[TowerTalk] 4L or 5L 15 meter From a 204BA

[Jim Idelson]

Rebuilding it as a 155CA is the best idea. Follow these steps:
1.  Input the 155CA Reflector dimensions [including tapering of the element] into your favorite modeling program. Look at the point of resonance.
2.  Build a new element in the model using the aluminum from the 204BA. Adjust the tip length to achieve the same resonance as the 155CA.
3.  Repeat steps 1 and 2 for DE, DIR 1 and DIR 2.
4.  Build a new DIR 3 from whatever aluminum you have available, matching the resonance to DIR 3 of the 155CA.
5.  Combine the models of the elements into complete yagi models, and compare performance.
6.  Build your 155CA copy and it will work just fine.

K5TR provides the modeling information you need here: http://www.kkn.net/~k5tr/hg155ca.txt

73,

Jim Idelson K1IR
email    k1ir at designet.com
web    http://www.k1ir.com