Joachim's Ham-Radio and Radio-Frequency Blog (A Solderful of Secrets) - from Longwave to Microwaves
Thursday, January 14, 2010
500kHz source update
Added a polystyrene varicap for tuning. Now, setting the range, some experimentation was unavoidable. A 39pF capacitor in series to the ceramic resonators "ground pin" (capacitive divider) to ground resulted in a 500.5kHz to 503kHz tuning range. Maybe replacing the 39pF by a somewhat smaller capacitance will bring the source up by just those couple of 100Hz.