WARC Triband antenna: Made using the pipes of an old Swan 4 elements after having destroyed the traps.
A nylon rope holds the long radiator.
On the top there is the 6m 5 El. Yagi described in theese pages.
Have a look to the MMANA files:
Model with constant diameters. You can start from this and adapt to your pipes.
Models with tapering: tap1 , tap2 , tap3.