the time trace 302 is only captured when the cable signal 132 is smaller than the upper threshold 1022 corresponding to the higher amplitude a 2 in fig4 in this case the shaded areas 1001 and 1002 can be plotted inside the upstream band 361 a as shown in fig1 b referring to fig1 a similar embodiment of presenting repetition properties of ingress noise is presented a plurality of repetition frequencies for each frequency are displayed on a common frequency axis graph 1110 disposed under the frequency spectrum 310 as a minimum the graph 1110 can include at least one repetition frequency far at least one frequency band for example a frequency band 1101 showing a single repetition frequency 1102 of approximately 25 khz the repetition frequency graph can also be disposed proximate to or superimposed with the frequency spectrum 310 while a detailed set of repetition frequencies is usually not known for each network location fair assumptions can often be made as what type of noise may be prevalent in what network area as technicians learn new sources of ingress noise they can associate those sources with particular network locations for future use by way of a non limiting example the ingress noise can be characterized at the first location 131 fig1 according to the method 200 of fig2 and then the network technician can proceed to a second cable network location associated with the first repetition frequency determined upon computing the autocorrelation function in step 203 for instance the technician can decide to.