From HB9ASB, JN36pt

Wish I could "wash" my ground rods down, as you do it in the flat land:
after 30-50cm I'm on solid rock! And unfortunately I'm not a drilling
Engineer.
My antenna is also surrounded by trees, but I'm not sure if they absorb
that much (The Top Load is in the clear). But they change the resonance
of my antenna. I have a shift of some kHz between summer and winter.

By the way: I've recalibrated my S-Meter and I must admit that I've
given completely wrong reports until now. The problem was my R&S
generator. It's output level is correct on short wave but much to low on
136kHz and so far I never checked it. As we say in German: Wer misst,
misst Mist!

73 de Toni