When winding coils on ferrite (toroids or rods) I've found that providing some space between wire and ferrite increases coil Q. If toroid size allows one can use narrow strips of tape for this purpose. Old style 'wite-out' adhesive tape works well on toroids. http://compare.ebay.com/like/400266471721?var=lv<yp=AllFixedPriceItemTypes&var=sbar Richard