Sorry, I didn't word my reply correctly. I didn't mean to suggest the KIO3B was responsible for the spikes of spectra. I realize those are the XG3 fundamental and harmonics. The XG3 phase noise just makes it impossible to see the audio noise floor of the KIO3B. My intention was just to advance your "darned good" comment to something measurable for comparison purposes. But, for all I know my pursuit of measuring USB audio spectrum quality may be moot if we're always RF noise-limited.
Stepping back a bit, my original intent was to determine whether the KIO3B was a suitable drop-in replacement for my DigiKeyer (to eliminate a box and associated connections to the K3). Part of that is audio-related the other part is interfacing-related (KEY, PTT, etc.). Someone pointed out off-forum that there is no FSK interface with the KIO3B so that is one disparity with the interfacing aspect. As for the audio aspect, I'm sure Joe's right in that they're essentially the same unless there was an implementation short-cut taken with the KIO3B - which isn't likely. That said, I am still curious if the proposed test setup of passing audio in and analyzing the monitor audio is a valid means of measuring the performance of the USB audio path - whether with the KIO3B or other USB audio interface. Can I, for example, conclude from my test that my DigiKeyer/K3 path has a -110 dB noise floor? 73, Dan AE9K -- View this message in context: http://elecraft.365791.n2.nabble.com/K3IOB-tp7611605p7612165.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
