On Feb 2, 2011, at 11:41 AM, Jim Brown wrote: > An important source of IMD (and harmonic distortion) is the sound card used > to generate the digital signal.
In the case of the K3, it is definitely poor IMD from the transmitter, since my K3's transmit IMD was even worse when set to use the internal PSK-D generator. I have tested a direct sound card -to- sound card link (no RF in between) and got better than -80 dBc IMD from cocoaModem's PSK31 interface. Even cheap sound cards like the Griffin iMic are pretty good with IMD. More than you can say about their second harmonic distortion, however (at least on the input side). 73 Chen, W7AY ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
