Did some cutting and soldering. With measures like "Pi mal Daumen" and a look at the previous shielded loop (resonanting between 49m and 40m, remember?), I managed to arrive at a shielded magnetic loop resonating at 30m. Diameter is about 30cm, I will however publish more precice values soon. Same materials used, some polystyrol vari-cap. Coupling done with a T37-6.
The loop receives, levels, however, are very low, as expected.
Next step, a preamp. Not sure what design to choose.