There was no response to the question of my original post. I assume that this was because it was too open ended. So I'll be more specific.
I'm running debian Wheezy with a SignaLink USB sound card and fldigi software. The transmitter is a K3 tuned to 14.070, TX DATA mode USB. My computer uses PulseAudio as default. Alsamixer also sees the presence of SignaLink's USB Audio CODEC, which is un-muted and at 84%. The SignaLink USB instructions tell me to make sure the software's transmit and receive audio card is set to USB Audio CODEC. I go to fldigi, Configure, Soundcard. Although PulseAudio is present on the computer, not wishing to use PulseAudio for fldigi, I have selected PortAudio. I assume I can do this. Am I wrong? PortAudio does not offer an option to choose the Transmit and Receive audio card, but instead the Capture and Playback card. I set PortAudio Capture to the SignaLink's USB Audio CODEC card. But the fldigi PortAudio Playback does have that option. Its options are Xonar DX (my computer's sound card) HDA NNvidia (motherboard audio chip), iec958, spdif (a cable?), pulse (PulseAudio?) and default (my computer's Xonar sound card?). USB Audio CODEC is not a choice. Should it be? Should I instead use iec958? Pavucontrol sees "ALSA Plugin [fldigi]" for ALSA Capture under Recording and sees PCM2904 Audio Codec Analog Stereo among Output Devices. Question: shouldn't what pavucontol sees and the values it sets be irrelevant? And the fldigi waterfall is strange. Fldigi is set to PSK31 at 14070.000. The waterfall sees noise only in a band at its center (14071.240 to 14071.716) and at its extreme left edge (14070.041). While the middle region has nothing that looks like signals (unless it itself is a broadband signal), the left edge looks as though it is close to the IM distortion of a signal just out of range. Although the central region has no visible PSK31 signals and I hear no PSK31 warble, it and the extreme left produce garbage text ("e S tite ate oee o e too="), whether I set the demodulation for frequency or phase shift. The only effect changing the demodulation is that with RTTY, the garbage is upper case. Please help. Haines Brown KB1GRM -- To unsubscribe from this list: send the line "unsubscribe linux-hams" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html