qrz.com Call sign lookup

arrl.org/advanced-call-sign-search FCC License Data Search

na5b.com:8901 HF WebSDR in Washington DC

na5b.com:8902 VHF WebSDR in Washington DC

https://stephenhouser.com/qso-mapper/ QSO/ADIF mapper

hamalert.org/about Ham Alert

lightningmaps.org Live lightning map

https://www.scadacore.com/tools/rf-path/rf-line-of-sight/ RF line of sight mapping

https://kv5r.com/ham-radio/coax-loss-calculator/ Coax Loss Calculator/ERP Calculator

https://www.arrl.org/rf-exposure-calculator RF exposure calculator