John; You might want to try Yagimax. It allows changes to a design that you can enter and then graphs results. Its very easy to use. You can download it at http://www.geocities.com/SiliconValley/Garage/2930/others/eda.html . Also I see that there is another programn called Yagicad at the site. Haven't tried it yet but looks interesting. Good luck. 73's Jon, K0FQA