Sorry all, but I was very tired and not thinking clearly when I made the post to the list on the core materials. We need to use 43 material, good for freq. from 25 Mhz to 200 Mhz. I had 73 on my mind from the use on another project. 73 is good up to 30 Mhz. So I repeat Use 73 Material.....The Fair-Rite Proucts Corp P/N is 2643002402 Howard Rudy KA7YWO SLC, UT. RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]