``` Mike, G3XDV wrote: ``````1. No top load Efficiency: 10.8% ``````2. One horizontal top load wire of 5 m `````` Efficiency: 12.5% ``````4. One horizontal top loading wire of 10 m ``````Efficiency: 11.9% ``````6. One horizontal top loading wire of 20 m Efficiency: 10.0% `````` Dick, There's something wrong here isn't there?. You have a reducing efficiency for increasing top load length. Surely that can't be right. Yes, I agree it looks strange. But it results from the way efficiency is calculated: radiation resistance divided by the sum of radiation and loss resistance. When the loss resistance increases more than the radiation resistance efficiency goes down. In the real world the actual efficiency will certaily get better as the small increase of wire loss is almost swamped by the total resistance of the system: earth loss + coil loss + wire loss. What really matters is the increase of Rs. It is better to ignore the efficiency figures; I used them only to calculate Rs from the real part in Z = R + jX 73, Dick, PA0SE ```