User talk:Stuuf
FM synthesizer with modulation
[edit]Hi. I saw your nice diagram on the "frequency synthesizer" page. Do you still have the original file, and would it be easy to add an optional frequency modulation feature to the circuit you've drawn? Just insert an analog signal summer (Greek letter capital sigma) between the LPF and the VCO, and inject the modulation into that summer so it's added to the output of the LPF and the sum drives the VCO. That's how a lot of frequency synthesized FM rigs work, though the methods have gotten a little more sophisticated in recent years. Thanks! Karn (talk) 02:10, 12 December 2011 (UTC)