On Sat, Dec 12, 2020 at 12:11 AM, Jorge Garzón wrote:

Thanks Gary. I also have the FSL 5" document, full of useful info. 

 

What about ferrite providers? 

Jorge,

If you wish to build a 5" FSL antenna using the same 125mm x 8mm ferrite rods that my design uses, the Russian surplus ferrite rods are available at this link  6 pcs Ferrite Rod NiZn 8 x 125mm for Amateur and Crystal Radio Coils, AM SW USSR | eBay
The seller in the Ukraine says that he only has 5 lots of 6 rods available, but he typically lists more identical rods immediately after these are sold.

Gary