@germaniohm,
we have had a log discussion. If the saying"a picture is worth 1000words" is true, i personally feel, a schematic of what has been done would better explain for further thought sharing.
There are specific methods of interference control. at times the transformers under consideration can be oriented at right angles so that induction can be cancelled. Of course, induction on a closed E/I core packing as used in power transformers is not heard of. You might have seen power transformers with metal clap surrounding the core. It also helps.
I feel you can take the pain of making a schematic, even few photo shots to give a clear picture of the set up as made by you. It really helps to analyse.