VHF/UHF BEACONS
www. gooddx.net/
www. dxinfocentre.com/tropo/
www. newsvhf.com/beacons/
www.data.dcc. rsgb.org/
www. vhfdx.net/beacons/
www. vklogger.com/
TEMPERATURE INVERSION
3D picture (use red/green glasses)
TOTAL SOLAR ECLIPSE UMBRA