Guest Wilson Posted November 28, 2003 Report Share Posted November 28, 2003 Hi,I built the FM Radio (http://www.electronics-lab.com/projects/rf/020/index.html) on a proto-board and I used a BB204B variable capacitor instead of BB329, but it didn't work. Anyone could tell me what modifications do I need to do in order to use the BB204B.Thanks for any comment!Wilson Quote Link to comment Share on other sites More sharing options...
AVRFreakMan Posted November 28, 2003 Report Share Posted November 28, 2003 I don't have the specifications for the varicaps. You should find them and check if they have similar capacitance vs reverse voltage curve.The next step is to play with the coil. There is no need to keep it in form, you can stretch it, pull it, push it, put a nail in it, make it an ugly thing until it works :-).Ok, don't overact a lot!!!If it still doesn't tune in FM, try another coil and play with the turns, add or remove one or more turns.You should find the golden edge somewhere there.Kyriakos Quote Link to comment Share on other sites More sharing options...
NATHKAMLA Posted December 2, 2005 Report Share Posted December 2, 2005 hi, i dont know what u mean by proto board but if it is the vero type of thing, stray capacitance could alter the oscillation try and make a pcb for it and be carefull with the layout especially the osc. section. or use the philips pcb template on thier website. goodluckadams Quote Link to comment Share on other sites More sharing options...
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