If L3 is a part of colpitts how to ... put that to formula?
And than modulation... there's written:"the modulator allows a resolution of 80 characters per line"... which elements this depends on?
I guess C1 and C4 blocks DC, R4 gives output impedance, L4 is HF filter...
Are L1 and L2 just "blocking" inductors?... why then R1?
And the last why :roll: what is C5 for?