The modulator is one of those ubiquitous SA202 devices but used in a different way, the audio goes in directly and mixes with the 7090KHz RF from the oscillator. The output is Dsb… I hope.
The PA is fairly conventional, but uses a better MOSFAT than common designs you see (which tend to all use the IRF510, not designed for RF!). TheSA202 is matched to the MOSFET by a 4:1 transformer, and the output also has a 4:1 transformer to present the right impedance to the MOSFET.
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