WA3GIN wrote: > Does anyone know what the resonant freq. is of the 30ft of 3" tubing > without the addition of a top hat? > > Thanks, > dave > wa3gin > EZNEC predicts the resonant frequency is near 7.9 MHz. Adding a top hat of 4 spokes 2.5 feet long lowers it to near 7.1 MHz. Adding 2 spokes 2.5 feet long brings it near 7.4 MHz 73 de Red