A contest is going on now, and many signals are observed even with my antenna.
The upper half of the waterfall shows the signal from IC-7410 (LSB mode, 3kHz bandwidth), and the lower half from Soft66LC4 with its LO at 7025kHz. (The contest band for 7MHz CW is 7010kHz-7040kHz.)
% sprigmm /dev/ttyUSB0 hw:2,0 32000 1 hw:0,0 48000 2
You can not tune IC-7410 very close to the LO of Soft66LC4, because the LO is strongly received with my simplest splitter which gives only 0dB isolation.
A low frequency componet comes from the LO, and see its ampllitude compared with those of other signals.