I am interested in a circuit which will amplify RF in the first stage of a Kitchin regenerative receiver which will receive frequencies between 4 and 7.5 mHz. The circuit I have uses this circuit for stage one. The top of the L1 inductor attaches to a nine volt power source. The design requires a low impedance input for this stage. I have limited knowledge of impedance and would appreciate it very much if someone can show me how to calculate the input impedance of this stage.
I am sure someone out there can help. thanks in advance.