostly they are three sides of brick that are attached to the house with galvanized steel straps layed up between the mortar layers and nailed to the house walls. 
A properly designed chimney is free standing with *no* attachment to the 
house.  On a two story house with a chimney in the middle you can see 
the roof move several inches in relation to the chimney on a windy day.  
Don't depend on any aid from the house structure.  Attaching a chimney 
to the structure would be very hard on the structure of the chimney as 
it'd be holding the house on a windy day rather than the other way around.
>  A good wind blowing against a decent size antenna load above the roof could push this entire chimney assembly over onto the ground.  As others have suggested, a roof-top tower, properly tied into the roofing trusses, would be a much safer alternative.
>   
Roger (K8RI - ARRL Life Member)
www.rogerhalstead.com
N833R (World's oldest Debonair)