PI monocoil shielding and ground contact questions

[maikl]

Works stable on dry ground, only problem is the wet soil.
I tried to change the damping resistor's value and the impulse length but no success. I guess the aluminium foil should be a wrong material or it is too thick.

It's probably too thick aluminum foil, and not the best solution...
Graphite is a better solution (graphite is not a metal).
The problem with wet soil will have and with the best shield, if you use the detector off the beach (forest or meadow)...
Best regards.

[joop]

Wound the spiral coil today. To make life easy I am going to use 2 plant saucers for the coil housing. The inside will be sprayed with graphite. I have managed to get some 135 Ohm coax (POPE H37), which has very little capacitance. Don't think it is still in production.

Will post coil measurements later on.

[joop]

detail of the coil connection. You can see the wire which is glued to graphite and wrapped around the coax shield. I have used some foam material (the white stuff) as a spacer between coil and housing.