kitz, thank you so much for your detailed explanations, much appreciated.
I have diligently read all of your excellent site guides but could not find any detailed, definitive guide to analysis of Hlog & QLN, this explanation certainly helps a lot.
Zooming of the graphs is now so easy on the MDWS site, can certainly home in on the tone ranges in question for more detailed analysis.
Am I correct in thinking that the Hlog & QLN graphs represent a snapshot of a very small area in time as they are taken just prior to the modem synch'ing with the DSLAM so would really only represent that instant in time ?