Yo, On adding 40 meters to TH11 or a 24 ft boom yagi: I found it. You need to have copies of NCJ (Paper or on CD). I haven't looked at the article. MAR 1998 - NCJ (PG. 21) Boom Matching = 40/30 Meter Rotary Dipole Author: Russell, Tom, N4KG K9WN Jake