On Sun, 21 Sep 2008 09:11:22 -0400, Paul Christensen wrote: >the square-wave impulse response >of the transformer becomes less meaningful.
As long as there is impulse noise, the square wave response of the line out transformer is definitely relevant! As the folks at Elecraft have noted, the primary function of the Line Out is to drive data decoders of one sort or another. Those decoders see signal plus noise. Any distortion in the transformer is additional noise as far as the decoder is concerned. The square wave response of the circuit is simply another way of LOOKING at those distortion products. The analysis of the K3 Line Out that I did back in June using band noise as a source of excitation show the same problems as Jack's analysis using very different signal sources, but my excitation, being broadband, exposes the IM distortion as apparent broadening of the filter skirts. Jack measures IM using traditional two-tone methods. In other words, we both see the same problems using very different methods to study them. Those of us working in pro audio learned long ago that broadband noise (we use pink noise) is a VERY powerful analysis tool. 73, Jim Brown K9YC Audio Systems Group, Inc. _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
