To increase the range:
Replace the coil antenna inside the soil sensor by a 17.5 cm wire.
Drill a small hole in the top of the sensor (where the coil was) for the wire,
Make the sensor water tight again with some silicone sealant.
Replace the coil antenna inside the soil sensor by a 17.5 cm wire.
Drill a small hole in the top of the sensor (where the coil was) for the wire,
Make the sensor water tight again with some silicone sealant.
Comment