I have been tuning the 630 M band on and off for a while and only have heard a few listenable CW signals over the months. Any DIGI signals that may be in there I can not confirm if they are Amateur modes or switching power supply garbage. I am ready to give up the monitoring. So far I have been using either a 160 M dipole of a 140 ft wire loop up in trees at 35 Ft and a tunable preamp to my FT990. That has been good enough to hear NDB signals frlom local , out to Manitoba.