Today, I increased coupling from 2p2 to 18p (orginally 47p), that again seems too strong, massive impact on the oscillator creating a really ugly but strong signal in my neighbor's grabber. Even the 2N2222's heat sink warms up now... Maybe reduce coupling again, to let's say maybe 10p ....
I further changes the capacitor terminating the crystal filter, from 33p to 22p, seems to have some impact too: