This linear amplifier delivers 10-W PEP output; with 1.25-W drive on 10 m. Tl, T2, and T3 are 10 turns of bifilar windings on an FT-50-43 toroidal core. The transformers are broadband. Filters for other bands, if desired, are shown. Note: use #26 wire for C1 and C2. Use capacitors that are closest to these suggested values. As the operating frequency decreases, the gain will Increase as well as the possibility for instability. You may have to use RC feedback to negate this effect.
Values for the above table were obtained from the QRP Notebook by Doug DeMaw.