Take a look at the picture below showing all the spikes in the QLN for my line #4, compared with the other lines, in which almost all are absent:
How can the pictures be different? The lines run along the same route, with the slight exception of line 2 which is not an EO line, so we believe?
Any idea if these are radio stations or some such and if so what?
The bits per bin graph for line 4 indicates that the spikes above tone 170 don’t matter anyway because zero bits are allocated to those higher bins.
Line 4:
And for comparison:
Line 1:
Line 2:
Line 3:
Bits per bin for
line 4: