Are "generic" ferrite-rod aerials tuned?
I know they are fairly broadband, but in these cheap 'n' cheerful MW BC receivers, are the feerite-rods tuned, like a set number of turns, or does the manufacturer just just do a hundred or so turns of thin wire and say "That'll do 👍"?
I was wondering if I canabalised a couple more from old knackered radios, could I join them in series and make a better aerial?