Topband: 3" to 2"

[George (K8GG) & Marijke Guerin]

WY7I wrote:

Subject: Topband: 3" to 2"


> Argh!
>
> Has anyone found a way to join 3" to 2" aluminum irrigation pipe, probably 
> using Schedule 40 PVC??
> I am drawing a blank, nothing seems to fit very well amongst the various 
> adapters...
>
> WY7I


Another approach seen in ON4UN's "Low Band DXing" books is to machine a 
couple of aluminum donuts or torroids 1+ inches thick with an ID that just 
fits over the 2 inch irrigation tubing and an OD that just fits into the 3 
inch irrigation tubing.   Spacing them about 12 inches apart should also 
make a good transition.  Connect them as shown in the 40 meter beam 
construction section where the transition is from a 2 inch OD section to a 1 
or 1-1/8 inch section.

Also, why not ask the irrigation people what they think?
The irrigation companies may even make a tapered reducer to go from 3" to 2" 
which would also solve your problem.

GL de George    K8GG