Hi all, I've put up a new VCO design. Based on a 4069 hex inverter and tree transistors. No difficult to obtain tempcos and yet compensated. A more detailed description and some constructional hints are located at: http://www.uni-bonn.de/~uzs159/vco4069.html Have fun. René -- uzs159 at uni-bonn.de http://www.uni-bonn.de/~uzs159