George, The Delta 44 is expecting a line level input. We get around this by providing digital amplification within our program, but this will not work for other applications which do not provide such gain. The input level you saw on the Delta 44 control panel is normal.
Consumer sound cards typically include a Mic preamp (and sometimes an additional 20dB boost). You can buy an external one for the Delta 44 and it _will_ improve the signal/noise ratio when transmitting on the PowerSDR software. It is not necessary, however, thanks to the power of digital amplification (aka multiplication). Eric Wachsmann FlexRadio Systems > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > radio.biz] On Behalf Of George Heron N2APB > Sent: Thursday, October 20, 2005 8:46 AM > To: '' FlexRadio '' > Subject: [Flexradio] Mic problem with D44 card > > I recently upgraded to the Delta-44 sound card and things are almost > working as expected. > > Things are fine with SDR receive functions and for normal multimedia > playback on the computer > (like playing MP3 audio files). But then in testing out the mic input > function in prep for > SDR transmit tests, I notice that I just cannot get any audio gain like I > used to with the > Santa Cruz card previously used. I can hardly even get 1/4 scale readings > in the sound card > control panel when speaking loudly into the mic. > > The mic is proper impedance for "mutlimedia sound cards", and indeed > worked fine with the > Santa Cruz card before. The gain setting is indeed "-10dB" in the control > panel. (I've > tried all setting combinations.) > > Someone had privately suggested that perhaps the D44 doesn't provide a > bias voltage for the > mic input, as some/most cards do ... > > Has anyone else experienced this condition with the D44? > > Thanks. > > 73, George N2APB > > > > > > _______________________________________________ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
