Hello group !

I found that almost all amp configurations generate harmonics. In case of a homebrewed HF amp, with a push –pull design, I had to build hi-pass filters with a resistive termination, so called split filters, for each band. Without dissipating the harmonic energy the stage will have to cope with excess voltages and thus bury the MosFets .

My last amp stage for the DI2BJ-beacon is followed by a hi-pass that opens at 750 kcs . This way the first harmonic and all the higher ones go into thermal dissipation.

A T-type adjustable low-pass is used to match and reduce harmonics further.

Have fun                     de wolf  df2py