I was wondering where to put a current balun. The current balun should eliminate QRM a little, and eliminate unbalanced current flow on the balanced coax line.
With the balun placed at the ATU, the feedline is balanced up to the ATU. When placed at the TRX, the coax will be part of the radiation pattern so HF will be introduced in the shack.

Enough text, here are the pictures:


40 meter band, balun at ATU


40 meter band, balun at TRX


20 meter band, balun at ATU


20 meter band, balun at TRX



10 meter band, balun at ATU

10 meter band, balun at TRX

Picture says all right? Let's compile a small table with the data:

Balun at the TRX gives less QRM it seems. Next is testing HF influence in the shack, to be continued…