The coils close together show a large signal on the oscilloscope. The current in the source is in phase with current across the resistor. The voltage in the resistor
The coils far apart show a small signal on the oscilloscope.
This is the circuit diagram. The connections for the scope are moved during the demo. The wires should be color coded so that the correct polarity is displayed after the switch.
The receiving coil is disconnected to see the raw signal.
The circuit for the transmitting coil.
The circuit for the receiving coil.
The external trigger was needed to keep the trace from drifting. For this camera set up the camera needs to be mounted upside down since it reflects in two mirrors.