After a discussion with well known 6 meter dxer Johan Minnema PF7M I decided to go back to one coax line to my six meter yagi. The last years since I have a preamp in the tower I always had two coax lines and a coaxial relay on the top of the tower. The switching was not as good as my to meters system. On two meter I switch in the correct order. On six meter my pa saw sometimes very short a bad swr. So I decided to change to simple. One line! No preamp anymore.
First I have to bring back the FTV-1000 transverter back to one output. This is now finished. I switched the coax relay at the tower to the tx position and tried it. It is working fine.