Combination Polydoroff and contra wound FSL

Camille LeBlanc

Hello Gang,

I just finished all the pre-wiring stages of my new FSL. It will give about a 7 inch diameter coil and comprises of 3 rows of 47 each 100 mm ferrite rods for a total of length of 300 mm (12 inches) using 141 rods. Now before winding any wire on this thing, and reading all the articles in the files section, I got to thinking if anyone has ever had the idea of combining both winding methods into one design. I was thinking of two possibilities.

Possibility 1:
Coil 1 and 3 wound in one direction then coil 2 and 4 wound contra. Coil 1 and 3 connected in Polydoroff fashion along with coil 2 and 4 also connected with the Polydoroff method. Each Polydoroff pair could be regarded as a single coil and brought out to a 4PDT switch to allow for series/parallel band switching.

Possibility 2:
Coil 1 and 2 connected in Polydoroff, then coil 3 and 4 also connected in Polydoroff but coils 3 and 4 wound contra to coils 1 and 2. Again each pair could be regarded as one single coil and also switched by a 4PDT switch for band switching.

It would seem to me that this combining of both winding methods would give the best of both worlds and provide all the desired advantages of both methods. Maybe I'm missing something here because sometimes I get crazy ideas. Does anyone know if either scheme would work?


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