Hi, There is little doubt that most of the noise/blips in that spectrogram is not related to the KIO3B, but rather the K3 RF chain and possibly the KX3 phase noise. I was just trying to show that the audio produced by the USB codec is darned good from an HF radio (and in my case demonstrably better than what I got from the line out on my old K3). I have never tried to see what the port can do with the transmit audio.
AB2TC - Knut Dan AE9K wrote > After staring at Knut's KIO3B spectrum with an XG3 signal source, I am > wondering how much of that spectrum can be attributed to the KIO3B and how > much is due to the K3S RF chain and XG3 phase noise and harmonics. > > I tried a different approach with my K3 and DigiKeyer keeping everything > at AF and avoiding the RF and XG3 related variables - I think. > > I sent the K3 a 1 kHz test tone to LINE IN while the K3 was keyed in TX > TEST mode. At the same time an instance of Spectrum Lab analyzed the > return audio (i.e. the monitor audio returned over LINE OUT). > > The resulting spectrum lacks the significant harmonics Knut observed > although I show some AC spectra (fundamental + 3rd, 5th and 7th harmonics) > which might be attributable to my DigiKeyer sitting directly above the > KPA500's transformer. <http://elecraft.365791.n2.nabble.com/file/n7612159/1_kHz_test_tone.png> > > Is analaysis of recovered transmit audio while in TX TEST a viable way to > eliminate the RF and XG3 related variables or have I missed something? If > it is viable, I would be interested in the same being done with a KIO3B > for comparison purposes. > > 73, > > Dan > AE9K -- View this message in context: http://elecraft.365791.n2.nabble.com/K3IOB-tp7611605p7612160.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
