Emi problem

[Daves]

EMI inside the house is normal. Next thing you need to show is what cable you used, exactly how it is connected, and how you shielded the coil.

cable attached
Note: There is a small pcb inside the coil. The main pcb is inside the main unit.

[Carl-NC]

What's on the PCB in the coil? How did you shield the coil?

[Daves]

What's on the PCB in the coil? How did you shield the coil?

There is an rx input (opamp output rxp, rxn) on the small pcb.
rx first enters the buffer opamp, then rxp and rxn are produced in the second opamp.

1. First graphite shield is applied to the coil plastic
2. coils are placed and adjustment is made.
3. 1st layer epoxy
4. Final adjustment is made with adjustment wire.
5. 2nd layer graphite shield is applied on 1st layer epoxy. (1st layer and 2nd layer graphite shield are connected to pcb with the same wire)
6. 2nd layer epoxy and closing.