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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>A company contacted me looking to hire someone to write them an FSK<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>modulator for a smart phone.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Turns out, the tones are the same standard 170 Hz shift used for decades<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>for RTTY and at 100 baud.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’ve already done this, in a general way, for any reasonable set of tones, bit rate, audio sample rate. <o:p></o:p></p><p class=MsoNormal>It should be easy to extract the code and repackage it.<o:p></o:p></p><p class=MsoNormal>Could you be more specific about the requirements?<o:p></o:p></p><p class=MsoNormal>What is the larger context? <o:p></o:p></p><p class=MsoNormal>Is HF SSB involved at all so that it needs to compensate for mistuning?<o:p></o:p></p><p class=MsoNormal>Is it a modem (send/receive) or just the AFSK modulator?<o:p></o:p></p><p class=MsoNormal>Does it need to be written in some specific language?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>73,<o:p></o:p></p><p class=MsoNormal>John WB2OSZ<o:p></o:p></p></div></body></html>