Re: Building a FSL antenna
Sorry that I can't recommend where to get parts in Spain. I suppose ordering from the US would be too costly. I could find the place that I ordered the currently recommended variable capacitor if you would like. It is also documented in the forum here in a few places, including an alternate source.
I found this:
You can play with values to see what should work. As Gary mentioned, he believes that there is some information on dual coil designs for covering both long wave and medium wave frequencies (in single or separate antennas) in the files/photos section here.
Though, those designs were for larger models of FSL IIRC.