Does anyone have construction and electrical details on the 4:1 transformer used in the tank circuit of the HF-2500DX amplifier? Number of turns, wire size, toroid size, core material, inductance, etc.? Also, are there are other 4:1 xfmrs that have been designed, suitable for QRO use? I'm interested in 160m and 80m designs, mostly. Tnx, Jim W8ZR