Links
IARU Monitoring System (Bandwacht)
SGO Meteor Radar
Space Weather: GOES X-Ray Flux
MUF
VIRGO
MMMonVHF
VHFDX.EU
ON4KST chat
N0UK EME chat
Geschichte UKW-Funk (History of VHF radio)
My friend DL8SCQ
For interests - read the book Technical Handbook for Radio Monitoring: