I always line the holes in those cores with irradiated polyolefin HST. You just have to stretch it a little, and it will easily pull into the holes. (Photos at www.w0btu.com/Beverage_antennas.html#Beverage_Antenna_Transformers
Then we can just use magnet wire, 24, 26, or 28 AWG. I mostly use #26. The larger the wire, the better chance that it will survive a lightning-induced surge even with protective GDTs. Two turns on the low-Z winding are all that are needed. 73, Mike www.w0btu.com _________________ Topband Reflector Archives - http://www.contesting.com/_topband
