While I'm still on a roll with high stability off-air monitoring, here is a plot of the one remaining 100kHz transmission, from Anthorn, taken overnight. http://www.g4jnt.com/DropF/clipboard_20180
Yes it is "just there", the unbalanced pulsegroups are part of the phase coding specification: http://jproc.ca/hyperbolic/loran_c_sigchar.html ++--+-+- + master A +--+++++ - master B +++++--+ seconda