Does anyone know what length of coax is used for a stub on 20mtrs. I have gotten to SO2R to work with FT1000MP and a FT1000D but when I transmit on the MP into my hytower on 40mtrs I have a harmonic on a even multiple on 20mts. I have the ICE419a installed and welll grounded but still I have the signal. Has anyone else run into that. PTL bill brown K0UK