Hi Dick, LFers, Coils wound on toroid cores are supposedly self shielded due to the geometry of the core, but I think that you'd want more than 4 inches of spacing from your loading coil. Since there
Hi Dick I am not sure what the mechanism is. Jim seems to think it is RF getting into the diode and meter circuitry of the secondary, but I am not sure. I have not had enough power to experiment with