Mike, If you look at the code that creates the AM signal, it is something like the following:
Sample = 0.5 + 0.5 * mic_signal; The first 0.5 is the carrier and the second part is the modulation produced by the microphone. If the variation is coming from anywhere you can track with software, it would have to be the incoming microphone signal. The rest is all constant. How is your grounding setup? I have heard that ground loops can cause power fluctuations in AM. Eric Wachsmann FlexRadio Systems > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > radio.biz] On Behalf Of Mike WA8BXN > Sent: Monday, January 09, 2006 9:29 PM > To: FlexRadio List > Subject: [Flexradio] AM - variations in unmodulated carrier level > > Making progress in transmitting AM here. I have noticed that there is a > fluctuation in the power in an unmodulated AM carrier, noticeable both on > the computer power output display and on an external analog watt meter. > Maybe a 5% variation at most with a frequency of a couple cycles per > second > roughly as it varies. I see this even with the microphone input shorted > (using a delta sound card) feeding the rig into a dummy load. I don't > notice > such variations in tune, CW or NFM modes. Any idea what is going on? > > 73 - Mike WA8BXN > > _______________________________________________ > FlexRadio mailing list > [email protected] > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
