ORIGINAL: Gary L.
I am in no way an expert, but, I would think the ant. would need to be up at 20ft.
I do know something about CB radio's, and would think the Futaba Tx would fall in line here, on CB's you have to set the S/W/R's for the CB to transmet the best, but like I said , I'm new here and dont know...
Gary, the point here is to have a greatly reduced signal as compared to the regular signal. The idea is to simulate the signal strength at maximum range. During these tests SWR is not a concern. Normally with the antenna down there should be no problem operating the system at distances of up to 100 feet. On some units it helps to extend the lower section and in fact the antenna is totally disconnected if this is not done on some units.
The SWR does come into play in that you don't want to transmit very long like this because it can cause overheating of the final amplifier portion of the TX.